Note: Descriptions are shown in the official language in which they were submitted.
CA 02750143 2016-08-31
SYSTEMS AND PROCESSES FOR APPLYING HEAT TRANSFER LABELS
[0001]
Field of the Invention
[0002] The
present invention relates to equipment and methods for applying heat transfer
labels to
a curved surface, and particularly to a compound curved surface. The present
invention also relates to
labeling processes and in particular, applying heat transfer labels to
containers. The invention is
particularly directed to application of labels onto curved container surfaces
and defect-free retention
thereon.
Page 1
CA 02750143 2016-08-31
Background of the Invention
[0003] It is known to apply labels to containers or bottles to provide
information such as the
supplier or the contents of the container. Such containers and bottles are
available in a wide variety of
shapes and sizes for holding many different types of materials such as
detergents, chemicals, personal
care products, motor oil, beverages, etc.
[0004] Polymeric film materials and film facestocks have been used as
labels in various fields.
Polymeric labels are increasingly desired for many applications, particularly
transparent polymeric labels
since they provide a no-label look to decorated glass and plastic containers.
Paper labels block the
visibility of the container and/or the contents in the container. Clear
polymeric labels enhance the
visual aesthetics of the container, and therefore the product. The popularity
of polymeric labels is
increasing much faster than that of paper labels in the package decoration
market as consumer product
companies are continuously trying to upgrade the appearance of their products.
Polymeric film labels
also have superior mechanical properties as compared to paper labels, such as
greater tensile strength
and abrasion resistance.
[0005] Traditional polymeric pressure sensitive (PSA) labels often exhibit
difficulty adhering
smoothly to containers having curved surfaces and/or complex shapes without
wrinkling, darting or
lifting on the curved surfaces. As a result, heat shrink sleeve labels have
typically been used on these
types of containers having compound curved surfaces. Labeling operations for
sleeve type labels are
carried out using processes and methods that form a tube or sleeve of the heat
shrink film that is placed
over the container and heated in order to shrink the film to conform to the
size and shape of the
container. Alternatively, the containers are completely wrapped with a shrink
label using a process in
which the shrink film is applied to the container directly from a continuous
roll of film material and then
heat is applied to conform the wrapped label to the container. Regardless,
label defects frequently
occur during labeling operations of simple or compound shaped bottles during
label application or in
post label application processes. These misapplied labels result in high scrap
or extra processing steps
that can be costly.
[0006] Accordingly, a need exists for a process in which a design and/or
indicia could be applied to a
curved surface and particularly a compound curved surface without the
occurrence of defects.
[0007] Eliminating or reducing the previously noted problems may also lead
to additional
advantages such as reducing overall capital costs for process equipment,
reducing floor space associated
with a labeling process, increasing equipment life by reducing exposure to
heat, and improving process
consistency and reliability as a result of process simplification.
Page 2
CA 02750143 2016-08-31
Summary of the Invention
[0008] The present invention provides advances in labeling operations, and
particularly for methods
of applying designs to articles by heat transfer labeling.
[0009] The difficulties and drawbacks associated with previously known
systems and methods are
overcome in the present method and apparatus relating to a heated flexible
member that readily and
consistently applies one or more designs to containers using heat transfer
label assemblies, and
particularly containers with compound curved surfaces, without the occurrence
of defects.
[0010] In one aspect, the present invention provides a method of applying a
heat transfer design
from a support member or web to a container. The heat transfer design includes
a region of ink or other
pigmented formulation disposed on the support member. The method comprises
providing a label
processor comprising (i) a rigid frame defining a first face and an oppositely
directed second face, the
frame defining an opening extending between the first and the second faces;
and (ii) a flexible member
disposed adjacent to at least one of the first face and the second face of the
frame and extending
through the opening of the frame and projecting outward from the second face
of the frame. The
flexible member defines an outer surface for contacting the support member.
The flexible member also
defines an interior hollow region accessible from the first face of the frame.
The flexible member is
deformable upon application of a label contacting force to a portion of the
member projecting outward
from the second face of the frame. The method also comprises heating the
flexible member. The
method further comprises positioning the heat transfer design and the support
member between the
outer surface of the flexible member and the container. The method
additionally comprises contacting
the outer surface of the flexible member with the support member and
contacting the heat transfer
design with the container. The method also comprises applying a label
contacting force to the flexible
member whereby the flexible member is deformed and the heat transfer design is
at least partially
transferred to the container.
[0011] In another aspect, the invention provides a label processing system
comprising a heat
transfer label including a support member or web, and a region of ink or other
pigmented formulation
disposed on the support member. The label processing system also comprises a
label processor for
concurrently heating and contacting a label to a container. The label
processor includes (i) a rigid frame
defining a first face and an oppositely directed second face, the frame
defining an opening extending
between the first and the second faces, and (ii) a flexible member disposed
adjacent to at least one of
the first face and the second face of the frame and extending through the
opening of the frame and
Page 3
CA 02750143 2016-08-31
projecting outward from the second face of the frame. The flexible member
defining an outer surface
for contacting a label. The flexible member also defines an interior hollow
region accessible from the
first face of the frame. The flexible member is deformable upon application of
a label contacting force
to a portion of the member projecting outward from the second face of the
frame.
[0012] As will be realized, the invention is capable of other and different
embodiments and its
several details are capable of modifications in various respects, all without
departing from the invention.
Accordingly, the drawings and description are to be regarded as illustrative
and not restrictive.
Brief Description of the Drawings
[0013] Figure 1 is an illustration of a representative container having a
compound curved surface.
[0014] Figure 2 is an illustration of the container of Figure 1 with a
label ideally applied to the outer
surface of the container and extending in the region of the compound curved
surface.
[0015] Figure 3 is an illustration of the container of Figure 1 with a
label and darts as typically
resulting after application to the container using currently known techniques.
[0016] Figure 4 is a schematic perspective view of a preferred embodiment
flexible member in
accordance with the present invention.
[0017] Figure 5 is a side view of the flexible member shown in Figure 4.
[0018] Figure 6 is a front view of the flexible member shown in Figures 4
and 5.
[0019] Figure 7 is a front perspective view of the flexible member retained
and supported in a
preferred embodiment frame assembly and enclosure in accordance with the
present invention.
[0020] Figure 8 is another front perspective view revealing an interior
region of the flexible member,
frame assembly, and enclosure depicted in Figure 7.
[0021] Figure 9 is a rear perspective view of the flexible member, frame
assembly, and enclosure of
Figures 7 and 8.
[0022] Figure 10 is a cross sectional view of the flexible member, frame
assembly, and enclosure
taken across line AA in Figure 9.
[0023] Figure 11 is a front view of the preferred flexible member and
another preferred
embodiment frame assembly in accordance with the present invention.
[0024] Figure 12 is a perspective view of the preferred embodiment frame
assembly shown in Figure
11 without the flexible member.
[0025] Figure 13 is a perspective view of a container having a label
partially adhered to the
container in accordance with a preferred method of the present invention.
Page 4
CA 02750143 2016-08-31
[0026] Figure 14 is a top view of the container and partially adhered label
depicted in Figure 13.
[0027] Figure 15 is a schematic view illustrating initial contact between
the label and container of
Figures 13 and 14, with a preferred flexible member in accordance with a
preferred method of the
invention.
10028] Figure 16 is a schematic view illustrating further contact between
the label and container and
the flexible member, after the state shown in Figure 15.
[0029] Figure 17 is a schematic view illustrating further contact between
the label and container and
the flexible member, after the state depicted in Figure 16.
[0030] Figure 18 is a schematic view illustrating further contact between
the label and container and
the flexible member, after the state depicted in Figure 17.
[0031] Figure 19 is a schematic view illustrating further contact between
the label and container and
the flexible member, after the state shown in Figure 18. Figure 19 illustrates
a typical rolling
configuration adopted by the flexible member toward a latter stage.
[0032] Figure 20 is a perspective view illustrating deformation of the
flexible member resulting from
contact with a container having a curved outer contour.
[0033] Figure 21 is a preferred assembly of flexible members and frame
assemblies for concurrently
applying multiple labels onto multiple containers.
[0034] Figure 22 is a top elevational view of a preheating assembly for use
with the assembly in
Figure 21.
[0035] Figure 23 is a top elevational view of the assembly depicted in
Figure 21 with additional
components.
[0036] Figure 24 is a schematic front view of another preferred embodiment
flexible member in
accordance with the invention.
[0037] Figure 25 is a schematic front view of yet another preferred
embodiment flexible member in
accordance with the invention.
[0038] Figure 26 is a front view of representative guides corresponding to
the shape of a container
to be labeled.
[0039] Figure 27 is a perspective view of a preferred embodiment quick
change assembly having a
flexible member in accordance with the invention.
[0040] Figure 28 is a perspective view of a collection of quick change
assemblies according to the
invention.
[0041] Figure 29 is a front view of the collection of assemblies depicted
in Figure 28.
Page 5
CA 02750143 2016-08-31
[0042] Figure 30 is a front view of a collection of quick change
assemblies, each using a different
sized bladder.
[0043] Figure 31 is a perspective view of a representative container and
partially applied label.
[0044] Figure 32 is a top planar view of the container and label depicted
in Figure 31.
[0045] Figure 33 is a perspective view of a preferred embodiment wiping
assembly in accordance
with the present invention.
[0046] Figure 34 is a perspective view of a preferred embodiment wiper
member used in the wiping
assembly of Figure 33.
[0047] Figure 35 illustrates the preferred embodiment wiping assembly
applying regions of a label
to a container.
[0048] Figures 36 and 37 schematically illustrate a configuration of a
container and partially
contacted label.
[0049] Figures 38 and 39 schematically illustrate another configuration of
a container and partially
contacted label.
[0050] Figures 40 and 41 schematically illustrate another configuration of
a container and partially
contacted label.
[0051] Figures 42-44 and 46-49 schematically depict a preferred embodiment
process in accordance
with the present invention.
[0052] Figure 45 illustrates an undesirable state that can potentially
occur during a labeling
operation.
Detailed Description of the Embodiments
[0053] The present invention provides further advances in strategies,
methods, components, and
equipment for applying labels and films onto curved surfaces such as outer
curved surfaces of various
containers. Although the present invention is primarily described in terms of
applying heat transfer
labels or related assemblies to containers, it will be understood that the
invention is not limited to
containers. Instead, the invention can be used to apply a variety of labels or
films onto surfaces of
nearly any type of article. The invention is particularly directed to applying
heat transfer labels onto
curved container surfaces. And, the invention is also particularly directed to
applying labels such as heat
transfer labels onto compound curved surfaces of various containers. Although
descriptions of various
preferred equipment are provided herein with regard to applying pressure
sensitive labels and/or shrink
Page 6
CA 02750143 2016-08-31
labels, it will be appreciated that the preferred equipment and associated
components can also be used
in conjunction with heat transfer labeling.
[0054] References are made herein to containers having curved surfaces or
compound curved
surfaces. A curved surface is a surface defined by a line moving along a
curved path. A compound
curved surface is a particular type of curved surface in which the previously
noted line is a curved line.
Examples of a compound curved surface include, but are not limited to, the
outer surface of a sphere, a
hyperbolic parabloid, and a dome. It is to be understood that the present
invention can be used for
applying labels and films onto a wide variety of surfaces, including planar
surfaces and simple curved
surfaces. However, as explained in greater detail herein, the invention is
particularly well suited for
applying labels and films onto compound curved surfaces.
Heat Transfer Labeling
[0055] A widely employed method for imprinting designs onto articles is
heat transfer labeling. This
process typically uses a paper base sheet or web carrying a label including a
release layer over which a
design is imprinted in ink or other pigmented formulation. In one successful
technique of heat transfer
decoration, labels are transferred to bottles or other articles using heat and
pressure by feeding the
article to a transfer site, where a label-bearing web is pressed against the
article to transfer the label, i.e.
the design onto the outer surface of the article.
[0056] In accordance with another aspect of the present invention, the
various label processors and
particularly their corresponding flexible members are used to apply one or
more designs from a web or
other transfer member to a container, bottle, or other article of interest.
The preferred embodiment
label processors and their flexible members are well suited for use in a heat
transfer labeling operation
and particularly well suited for applying designs to compound curved surfaces.
[00571 More specifically, the invention provides a heat transfer labeling
method employing a
decorative laminate including a design which is transferred from a support
member or web to an article.
The support member or web is heated to a first temperature, permitting
separation of the design of the
decorative lamination from the support member. In certain embodiments, the
surface of the flexible
member is advantageously at a second, somewhat lower temperature. In other
embodiments, the
surface of the flexible member is at a second temperature higher than the
temperature of the web. And
in still other embodiments, the surface of the flexible member is at the same
temperature as the
temperature of the web. The decorative laminate and design are pressed against
the article forming an
adhesive bond thereto. Upon withdrawal of the flexible member, the support
member or web readily
Page 7
CA 02750143 2016-08-31
separates from the design now adhered or otherwise disposed on the article. In
the following
description, a heat transfer label assembly generally comprises a decorative
laminate that includes one
or more designs to be transferred to corresponding articles. And, the heat
transfer label assembly also
comprises a support member or web which carries the decorative laminate. The
heat transfer label
assembly may include one or more release layers between the decorative
laminate and the web to
facilitate separation of the design from the web. The decorative laminate may
also include additional
components such as an outer layer of a heat transfer adhesive. Upon contacting
the decorative
laminate to an article, the adhesive promotes retention and adherence of the
design to the article.
[0058] In a preferred embodiment, the heat transfer label assembly includes
a non-wax based
adhesive/release layer which is in direct contact with the support member or
web. The adhesive/release
layer functions as a release layer permitting separation of the decorative
laminate from the support as
the support member is heated and as an adhesive as the decorative laminate is
pressed against the
article and transferred from the web to the article. The heat transfer label
assembly may include a wax
based release layer intermediate the adhesive/release layer and the support.
The nonwax
adhesive/release layer is softened by the heating of the support member and
separated therefrom
during transfer. This layer may also function as an adhesive forming a
permanent bond to the article
during transfer.
[0059] The heat transfer label assembly further includes an ink design.
Optionally, the heat transfer
label assembly includes a protective coating layer over the ink layer.
However, this layer may be
omitted in many applications.
[0060] Optionally, the heat transfer label assembly further includes a
barrier layer intermediate the
adhesive/release layer and the ink layer. The barrier layer, where included,
functions to prevent
absorption of ink into the nonwax adhesive/release layer.
[0061] The embodiment has the advantage that the decorative laminate may be
composed of either
a single colored decorative design or a multicolored decorative design
including halftone colors. Another
advantage of the embodiment is that the decorative laminate may be transferred
to virtually any type of
article irrespective of its shape or degree of surface curvature without
causing distortion to the design
imprint. Thus, the article may, for example, be composed of ceramic, glass,
plastic, paper foil, and a
variety of polymeric materials, and the surface to which the transfer
substrate is transposed may be flat
or include compound curves, irregular surfaces, or recessed panels. As
described in greater detail, for
certain applications, the articles to which the design(s) are transferred are
fabrics or textiles, including
woven and nonwoven materials.
Page 8
CA 02750143 2016-08-31
[0062] The heat transfer label assembly of the preferred embodiment
includes a paper sheet or
web, which is coated on one side with the various layers constituting
decorative laminate. The
decorative laminate generally includes a resinous coating layer in contact
with the support (i.e., the
adhesive/release layer), an ink layer covering the resinous coating layer and
a protective coating layer
over the ink layer.
[0063] In yet another embodiment, the various label processors as described
herein can be used in
conjunction with heat transfer labeling and permeable or "breathable"
adhesives to apply designs onto
fabrics, textiles, and the like.
[0064] A representative heat transfer label providing permeable adhesives
and/or inks is as follows.
Typically, the heat transfer label has four layers: a layer of temporary
support, a layer of indicia, a layer
of heat transfer adhesive, and a release layer between and in contact with the
layer of indicia and the
support. Upon application onto a fabric, the label is placed on the fabric
with the heat transfer adhesive
layer in contact with the fabric. The label application process can be
accomplished in any of a number of
known labeling processes, direct attached, tip on, blown on, etc. and then
secured. Preferably, the label
processor and its flexible member as described herein are used to apply the
layer of indicia and the layer
of heat transfer adhesive to the fabric.
[0065] Heat can be applied through the side of the temporary support. The
temporary support is
then withdrawn with the release layer and leaving only the printed indicia
attached to the fabric surface
through the adhesive. The temporary support and the release layer form the
support portion of the
label, which functions as carrier for the label but do not get transferred to
the fabric. The layer of indicia
and the layer of heat transfer adhesive form the transfer portion of the
label, which will be transferred
onto the fabric. Each layer in the transfer portion of the label is preferably
breathable. Each layer in the
support portion does not necessarily need to be breathable as it does not get
transferred to the fabric.
[0066] The heat transfer label can further include at least one of the
following layers in the transfer
portion: a white layer situated between the indicia and the adhesive layer, a
clear layer situated
between the indicia and the release layer, and a clear layer situated between
the white layer and the
adhesive layer when a white layer is used. A white layer can provide a
contrasting background color for
the indicia so that the appearance of the indicia is not offset significantly
by the color of the fabric. A
clear layer can be used to protect the indicia layer and modify adhesion of
the indicia layer to the
release layer. Another clear layer can be used to modify the adhesion between
the adhesive layer and
the white layer.
Page 9
CA 02750143 2016-08-31
[0067] The
carrier support or web provides mechanical strength for the label structure
for ease of
processing and handling. It also allows the label sheet to be rolled up or
stacked for storage until further
processing or attachment to the apparel item occurs. Paper or polymer films
can be used as the carrier.
A preferred carrier is thermally stabilized polymer film such as PET. A wide
array of materials can be
used for the carrier, support member, or web. In addition to the materials
noted herein, it is also
contemplated that fabrics, textiles, non-wovens, and woven materials could be
used as carriers. It is
also contemplated that the heat transfer label assemblies could include one or
more fabric or textile
layers. Combinations of all of these materials are contemplated. A preferred
thickness for the carrier
film is 2 to 7 mil thick. It is more preferred to be 4 to 6 mil.
[0068] The
release layer is a low melting point material with suitable adhesion to the
indicia layer or
clear coating when used. Suitable adhesion means the indicia or clear coating
can be deposited on the
release layer but can also be separated from the release layer in the heat
transfer process. The release
for the release layer can be wax based material or silicone. The release may
further include a polymer
binder and other additives such as matting agents. In situations where a wax
is selected for the release,
certain types of wax could contaminate the surface of the breathable label
after the heat transfer
occurs, hydrophilic wax is preferred. Preferred melting points for the wax
range from 70 to 150 C. It is
more preferred to use wax with a melting point in the range of 100 to 120 C.
One example of
hydrophilic wax is Unithox D-300, a non-ionic wax emulsion from Baker
Petrolite that is 23.5% in solids.
Another example is E6 Release available from Avery Dennison RIS division. The
wax layer can be solvent
or water based and can include the same set of additives as layers in the
transfer portion of the label, to
be discussed in detail later. The wax layer can be printed or coated. The
thickness of wax release layer
is between about 1 to about 10 microns but is more preferably between about 1
to about 5 microns.
[0069] In
certain embodiments, each layer of the heat transfer label that is attached to
the article
preferably exhibits breathability, that is, to allow moisture to penetrate
through. The breathability
results from the use of polymers that can form a breathable film. Those
polymers are hydrophilic in
nature and form a monolithic film, that is, a film without microporous
interconnected structures. The
breathability of these hydrophilic polymers is the result of molecular water
diffusion and conduction
along the hydrophilic polymer side chain. This mechanism is described in
detail in J. Mater. Chem.,
2007, 17, 2775-2784. The
hydrophilic polymers can
also absorb condensed water and allow the water to pass through the polymer
film, a process
commonly referred to as water wicking.
Page 10
CA 02750143 2016-08-31
[0070]
Breathable hydrophilic polymers include water based dispersions and solvent
based
dispersions. Examples of water based hydrophilic polymer dispersions include
Permax 202, Permax 230,
Permax 300, and Permax 803, all of which are from Lubrizol Corp. of Wickliffe,
Ohio, USA. The preferred
hydrophilic breathable polymers have polyalkyleneoxide grafted as side chains
instead of the being part
of the main backbone as described by Lubnin et al. in U.S. Patent No.
6,897,281. Permax 230 is a non-
ionic stabilized polyurethane dispersion with solid value of 33%. It has an
MVTR value for the dried film
of 500g/m2/day using the upright water cup (ASTM E-96B) and 4500 g/m2/day
using the inverted water
cup (ASTM E-96BW). Permax 230 has also a melt viscosity that allows it to flow
into the fabrics when
molten at a temperature above 250 7, making it ideal for formulating
breathable hot melt adhesives.
[0071]
Examples of solvent based hydrophilic polymers include the breathable
polyurethane SU-55-
074 from Stahl Corp, which is a 30% solid solution in a toluene / IPA mixture.
Such polymers can also be
crosslinked via the urethane group using poly-isocyanates such as the HDI
trimer Coronate HXLV from
Nippon Polyurethane Industry Co. Preferred solvents for such polymers include
propylene and di-
propylene glycol.
[0072]
Besides hydrophilic polymer, the formulation for each layer in the transfer
portion may
further include a liquid carrier, and one or more of the following components:
polymers, waxes,
additives, pigments, etc. The additives include chemicals such as humectants,
rheology modifiers,
surface tension modifiers, leveling agents, release agents etc.
[0073] The liquid carrier can be water or solvent.
Examples of suitable solvents include
dipropyleneglycol dimethylether, dipropyleneglycol
monomethylether, dipropyleneglycol
monobutylether, dipropyleneglycol monomethylether acetate, gama butyrolactone,
n-ethyl
pyrolidinone etc. When water is used as a liquid carrier, it may still require
the presence of a co-solvent
to help the stability of the formulation. Suitable co-solvents include
propylene glycol ethers, esters and
ethylene glycol ether / esters. Examples of co-solvents include di-propylene
glycol di-methyl ether, di-
propylene glycol mono methyl ether, di-propylene glycol monobutylether, di-
propylene glycol mono
methyl ether acetate, and the mono propylene glycol series.
[0074]
Humectants maintain the mobility and wetting of the formulation during
processing.
Examples of humectants include: mono-propylene glycol, di-propylene glycol, di-
ethylene glycol,
glycerol, etc or mixtures of glycols and waxes, such as Aqualube AQ54 from
Nazdar Corp.
[0075]
Rheology modifiers provide the suitable flow characteristics for the
formulation. Newtonian
or viscoelastic flow properties are preferred for the formulations. For screen-
printing, the viscosities of
the formulations are preferred to be from 10,000 cp to 100,000 cp. For other
printing methods such as
Page 11
CA 02750143 2016-08-31
flexo or gravure, the viscosities of the formulations are preferably in a
lower range, e.g. 5-250 cp and
Newtonian flow property is preferred. Examples of rheology modifiers include
associated hydrophilic
polyurethanes such as DSX1415 from Cognis Corp., BorchiGel L75N from Borchers,
or alkali-swellable
thickeners such as UCAR Polyphobes 102 and 106 from Dow Chemical.
[0076] Surface tension modifiers or surfactants can be anionic or non-
ionic. The preferred ones are
non-ionic and non-fluorinated with low foaming ability. Examples of suitable
surface tension modifiers
include alkoxylated silicones such as TegoWet 270 from Tego ¨ Degussa or BYK
319 from BYK Chemie,
ethoxylated hydrocarbons such Triton CF-10 from Dow Chemical, or acetylene
derived alcohols such as
Surfynol 104E from Air Products and Chemicals, Inc.
[0077] Defoamers such as BYK 24, 28, 19 from BYK Chemie can also be used.
[0078] Pigments are important for the indicia layer and white layer.
Pigment pastes that are pre-
dispersed in water or organic solvent are preferred. Examples of such pigments
include Aurasperse
series of pigment concentrates from BASF. Aurasperse W-308, for example, is a
white TiO2 concentrate
with 71% solids. It can be used in the white background layer. Aurasperse W-
7012 is a black pigment
concentrated with 35% solids. It can be used in the black color ink of the
color layer.
[0079] pH buffers could also be a part of the formulations. The role of the
buffers is to maintain the
pH value of the formulation and prolong the pot life of the liquid ink by
moderating the reactivity of the
cross linker. The pH buffers are also used to control the rheology of the
formulations when any form of
alkali induced thickening is employed. A suitable pH buffer is DMAMP-80, an
amino alcohol product
from Dow Chemical that is an 80% solution of 2-Dimethylamino-2-Methyl-1-
Propanol in water.
DMAMP-80 could effectively thicken alkali-swellable thickeners such as UCAR
Polyphobes 102 and 106
from Dow Chemical.
[0080] The optional clear layer functions as a protective layer or varnish
to give the label increased
resistance to abrasion and scuffing effects. It also serves to tune the
adhesion of the label to the
supporting release layer. This layer should be deposited uniformly. The
preferred thickness is about 1 to
about 20 microns.
[0081] The indicia is a color design layer that functions to display the
visual information of the label.
This layer should be breathable but the breathability can be a function of the
solid pigment content of
the ink. Important for the color layer is the usage of color pigments as
compared to dyes. Color carriers
in the inks typically offer improved resistance to environmental factors and
do not exhibit propensity to
thermal sublimation. The preferred color carriers used in the indicia are the
organic and inorganic
pigments. The thickness of the indicia can be a function of pigment
concentration (lower limits or
Page 12
CA 02750143 2016-08-31
minimal necessary achieving the required color density is preferred) and
breathability (higher the
better). A preferred thickness is about 10 to about 50 microns.
[0082] The white background layer offers a contrasting background for the
color design layer. This
layer should be printed uniformly and be breathable. The preferred thickness
is about 20 to about 200
microns. It has all the features of the color design layer and in addition
requires an increased level of
white pigmentation (>50% pigment in the solid film mix) as its masking power
should overcome the
background color of the fabric the label is bonded onto. The white background
layer may be optional if
the color of the fabric substrate is white. It is preferred for this layer,
disregarding the color or nature of
the fabric substrate, to exhibit a consistent background for the indicia. The
preferred pigment for this
layer is silica or alumina treated TiO2 as they are also hydrophilic.
[0083] The optional clear layer functions as a tie layer if the white
background layer does not offer
satisfactory adhesion to the adhesive layer. This is especially required for
some heavily TiO2 loaded
white formulations.
[0084] The adhesive layer used in typical heat transfer labelS preferably
satisfies the following
requirements: a) melt and flow in the fabrics texture between about 250-350 F
when heated up for 5 to
about 50 seconds, b) have a suitable modulus to withstand high temperature
wash tests required by
some apparel manufacturers, and c) have suitable adhesion to synthetic fibers.
The adhesive thickness
can range between about 20 and about 500 microns.
[0085] As the adhesive layer will be in contact with the fabric after the
heat transfer process, and
therefore hidden behind the indicia layer and other layers when used, there
are two methods to render
this layer breathable: through the use of a breathable hot melt adhesive, or
through pattern printing of
a hot melt adhesive that is not breathable, or a combination of both. When
using pattern printing, the
adhesive is deposited at discrete locations, leaving space between adhesives
so that moisture or
condensed water can pass through. Breathable adhesives can be used to at least
partially fill up the
space between the non-breathable adhesives.
[0086] When using breathable heat transfer labels as described herein,
typically the heat transfer
label has a MVTR of at least 100g/m2/day when measured via ASTM 96E Procedure
D. Preferably, the
MVTR of the labels ranges from 400 to 900 g/m2/day when tested via ASTM 96E
Procedure D.
[0087] It will be appreciated that the preferred embodiment heat transfer
labeling methods are not
limited to the particular label, support member and configuration as
previously described. Instead, the
invention includes a wide array of alternate methods and strategies of
performing heat transfer labeling
using the preferred embodiment equipment and namely the label processor, as
described herein.
Page 13
CA 02750143 2016-08-31
Although the following description of various labeling equipment is generally
provided in terms of
applying polymeric film labels and particularly pressure sensitive labels
and/or heat shrink labels, it will
be understood that the equipment can also be used to apply one or more designs
such as in the form of
a decorative laminate from at heat transfer label assembly.
Application of Label Using Flexible Members
[0088] Specifically, the invention provides a flexible label applicator or
processor member and
associated assembly that when used in accordance with a preferred technique as
described herein,
applies labels onto curved surfaces without attendant problems of the
occurrence of defects such as
darts and wrinkles. The technique results in the application of labels onto
curved container surfaces
without defects by using a unique concurrent heating and wiping operation.
[0089] The flexible member, its various characteristics, and various frames
and related assemblies
for supporting and using the member are all described in greater detail
herein. Additionally, preferred
aspects of labels and films for application to containers are also described
herein. Moreover, preferred
aspects of adhesives associated with the labels and other aspects and details
of labels are described
herein. Furthermore, preferred processes for applying labels by use of the
flexible member(s) are all
described in greater detail herein.
Flexible Member
[0090] The present invention provides a flexible member or diaphragm that
is adapted for
contacting a label, label assembly, film(s), or other like components and
applying pressure to the label to
contact and adhere the label to a surface of a container. Typically, labels
are applied to the outer
surface of a container, which as previously noted, is curved or otherwise
exhibits a curved contour or
shape. In many instances, certain regions of the container may exhibit
compound curves. By use of the
present invention, labels may be applied over these regions in a defect-free
manner.
[0091] The flexible member is sufficiently rigid such that the member
maintains its shape prior to
contact with the label(s) or container(s). The member is not overly rigid, and
hence flexible, such that
the member readily deforms upon contact and under application of a load, such
as for example, a label
contacting force. This preferred characteristic is described in greater detail
herein, but generally
designated by reference to the flexible member as being deformable.
[0092] The flexible member may be provided in a wide variety of different
shapes, sizes, and
configurations so long as it exhibits the noted deformable feature.
Preferably, the flexible member
Page 14
CA 02750143 2016-08-31
defines an outwardly bulging or domed surface such as a convex surface for
contacting a label and/or
container. The flexible member also defines an interior hollow region,
preferably accessible from a
location opposite that of the outwardly bulging contact surface.
[0093] It is also preferred that the flexible member provide heat to the
label and/or container.
Accordingly, it is preferred that the flexible member transfer heat along at
least a portion of its outer
surface, and preferably along its outwardly bulging surface for subsequent
transfer of such heat to a
label and/or container, particularly when contacting the label. Heat may be
provided along the surface
of the flexible member in a variety of different ways. However, it is
generally preferred that a source of
heat be provided within the interior of the flexible member. Heat within the
interior of the flexible
member is then transmitted through a wall of the flexible member, such as by
conduction, to the outer
surface of the member. It will be understood that the invention includes
flexible members that do not
include any heating provisions. In this version of the invention, one or more
preheaters are used to heat
the labels and/or films.
[0094] A preferred source of heat for the flexible member is a flameless
heater such as an
electrically powered resistive heater. Alternatively, one or more coils of a
conduit through which a
heated medium is passed could also be positioned within the interior of the
flexible member. Yet
another source of heat is administering a heated medium directly within the
hollow interior of the
flexible medium. Examples of such mediums include but are not limited to air,
other gases, fluids, or
flowable liquids. For example, liquid hydrocarbons such as oils could be used
to heat and/or fill the
interior hollow region of the flexible member. However, air is often preferred
since it is readily available
and leakage is not a concern.
[0095] For embodiments in which a heating coil or heating unit is provided
within the interior of the
flexible member, the particular configuration of the coil or unit may be
provided so as to optimize the
transmission of heat to desired regions of the flexible member, e.g. outer
peripheral regions of the
region of the domed outer surface. Generally, the preferred configuration or
pattern of the heater is
dependent on the particular geometry of the bottle and its respective label,
to which the flexible
member is contacted. Preferably, an oval or circular pattern can be used, with
the heater being
positioned relatively close to the interior wall surface of the flexible
member along regions
corresponding to outer regions of the label being applied thereto. This is
preferred because it is
generally not necessary to heat portion(s) of the label that are already
adhered to the container, e.g. the
interior middle region(s). This is explained in greater detail herein.
Page 15
CA 02750143 2016-08-31
[0096] In the preferred versions of the flexible member, the outer domed
region and sometimes the
sidewalls attached thereto, are flexed, deformed and moved as the member is
contacted against a
container and label. Thus, it is generally preferred that any heating
provisions such as for example
electrically resistive heating elements, not be directly attached to the
flexible member. However, the
present invention contemplates that such constructions and arrangements could
be used. For example,
flexible printed heating elements could be applied onto the inner surface or
the outer surface of the
flexible member. It is also contemplated that an electrically powered
resistive heater could be formed
within or otherwise disposed within the flexible member.
[0097] Heating of the domed label-contacting outer surface of the flexible
member can be
accomplished in nearly any fashion. For example, multiple heating sources,
provisions, and/or other
techniques may be used. In certain applications, it may be preferred to employ
multiple heaters. For
example, a first heater can be used to heat air entering the interior hollow
region of the flexible
member. The first heater can for example be an electrically powered resistive
heater. A second heater
can be provided within the interior of the flexible member and be relatively
stationary. The second
heater can be in the form of an electrically powered resistive heater or
utilize one or more coils through
which a heat transfer fluid flows. Heating of the flexible member is performed
such that the outer
temperature of the flexible member is at least 38 C and most preferably from
about 120 C to about
150 C during label application operations. It will be appreciated that the
temperature or range of
temperatures to which the outer surface of the flexible member is heated,
depends upon numerous
factors, including for example, the heat shrink characteristics of the label
and the adhesive properties. It
is also contemplated that another set of heaters could be used to heat the
labels and/or the containers
prior to their contact with the flexible member. These heaters can be
positioned external to the flexible
member. For example, one or more infrared heaters could be utilized. Infrared
lamps are preferred
since they tend to heat objects of interest, i.e. the labels, and do not heat
the surrounding atmosphere.
Preferably, for certain applications, the labels are heated to a temperature
of at least 38 C prior to their
final application to a container. A wide array of heating strategies and
techniques can be used in order
to increase the temperature of the external surface of the flexible member.
[0098] For certain preferred embodiments, it is desirable to utilize a
single heat source. That is, for
certain applications it is preferred to use one or more inlet heaters to heat
incoming air during or prior
to its entrance into the flexible member, and not employ one or more heaters
within the flexible
member. Heaters provided within the interior of a flexible member are
preferably radiant heaters.
Elimination or avoidance of such interior heaters may provide significant cost
savings. However, it will
Page 16
CA 02750143 2016-08-31
be appreciated that the invention includes systems in which heating is
provided exclusively within the
flexible member, systems in which heating is provided by both inlet heaters
and heaters within the
flexible member, and by systems using tertiary or other supplemental heaters
in combination with inlet
heaters and/or heaters within the interior of the flexible member.
[0099] Another feature provided in certain preferred embodiments relates to
the use of one or
more air manifolds generally positioned within a flexible member. In a
preferred system configuration,
heated air is continuously cycled through one or more flexible members during
a labeling operation.
Excess air is exhausted as one or more flexible members are contacted and
pressed against
corresponding containers carrying labels. New air is then introduced upon
positioning the flexible
member away from and no longer in contact with the container and label. It is
preferred that the new
air is heated as such practice avoids the use of ambient temperature air which
would otherwise cool the
flexible member.
[00100] Many of the preferred embodiment flexible member, frame, and/or
enclosure assemblies
utilize a single entrance for incoming heated air along a rear wall that
encloses the interior of the flexible
member. Directing heated air into the flexible member interior and
particularly, through a single
entrance, results in the creation of regions of higher temperatures along the
flexible member. Such
regions of non-uniformity are undesirable.
[00101] Accordingly, for certain applications, it is preferred to use an
air manifold or diffuser
assembly within the interior of a flexible member. The air manifolds may be in
a wide array of shapes
and sizes. The air manifolds serve to distribute heated air within the
interior of a flexible member to
thereby more uniformly heat the flexible member.
[00102] The air flow manifold or diffuser may be in a variety of different
shapes, sizes, and/or
configurations. For example, one or more diffuser plates may be provided
against which incoming
heated air is directed toward. The flowing airstream is deflected by the
diffuser plate(s) and thereby
directed to other regions within the interior of the flexible member. The
diffuser plate can be
positioned directly within the flowing air stream such as by securing the
plate across the opening of an
air inlet port. Other members can be used in combination with a diffuser plate
such as one or more pins
or other flow deflecting members. Generally, any member that induces or
promotes turbulence of the
air flow within the interior of a flexible member may be used.
[00103] A particularly preferred embodiment of an air manifold is a tube
diffuser. A tube diffuser is
preferably in the form of a pipe or conduit in flow communication with the
heated air inlet and is sized
and shaped so as to fit within the interior of a flexible member. The pipe or
conduit defines a
Page 17
CA 02750143 2016-08-31
longitudinally extending interior flow channel. The pipe or conduit also
defines a plurality of holes or
other apertures in the sidewalls and any end walls of the pipe. Air entering a
flexible member through
the inlet is directed through the pipe and exits the pipe via the plurality of
holes. The pattern or
arrangement of apertures is such that the heated air exiting the pipe
uniformly heats, or substantially
so, the interior of the flexible member and preferably the front wall of the
flexible member which
ultimately contacts labels. For example, a representative pattern of apertures
may include two rows of
apertures extending along the length of the pipe. Each hole or aperture is
approximately 1.5 mm in
diameter, and spaced about 25 mm apart. The two rows are spaced 60 apart and
are directed toward
the inner sides and front surfaces within the interior of the flexible member.
Such orientation of the
rows serves to direct heated air to the lateral side regions of the flexible
member where such heat is
typically needed.
[00104] The interior hollow region of the flexible member may be open or in
communication with the
atmosphere and thus be at atmospheric pressure. Alternatively, communication
between the interior
region and the external atmosphere may be partially or entirely restricted,
such that the interior region
is at a pressure that is greater than or less than atmospheric pressure. The
flexible member may also be
configured or engaged with other components such that during deformation of
the flexible member, the
pressure within the interior hollow region of the member changes, and is
different from the pressure
within that region prior to deformation. For example, a preferred
configuration as described in greater
detail herein, provides partially restricted communication between the
interior hollow region of the
flexible member and the external atmosphere. Prior to deformation, the
restriction is not complete so
that the interior hollow region is at atmospheric pressure. Upon deformation,
the volume of the interior
hollow region is reduced. Due to the noted partial restriction and decrease in
volume, the pressure
within the interior hollow region of the flexible member increases to a
pressure greater than
atmospheric pressure. The increase in pressure is preferably temporary as air
within the interior hollow
region is allowed to exit the interior region of the flexible member. These
aspects are described in
greater detail herein.
[00105] Preferably, the flexible member is not pressurized prior to a label
application process. That
is, preferably, the interior hollow region of the flexible member is at
atmospheric pressure. By
selectively controlling the flow restriction of air exiting the flexible
member during a label application
operation, controlled increase and maintenance of pressure within the flexible
member is achieved.
Preferably, the contents of the flexible member are exhausted after each label
application operation so
that the pressure within the interior of the flexible member returns to
atmospheric. Preferably, the
Page 18
CA 02750143 2016-08-31
peak pressure as measured within the interior hollow region of the flexible
member is less than 34,500
N/m2, more preferably less than 27,600 N/m2, and most preferably less than
20,700 N/m2. However, it
will be understood that the present invention includes other venting
strategies and the use of peak
pressures lesser than or greater than these noted. Generally, over the course
of a label application
operation, a somewhat steady and constant inflow of air to the flexible member
is provided through
open exhaust ports. The flexible member will partially deflate as it contacts
the label and container and
in certain instances, may collapse as it fully contacts the label and
container.
[00106] It will be appreciated that the present invention may utilize a
wide array of assemblies in
addition to or in certain applications, instead of, the flexible members
described herein for applying a
label or film onto a curved surface. For example, various mechanical
assemblies particularly using
springs or other biasing members could be used. It is also contemplated that
label applicator or label
processing members using compressible foams could be used.
[00107] The flexible member may be formed from nearly any material so long as
the member is
sufficiently flexible, i.e. deformable, and exhibits good thermal
conductivity, durability, and wear
properties. A preferred class of materials for the flexible member is
silicones.
[00108] More precisely called polymerized siloxanes or polysiloxanes,
silicones are mixed inorganic-
organic polymers with the chemical formula [R2SiOl0, where R is an organic
group such as methyl, ethyl,
or phenyl. These materials typically include an inorganic silicon-oxygen
backbone (...-Si-O-Si-O-Si-0-...)
with organic side groups attached to the silicon atoms, which are four-
coordinate.
[00109] In some cases, organic side groups can be used to link two or more
of these -Si-0- backbones
together. By varying the -Si-0- chain lengths, side groups, and crosslinking,
silicones can be synthesized
with a wide variety of properties and compositions. They can vary in
consistency from liquid to gel to
rubber to hard plastic. The most common siloxane is linear
polydimethylsiloxane (PDMS), a silicone oil.
The second largest group of silicone materials is based on silicone resins,
which are formed by branched
and cage-like oligosiloxanes.
[00110] A particularly preferred silicone for use in forming the flexible
member is a commercially
available silicone elastomer designated as Rhodorsil. V-240. Rhodorsil. V-240
is available from Bluestar
Silicones of Rock Hill, SC. This silicone elastomer is a two component,
addition cure, room temperature
or heat accelerated cure silicone rubber compound. It is designed as a 60
Durometer (Shore A) rubber
with high strength properties, long library life, low shrinkage, excellent
detail reproduction, good release
characteristics, and improved resistance to inhibition. The formulation of
Rhodorsir V-240 is generally
as shown in Table 1 below:
Page 19
CA 02750143 2016-08-31
[00111] Table 1 - Formulation of Rhodorsil*
Component CAS Reg Number Percentage
Methylvinylpolysiloxane
Quartz (SO2) 14808-60-7 15 - 40
Filler
Calcium Carbonate 471-34-1 1 - 5
Platinum Complex <0.1
[00112] As explained herein, in certain applications, it is desirable to
heat the label prior to or during
application, of the label to the surface of interest. And, as previously
noted, heating provisions can be
incorporated within the interior hollow region of the flexible member.
Accordingly, it is desirable that
the material of the flexible member exhibit a relatively high thermal
conductivity to promote heat
transfer to the outer surface of the flexible member. Preferably, the thermal
conductivity of the flexible
member is at least 0.1 W/(m. C), more preferably at least 0.15 W/(m. C), more
preferably at least 0.20
W/(m. C), more preferably at least 0.25 W/(m. C), and most preferably at least
0.275 W/(m. C).
[00113] For embodiments in which the flexible member is formed from a
silicone elastomer, the
thickness of the walls of the flexible member are preferably from about 2.3 mm
to about 3.0 mm. It will
be understood that the particular wall thickness depends upon material
selection, desired deformability
characteristics, and other factors. Accordingly, in no way is the present
invention limited to these wall
thicknesses.
[00114] Most preferably, the flexible member is a domed outwardly
projecting deformable member.
The member may include one or more arcuate side walls or a plurality of
straight walls arranged so as to
form the interior hollow region. In a preferred version, the flexible member
includes four side walls that
extend between a base and a domed label-contacting surface. The four walls are
arranged transversely
with neighboring walls so as to form a square or rectangular shape. The base
is preferably in the form of
a lip that extends along a common edge of the four side walls. The domed
surface extends from an edge
of the side walls opposite the lip. The entire flexible member, i.e. its base,
side walls, and domed
surface, can be readily formed by molding a silicone elastomer, such as the
previously noted Rhodorsil.
V-240. The exact shape, size, and configuration of the flexible member
primarily depends upon the
shape, size, and configuration of the bottle to which a label is to be
applied. For many applications, the
Page 20
CA 02750143 2016-08-31
flexible member may be in the shape of an oval with a domed front face.
However, it will be
appreciated that the present invention includes flexible members of nearly any
shape.
[00115] The particular shape and/or configuration of a flexible member
primarily depends upon the
shape of the label and the shape or contour of the container. Although for
many applications, a flexible
member having a generally rectangular and symmetrical frontal profile with
arcuate or rounded edges
may be suitable, for certain applications, it may be preferred to use flexible
members having non-
symmetrical frontal and/or side profiles. Examples of flexible members having
non-symmetrical profiles
are provided and described herein.
Flexible Member Frame and Assembly
[00116] The present invention also provides a frame for supporting the
flexible member and
preferably engaging the member to facilitate positioning and contacting the
member against a label
and/or container. The frame is preferably rigid and may be constructed from
one or more metals,
polymeric materials, or composite materials exhibiting the requisite
properties as more fully described
herein.
[00117] Preferably, in one form, a frame having a relatively planar shape
defining two oppositely
directed sides and defining a relatively large central opening is provided.
The opening is sized and
shaped to accommodate and receive the flexible member. Accordingly, upon
positioning the flexible
member within the frame's opening, the frame extends about the flexible member
and provides support
for the member and facilitates movement or positioning of the flexible member.
In a preferred
embodiment, the flexible member includes a plurality of side walls. Thus,
preferably, the frame defines
an opening having the same shape as the plurality of side walls of the
flexible member. For collections
of linear side walls of a flexible member, the shape of the opening defined in
the frame preferably
corresponds to the shape of the collection of side walls. And, preferably, the
number of linear side walls
corresponds to the number of interior linear edges of the opening of the
frame.
[00118] In certain applications, it may be preferred to provide one or more
guides extending from the
frame and generally alongside the flexible member when coupled with the frame.
The one or more
guide(s) are positioned and oriented relative to the flexible member such that
they serve to limit the
extent and/or direction of deformation of the flexible member. The guides may
be affixed or otherwise
formed with the frame by techniques known in the art. The guides are
preferably located about the
previously noted frame opening. The guides preferably extend or otherwise
project from a face of the
frame, and in certain embodiments, may extend transversely therefrom.
Page 21
CA 02750143 2016-08-31
[00119] Each guide may also comprise one or more additional components or
may itself extend in a
desired direction relative to the flexible member. For example, an adjustably
positionable secondary
guide member may be provided along a distal end region of a guide. The
secondary guide member may
extend transverse to, or at some angle, with respect to the longitudinal axis
of the guide. The position
and specifically, the angular orientation of the secondary guide is preferably
selectable so that a user
may vary the orientation and position of the secondary guide member relative
to the flexible member as
desired.
[00120] Yet another preferred feature in many of the embodiments is the
provision of guides having
particular shapes or profiles along their inner faces, i.e. the faces of
guides that are directed toward a
flexible member. The use of shaped or contoured inner sides of guides promotes
improved contact
between flexible members and containers/labels. For certain containers having
curved or sloping
sidewall and/or arcuate front or rear faces, the use of guides having
contoured inner sides promotes
rolling contact between the flexible member and label. In addition, the
provision of guides having inner
sides that match or generally correspond to the contour of the container sides
promotes further
displacement of the flexible member around the contour of the container.
Furthermore, the use of
guides having inner sides that correspond to the shape of the container has
also been found to promote
label application of corner and outer end regions of the label to the
container.
[00121] The frame is preferably formed from steel or aluminum, although a
wide array of other
materials are contemplated. The guides and/or the secondary guide members are
also preferably
formed from steel or aluminum. The guides can be integrally formed with the
frame. Alternatively, the
guides can be affixed to the frame after formation of the frame such as by
welding or by the use of one
or more fasteners. As noted, it is preferred that the secondary guide
member(s) be positionable with
respect to the guide(s) and/or the frame. And so, it is preferred that a
selectively positionable assembly
be used to releasably affix each secondary guide to a corresponding guide.
[00122] The present invention also provides an enclosure or other mounting
assembly. Preferably,
the frame and/or the flexible member are attached to the enclosure. The
enclosure is preferably sized,
shaped, and configured to be affixed to or otherwise secured to the frame. The
enclosure may also
serve to house heating provisions for the flexible member. These aspects are
all described in greater
detail herein.
[00123] Additionally, for certain embodiments it may be preferred to
provide adjustment assemblies
such that the position of the guides can be selectively adjusted relative to
the frame. Such adjustment
assemblies can be provided in many forms, however a preferred assembly
includes a pair of vertically
Page 22
CA 02750143 2016-08-31
oriented rails upon which the guides can be selectively positioned and
engaged. The use of such an
adjustment assembly enables the vertical position of one or more guides to be
readily and conveniently
positioned as desired. Vertical positioning of a guide may be desirable to
accommodate application of
labels of different sizes and/or placement positions on the containers of
interest.
[00124] The assembly of frame and enclosure, and ultimately including the
flexible member, may
further include one or more additional components. As previously noted,
heating provisions are
preferably provided within the interior hollow region of the flexible member.
Preferably, such heating is
provided by one or more electrically powered resistive heating element(s). The
element can be in a
variety of different shapes and configurations. Also, as previously noted, a
conduit carrying a flowable
heating medium can be positioned in the interior hollow region of the flexible
member. It is generally
preferred that appropriate insulating members be provided in association with
the heating element to
prevent direct contact with the flexible member. However, if the flexible
member is formed from a
material that is sufficiently resistant to high temperatures such insulating
members may not be
necessa ry.
[00125] The assembly of frame, flexible member, and enclosure preferably
further includes a vent
plate that extends across the open rear region of the flexible member. The
vent plate provides access to
the interior hollow region of the flexible member. Upon incorporation in the
assembly, the vent plate
contacts, and preferably sealingly contacts a rearwardly directed face of the
flexible member and/or the
frame. The vent plate preferably defines one or more openings extending
through the vent plate that
allow air to pass. Air can be introduced through these openings to pressurize
the interior of the flexible
member and/or to heat the flexible member. Upon deformation of the flexible
member, such as after
contact with a label and container, air is directed out of the hollow interior
of the flexible member
through the one or more openings defined in the vent plate. The total flow
area of the openings of the
vent plate can be selected or varied such that the rate of air exiting or
entering the flexible member is
limited or otherwise controlled. This strategy can be utilized to slow the
rate of deformation of the
flexible member. These aspects are described in greater detail herein.
[00126] In certain applications, particularly those involving high volume
manufacturing, it is preferred
to utilize multiple assemblies of frame(s), flexible member(s) and/or
enclosure(s) such as in a parallel
configuration in which the components are alongside one another.
[00127] Another optional feature of the invention is the provision of a
"quick change" head assembly.
In these embodiments, a releasable head assembly which carries a flexible
member, optional heater(s)
within the flexible member, frame, and electrical components is provided. The
releasable head
Page 23
CA 02750143 2016-08-31
assembly can be readily engaged with and removed from a larger frame or
support assembly, or with a
walking beam apparatus as known in the art. The provision of a releasable head
assembly enables fast
and efficient changing of one flexible member and associated assembly for
another flexible member and
its associated assembly. This may be desirable when the use of a flexible
member having a particular
configuration is preferred over another flexible member having a different
configuration. The releasable
head assemblies are preferably configured such that they are easily engageable
or securable to the
other frame or walking beam apparatus. Electrical power and signal connections
are preferably made
by plug connections, although the invention includes the use of other
connecting systems. These and
other aspects are described in greater detail herein in conjunction with a
description of a representative
preferred embodiment.
Labels/Film
[00128] As previously noted, it is preferred that the various systems,
equipment, and components be
used for applying heat transfer labels and/or indicia to articles, it will be
understood that the systems,
equipment, and components can also be used to apply pressure sensitive labels
and/or shrink labels to
articles.
[00129] The polymeric films useful in the label constructions, the
application of which the present
invention is directed, preferably possess balanced shrink properties. The
balanced shrink properties
allow the film to shrink in multiple directions to thereby follow the contour
of a compound curved
surface as the label is applied upon the curved surfaces. Films having
unbalanced shrink, that is, films
having a high degree of shrink in one direction and low to moderate shrink in
the other direction, can be
used. Useful films having balanced shrink allow for a wider variety of label
shapes to be applied to a
wider variety of container shapes. Generally, films having balanced shrink
properties are preferred.
[00130] In one embodiment, the polymeric film has an ultimate shrinkage (S)
as measured by ASTM
procedure D1204 in at least one direction of at least 10% at 90 C and in the
other direction, the
shrinkage is within the range of S +/- 20%. In another embodiment, the film
has an ultimate shrinkage
(S) in at least one direction of about 10% to about 50% at 70 C and in the
other direction, the shrinkage
is within the range of S +/- 20%. In one embodiment, the ultimate shrinkage
(S) is at least 10% at 90 C
and in the other direction, the shrinkage is within the range of S +/- 20%.
The shrink initiation
temperature of the film, in one embodiment, is in the range of about 60 C to
about 80 C.
[00131] The shrink film must be thermally shrinkable and yet have
sufficient stiffness to be
dispensed using conventional labeling equipment and processes, including
printing, die-cutting and label
Page 24
CA 02750143 2016-08-31
transfer. The stiffness of the film required depends on the size of the label,
the speed of application and
the labeling equipment being used. In one embodiment, the shrink film has a
stiffness in the machine
direction (MD) of at least 5 mN, as measured by the L&W Bending Resistance
test. In one embodiment,
the shrink film has a stiffness of at least 10 mN, or at least 20 mN. The
stiffness of the shrink film is
important for proper dispensing of labels over a peel plate at higher line
speeds.
[00132] In one embodiment, die-cut labels are applied to the article or
container in an automated
labeling line process at a line speed of at least 30 units per minute, and
preferably from at least 250
units per minute to at least 500 units per minute. It is contemplated that the
present invention could be
used in conjunction with processes operating as fast as 700 to 800 units per
minutes, or more.
[00133] In one embodiment, the shrink film has a 2% secant modulus as
measured by ASTM D882 in
the machine direction (MD) of about 138,000,000 N/m2 to about 2,760,000,000
N/m2, and in the
transverse (or cross) direction (TD) of about 138,000,000 N/m2 to about
2,760,000,000 N/m2. In another
embodiment, the 2% secant modulus of the film is about 206,000,000 N/m2 to
about 2,060,000,000
N/m2 in the machine direction and about 206,000,000 N/m2 to about
2,060,000,000 N/m2 in the
transverse direction. The film may have a lower modulus in the transverse
direction than in the machine
direction so that the label is easily dispensed (MD) while maintaining
sufficiently low modulus in the TD
for conformability and/or squeezability.
[00134] The polymeric film may be made by conventional processes. For
example, the film may be
produced using a double bubble process, tenter process or may comprise a blown
film.
[00135] The shrink film useful in the label may be a single layer
construction or a multilayer
construction. The layer or layers of the shrink film may be formed from a
polymer chosen from
polyester, polyolefin, polyvinyl chloride, polystyrene, polylactic acid,
copolymers and blends thereof.
[00136] Polyolefins comprise homopolymers or copolymers of olefins that are
aliphatic hydrocarbons
having one or more carbon to carbon double bonds. Olefins include alkenes that
comprise 1-alkenes,
also known as alpha-olefins, such as 1-butene and internal alkenes having the
carbon to carbon double
bond on nonterminal carbon atoms of the carbon chain, such as 2-butene, cyclic
olefins having one or
more carbon to carbon double bonds, such as cyclohexene and norbornadiene, and
cyclic polyenes
which are noncyclic aliphatic hydrocarbons having two or more carbon to carbon
double bonds, such as
1,4-butadiene and isoprene. Polyolefins comprise alkene homopolymers from a
single alkene monomer,
such as a polypropylene homopolymer, alkene copolymers from at least one
alkene monomer and one
or more additional olefin monomers where the first listed alkene is the major
constituent of the
copolymer, such as a propylene-ethylene copolymer and a propylene-ethylene-
butadiene copolymer,
Page 25 =
CA 02750143 2016-08-31
cyclic olefin homopolymers from a single cyclic olefin monomer, and cyclic
olefin copolymers from at
least one cyclic olefin monomer and one or more additional olefin monomers
wherein the first listed
cyclic olefin is the major constituent of the copolymer, and mixtures of any
of the foregoing olefin
polymers.
[00137] In one embodiment, the shrink film is a multilayer film comprising
a core layer and at least
one skin layer. The skin layer may be a printable skin layer. In one
embodiment, the multilayer shrink
film comprises a core and two skin layers, wherein in at least one skin layer
is printable. The multilayer
shrink film may be a coextruded film.
[00138] The film can range in thickness from 12 to 500, or 12 to 300, or 12
to 200, or 25 to 75
microns. The difference in the layers of the film can include a difference in
thermoplastic polymer
components, in additive components, in orientation, in thickness, or a
combination thereof. The
thickness of the core layer can be SO to 95%, or 60 to 95% or 70 to 90% of the
thickness of the film. The
thickness of a skin layer or of a combination of two skin layers can be 5 to
50%, or 5 to 40% or 10 to 30%
of the thickness of the film.
[00139] The film can be further treated on one surface or both the upper
and lower surfaces to
enhance performance in terms of printability or adhesion to an adhesive. The
treatment can comprise
applying a surface coating such as, for example, a lacquer, applying a high
energy discharge to include a
corona discharge to a surface, applying a flame treatment to a surface, or a
combination of any of the
foregoing treatments. In an embodiment of the invention, the film is treated
on both surfaces, and in
another embodiment the film is treated on one surface with a corona discharge
and is flame treated on
the other surface.
[00140] The layers of the shrink film may contain pigments, fillers,
stabilizers, light protective agents
or other suitable modifying agents if desired. The film may also contain anti-
block, slip additives and
anti-static agents. Useful anti-block agents include inorganic particles, such
as clays, talc, calcium
carbonate and glass. Slip additives useful in the present invention include
polysiloxanes, waxes, fatty
amides, fatty acids, metal soaps and particulate such as silica, synthetic
amorphous silica and
polytetrafluoroethylene powder. Anti-static agents useful in the present
invention include alkali metal
sulfonates, polyether-modified polydiorganosiioxanes, polyalkylphenylsiloxanes
and tertiary amines.
[00141] In one embodiment, the shrink film is microperforated to allow
trapped air to be released
from the interface between the label and the article to which it is adhered.
In another embodiment, the
shrink film is permeable to allow fluid to escape from the adhesive or from
the surface of the article to
escape. In one embodiment, vent holes or slits are provided in the shrink
film.
Page 26
CA 02750143 2016-08-31
[00142] The
present invention can be used for applying, processing, and otherwise in
association
with, a wide array of labels, film, and other members. For example, the
invention can be used in
conjunction with shrink labels, pressure sensitive labels, pressure sensitive
shrink labels, heat seal labels,
and nearly any type of label or film known in the packaging and labeling arts.
Adhesive and Additional Aspects of Labels
[00143] A
description of useful pressure sensitive adhesives may be found in
Encyclopedia of Polymer
Science and Engineering, Vol. 13, Wiley-Interscience Publishers (New York,
1988). Additional
description of useful PSAs may be found in Polymer Science and Technology,
Vol. 1, Interscience
Publishers (New York, 1964). Conventional PSAs, including acrylic-based PSAs,
rubber-based PSAs and
silicone-based PSAs are useful. The PSA may be a solvent based or may be a
water based adhesive. Hot
melt adhesives may also be used. In one embodiment, the PSA comprises an
acrylic emulsion adhesive.
[00144] The
adhesive and the side of the film to which the adhesive is applied have
sufficient
compatibility to enable good adhesive anchorage. In one embodiment, the
adhesive is chosen so that
the labels may be cleanly removed from PET containers up to 24 hours after
application. The adhesive is
also chosen so that the adhesive components do not migrate into the film.
[00145] In
one embodiment, the adhesive may be formed from an acrylic based polymer. It
is
contemplated that any acrylic based polymer capable of forming an adhesive
layer with sufficient tack to
adhere to a substrate may function in the present invention. In certain
embodiments, the acrylic
polymers for the pressure sensitive adhesive layers include those formed from
polymerization of at least
one alkyl acrylate monomer containing from about 4 to about 12 carbon atoms in
the alkyl group, and
present in an amount from about 35 to 95% by weight of the polymer or
copolymer, as disclosed in U.S.
Pat. No. 5,264,532. Optionally, the acrylic based pressure sensitive adhesive
might be formed from a
single polymeric species.
[00146] The
glass transition temperature of a PSA layer comprising acrylic polymers can be
varied by
adjusting the amount of polar, or "hard monomers", in the copolymer, as taught
by U.S. Pat. No.
5,264,532. The greater the percentage by weight of hard monomers included in
an acrylic copolymer,
the higher the glass transition temperature of the polymer. Hard monomers
contemplated useful for
the present invention include vinyl esters, carboxylic acids, and
methacrylates, in concentrations by
weight ranging from about 0 to about 35% by weight of the polymer.
[00147] The
PSA can be acrylic based such as those taught in U.S. Pat. No. 5,164,444
(acrylic
emulsion), U.S. Pat. No. 5,623,011 (tackified acrylic emulsion) and U.S. Pat.
No. 6,306,982. The adhesive
Page 27
CA 02750143 2016-08-31
can also be rubber-based such as those taught in U.S. Pat. No. 5,705,551
(rubber hot melt). The
adhesive can also include a radiation curable mixture of monomers with
initiators and other ingredients
such as those taught in U.S. Pat. No. 5,232,958 (UV cured acrylic) and U.S.
Pat. No. 5,232,958 (EB cured).
[00148] Commercially available PSAs are useful in the invention. Examples
of these adhesives include
the hot melt PSAs available from H.B. Fuller Company, St. Paul, Minn. as HM-
1597, HL-2207-X, HL-2115-
X, HL-2193-X. Other useful commercially available PSAs include those available
from Century Adhesives
Corporation, Columbus, Ohio. Another useful acrylic PSA comprises a blend of
emulsion polymer
particles with dispersion tackifier particles as generally described in
Example 2 of U.S. Pat. No.
6,306,982. The polymer is made by emulsion polymerization of 2-ethylhexyl
acrylate, vinyl acetate,
dioctyl maleate, and acrylic and methacrylic comonomers as described in U.S.
Pat. No. 5,164,444
resulting in the latex particle size of about 0.2 microns in weight average
diameters and a gel content of
about 60%.
[00149] A commercial example of a hot melt adhesive is H2187-01, sold by
Ato Findley, Inc., of
Wauwatusa, Wis. In addition, rubber based block copolymer PSAs described in
U.S. Pat. No. 3,239,478
also can be utilized in the adhesive constructions of the present invention.
[00150] In another embodiment, the pressure sensitive adhesive comprises
rubber based elastomer
materials containing useful rubber based elastomer materials include linear,
branched, grafted, or radial
block copolymers represented by the diblock structure A--B, the triblock A--B--
A, the radial or coupled
structures (A--B)0, and combinations of these where A represents a hard
thermoplastic phase or block
which is non-rubbery or glassy or crystalline at room temperature but fluid at
higher temperatures, and
B represents a soft block which is rubbery or elastomeric at service or room
temperature. These
thermoplastic elastomers may comprise from about 75% to about 95% by weight of
rubbery segments
and from about 5% to about 25% by weight of non-rubbery segments.
[00151] The non-rubbery segments or hard blocks comprise polymers of mono-
and polycyclic
aromatic hydrocarbons, and more particularly vinyl-substituted aromatic
hydrocarbons that may be
monocyclic or bicyclic in nature. Rubbery materials such as polyisoprene,
polybutadiene, and styrene
butadiene rubbers may be used to form the rubbery block or segment.
Particularly useful rubbery
segments include polydienes and saturated olefin rubbers of ethylene/butylene
or ethylene/propylene
Page 28
CA 02750143 2016-08-31
copolymers. The latter rubbers may be obtained from the corresponding
unsaturated polyalkylene
moieties such as polybutadiene and polyisoprene by hydrogenation thereof.
[00152] The block copolymers of vinyl aromatic hydrocarbons and conjugated
dienes that may be
utilized include any of those that exhibit elastomeric properties. The block
copolymers may be diblock,
triblock, multiblock, starblock, polyblock or graftblock copolymers.
Throughout this specification, the
terms diblock, triblock, multiblock, polyblock, and graft or grafted-block
with respect to the structural
features of block copolymers are to be given their normal meaning as defined
in the literature such as in
the Encyclopedia of Polymer Science and Engineering, Vol. 2, (1985) John Wiley
& Sons, Inc., New York,
pp. 325-326, and by J. E. McGrath in Block Copolymers, Science Technology,
Dale J. Meier, Ed., Harwood
Academic Publishers, 1979, at pages 1-5.
[00153] Such block copolymers may contain various ratios of conjugated
dienes to vinyl aromatic
hydrocarbons including those containing up to about 40% by weight of vinyl
aromatic hydrocarbon.
Accordingly, multi-block copolymers may be utilized which are linear or radial
symmetric or asymmetric
and which have structures represented by the formulae A--B, A--B--A, A--B--A--
B, B--A--B, (AB)0,1,2.., BA,
etc., wherein A is a polymer block of a vinyl aromatic hydrocarbon or a
conjugated diene/vinyl aromatic
hydrocarbon tapered copolymer block, and B is a rubbery polymer block of a
conjugated diene.
[00154] The block copolymers may be prepared by any of the well-known block
polymerization or
copolymerization procedures including sequential addition of monomer,
incremental addition of
monomer, or coupling techniques as illustrated in, for example, U.S. Pat. Nos.
3,251,905; 3,390,207;
3,598,887; and 4,219,627. As well known, tapered copolymer blocks can be
incorporated in the multi-
block copolymers by copolymerizing a mixture of conjugated diene and vinyl
aromatic hydrocarbon
monomers utilizing the difference in their copolymerization reactivity rates.
Various patents describe
the preparation of multi-block copolymers containing tapered copolymer blocks
including U.S. Pat. Nos.
3,251,905; 3,639,521; and 4,208,356.
[00155] Conjugated dienes that may be utilized to prepare the polymers and
copolymers are those
containing from 4 to about 10 carbon atoms and more generally, from 4 to 6
carbon atoms. Examples
include from 1,3-butadiene, 2-
methyl-1,3-butadiene(isoprene), 2,3-dimethy1-1,3-butadiene,
chloroprene, 1,3-pentadiene, 1,3-hexadiene, etc. Mixtures of these conjugated
dienes also may be used.
[00156] Examples of vinyl aromatic hydrocarbons which may be utilized to
prepare the copolymers
include styrene and the various substituted styrenes such as o-methylstyrene,
p-methylstyrene, p-tert-
butylstyrene, 1,3-dimethylstyrene, alpha-methylstyrene, beta-methylstyrene, p-
isopropylstyrene, 2,3-
dimethylstyrene, o-chlorostyrene, p-chlorostyrene, o-bromostyrene, 2-chloro-4-
nnethylstyrene, etc.
Page 29
CA 02750143 2016-08-31
[00157] Many of the above-described copolymers of conjugated dienes and
vinyl aromatic
compounds are commercially available. The number average molecular weight of
the block copolymers,
prior to hydrogenation, is from about 20,000 to about 500,000, or from about
40,000 to about 300,000.
[00158] The average molecular weights of the individual blocks within the
copolymers may vary
within certain limits. In most instances, the vinyl aromatic block will have a
number average molecular
weight in the order of about 2000 to about 125,000, or between about 4000 and
60,000. The
conjugated diene blocks either before or after hydrogenation will have number
average molecular
weights in the order of about 10,000 to about 450,000, or from about 35,000 to
150,000.
[00159] Also, prior to hydrogenation, the vinyl content of the conjugated
diene portion generally is
from about 10% to about 80%, or from about 25% to about 65%, particularly 35%
to 55% when it is
desired that the modified block copolymer exhibit rubbery elasticity. The
vinyl content of the block
copolymer can be measured by means of nuclear magnetic resonance.
[00160] Specific examples of diblock copolymers include styrene-butadiene
(SB), styrene-isoprene
(SI), and the hydrogenated derivatives thereof. Examples of triblock polymers
include styrene-
butadiene-styrene (SBS), styrene-isoprene-styrene (Sts), alpha-methylstyrene-
butadiene-alpha-
methylstyrene, and alpha-methylstyrene-isoprene alpha-methylstyrene. Examples
of commercially
available block copolymers useful as the adhesives in the present invention
include those available from
Kraton Polymers LLC under the KRATON trade name.
[00161] Upon hydrogenation of the SBS copolymers comprising a rubbery
segment of a mixture of
1,4 and 1,2 isomers, a styrene-ethylene-butylene styrene (SEBS) block
copolymer is obtained. Similarly,
hydrogenation of an SIS polymer yields a styrene-ethylene propylene-styrene
(SEPS) block copolymer.
[00162] The selective hydrogenation of the block copolymers may be carried
out by a variety of well
known processes including hydrogenation in the presence of such catalysts as
Raney nickel, noble
metals such as platinum, palladium, etc., and soluble transition metal
catalysts. Suitable hydrogenation
processes which can be used are those wherein the diene-containing polymer or
copolymer is dissolved
in an inert hydrocarbon diluent such as cyclohexane and hydrogenated by
reaction with hydrogen in the
presence of a soluble hydrogenation catalyst. Such procedures are described in
U.S. Pat. Nos. 3,113,986
and 4,226,952. Such hydrogenation of the block copolymers which are carried
out in a manner and to
extent as to produce selectively hydrogenated copolymers having a residual
unsaturation content in the
polydiene block of from about 0.5% to about 20% of their original unsaturation
content prior to
hydrogenation.
Page 30
CA 02750143 2016-08-31
1001631 In one embodiment, the conjugated diene portion of the block
copolymer is at least 90%
saturated and more often at least 95% saturated while the vinyl aromatic
portion is not significantly
hydrogenated. Particularly useful hydrogenated block copolymers are
hydrogenated products of the
block copolymers of styrene--isoprene-styrene such as a styrene-
(ethylene/propylene)-styrene block
polymer. When a polystyrene-polybutadiene-polystyrene block copolymer is
hydrogenated, it is
desirable that the 1,2-polybutadiene to 1,4-polybutadiene ratio in the polymer
is from about 30:70 to
about 70:30. When such a block copolymer is hydrogenated, the resulting
product resembles a regular
copolymer block of ethylene and 1-butene (EB). As noted above, when the
conjugated diene employed
as isoprene, the resulting hydrogenated product resembles a regular copolymer
block of ethylene and
propylene (EP).
[00164] A number of selectively hydrogenated block copolymers are available
commercially from
Kraton Polymers under the general trade designation "Kraton G." One example is
Kraton G1652 which is
a hydrogenated SBS triblock comprising about 30% by weight of styrene end
blocks and a midblock
which is a copolymer of ethylene and 1-butene (EB). A lower molecular weight
version of G1652 is
available under the designation Kraton G1650. Kraton G1651 is another SEBS
block copolymer which
contains about 33% by weight of styrene. Kraton G1657 is an SEBS diblock
copolymer which contains
about 13%w styrene. This styrene content is lower than the styrene content in
Kraton 61650 and
Kraton G1652.
[00165] In another embodiment, the selectively hydrogenated block copolymer
is of the formula:
B(AB)OAp wherein n=0 or 1; o is 1 to 100; p is 0 or 1; each B prior to
hydrogenation is predominantly a
polymerized conjugated diene hydrocarbon block having a number average
molecular weight of about
20,000 to about 450,000; each A is predominantly a polymerized vinyl aromatic
hydrocarbon block
having a number average molecular weight of from about 2000 to about 115,000;
the blocks of A
constituting about 5% to about 95% by weight of the copolymer; and the
unsaturation of the block B is
less than about 10% of the original unsaturation. In other embodiments, the
unsaturation of block B is
reduced upon hydrogenation to less than 5% of its original value, and the
average unsaturation of the
hydrogenated block copolymer is reduced to less than 20% of its original
value.
[00166] The block copolymers may also include functionalized polymers such
as may be obtained by
reacting an alpha, beta-olefinically unsaturated monocarboxylic or
dicarboxylic acid reagent onto
selectively hydrogenated block copolymers of vinyl aromatic hydrocarbons and
conjugated dienes as
described above. The reaction of the carboxylic acid reagent in the graft
block copolymer can be
effected in solutions or by a melt process in the presence of a free radical
initiator.
Page 31
CA 02750143 2016-08-31
[00167] The preparation of various selectively hydrogenated block
copolymers of conjugated dienes
and vinyl aromatic hydrocarbons which have been grafted with a carboxylic acid
reagent is described in
a number of patents including U.S. Pat. Nos. 4,578,429; 4,657,970; and
4,795,782, and the disclosures of
these patents relating to grafted selectively hydrogenated block copolymers of
conjugated dienes and
vinyl aromatic compounds, and the preparation of such compounds. U.S. Pat. No.
4,795,782 describes
and gives examples of the preparation of the grafted block copolymers by the
solution process and the
melt process. U.S. Pat. No. 4,578,429 contains an example of grafting of
Kraton G1652 (SEBS) polymer
with maleic anhydride with 2,5-dimethy1-2,5-di(t-butylperoxy) hexane by a melt
reaction in a twin screw
extruder.
[00168] Examples of commercially available maleated selectively
hydrogenated copolymers of
styrene and butadiene include Kraton FG1901X, FG1921X, and FG1924X, often
referred to as nnaleated
selectively hydrogenated SEBS copolymers. FG1901X contains about 1.7% by
weight bound functionality
as succinic anhydride and about 28% by weight of styrene. FG1921X contains
about 1% by weight of
bound functionality as succinic anhydride and 29% by weight of styrene.
FG1924X contains about 13%
styrene and about 1% bound functionality as succinic anhydride.
[00169] Useful block copolymers also are available from Nippon Zeon Co., 2-
1, Marunochi, Chiyoda-
ku, Tokyo, Japan. For example, Quintac 3530 is available from Nippon Zeon and
is believed to be a linear
styrene-isoprene-styrene block copolymer.
[00170] Unsaturated elastomeric polymers and other polymers and copolymers
which are not
inherently tacky can be rendered tacky when compounded with an external
tackifier. Tackifiers, are
generally hydrocarbon resins, wood resins, rosins, rosin derivatives, and the
like, which when present in
concentrations ranging from about 40% to about 90% by weight of the total
adhesive composition, or
from about 45% to about 85% by weight, impart pressure sensitive adhesive
characteristics to the
elastomeric polymer adhesive formulation. Compositions containing less than
about 40% by weight of
tackifier additive do not generally show sufficient "quickstick," or initial
adhesion, to function as a
pressure sensitive adhesive, and therefore are not inherently tacky.
Compositions with too high a
concentration of tackifying additive, on the other hand, generally show too
little cohesive strength to
work properly in most intended use applications of constructions made in
accordance with the instant
invention.
[00171] It is contemplated that any tackifier known by those of skill in
the art to be compatible with
elastomeric polymer compositions may be used with the present embodiment of
the invention. One
such tackifier, found useful is Wingtak 10, a synthetic polyterpene resin that
is liquid at room
Page 32
CA 02750143 2016-08-31
temperature, and sold by the Goodyear Tire and Rubber Company of Akron, Ohio.
Wingtak 95 is a
synthetic tackifier resin also available from Goodyear that comprises
predominantly a polymer derived
from piperylene and isoprene. Other suitable tackifying additives may include
Escorez 1310, an aliphatic
hydrocarbon resin, and Escorez 2596, a C5 to C, (aromatic modified aliphatic)
resin, both manufactured
by Exxon of Irving, Tex. Of course, as can be appreciated by those of skill in
the art, a variety of different
tackifying additives may be used to practice the present invention.
[00172] In addition to the tackifiers, other additives may be included in
the PSAs to impart desired
properties. For example, plasticizers may be included, and they are known to
decrease the glass
transition temperature of an adhesive composition containing elastomeric
polymers. An example of a
useful plasticizer is Shellflex 371, a naphthenic processing oil available
from Shell Lubricants of Texas.
Antioxidants also may be included in the adhesive compositions. Suitable
antioxidants include lrgafos
168 and Irganox 565 available from Ciba-Geigy, Hawthorne, N.Y. Cutting agents
such as waxes and
surfactants also may be included in the adhesives.
[00173] The pressure sensitive adhesive may be applied from a solvent,
emulsion or suspension, or as
a hot melt. The adhesive may be applied to the inner surface of the shrink
film by any known method.
For example, the adhesive may be applied by die coating curtain coating,
spraying, dipping, rolling,
gravure or flexographic techniques. The adhesive may be applied to the shrink
film in a continuous
layer, a discontinuous layer or in a pattern. The pattern coated adhesive
layer substantially covers the
entire inner surface of the film. As used herein, "substantially covers" is
intended to mean the pattern
in continuous over the film surface, and is not intended to include adhesive
applied only in a strip along
the leading or trailing edges of the film or as a "spot weld" on the film.
[00174] In one embodiment, an adhesive deadener is applied to portions of
the adhesive layer to
allow the label to more readily adhere to complex shaped articles. In one
embodiment, non-adhesive
material such as ink dots or microbeads are applied to at least a portion of
the adhesive surface to allow
the adhesive layer to slide on the surface of the article as the label is
being applied and/or to allow air
trapped at the interface between the label and the article to escape.
[00175] A single layer of adhesive may be used or multiple adhesive layers
may be used. Depending
on the shrink film used and the article or container to which the label is to
be applied, it may be
desirable to use a first adhesive layer adjacent to the shrink film and a
second adhesive layer having a
different composition on the surface to be applied to the article or container
for sufficient tack, peel
strength and shear strength.
Page 33
CA 02750143 2016-08-31
[00176] In one embodiment, the pressure sensitive adhesive has sufficient
shear or cohesive strength
to prevent excessive shrink-back of the label where adhered to the article
upon the action of heat after
placement of the label on the article, sufficient peel strength to prevent the
film from label from lifting
from the article and sufficient tack or grab to enable adequate attachment of
the label to the article
during the labeling operation. In one embodiment, the adhesive moves with the
label as the shrink film
shrinks upon the application of heat. In another embodiment, the adhesive
holds the label in position
so that as the shrink film shrinks, the label does not move.
[00177] The heat shrinkable film may include other layers in addition to
the monolayer or multilayer
heat shrinkable polymeric film. In one embodiment, a metalized coating of a
thin metal film is deposited
on the surface of the polymeric film. The heat shrinkable film may also
include a print layer on the
polymer film. The print layer may be positioned between the heat shrink layer
and the adhesive layer,
or the print layer may be on the outer surface of the shrink layer. In one
embodiment, the film is
reverse printed with a design, image or text so that the print side of the
skin is in direct contact with the
container to which the film is applied. In this embodiment, the film is
transparent.
[00178] The labels of the present invention may also contain a layer of an
ink-receptive composition
that enhances the printability of the polymeric shrink layer or metal layer if
present, and the quality of
the print layer thus obtained. A variety of such compositions are known in the
art, and these
compositions generally include a binder and a pigment, such as silica or talc,
dispersed in the binder. The
presence of the pigment decreases the drying time of some inks. Such ink-
receptive compositions are
described in U.S. Pat. No. 6,153,288.
[00179] The print layer may be an ink or graphics layer, and the print
layer may be a mono-colored or
multi-colored print layer depending on the printed message and/or the intended
pictorial design. These
include variable imprinted data such as serial numbers, bar codes, trademarks,
etc. The thickness of the
print layer is typically in the range of about 0.5 to about 10 microns, and in
one embodiment about 1 to
about 5 microns, and in another embodiment about 3 microns. The inks used in
the print layer include
commercially available water-based, solvent-based or radiation-curable inks.
Examples of these inks
include Sun Sheen (a product of Sun Chemical identified as an alcohol
dilutable polyamide ink), Suntex
MP (a product of Sun Chemical identified as a solvent-based ink formulated for
surface printing acrylic
coated substrates, PVDC coated substrates and polyolefin films), X-Cel (a
product of Water Ink
Technologies identified as a water-based film ink for printing film
substrates), Uvilith AR-109 Rubine Red
(a product of Daw Ink identified as a UV ink) and CLA91598F (a product of Sun
Chemical identified as a
multibond black solvent-based ink).
Page 34
CA 02750143 2016-08-31
[00180] In one embodiment, the print layer comprises a polyester/vinyl ink,
a polyamide ink, an
acrylic ink.and/or a polyester ink. The print layer may be formed in the
conventional manner by, for
example, gravure, flexographic or UV flexographic printing or the like, an ink
composition comprising a
resin of the type described above, a suitable pigment or dye and one or more
suitable volatile solvents
onto one or more desired areas of the film. After application of the ink
composition, the volatile solvent
component(s) of the ink composition evaporate(s), leaving only the non-
volatile ink components to form
the print layer.
[00181] The adhesion of the ink to the surface of the polymeric shrink film
or metal layer if present
can be improved, if necessary, by techniques well known to those skilled in
the art. For example, as
mentioned above, an ink primer or other ink adhesion promoter can be applied
to the metal layer or the
polymeric film layer before application of the ink. Alternatively the surface
of the polymeric film can be
corona treated or flame treated to improve the adhesion of the ink to the
polymeric film layer.
[00182] Useful ink primers may be transparent or opaque and the primers may
be solvent based or
water-based. In one embodiment, the primers are radiation curable (e.g., UV).
The ink primer may
comprise a lacquer and a diluent. The lacquer may be comprised of one or more
polyolefins,
polyamides, polyesters, polyester copolymers, polyurethanes, polysulfones,
polyvinylidine chloride,
styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers,
ionomers based on sodium or
zinc salts or ethylene methacrylic acid, polymethyl methacrylates, acrylic
polymers and copolymers,
polycarbonates, polyacrylonitriles, ethylene-vinyl acetate copolymers, and
mixtures of two or more
thereof. Examples of the diluents that can be used include alcohols such as
ethanol, isopropanol and
butanol; esters such as ethyl acetate, propyl acetate and butyl acetate;
aromatic hydrocarbons such as
toluene and xylene; ketones such as acetone and methyl ethyl ketone; aliphatic
hydrocarbons such as
heptane; and mixtures thereof. The ratio of lacquer to diluent is dependent on
the viscosity required for
application of the ink primer, the selection of such viscosity being within
the skill of the art. The ink
primer layer may have a thickness of from about 1 to about 4 microns or from
about 1.5 to about 3
microns.
[00183] A transparent polymer protective topcoat or overcoat layer may be
present in the labels
applied in accordance with the invention. The protective topcoat or overcoat
layer provide desirable
properties to the label before and after the label is affixed to a substrate
such as a container. The
presence of a transparent topcoat layer over the print layer may, in some
embodiments provide
additional properties such as antistatic properties stiffness and/or
weatherability, and the topcoat may
protect the print layer from, e.g., weather, sun, abrasion, moisture, water,
etc. The transparent topcoat
Page 35
CA 02750143 2016-08-31
layer can enhance the properties of the underlying print layer to provide a
glossier and richer image. The
protective transparent protective layer may also be designed to be abrasion
resistant, radiation resistant
(e.g, UV), chemically resistant, thermally resistant thereby protecting the
label and, particularly the print
layer from degradation from such causes. The protective overcoat may also
contain antistatic agents, or
anti-block agents to provide for easier handling when the labels are being
applied to containers at high
speeds. The protective layer may be applied to the print layer by techniques
known to those skilled in
the art. The polymer film may be deposited from a solution, applied as a
preformed film (laminated to
the print layer), etc.
[00184] When a transparent topcoat or overcoat layer is present, it may
have a single layer or a
multilayered structure. The thickness of the protective layer is generally in
the range of about 12.5 to
about 125 microns, and in one embodiment about 25 to about 75 microns.
Examples of the topcoat
layers are described in U.S. Pat. No. 6,106,982.
[001851 The protective layer may comprise polyolefins, thermoplastic
polymers of ethylene and
propylene, polyesters, polyurethanes, polyacryls, polymethacryls, epoxy, vinyl
acetate homopolymers,
co- or terpolymers, ionomers, and mixtures thereof.
[00186] The transparent protective layer may contain UV light absorbers
and/or other light
stabilizers. Among the UV light absorbers that are useful are the hindered
amine absorbers available
from Ciba Specialty Chemical under the trade designations "Tinuvin". The light
stabilizers that can be
used include the hindered amine light stabilizers available from Ciba
Specialty Chemical under the trade
designations Tinuvin 111, Tinuvin 123, (bis-(1-octyloxy-2,2,6,6-tetramethy1-4-
piperidinyl) sebacate;
Tinuvin 622, (a dimethyl succinate polymer with 4-hydroxy-2,2,6,6-tetramethy1-
1-piperidniethanol);
Tinuvin 770 (bis-(2,2,6,6-tetramethy1-4-piperidiny1)-sebacate); and Tinuvin
783. Additional light
stabilizers include the hindered amine light stabilizers available from Ciba
Specialty Chemical under the
trade designation "Chemassorb", especially Chemassorb 119 and Chemassorb 944.
The concentration of
the UV light absorber and/or light stabilizer is in the range of up to about
2.5% by weight, and in one
embodiment about 0.05% to about 1% by weight.
[00187] The transparent protective layer may contain an antioxidant. Any
antioxidant useful in
making thermoplastic films can be used. These include the hindered phenols and
the organo phosphites.
Examples include those available from Ciba Specialty Chemical under the trade
designations Irganox
1010, Irganox 1076 or Irgafos 168. The concentration of the antioxidant in the
thermoplastic film
composition may be in the range of up to about 2.5% by weight, and in one
embodiment about 0.05% to
about 1% by weight.
Page 36
CA 02750143 2016-08-31
[00188] A release liner may be adhered to the adhesive layer to protect the
adhesive layer during
transport, storage and handling prior to application of the label to a
substrate. The liner allows for
efficient handling of an array of individual labels after the labels are die
cut and the matrix is stripped
from the layer of facestock material and up to the point where the individual
labels are dispensed in
sequence on a labeling line. The release liner may have an embossed surface
and/or have non-adhesive
material, such as microbeads or printed ink dots, applied to the surface of
the liner.
Process For Label Application Using Flexible Member
[00189] The present invention provides a unique process in which a label is
selectively and
concurrently heated, shrunk, and applied onto a surface of interest, and
preferably onto a compound
curved surface of a container. The preferred embodiment flexible member is
contacted with a label
positioned between the flexible member and a surface targeted to receive the
label. The domed surface
of the flexible member promotes that contact between the label and the
flexible member initially occur
in a central region of the label, so long as the label and the flexible member
are appropriately aligned.
The flexible member is urged against the label, which is in contact with the
surface of interest. As
explained in greater detail herein, in a preferred method, prior to contact
between the label and the
flexible member, the label is partially in contact with and adhered to the
surface of interest, at least
along a central portion or region of the label. As the flexible member is
urged against the label, further
contact occurs between the flexible member and the label which in turn causes
increasing contact area
between the label and the surface of interest. The areas of contact between
(i) the flexible member and
the label, and (ii) the label and the surface of interest, increase over the
course of label application and
typically increase in an outward direction from the central portion of the
label and/or the location on
the label at which the domed surface of the flexible member first contacts.
Greater amounts of area of
the flexible member contact the label as the flexible member is further urged
against the label. As will
be appreciated and described in greater detail herein, the flexible member
deforms and adopts the
shape of the container surface to which the label is being applied. As a
result, the label is fittingly
applied onto the container. This feature in conjunction with the manner by
which increasing contact
occurs, i.e. progressively outward from a central location, is believed to be
a significant factor in the
resulting defect-free label application.
[00190] In addition, in accordance with another aspect of the present
invention, this strategy is
performed using a heated flexible member. This enables concurrent application
of heat during
progressive outward application of label. For applications in which the label
includes a heat shrink
Page 37
CA 02750143 2016-08-31
material, such as a pressure sensitive heat shrink label, the method is
preferably performed such that
the label is heated and shrunk to an extent just prior to contact and adhesion
with a curved surface so
that the label area corresponds to the area of the surface about to receive
and contact that region of
the label. Any air trapped along the interface of the label and surface of
interest is urged outward
toward the label edge due to the progressive outward contact by the flexible
member. This process is
continued until the outer edges of the label are contacted and adhered to the
surface of interest.
[00191] During application of a label to a container, the flexible member
is contacted against the
label and container. The amount of force applied to the label by the flexible
member is referred to
herein as a label-contacting force. Generally, that amount of force depends
upon the characteristics of
the label, container, and adhesive. However, typically it is preferred that
the label contacting pressure
be at least from about 690 N/m2 to about 6900 N/nn2. It is to be appreciated
however that the present
invention includes the use of label application forces greater than or lesser
than these amounts.
[00192] In accordance with the present invention, labels are applied
utilizing a "center-out" strategy.
Thus, contact between the flexible member and the label occurs in a center-out
process also. The term
"center-out" refers to the order or sequence by which regions or portions of a
label are applied or
contacted. First, one or more center regions of the label are contacted. Then,
as that contact is
maintained, one or more additional regions of the label located outward from
the center or central
region of the label are then contacted. This process is continued such that
after contact and adherence
of the label regions located outward from the center regions, that contact is
maintained and one or
more additional regions of the label located further outward from the
previously noted regions are then
contacted. This process is continued until the edge regions of the label are
contacted and adhered to
the container. Use of this technique ensures, or at least significantly
reduces the occurrence of, air
bubbles becoming trapped under the label or between the label and container.
[00193] The present invention includes the use of a wide range of cycling
times. For example, in a
high volume manufacturing environment, total time periods for one cycle of a
flexible member and
label/container being displaced toward one another, contacting, the label
being adhered to the
container, and the flexible member and label/container then being displaced
away from another, is from
about 0.5 to about 2.0 seconds, with about 0.9 seconds being preferred. The
present invention includes
cycle times greater than or lesser than these values.
[00194] A particularly preferred process aspect which may be utilized is
referred to herein as a
"double hit" operation. For certain labeling operations, it is desirable to
apply labels that extend
laterally around a container or at least partially so. For example, for a pair
of labels that each extend or
Page 38
CA 02750143 2016-08-31
approach a 180 wrap around a container periphery, it is often difficult to
achieve contact between the
flexible member and the outer peripheral regions of each label. By use of a
double hit strategy, greater
contact can occur between a first flexible member and its label on one
container face, and a second
flexible member and its corresponding label on the other container face. The
double hit operation uses
a combination of particular stroke delay and/or stroke length of one flexible
member relative to that of
its opposing flexible member.
[00195] Generally, in this particular strategy for applying labels along
oppositely directed faces of a
container, a first label processor having a flexible member as described
herein is progressively contacted
with a label on a first face of the container by displacing or moving the
member through a first stroke
distance toward the container. A second label processor having a flexible
member and generally located
along an opposite side of the container is also and preferably concurrently
contacted with a label on a
second face of the container. The second face is generally opposite the first
face. The flexible member
of the second label processor is progressively contacted with the second label
by displacing or moving
that member through a second stroke distance toward the container. It is
preferred that the first and
second stroke lengths are different from one another. For the present
description, the first stroke
length is greater than the second stroke length. After progressive contact
from the first and second
flexible members, the members are withdrawn from contact with the container.
Then, the process is
repeated except that the stroke length of the second label processor is
greater than that of the first
label processor. Preferably, the stroke length of the second label processor
in this second portion of the
''double hit" operation is equal to the stroke length of the first label
processor in the first portion of the
operation.
[00196] More specifically, in a preferred double hit operation, a first
flexible member on one side of a
container is moved toward the container, typically in a direction transverse
to the direction of a
conveyor on which the container is positioned. Concurrently with movement of
the first flexible
member, a second flexible member on an opposite side of the container is also
moved toward the
container, and also in a transverse direction. However, the stroke or distance
of movement of the first
flexible member is greater than the stroke or distance of the opposing second
flexible member. This
enables the first flexible member in motion during the longer stroke to more
fully wrap around the
container and a first label because the second member is not blocking or
otherwise hindering wrapping
of the first flexible member alongside the outer regions of the container.
Upon completion or full stroke
of the first flexible member, both flexible members are then retracted. Upon
retraction, the first and
second flexible members are then again positioned toward the container.
However, the second flexible
Page 39
CA 02750143 2016-08-31
member is fully extended and urged against the container and a second label,
while the first flexible
member undergoes the shorter stroke. Upon completion of contact between the
second label and the
second flexible member, the first and the second flexible members are
retracted.
[00197] Figure 1 illustrates a representative container 10 having one or
more regions that include
curved outer surfaces, and particularly one or more compound curved surfaces.
The container 10
defines an outer surface 12 which includes at least one compound curved region
16. The compound
curved region 16 typically extends within or along locations at which adjacent
faces of the container 10
intersect or adjoin one another. Typically, one or more flat or substantially
flat regions 14 are also
included within the outer surface 12 of the container 10. It will be
understood that the container may
include few or no flat regions, such as in the case of a sphere-shaped
container.
[00198] Figures 2 and 3 illustrate the representative container 10 depicted
in Figure 1 with a label 20
applied onto the outer surface 12 and onto at least a portion of a compound
curved region 16 of the
container 10. The label 20 generally defines a central region 22 and an outer
edge 26 extending about
the outer periphery of the label 20. The label 20 also defines one or more
outer peripheral region(s) 24
extending between the central region 22 of the label and the edge 26. Figure 2
illustrates a preferred
application of the label 20 in which the label is free of darts or other
defects. Figure 3 illustrates an
undesirable result and which typically occurs after applying a label to a
compound curved region of a
container. The label in the undesirable applied state shown in Figure 3 is
designated as 20'. The label
20 is typically characterized by one or more darts, wrinkles, or other
defects, collectively designated as
21. The darts 21 usually occur in regions of the label that overlie compound
curved regions 16 of the
container 10. Typically, the darts 21 and/or other defects exist in the outer
region(s) 24 of the label 20.
As will be appreciated, the container 10 and label 20 as applied and shown in
Figure 2 is desired. And,
the state of the label 20' containing numerous darts 21 or other defects shown
in Figure 3 is
undesirable.
[00199] Figures 4 to 6 schematically illustrate a preferred embodiment
flexible member 30 in
accordance with the present invention. The flexible member 30 preferably
comprises a base 32, a
domed region 36, and one or more side walls 34 extending between the base 32
and the domed region
36. The member 30 defines an outer surface 46 and an inner surface 48. The
inner surface 48 defines
an interior hollow region within the flexible member 30. The interior hollow
region is accessible from
the rear of the flexible member and is described in greater detail herein. The
flexible member 30 can
also be described in terms of various regions. The domed region 36 preferably
exhibits an outwardly
bulging or convex contour and defines a distalmost location 40, that is a
location along the outer surface
Page 40
CA 02750143 2016-08-31
46 of the flexible member 30 that is farthest from the base 32 or the plane
within which the base 32
extends. The distalmost location 40 resides within a central region 38 defined
along the domed region
36, and preferably in the middle or center of the domed region 36. Extending
between the central
region 38 on the domed region 36 and the side walls 34, are one or more outer
region(s) 42 of the
domed region 36. It will be appreciated that the invention includes a wide
array of flexible members
having various shapes and configurations. In a preferred aspect, many of the
flexible members utilize
rounded or arcuate edges and corners.
[00200] Figures 7 to 10 illustrate a preferred assembly of the previously
described flexible member
30 retained, supported, and mounted by a frame 50 and an enclosure 90. Figure
7 illustrates the
assembly only partially assembled to reveal a vent plate 80 generally disposed
rearwardly of the flexible
member 30. As generally shown in Figure 7, the frame 50 defines a rearwardly
directed first face 52, a
second oppositely directed, i.e. forwardly directed, second face 54, an outer
edge 56 extending about
the outer periphery of the frame 50 and between the faces 52 and 54, and an
inner edge 58. The inner
edge 58 defines an opening 60 that is preferably sized and shaped to receive
the flexible member 30. In
the illustrated embodiment, the opening 60 is rectangular with rounded or
arcuate corners. This shape
corresponds to the shape of the side walls 34 of the flexible member 30. It
will be understood that the
present invention includes nearly any shape for the opening 60. Preferably,
the frame 50 is flat or
relatively planar. The flexible member 30 is inserted through the opening 60
defined in the frame 50.
Preferably, the base 32 (not shown in Figure 7) of the flexible member 30
contacts and is disposed
immediately adjacent to the first face 52 of the frame 50. And, the side walls
34 and the domed region
36 of the flexible member 30 extend through the opening 60 and outward beyond
the second face 54 of
the frame 50.
[00201] Figure 7 also illustrates one or more guides 62 that are preferably
provided in conjunction
with the frame 50. The one or more guides 62 are preferably affixed to or
otherwise formed with the
frame 50 and preferably project from the second face 54 of the frame 50. The
guides 62 generally
define a distal edge 64, an inner wall 66 (see Figure 8) and an oppositely
directed outer wall 68. In
certain applications, the guides 62 are preferably located proximate the
opening 60 defined in the frame
50. In the embodiment depicted in Figures 7 to 8 for example, two guides 62
are utilized, arranged
along opposite sides of the opening 60 defined in the frame 50. However, it
will be appreciated that in
numerous other applications the guides can be located elsewhere. For example,
the guides may be
positioned so as to distort the flexible member to a shape other than its
natural or default shape. And,
the guides 62 are preferably oriented parallel to each other and parallel to
the longitudinal axis of the
Page 41
CA 02750143 2016-08-31
semi-rectangular shaped opening 60. Figure 7 also illustrates that the guides
62 extend an equal
distance from the second face 54 of the frame 50, and may extend from about
10% to about 100% of
the distance to which the flexible member 30 extends from the second face 54.
For many applications,
it is preferred that the guides 62 extend to a distance as measured from the
second face 54 of the
frame, that is about 25% to about 75% of the distance measured between the
second face 54 and the
distalmost location 40 of the flexible member 30.
[00202] Referring to Figures 7 to 10 further, the assembly also includes an
enclosure 90. Preferably,
the enclosure 90 is a housing or other structure for mounting and retaining
various components.
Generally, the enclosure 90 includes one or more walls 92 and a rear wall 94.
Walls 92 can include a top
wall, a bottom wall, and opposing side walls. One or more conduits 96 and
mounting provisions 98 can
be provided, preferably along the rear of the enclosure. These aspects are
described in greater detail in
conjunction with Figures 9 and 10.
[00203] As previously noted, Figure 7 also illustrates a vent plate 80 used
in the preferred assembly.
The vent plate 80 defines one or more vent passages 82 as illustrated in
Figure 8 extending through the
plate 80 to allow a fluid such as air to enter and exit the interior hollow
region of the flexible member
30. As shown in Figure 7, the vent plate 80 is preferably positioned between
the frame 50 and the
enclosure 90.
[00204] Figure 8 illustrates the assembly of Figure 7 fully assembled, with
the flexible member 30
shown in dashed lines thereby revealing the interior of the flexible member
30. As noted, it is preferred
to provide a heat source within the flexible member 30. Accordingly, the
assembly 100 includes a
heater 100 preferably disposed within the interior hollow region of the
flexible member 30. As
previously noted, the heater can be in many different forms. For the present
embodiment, the heater
100 is an electrically powered resistive heater such as a 480 volt 600 watt
heater. A reflector 102 or
other protective shield is preferably provided. The reflector 102 preferably
extends between the heater
100 and the sidewalls 34 (not shown) of the flexible member 30. The reflector
102 may include a
reflective surface to reflect radiant heat energy from the heater 100 away
from an adjacent sidewall 34
of the flexible member 30. One or more temperature sensors 104 can be disposed
in the interior of the
flexible member 30 to obtain information as to heating and temperature
conditions. Figure 8 also
illustrates a portion of the vent plate 80 and a vent passage 82 defined in
the plate 80.
[00205] Figure 8 also illustrates one or more optional apertures 91 that
can be provided in the
enclosure 90, in the guides 62, or both, or in other components. The apertures
91 may be provided to
allow for circulation of air from inside of the enclosure 90 to one or more
regions external to and along
Page 42
CA 02750143 2016-08-31
the outer surface of the flexible member 30. The optional apertures 91 may
serve to promote heating
of the outer surface of the flexible member as a result of relatively hot air
exiting the enclosure 90 and
being directed toward or at least alongside the flexible member 30.
[00206] Figures 9 and 10 illustrate additional components and provisions of
the preferred assembly
of the flexible member 30, the frame 50, and the enclosure 90. One or more
conduits 96 preferably
extend from the rear wall 94 of the enclosure 90 and serve to direct air or
other fluid into the interior of
the flexible member 30. Air, typically under pressure, is directed into an
entrance 95 defined in the
conduit 96. Air flowing through the conduit 96 enters the interior hollow
region of the flexible member
30 through the vent passage 82.
[00207] A preheater 110 can be provided such as inline or otherwise in flow
communication with the
conduit 96. The heater 110 serves to heat air or other fluid entering the
conduit 96 to lessen the
heating burden otherwise imposed upon the heater 100 disposed within the
flexible member 30. It will
be understood that the preheater 110 may include an integral section or
portion of conduit. Although a
wide array of heating devices and strategies can be used for the preheater
110, a preferred heater is an
electrically powered resistive heater such as a 170 volt 1,600 watt heater
available from Sylvania of
Exeter, New Hampshire.
[00208] With further reference to Figures 9 and 10, it is also preferred to
provide one or more
mounting provisions 98 on the enclosure, such as along the rear wall 94 of the
enclosure 90. The
mounting provisions 98 enable convenient and secure affixment of the enclosure
90 including the
flexible member 30 to one or more support members.
[00209] Figure 10 is a cross sectional view of the flexible member 30,
frame 50, enclosure 90, and
conduit 96 taken across line AA in Figure 9. Figure 10 illustrates a preferred
configuration for the
heaters 100 and 110, and the conduit 96 for administering air into and out of
the hollow interior of the
flexible member 30, through one or more vent passages 82. It will be
appreciated that a single vent
passage 82 may be used for providing communication between the interior of the
flexible member 30
and the conduit 96. Thus, air entering the flexible member 30 travels through
the conduit 96 and
through the vent passage 82. The present invention also includes an air flow
configuration in which air
enters the flexible member 30 through the conduit 96 and the vent passage 82,
and exits the flexible
member through one or more other vent passages (not expressly identified in
Figure 10) provided in the
vent plate 80 and/or the enclosure 90.
[00210] Figures 11 and 12 illustrate another preferred embodiment frame
150. Figure 11 shows the
frame 150 in assembled relation with a flexible member 30, and Figure 12
illustrates the frame 150 by
Page 43
CA 02750143 2016-08-31
itself. The frame 150 defines a first face 152, a second oppositely directed
face 154, an outer edge 156,
and an inner edge 158. The inner edge 158 defines an opening 160 sized and
shaped to engage and
receive a flexible member 30. The frame 150 includes two guides 162 extending
from the second face
154 of the frame 150. Each guide 162 defines a distal edge 164, an inner wall
166, and an oppositely
directed outer wall 168. Preferably disposed along a distal region of each
guide 162, is a secondary
guide 170 or wing member. The secondary guide 170 preferably extends at some
angle with respect to
its corresponding guide 162. Each secondary guide 170 defines an inner end 172
and an opposite outer
end 174. Each secondary guide 170 is preferably releasably secured to a
corresponding guide 162 such
that the position of the secondary guide 170 can be selectively changed. Each
secondary guide 170 is
preferably selectively positionable with respect to its corresponding guide
162 by use of an adjustable
affixment assembly 176. The affixment assembly 176 provides secure attachment
of a secondary guide
170 to a distal portion of a corresponding guide 162, and most preferably
allows the relative position of
the secondary guide 170 to be changed. A threaded fastener extending through a
slot in the secondary
guide as shown can be utilized. The secondary guides 170 serve to provide
further physical limits for
deformation of the flexible member 30. Figure 11 illustrates the flexible
member 30 in a deformed state,
and the side walls 34 of the member 30 contacting the inner ends 172 of the
secondary guides 170 to
limit further deformation outward by the sidewalls 34 of the flexible member
30.
[00211] Figures 13 to 18 schematically illustrate application of a label to
a container, and particularly,
a container having one or more compound curved region(s) 16, using the
flexible member 30 in
accordance with the present invention. Referring to Figures 13 and 14, the
container 10 previously
described in conjunction with Figures 1 to 3 is provided. A label 120 defining
a central region 122, an
outer edge 126, and an outer peripheral region 124 extending between the
central region 122 and the
edge 126 is provided. It will be appreciated that the thickness of the label
120 has been exaggerated for
ease in showing the label. The label 120 also defines an outer face 128 and an
inner face 130. An
effective amount of a pressure sensitive adhesive preferably extends across
the inner face 130 of the
label 120. The label 120 includes a heat shrink material and preferably, one
exhibiting balanced shrink
properties as described herein.
[00212] Preferably, the label 120 is initially contacted and retained along
a region of the container 10.
Preferably, the inner face 130 of the label within a central region 122 of the
label, is contacted with a
flat region 14 of the container 10. Other regions of the label 120 such as the
outer peripheral regions
124 which overlie compound curved regions 16 of the container 10, are not
contacted therewith. The
inner face 130 of the label 120 preferably contains a pressure sensitive
adhesive, thus upon the noted
Page 44
CA 02750143 2016-08-31
contact, the label 120 is maintained in contact with the container 10. It will
be understood that the
present invention includes a wide array of label application techniques,
labels, containers, and label
materials. As previously noted, the present invention can be used to apply
films and labels onto other
surface configurations besides those that include compound curves. For
example, the present invention
could be used to apply a label onto a container surface that was planar,
included only a simple curve, or
combinations of these geometries.
[00213] Figures 15 to 19 illustrate progressively contacting the label 120
to the container 10. After
initial contact between the label 120 and the container 10; the flexible
member 30, and particularly the
domed region 36 of the flexible member, is brought into contact with the outer
face 128 of the label
120. This is shown in Figure 15. It will be appreciated that this contact may
be accomplished by (i)
moving the flexible member 30 toward a stationary container 10 and label 120,
(ii) by moving the
container 10 and label 120 toward a stationary flexible member 30, or (iii) by
moving the container 10
and label 120, and the flexible member 30 into contact. The contact between
the flexible member 30
and the label 120 preferably initially occurs within a central region 38 and
most preferably occurs within
or including a distalmost location 40 defined along the domed region 36 of the
flexible member 30.
Regarding the label 120, contact with the flexible member 30 preferably
initially occurs within the
central region 122 of the label 120.
[00214] The flexible member 30 is urged against the container 10 and label
120 as shown in Figures
16 to 19. Due to the flexible characteristic of tile member 30, the member 30
begins to deform and
continues to deform whereby it adopts the contour and/or shape of the
container 120. The flexible
member 30 is urged against the container 10 and label 120 (or the container
and label are urged against
the flexible member), by application of a load or other force. As previously
noted, the amount of the
load is such that the pressure applied to the label is preferably from about
690 N/m2 to about 6900
N/m2. Progressive contact between the flexible member 30 and the container 10
and label 120 can be
seen in the sequence of Figures 15 to 19. After contact to the extent depicted
in Figure 19, the flexible
member 30 and/or the container 10 to which the label 120 is fully adhered, are
disengaged from one
another. The result is that the label is fittingly applied onto the container.
[00215] Throughout the entire process depicted by the sequence of Figures
14 to 19, the flexible
member 30 is preferably heated. As previously explained, the heating
preferably occurs such that the
outer regions 42 (see Figure 4) of the domed region 36 of the flexible member
are preferentially heated
as compared to the central region 38 of the domed region 36. This practice
promotes heating of only
outer peripheral regions 124 of the label 120. Typically, the regions of a
label that contact compound
Page 45
CA 02750143 2016-08-31
curved surfaces of a container, are the outer peripheral label regions 124. In
accordance with the
present invention, factors such as the amount of heat, rate of heating, rate
of increasing contact
between the flexible member and the container/label, and label application
force are controlled such
that the outer peripheral regions of a label are heated and shrunk to an
appropriate extent such that
upon contact with a compound curved container surface, the label is free from
darts, wrinkles, or other
defects. And, upon contact between label and container, the adhesive bond
precludes subsequent
movement of the portion of label in contact with the container.
[002161 Figure 20 is a perspective view illustrating contact between the
flexible member 30 and the
container 10, showing a typical extent of deformation of the flexible member
30. In this illustration, the
container 10 is transparent thereby revealing the label 120 adhered thereto.
The function Of the guide
162 and the secondary guide 170 is clearly shown. Outward lateral deformation
of the flexible member
30, such as in the direction of arrow B, is prevented due to the presence of
the guide 162 and the
secondary guide 170. Contact occurs between a region of the sidewall 34 of the
flexible member 30 and
the guides 162 and 170.
[00217] Figure 21 illustrates an assembly 200 of a plurality of flexible
members, each supported and
housed within a corresponding frame and enclosure as previously described and
collectively referred to
as a label applicator 210. Specifically, the assembly 200 includes a first set
220 of label applicators 210
and a second set 230 of label applicators 210. The two sets 220 and 230 are
preferably arranged across
from one another aligned, and separated by a conveyor 240 or other product
transport system. The
assembly 200 is shown as configured for applying labels onto opposite sides of
a container (not shown),
and in particular, upon six (6) containers at a time. In accordance with this
aspect of the present
invention, a plurality of containers (not shown), evenly spaced from one
another, are positioned on the
moving conveyor 240. The conveyor 240 moves the containers in the direction of
arrow C. Each set
220, 230 of the label applicators 210 is selectively positionable in the
directions X and Y as shown in
Figure 21. The movement, i.e. direction and speed, of each set 220, 230 is
coordinated to match a set of
six adjacent containers moving on the conveyor 240. A representative cycle is
as follows. Each of the
sets 220, 230 is retracted by movement in the directions of X1, and y1. As a
set of targeted containers, six
in number, each preferably carrying a partially contacted label as shown in
Figure 13, moves alongside
the sets 220, 230, the sets are then moved in the direction of X2. The speed
of each set 220, 230 in the
direction of X2 is matched to that of the targeted containers moving on the
conveyor 240. Concurrently
with movement in the direction of X2, each set 220, 230 is moved in the
direction of Y, towards the
targeted containers on the conveyor 240. Movement of each set 220, 230
continues as contact occurs
Page 46
CA 02750143 2016-08-31
between each flexible member 30 and a corresponding label. Each label is
applied to its corresponding
container as previously described in conjunction with Figures 14 to 19. As the
labels are being applied,
the collection of the sets 220, 230 and the six targeted containers are moving
in the direction of arrows
C and X2. After label application, each set 220, 230 is retracted by moving it
in the direction of arrow Y1.
When the sets 220, 230 are retracted in the Y1 direction, the beam is still
moving in the X2 direction. It is
not until after the heads are fully retracted in the Yi direction that the
beam begins to move in the X1
direction in preparation for the next set of targeted containers.
[00218]
Movement of the sets 220, 230 can be performed by a variety of different
techniques and
assemblies. In one approach, each of the sets is positioned on a movable slide
assembly that can be
selectively positioned on a linear track by one or more electrically powered
servo motors. It is also
contemplated that one or more cam assemblies could be used to impart the
desired motion to each of
the sets 220, 230.
[00219]
Although the foregoing description is provided in the application of labels to
six (6)
containers at a time, it will be appreciated that the present invention can be
tailored to concurrently
apply labels to nearly any number of containers, designated herein as "n."
Preferably, n typically ranges
from about 1 to about 20, and more preferably from about 4 to about 10. It
will be appreciated that in
no way is the present invention limited to these configurations. Instead, the
invention can be utilized to
simultaneously apply, or nearly so, labels to sets of containers numbering
more than 20. Moreover,
although the assembly depicted in Figure 21 is for applying labels to two
oppositely directed faces of a
container, the invention includes configurations in which only a single label
is applied per container, or
three or more labels are concurrently applied per container.
[00220]
Figure 22 is a top planar view of a preheating stage 300 that can be used in
combination with
the assembly 200 depicted in Figure 20. Referring to Figure 22, the conveyor
240 is shown transporting
a plurality of containers 310. Each container 310 carries a label on each of
its two major faces. Each
label is partially contacted and adhered to a corresponding container face in
the manner as shown in
Figure 14. The collection of containers 310 are transported alongside a
collection of heaters such as a
first heater 320 for heating labels on a first side of the containers 310 and
a second heater 330 for
heating labels on a second side of the containers 310. As previously noted, a
wide variety of heater
types, heat outputs, and configurations can be used. However, it is preferred
that the heaters 320 and
330 be in the form of infrared heaters.
Labels exiting this preheating stage typically exhibit
temperatures of about 38 C. However, it is to be appreciated that the
particular temperature to which
Page 47
CA 02750143 2016-08-31
the labels are heated, depends upon numerous factors including for example the
heat shrink activation
temperature of the labels.
[00221] Referring to Figure 23, containers 310 and labels exiting the
preheating stage 300 from
Figure 22 enter the assembly 200 as previously described in conjunction with
Figure 21. Containers
having fully applied labels are designated as containers 310. It will be
appreciated that during transport
through the assembly 200, the containers and their corresponding labels are
subjected to the operations
depicted in Figures 15-19.
[00222] Figure 24 schematically illustrates a front view of a preferred
embodiment flexible member
430 comprising a base 432, a domed region 436, and one or more side walls 434.
As shown, the flexible
member 430 generally has a rectangular shape with rounded corners or edges
when viewed along its
front face. The base 432 generally extends around the outer periphery of the
member 430. The
member 430 is generally symmetrical about its longitudinal (and vertical) axis
designated as axis Y. The
member 430 is also generally symmetrical about its width (and horizontal) axis
designated as X.
[00223] Figure 25 schematically illustrates a front view of another
preferred embodiment flexible
member 530 comprising a base 532, a domed region 536, and one or more side
walls 534 extending
therebetween. The domed region 536 includes outwardly extending lower corner
regions 536a and
536b. In this embodiment, the flexible member 530 features a symmetrical shape
about only one axis,
its longitudinal axis Y. The shape of the flexible member 530 is different and
non-symmetrical about axis
X. As previously noted, the shape and/or contour of a flexible member depends
at least upon the shape
of the label and/or the shape or contour of the container. The flexible member
530 depicted in Figure
25 more fully contacts lower edge and lower corner regions of a label than the
flexible member 430 of
Figure 24, due to the outwardly extending lower corner regions 536a and 536b.
Again, it will be
understood that the present invention includes a wide array of shapes and
configurations for the flexible
member. The particular shape and configuration of a flexible member is
primarily dictated by the
characteristics of labels and containers. Thus, it will be appreciated that in
no way is the invention
limited to the particular flexible members described herein such as members
430 and 530.
[00224] Figure 26 illustrates a pair of guides 662 adjustably and
selectively engaged or positionable
with a frame or other support member by use of threaded members 685 extending
through apertures
687 defined in each guide 662. Each guide includes an upper region 664, a
lower region 666, and an
inner side 665 extending therebetween. As shown in Figure 26, a container 10
is positioned between
the pair of spaced apart guides 662. The container 10 has curved sides or side
regions as shown in
Figure 26. The guides 662 are each preferably shaped or contoured to match,
follow, or generally
Page 48
CA 02750143 2016-08-31
correspond to the lateral side regions of the container 10. Thus, the inner
side 665 of each guide 662
preferably extends alongside the container 10 and is relatively closely spaced
therefrom.
[00225] More specifically, as depicted in Figure 26, container 10 defines
an outwardly projecting or
convex lateral region 10a and the guide inner side 665 defines a corresponding
inwardly recessed
concave guide inner side region 665a. In addition, container 10 further
defines an inwardly recessed
concave lateral region 10b and the guide inner side 665 defines a
corresponding outwardly projecting or
convex guide inner side region 665b. For many applications, it is particularly
preferred that the
configuration of an inner side closely correspond to and generally follow the
contour of the container of
interest. Thus, spacing between the inner side of a guide and a container,
when positioned into
appropriate relationship therewith, is relatively uniform and constant from a
guide upper region to a
guide lower region. This is in contrast to the particular arrangement depicted
in Figure 26, in which a
relatively large spacing is provided between container and guide inner sides,
proximate the guide lower
regions, and a relatively narrow spacing adjacent the guide upper regions.
100226] Figure 27 further illustrates a perspective view of a preferred
embodiment "quick change"
system 700. The quick change system includes a flexible member 730, guides
762, and a frame
assembly 750. The guides 762 are adjustably and selectively positionable with
respect to the frame 750
and preferably vertically positionable by use of one or more rail members 752.
The system 700 includes
a wide array of provisions for releasably engaging the system 700 to a larger
frame or support, or as
previously noted, to a walking beam apparatus (not shown). An example of such
releasable engagement
provisions include clamping members such as depicted as 710. Other fastening
means can be used such
as threaded fasteners.
[00227] Figures 28 and 29 illustrate a plurality of quick change systems
700 collectively referred to as
a labeling group 800. Figure 22 is a perspective view and Figure 29 is a front
elevational view of the
labeling group 800. Each system 700 is as previously described with respect to
Figure 27. Each system
700 is selectively engageable with a frame portion 780. Each frame portion 780
includes provisions for
directing heated air into a flexible member 730 such as air inlet 740 having
an inline electrically operated
heater 743, and an air exit 744. Referring further to Figures 28 and 29,
defined in frame 750, are an air
inlet opening 741 and an air outlet opening 742. As previously described in
association with heater 110
in Figure 10, the heater 743 may include an interior flow region or conduit
section. Thus, heated air
flowing past heater 743 through inlet 740 enters the interior of a flexible
member 730 via opening 741.
Heated air circulates within the flexible member 730, preferably further
distributed by an air manifold or
diffuser (not shown), and exits via opening 742 and through air exit 744.
Positioned within each flexible
Page 49
CA 02750143 2016-08-31
member 730 is a heater 790. Clamping members 710 or other securing assemblies
can be used to
selectively and releasably disengage a flexible member 730, its guides 762,
and its frame 750 from the
other frame 780.
[00228] Figure 30 illustrates five different quick change systems
designated as 700a, 700b, 700c,
700d, and 700e, each using a different size flexible member, shown as 730a,
730b, 730c, 730d, and
730e. Each system may include one or more guides such as 762c and 762e, or be
free of such guides. In
addition, each system may include different sizes, shapes, and configurations
of heaters 790a, 790b,
790c, 790d, and 790e, disposed within the flexible members. Clamping or other
releasable engagement
provisions 710 are provided for each system 700a ¨ 700e. Figure 30 also
depicts a preferred
arrangement of the air openings 741 and 742 relative to flexible members 730a
¨ 730e. Regardless of
the size of the flexible member 730a ¨ 730e, upon engaging the frame 750 to
the frame 780 (see Figure
28), the air openings 741 and 742 are aligned with air inlet 740 and air exit
744. This configuration
further facilitates fast and easy removal and installation of one system 700
for another, such as
replacing system 700e with system 700a or vice versa. As will be appreciated,
this enables convenient
changeout of one flexible member for another. Thus, a flexible member having a
particular
configuration designed for one label and/or container type can be easily
changed when another
container and/or label are used. Figure 30 also illustrates a representative
air manifold 737 having a
hollow interior and defining a plurality of apertures 738 extending through
the side wall of the manifold.
It will be understood that the air manifold 737 may utilize nearly any pattern
or arrangement of
apertures 738, and in no way is limited to the particular embodiment depicted
in Figure 30.
[00229] The invention also provides various label processing systems for
contacting a label to a
container. These systems comprise a label processor for concurrently heating
and contacting a label to
a container. The label processors are preferably as described herein. The
label processing systems also
comprise one or more labels for heating and contacting to a container by the
processor.
Application of Label Using Wiping Members
[00230] In general, the present invention provides various techniques and
assemblies for selectively
applying one or more regions of a label or label assembly to a container.
Specifically, the techniques
and assemblies are utilized to control the regions of a label that are
contacted with a container. By
selectively controlling the geometry and size or proportions of label "flags"
during a labeling operation,
greater overall control of a labeling process can be achieved. The techniques
and assemblies as
Page 50
CA 02750143 2016-08-31
described herein have particular significance in labeling operations using
heat shrink labels and pressure
sensitive adhesives.
[00231] In certain labeling operations such as for applying labels onto
complex curved surfaces, a
multi-step strategy is utilized. In particular, this multi-step strategy is
useful for applying heat shrink
labels using pressure sensitive adhesives. The label or label assembly is
initially applied to a container or
other receiving surface by contacting only a portion of label to a desired
region of the container.
Exposed adhesive such as pressure sensitive adhesive along a rear face of the
label contacts the
container and retains the label relative to the container, which is typically
moving on a conveyor. The
resulting regions of the label that are not in contact with the container are
sometimes referred to in the
industry as "flags" or "wings."
[00232] The label is then fully contacted with and adhered to the container
in a variety of different
techniques, largely depending upon the geometry of the container and
characteristics of the label and
adhesive. For heat shrink labels using pressure sensitive adhesives, the
remaining uncontacted label
portions or "flags" are preferably contacted with the container using a
deformable heated member. The
motion and temperature of the heated member are carefully controlled to heat
the label or portion(s)
thereof, to desired temperatures in order to achieve a desired degree of
shrinkage in the label
portion(s). The heating is carefully controlled relative to occurrence of
contact between the label and
container with a goal of reducing or ideally avoiding, the occurrence of
wrinkles, darts, edge lifting, or
other defects in the applied label.
[00233] The present invention provides systems arid methods for partially
or fully applying a label to
a moving container in a defect-free manner. The label is initially contacted
with and carried by the
moving container. In one version of the invention, the label is further
applied to the container however
not fully applied, so that one or more label flags remain. The label can be
fully applied to the container
and label flags applied to corresponding regions of the container by one or
more subsequent operations
such as use of a heated flexible wiping member. In another version of the
invention, the label is
completely applied to the container. In this version, the flags resulting
after initial contact between the
label and the container are fully contacted with the container.
[00234] Figure 31 illustrates a typical container 810 having a container
exterior surface 812 to which
a label 820 is applied in accordance with the present invention. Specifically,
a label is initially only
partially contacted to a container or receiving surface such that one or more
desired label portions
remain uncontacted with the container. Figure 31 illustrates such a state in
which the label 820 is
partially contacted with and partially adhered to the container 810.
Page 51
CA 02750143 2016-08-31
[00235] The region of initial contact between the label 820 and the
container 810 is depicted in
Figures 31 and 32 as region 830. The remaining label regions that are not in
contact with the container
are flags 832a and 832b. As previously noted, the term "flag" as used herein
refers to an uncontacted
portion of a label, typically including one or more edge regions. Although two
separate flag portions
832a and 832b are illustrated in Figures 31 and 32, it will be appreciated
that three or more flags, or a
single flag, may be associated with a label and its initial application to a
container. The front face of the
label 820 is generally designated as a front face 824. And, the rear face of
the label 820 is designated as
rear face 822. An effective amount of adhesive 828 such as a pressure
sensitive adhesive, is typically
disposed along the rear face 822 of the label 820.
[00236] Specifically, the present invention is directed to a multi-step
labeling operation in which a
pressure sensitive label is initially partially contacted to a desired
location along an outer face of a
container. The label is concurrently and incrementally subjected to a wiping
operation whereby
additional regions of the label are contacted with and applied to the
container. Preferably, the wiping
operation is terminated prior to the entire label being contacted with the
container. Most preferably,
wiping is performed only until at least one or more flags exist. At this
juncture, the wiping operation is
completed and the container now carrying the partially applied label is
directed to another process
operation such as contact from a flexible heated member. However, as
previously noted,. the present
invention includes a labeling operation in which a label and preferably a
pressure sensitive label, is fully
contacted with and applied to a container so that the applied label is free of
flags.
[00237] Although not wishing to be bound to any particular theory, this
multi-step labeling operation
has been discovered to be particularly well suited for applying heat shrink
pressure sensitive labels onto
curved container surfaces and especially container surfaces exhibiting
compound curved surfaces.
Typically, such containers exhibit a somewhat planar or slightly arcuate and
convex front or rear region
that along its lateral regions, dramatically curves inward to form complex
curved shoulders or sides that
meet a corresponding surface from the other side of the container. Attempting
to apply a label and in
particular, a heat shrink pressure sensitive label, in a defect-free manner
over the sharply curved and
typically complex curved regions is very difficult. Surprisingly, by use of
the present invention, a label
can be readily applied by initially contacting a select region of the label to
a portion of the container and
then contacting and applying additional amounts of the label to the container
by selectively wiping the
label. Preferably, wiping is performed to an extent such that at least one or
more label regions remain
which are not contacting the container. The label portions not in contact with
the container are label
flags. Preferably, the flags that are formed correspond to and thus overlie
regions of the container that
Page 52
CA 02750143 2016-08-31
exhibit compound curvature. The flags are subsequently applied to the
compoundly curved container
surfaces by one or more subsequent operations such as the noted flexible
heated member for example.
In certain applications, it may be possible to fully apply the label so that
no label flags remain. For these
applications, it would likely not be necessary to subject the labeled
container to a flexible heated
member.
[00238] Figure 33 is a perspective view of a preferred embodiment wiping
assembly 840 in
accordance with the present invention. The various wiping assemblies described
herein are used to
selectively apply a label and controllably wipe, i.e. incrementally contact,
one or more regions of the
label including (i) all or a portion of a contacted label region such as
region 830 in Figures 31 and 32, and
(ii) all or a portion of a flag region such as one or both of regions 832a and
832b in Figures 31 and 32.
The preferred embodiment wiping assembly 840 is utilized to initially apply a
label from a label
dispenser (not shown in Figure 33) and further utilized thereafter to
incrementally apply and "wipe" the
label to the container. The wiping assembly 840 comprises a frame 850, a wiper
member 860, a cam
880, and a cam follower member 870. Each of these components is described in
greater detail herein.
[00239] The frame 850 generally includes one or more members for supporting
and positioning the
wiper member 860. Preferably, the frame 850 includes an upper frame member
852, a lower frame
member 854, and one or more support members extending therebetween such as a
vertical support
member 856. The materials used for the frame can be nearly any material
exhibiting suitable strength
and rigidity. Non-limiting examples for frame materials include metals such as
steel and aluminum, and
relatively rigid plastics. One or more mounts 858 or other affixment
components can be used to affix or
otherwise attach the wiper member 860 to the frame 850. The frame 850 is
pivotally mounted to a
support or other fixture (not shown) such that the frame 850 can be pivoted
about a pivot axis 842 as
shown in Figure 33. Preferably, the frame 850 and the wiper member 860 affixed
thereto, can be
pivoted about the axis 842 in the direction of arrow B. The manner by which
pivotal movement of the
frame is achieved is explained in greater detail herein.
[00240] The wiper member 860 is illustrated in isolation in Figure 34.
Although the present invention
includes a variety of forms and configurations for the wiper member 860, the
member 860 preferably
has a relatively planar shape defining a front face 861 and an oppositely
directed rear face 863. The
wiper member 860 also includes one or more blades 862 that preferably extend
from an edge or side
region laterally outward. The blade 862 is preferably flexible and deformable
and so the materials
selected for the blade are accordingly selected. Representative examples for
materials for the blade 862
include, but are not limited to silicones, rubbers, flexible plastics, and
various composite materials. The
Page 53
CA 02750143 2016-08-31
wiper member 860 also includes a wiping element 864 preferably disposed along
a distal edge or region
of the blade 862. During use of the wiping assembly 840, the wiping element
864 contacts a label along
one or more contacting regions 866 of the wiping element 864. The material(s)
selected for use as the
wiping element 864 depend upon the label characteristics and the smoothness of
the wiping element
864 and tendency for the element to move across the label. Non-limiting
examples of materials that
may be suitable as the wiping element 864 include, but are not limited to
woven and nonwoven fibers of
cotton, polymeric materials, molded elastomeric materials and the like.
Depending upon the materials
of the label and characteristics of any printing or overcoat layers, it may
also be desirable to use one or
more lubricating or friction-reducing agents along the wiping element. Again,
it is to be understood that
the invention includes a wide array of shapes, configurations, and materials
for the wiper member 860.
For the particular preferred wiping assembly 840 described herein, it is
preferred that the wiping
element 864 continuously extends over the entire length or substantially so,
of the blade 862. And, it is
preferred that the blade 862 continuously extends over the entire length or
substantially so, of the
wiper member 860.
[00241] The preferred embodiment wiping assembly 840 also includes a cam
follower member 870.
The cam follower member 870 is engaged to, and preferably affixed to, the
frame 850 such that
movement of the member 870 is imparted to the frame 850. As depicted in Figure
33, the cam follower
member 870 can be affixed to an upper frame member 852 of the frame 850 by one
or more bolts or
other fasteners. Other affixment means can be used such as welding, adhesives,
or integrally forming
the cam follower member 870 with one or more members of the frame 850. The
preferred
configuration depicted in Figure 33 is described in greater detail herein. The
cam follower member 870
may be in a wide variety of shapes and configurations. Preferably, the member
870 defines a proximal
end 876 at which the member 870 is attached to the frame 850, and an opposite
distal end 874. The
distal end 874 preferably defines a cam follower surface 872 that is directed
toward the cam member
880. In a preferred configuration of the member 870, the cam follower surface
872 is provided along a
laterally directed side or edge region of the member 870 and particularly
along the distal end 874 or
portion thereof. The cam follower member 870 can be formed from nearly any
material such as metals
including steel and aluminum for example, or plastics such as Lexan,
polyethylene, or other low surface
energy materials.
[00242] The wiping assembly 840 in certain embodiments may also include a
cam member 880. The
cam member 880 is positioned to be in operable engagement with the cam
follower member 870 such
that movement of the member 880 induces a predefined cyclical and preferably
reciprocal movement of
Page 54
CA 02750143 2016-08-31
the follower member 870. In the representative configuration depicted in
Figure 33, the cam member
880 moves in a linear fashion in the direction of arrow A which due to the
operable engagement with
the cam follower member 870, induces reciprocating pivotal movement of the
frame 850 and the wiper
member 860 in the direction of arrow B, and specifically, about the pivot axis
842. Preferably, the cam
member 880 defines a cam surface 882 directed toward the cam follower member
870, and particularly
toward the cam follower surface 872. As will be understood, upon and during
engagement between the
cam member 880 and the cam follower member 870, a portion of the cam follower
surface 872 is in
contact with a portion of the cam surface 882.- Although the invention
includes a wide array of
configurations and arrangements, preferably, the cam member 880 and the cam
follower member 870
are arranged such that linear displacement of the cam member 880 results in
reciprocating pivotal
movement of the cam follower member 870.
[00243]
Figure 35 illustrates typical positioning and orientation of a container 810
carrying a partially
contacting label 820. The label is initially contacted to the container
upstream and preferably
immediately upstream of the wiping assembly 840. In a particularly preferred
process described in
greater detail herein, the label 820 is initially contacted to the container
810 by the wiping assembly
840. Once contacted therewith, the container continues to carry the partially
applied label toward the
wiping assembly 840 at which the label is further contacted with and applied
to the container. Typically,
the container 810 is disposed on a conveyor 890 that moves past the wiping
assembly 840. A wide array
of conveyors can be used in association with the various wiping assemblies of
the present invention.
Generally, the conveyor transports containers that are preferably arranged on
the conveyor such that
the containers are equally spaced from ore another and uniformly aligned with
respect to one another.
The containers are preferably arranged in a single file line on the conveyor,
although it will be
appreciated that the invention includes other container arrangements. As for
the configuration of the
conveyor, it is generally preferred to utilize a linear conveyor and in
particular, one having a conveyor
section that is linear and which transports containers in a straight line
direction past the wiping
assembly and in particular, the wiping member. It is also preferred that the
conveyor transports the
containers in a continuous fashion such that the containers are continuously
in motion and most
preferably, so that the containers are in continuous motion as they move past
the wiping member. The
movement of the conveyor 890 is preferably synchronized to that of the cam
member 880 (not shown)
such that as the container 810 moves toward the wiping assembly 840, the cam
follower 870 is first
moved away from the container 810 and then moved towards the container 810.
Specifically, it is
preferred that as the conveyor 890 and container 810 disposed thereon are
moved a first incremental
Page 55 ,
CA 02750143 2016-08-31
amount CI, the cam follower member 870, the frame 850, and the wiper member
860 pivotally move
about axis 842 (shown in Figure 33) in the direction of arrow D away from the
container 810. Upon
sufficient linear movement of the conveyor such as completion of the first
incremental amount C1, the
conveyor 890 continues and undergoes further linear movement such as a second
incremental amount
C2. As the conveyor 890 and container 810 disposed thereon moves through the
second incremental
amount C2, the cam follower member 870, the frame 850, and the wiper member
860 pivotally move
about axis 842 (shown in Figure 33) in the direction of arrow E toward the
container 810. Depending
upon the relative positions of the cam member 880 and the cam follower member
870, and the profile
or shape of the cam surface 882 and the cam follower surface 872, a wide array
of movements of the
wiper member 860 relative to a container 810 and its label 820, can be
achieved. As the container 810
and label 820 move past the wiper member 860, the portion of the label 820 not
in contact with the
container 810 and which is upstream of the member 860 at that moment, is then
pulled past the
member 860, and specifically past the wiping element 864. Depending upon the
shape and
configuration of the wiping element 864, all or only select regions of the
label can be urged toward the
container 810 and contacted therewith. Thus, depending upon the previously
noted aspects, the size,
shape, and orientation of one or more flags can selectively be controlled.
This is particularly desirable
prior to subjecting a container and partially attached label to a heated
flexible member for heat
shrinking and final label adherence to the container.
[00244] In
another preferred embodiment according to the present invention, the wiping
assembly
840 does not include, and is free of, the cam member 880. Instead, the cam
follower member 870 is
positioned to periodically contact the containers moving past the wiping
assembly. Most preferably, the
cam follower 870 is positioned to periodically contact an upper region of each
container such as an
outer portion of a container neck or upwardly extending threaded region which
receives a cap or other
container closure member. Configuring and positioning the cam follower member
870 so that the
member is actuated by the containers themselves promotes simplicity,
consistency, and accuracy in
operation of the associated process. This preferred embodiment is possible
because in most if not all
high speed, commercial container labeling operations, containers are held in
place along a moving
conveyor by an upper conveyor member. The contacting surface of the upper
conveyor member is
typically frictionally enhanced to promote engagement between that member and
the container. The
plurality of containers disposed between an upper and a lower conveyor are
sufficiently held in position
such that they can support, i.e. do not move, the cam follower member 870
contacting each container
as the collection of containers move alongside and past the wiping assembly.
Page 56
CA 02750143 2016-08-31
[00245] It will be appreciated that the present invention provides
assemblies enabling the selective
tailoring of the shape, size, and orientation of nearly any flag or other
uncontacted label region. Thus,
the invention can accommodate nearly any configuration of partially applied
label upon a container, and
be used to form or modify one or more flags associated with the label, prior
to final label application
and/or label heat shrinking. Or, the invention can be used to completely apply
a partially applied label
to a container so that no flags remain.
[00246] For example, Figure 36 depicts a container 810 having a label 820
partially contacted thereto.
The region of the label 820 in contact with the container 810 is shown as
region 830 and the label
regions not contacting the container 810 are shown as regions or flags 832a
and 832b. The container
810 is moving past a wiping element 864 in the direction of arrow F. Thus, the
flag 832a is downstream
of the wiping element 864 and the flag 832b is upstream of that element. In
this example, the wiping
element 864 of a wiper member 860 (not shown) is brought into contact with the
moving container 810
at a central location of region 830. As the container 810 and label 820 are
moved past the wiping
element 864, the element incrementally contacts or "wipes" the label 820 from
its initial central location
to a subsequent location proximate an outer edge region of the label 820 as
depicted in Figure 37. As
will be noted in Figure 37, after wiping of the label 820, the initial flag
832b has been entirely eliminated
by contacting that label region to the container 810. As a result, the
proportion or surface area of the
region 830 has increased. Since no wiping or contact occurred regarding the
downstream flag 832a, that
flag remains unchanged. It will be appreciated that primes are used in
association with regions 830 and
832a to designate those regions after the wiping operation by wiping element
864.
[00247] Figures 38 and 39 illustrate an initial container 810 and label 820
partially contacted
therewith such that the contacting region 830 is relatively small in
comparison to the flag regions 832a
and 832b. In this example, it is desired to simply reduce the size or
proportion of the upstream flag
832b and not to entirely eliminate that flag as in the example of Figures 36
and 37. A heated flexible
member (not shown) could then be used to apply the label flag 832b to the
container.
[00248] Figures 40 and 41 illustrate another example in which a label 820
is initially contacted with a
container 810 along a leading edge of the label 820. A relatively large
upstream flag 832b remains. The
preferred embodiment assembly can be used to increase the contact region
between the container 810
and the label 820, i.e. region 830, and thereby reduce or entirely eliminate
the upstream flag 832b as
shown in Figure 41.
[00249] In a particularly preferred process according to the invention, the
wiping assembly is used in
conjunction with a label dispenser. Figures 42-44 and 46-49 illustrate various
stages during a preferred
Page 57
CA 02750143 2016-08-31
embodiment labeling process in accordance with the invention. Figure 45
illustrates a potential problem
that can arise during a labeling operation. In
these figures, a series of detailed schematic
representations are provided depicting a preferred technique of applying a
label and wiping the label
using the preferred assemblies described. Generally, the various components of
the wiping assembly,
container, and label are as previously described and are denoted by similar
reference numerals in the
900 series. Thus, for example, a frame 950 is referenced in Figures 42-49. The
frame 950 corresponds
to frame 850 previously described herein. Each of Figures 42-49 illustrate a
container 910 during a
labeling operation in which a label 920 is applied to the outer surface of the
container by a wiper
member 960 carried on a frame 950. In these figures, a label dispenser is
schematically depicted as 935
having a label dispenser chute 936 from which the label 920 is administered.
Nearly any type of label
dispenser can be used in the assemblies, systems, and methods described
herein. Generally, the label
dispenser is configured or otherwise adapted to selectively position a label
alongside a desired outer
face of a container.
[00250]
Referring to Figure 42, the wiper member 960 and frame 950 are pivoted out of
the way so
the label can feed or dispense between the wiper and the container. This is
accomplished by the cam
follower, e.g. follower 870 illustrated in Figure 35, contacting and pushing
off from the neck of the
container. Specifically, as the container 910 is moved toward the wiping
member 960 and the frame
950 in the direction of arrow G, the wiper and frame are displaced away from
the container 910 in the
direction of arrow H. Preferably, movement of the wiper 960 and the frame 950
is a result of contact
between a cam follower (not shown) and the outer surface of a neck 915 of the
container 910. At this
particular stage of the labeling operation, displacement of the wiper 960 and
frame 950 in the direction
of arrow H generally occurs prior to arrival of the container 910 as indicated
by a center 902 of the
container 910 being upstream of the frame 950 in Figure 42. The center 902 is
the geometric center of
the container 910 and is defined by the intersection of container-bisecting
planes 902x and 902y. Figure
42 also depicts a preferred configuration for the distal end or chute 936 of
the label dispenser 935. In
this preferred orientation of the chute 936, the label 920 exits the dispenser
935 in a direction that is
parallel or at least substantially so to a line tangent with a face of the
container 910 directed toward the
wiper and frame, and contacting the container 910 at the intersection thereof
by plane 902y. This
tangential line is illustrated in Figure 42 as dashed line z.
[002511
Referring to Figure 43, as the container 910 continues to approach the wiper
and frame, the
cam follower starts to allow the wiper 960 to move toward the container 910.
The wiper then starts to
direct the label toward the container. Specifically, the container 910
continues to move toward the
Page 58
CA 02750143 2016-08-31
assembly of the wiper member 960 and the frame 950 in the direction of arrow
G. As a result of the
shape of the cam surface of the cam follower (not shown), the frame 950 is
then displaced toward the
moving container 910 in the direction of arrow I shown in Figure 43. Movement
in the direction of
arrow I continues so that a contacting region 966 of the wiper member 960
contacts the label 920 and
displaces the label 920 toward the container 910. At this stage in the
process, the center 902 of the
container is approaching the chute 936 of the label dispenser 935.
[00252] Referring to Figure 44, the wiper 960 places the label on the
container in a position that is
determined by the shape of the cam follower (not shown). This action creates a
label flag and controls
the length of the flag. It is significant that the label is applied to the
container by the wiper to eliminate
or avoid the formation of bubbles in the label. If the label is applied to the
container before the wiper
applies such, then an undesirable pre-tack condition can occur which will
often involve bubbles.
Specifically, in Figure 44, the assembly of the wiper member 960 and the frame
950 is further displaced
toward the moving container 910 in the direction of arrow J. This results in
the contacting region 966 of
the wiper member 960 contacting the label 920 to the container 910. It will be
noted that such contact
is made so that a leading edge of the label remains free of contact with the
container 910, thereby
creating a label flag 932a. At this stage of the labeling process the center
902 of the container is
approximately adjacent to the chute 936 of the label dispenser 935.
[00253] Figure 45 illustrates an example of undesirable condition of pre-
tack. In this condition,
contact occurs between the label 920 and the container 920 upstream of the
contacting region 966 of
the wiper member 960. As explained, this typically leads to the formation of
air bubbles under the label
920 within the region of the label denoted as T.
[00254] In Figure 46, the wiper moves along the container, thereby wiping
the label onto the
container. Specifically, at this stage of the labeling operation, the center
902 of the container 910 is now
downstream of the chute 936 of the label dispenser 935. The container
continues to move in the
direction of arrow G. Another preferred practice in accordance with the
invention is to adjust the rate
at which the label 920 is administered from the label dispenser 935 such that
the label 920 is slightly
tensioned or pulled from the label dispenser as a result of the label
contacting the moving container 910
at this juncture of the process. This practice has been discovered to promote
bubble-free application of
labels to containers.
[00255] Referring to Figure 47, the label separates from and completely
exits the chute 936. The
wiper continues wiping the label 920 onto the container. Specifically, as the
container continues moving
in the direction of arrow G, the label 920 is contacted with the container 910
and wiped by the wiper
Page 59
CA 02750143 2016-08-31
member 960. At this stage of the labeling operation, the center 902 of the
container is downstream of
the wiper 960 and the frame 950.
[00256] Referring to Figure 48, the wiper finishes wiping the label onto
the container but the wiper
does not fully wipe down the trailing label edge. This leaves a trailing flag.
The stroke of the wiper limits
the wiper from further contacting the container so the flag is created. It is
contemplated that by varying
the cam configuration, the wiper can be separated from the container so that
the length of the trailing
flag can be controlled. More specifically, at the stage of labeling depicted
in Figure 48, movement of the
container 910 is continued in the direction of arrow G. The label 920 is now
partially applied to the
container 910 such that a leading flag 932a and a trailing flag 932b exist. At
this stage of the process,
the contacting region 966 of the wiper member 960 is positioned downstream of
the container center
902 and between the center 902 and a trailing face 910b of the container 910.
[00257] In Figure 49, the wiper starts to move away from the path of the
moving container 910 so
that the process starts over for the next container. That is, the wiper member
960 and the frame 950
are displaced away from the container 910 in the direction of arrow K. This
process is repeated for
another container (not shown) upstream and following the container 910.
[00258] It will be understood that in no way is the present invention
limited to any of the labeling
practices described and shown herein. Although not wishing to be limited to
any particular practice,
generally a preferred practice is as follows. A label is initially contacted
with a container along an
upstream or leading edge or region of the label. The edge or region need not
include the leading-most
portion of the label but is generally defined proximate the leading-most label
portion. The leading-most
label portion is not in contact with the container and thus constitutes a
flag. The region of the container
corresponding to and underlying the leading-most flag is typically compoundly
curved. The flag can be
fully contacted and applied to the compoundly curved region of the container
in a later operation by a
heated flexible member for example.
[00259] The container carrying the partially applied label moves past the
wiping assembly as
described herein. The wiping assembly then further contacts the label to the
container by the selective
wiping operation described herein. Preferably, wiping is terminated such that
a trailing-edge flag is left
which is not in contact with an underlying container region, which as noted is
typically compoundly
curved. The trailing-edge flag can be fully contacted and applied to the
compoundly curved region of
the container in a later operation by a heated flexible member for example.
[00260] It is also contemplated that other components such as pneumatic or
hydraulic actuators or
electrical servo motors could be used to selectively position one or more
components to achieve
Page 60
CA 02750143 2016-08-31
=
additional label and container configurations. For example, instead of using a
pivoting arrangement for
the frame 850, a track system and one or more servo motors could be used to
selectively position the
wiper member 860 into position for wiping a label and out of position to allow
the container and/or
label flags to pass without interference from the wiper member 860.
[00261] The present invention also provides various methods for selectively
contacting a label, for
example to selectively wipe the label or portions thereof, that is carried on
a moving container. The
methods generally comprise providing a moveable cam member and a moveable
frame assembly. The
cam is configured such that its movement corresponds to movement of the
container and the label
carried on the container. The frame is preferably pivotally moveable about a
vertical pivot axis. A wiper
member is affixed or otherwise engaged to the moveable frame. The frame is
located relative to the
path of the moving container such that as the frame is pivoted, the wiper
member is moved between
two positions. In one of the positions, the wiper member is in contacting
proximity of the path of the
container. And in another position, the wiper is located a distance away from
the path of the container.
The term "contacting proximity" as used herein with regards to the wiper
member, refers to that
member being in a position such that a distal edge or end region of the wiper
member contacts a label
carried on a container as the container moves past the wiper member.
[00262] In a preferred method, a cam follower is provided in association
with the moveable frame.
The frame is positioned and oriented such that the cam follower is in operable
engagement with the
cam member. Most preferably, the cam, the cam follower, and movement of the
container are tied to
one another such that the frame is pivoted about the pivot axis such that when
the moving container is
alongside the frame, the wiper is in contacting proximity with the container
so that the wiper contacts
the label carried on the container. As the container moves past the frame, the
frame is pivoted about
the pivot axis such that the wiper member is displaced or moved away from the
path of the moving
container.
[00263] And, methods are provided for selectively contacting a label as
noted herein in which the
containers themselves serve as the cam member. The methods involve providing a
cam follower that is
operated by a collection of containers moving alongside the cam follower.
Periodic contact between the
cam follower and the containers, such as container necks, can be used to
govern the movement of the
wiper member.
[00264] It will be appreciated that the present invention includes
variations of this method and
provides an array of techniques for selectively contacting a label or portions
of a label that is carried on
a moving container.
Page 61
CA 02750143 2016-08-31
[00265] A wide array of labels, films, and/or assemblies of such can be
selectively applied to a
container using the various equipment, systems, and methods described herein.
For example, examples
of typical materials use for labels or label substrates include but are not
limited to paper, polyester
(Mylar), polyethylene and the like. As noted, the label or film may be in the
form of a heat shrink film.
The shrink film useful in the label may be a single layer construction or a
multilayer construction. The
layer or layers of the shrink film may be formed from a polymer chosen from
polyester, polyolefin,
polyvinyl chloride, polystyrene, polylactic acid, copolymers and blends
thereof. Generally, any of the
labels or film, adhesives, and additional aspects thereof previously noted
herein in conjunction with the
use of flexible members can be used in conjunction with the label application
systems and strategies
using wiping members. The present invention can be used for applying a wide
array of labels, film, and
other members. For example, the invention can be used in conjunction with
shrink labels, pressure
sensitive labels, pressure sensitive shrink labels, heat seal labels, and
nearly any type of label or film
known in the packaging and labeling arts. Labels applied using the equipment,
systems, and/or methods
described herein preferably exhibit several characteristics or aspects as
follows. The label is generally
sized such that upon fully contacting or adhering the label to the container,
the label does not extend
about the entire periphery of the container. Most preferably, upon full
contact with a container, the
edges or other regions of a label do not overlap with other edges or regions
of the same label.
[00266] The invention also provides various labeling systems for producing
a labeled container.
These systems comprise a label dispenser for selectively positioning a label
alongside a moving
container, a label or plurality of labels, and an assembly for selectively
contacting one or more regions of
a label positioned alongside a container by the label dispenser. The assembly
comprises a moveable
frame, the frame including at least one frame member pivotally moveable about
a pivot axis. The
assembly further comprises a wiper member engaged to the frame member and
moveable therewith.
The wiper member includes a wiping element for contacting the label. The
assembly also comprises a
cam follower affixed to the frame and moveable therewith. Movement of the cam
follower corresponds
to movement of a container, whereby the wiping element selectively contacts
the label onto the moving
container.
Post Heat Treatment
[00267] As explained in greater detail herein, various methods and systems
are provided for post
treating a label or film previously adhesively applied to a container or other
substrate. The methods
generally include heating the applied label or label assembly to a particular
temperature relatively
Page 62
CA 02750143 2016-08-31
quickly, and generally directly after label application. Preferably, during
this heating operation, the
adhesive disposed between the label and the surface of the container or
substrate is also heated in like
fashion as the label. The term "adhesively applied" as used herein with regard
to labels, refers to labels
that are applied and retained along exposed surfaces of containers or
substrates by one or more layers
of adhesive(s). Applied labels treated in accordance with the particular
methods described herein
exhibit reduced defect rates, improved label retention and adherence, and
better aesthetics as
compared to corresponding applied labels not subjected to the methods.
[00268] In particular, the present invention provides further advances in
strategies and methods for
applying labels and films onto curved surfaces such as outer curved surfaces
of various containers.
Although the present invention is described in terms of treatment strategies
for labels or films that have
previously been applied to containers, it will be understood that the
invention is not limited to
containers. Instead, the invention can be used to post-treat a variety of
labels or films previously
applied onto surfaces of nearly any type of article. The invention is
particularly directed to treating
shrink labels that have previously been applied onto curved container
surfaces. And, the invention is
also particularly directed to treating labels such as shrink labels that have
been applied onto compound
curved surfaces of various containers.
[00269] It is to be understood that the present invention can be used for
treating labels and films
that have been applied onto a wide variety of surfaces, including planar
surfaces and simple curved
surfaces. However, as explained in greater detail herein, the invention is
particularly well suited for post
treatment of labels and films and their associated adhesive(s) that have been
applied onto compound
curved surfaces.
[00270] Generally, in accordance with the preferred methods, heat is
applied to one or more
previously applied labels on containers at a particular time in a labeling
operation and within a certain
time period in order to thermally anneal the label film material after the
label has been applied to the
container. Preferably, the adhesive disposed between the label and the
receiving surface is also heated
to the same extent or substantially so as the label. The particular
temperatures to which the applied
labels are heated have been discovered to minimize label defects that
otherwise typically occur upon
aging such as darts, wrinkles, bubbles, lifts, etc. Such defects occurring
after label application are
generally and collectively referred to herein as "post-defects".
[00271] And, depending upon the particular labeling process, the post
heating treatment methods
may also enable one or more preheating operations to be eliminated. For labels
including heat shrink
materials, the preferred post application heating is performed after heat
shrinking of the label. Heat can
Page 63
CA 02750143 2016-08-31
be applied to labeled containers in a variety of methods such as by use of
infrared lamps, radiant
heaters, hot forced air ovens, shrink tunnels ...etc. The amount of heat is
generally determined by the
characteristics of the label material, the speed of the labeling process and
the amount of heat already
imparted into the label prior to the post heat section. For labels including
heat shrink materials, the
amount of heat also is determined by the shrink temperature of the material.
Nearly any type of
container having a label applied thereto can receive the treatment techniques
described herein. All of
these aspects are described in greater detail herein.
Preferred Treatment Methods
[00272] The preferred treatment methods involve heating a previously
applied label and adhesive to
a particular temperature, and at a specific time within or after a labeling
operation. Preferably, the
applied label and adhesive are at ambient temperature or approximately so, and
are heated to a
temperature of from about 30 C to about 150 C and more preferably, heated to a
temperature of from
about 50 C to about 100 C. Generally, heating of the applied label occurs
quickly, such as typically in less
than 5 seconds, preferably less than 3 seconds, and most preferably less than
1 second. The use of such
rapid heating times enables the treatment methods described herein to be
utilized in high speed
labeling operations.
[00273] In practice, achieving these particular temperatures in an applied
label can be accomplished
by exposing the applied label assembly to an environment having a temperature
of at least 100 C or
higher. Heating may be performed by any suitable method. Generally, heating
can be performed by
one or more heat transfer mechanisms such as conductive heating, convective
heating, radiant heating,
or combinations thereof. A wide array of heating equipment or devices can be
used to heat the applied
labels and associated adhesives. Non-limiting examples include, but are not
limited to, infrared lamps,
radiant heaters, hot forced air ovens, heated chambers, heated tunnels, heated
contact surfaces, and
the like. Preferably, heating is performed using radiant heaters in a chamber
or hot air guns in a
chamber, either with infrared (IR) sensors to measure the temperature of the
label upon exit. Heating
devices are well known in the art and readily available.
[00274] Preferably, the treatment process involves heating the label and
adhesive layer immediately
after application to a container or substrate. The term "immediately" as used
herein generally refers to
initiating heating of a label after application without delay such that
heating occurs following label
application. In practical terms, heating occurs preferably in less than 5
seconds after label application
and most preferably less than 1 second after label application. However, it
will be appreciated that the
Page 64
CA 02750143 2016-08-31
invention includes heating performed subsequent to label application, such as
after a time period of a
minute or more, and in certain applications even after a period of several
hours after label application.
Furthermore, it is contemplated that the heating techniques described herein
could be performed well
after label application such as up to 24 hours after label application. The
particular temperatures and
times largely depend upon the materials used in the label or film,
characteristics of the label, and the
adhesive.
[00275] Applied labels and adhesives treated in accordance with the
particular methods described
herein exhibit reduced defect rates, improved label retention and adherence,
and better aesthetics as
compared to corresponding applied labels not subjected to the methods.
Specifically, labels subjected to
the treatment techniques described herein, tend to remain in their as-applied
state and do not become
wrinkled, form darts, or exhibit lifting or separation along their edges or
the interface between label and
receiving surface. Accordingly, labels and adhesives subjected to the
treatment techniques of the
invention exhibit improved retention such as characterized by longer retention
periods and overall
stronger adherence to an underlying surface as compared to corresponding
labels not subjected to the
treatment techniques noted herein. The absence of defects such as wrinkles,
darts, bubbles, and/or lifts,
results in an improved appearance and a more aesthetically appealing label.
These characteristics are
desirable from a commercial perspective and particularly when the label is on
a container on display in a
retail environment.
[00276] Although not wishing to be bound to any particular theory, it is
believed that various internal
stresses within the polymeric label or film material are generated or
increased during label manufacture
and particularly during label application. Internal stresses in film materials
are particularly pronounced
during heat shrinking and/or application of heat shrink labels. Although the
relatively permanent bonds
provided by the label adhesive serve to retain the label in its initial as-
applied state, internal stresses in
the label material can result in subsequent distortion of the label and
movement from its as-applied
position. These effects are typically exhibited as label defects in the form
of wrinkles, darts, and the like.
Thus, in accordance with the invention, methods and systems for preventing
label post-defects are
provided. Generally, the methods involve comprising providing a substrate such
as a container, having a
polymeric label adhesively applied thereon. The methods also comprise, after
application of the label
and preferably immediately after adhesive application of the label, heating
the applied label to a
temperature that is sufficient to relieve at least a portion of the internal
stresses in the label material,
and thereby prevent or at least reduce label post-defects that would otherwise
occur.
Page 65
CA 02750143 2016-08-31
[00277] In accordance with the preferred embodiment methods described
herein, it has been
discovered that heating an applied label to a particular temperature and at a
particular point in a
labeling operation can sufficiently relieve stresses in the label material(s)
such that the noted label
defects do not otherwise occur. As noted, labels applied onto curved container
surfaces and especially
compound curved container surfaces, are prone to exhibit such defects. It is
surprising and unexpected
that these defects can be eliminated by the heating techniques described
herein. Furthermore, the
particular heating operations are performed such that no dimensional changes
occur in the label. This is
significant when using heat shrink materials. Moreover, the post-heating
operations described herein
can, if implemented in certain labeling operations, eliminate the need for one
or more preheating stages
typically used in known labeling processes.
Systems for Reducing Label Post-Defects
[00278] The present invention also provides various systems and related
equipment assemblies for
performing the noted methods and techniques described herein. Preferably, the
systems serve to
reduce and ideally, eliminate label post-defects. The systems generally
comprise an assembly for
adhesively applying a label to a container. Examples of label application
assemblies are provided in one
or more of the following US patents or published US patent applications:
4,192,703; 4,561,928;
4,724,029; 5,785,798; 7,318,877; 2005/0153427; and 2007/0113965. It will be
understood that in no
way is the present invention system limited to the use of one or more of these
representative labeling
assemblies. Instead, the present invention system for reducing label post-
defects can use nearly any
type of labeling equipment. The systems in accordance with the invention also
comprise one or more
heaters for heating the applied label immediately after adhesive application
of the label to the
container. The one or more heaters are preferably capable of heating the
applied labels from ambient
temperature to a temperature of from about 30 C to about 150 C within a time
period of less than
about 5 seconds. It will be appreciated that the present invention systems can
use heaters that perform
the noted heating of applied labels in time periods longer than 5 seconds.
Examples of suitable heaters
are those previously noted herein. Preferably, the systems and more.
particularly, the heaters are
capable of heating the noted labels to a temperature of from about 50 C to
about 100 C. Preferably,
the systems and more particularly, the heaters are capable of heating the
noted labels to the indicated
temperatures within a time period of less than 3 seconds and most preferably,
within a time period of
less than 1 second. Preferably, the heaters are radiant heaters. However, as
noted herein, a wide array
of heating devices can be used. The systems may also comprise one or more
temperature sensors such
Page 66
CA 02750143 2016-08-31
as infrared (IR) sensors to conveniently and accurately measure the
temperature of the label during and
after the heating operation.
Examples
[00279] Containers were labeled with polypropylene labels at a temperature
below which the labeled
containers would typically remain defect-free. All labels were applied without
defects at the time of
application. Labeled containers were then immediately placed in a 100 C oven
for various dwell times.
The final temperature of the labels was measured at the end of the oven aging.
Containers were then
inspected after 1 week aging at room temperature.
[00280] A control sample that was not exposed to a post-heat treatment
failed within 1 week due to
defect formation. All samples that were exposed to at least 30 seconds of
1000C post heat (squares)
passed inspection after 1 week aging. Based upon these results, it is believed
that an exit temperature
of at least 50 C is sufficient in the post heat step to prevent defects of
this particular label material.
[00281] Although the various treatment processes described herein have been
described in
conjunction with eliminating one or more heating steps prior to or during
label application, it will be
appreciated that the present invention also includes the use of the treatment
processes utilized in
conjunction with labeling operations that employ heating. Thus, the treatment
processes described
herein are contemplated for a host of labeling operations.
[00282] Although the present invention and its various preferred
embodiments have been described
in terms of applying labels, and particularly pressure sensitive shrink
labels, onto curved surfaces of
containers, it will be understood that the present invention is applicable to
applying labels, films, or
other thin flexible members upon other surfaces besides those associated with
containers. Moreover, it
is also contemplated that the invention can be used to apply such components
onto relatively flat planar
surfaces.
[00283] Additional details associated with applying pressure sensitive
labels, and particularly
pressure sensitive shrink labels, are provided in International Publication WO
2008/124581; US Patent
Application Publication 2009/0038736; and US Patent Application Publication
2009/0038737.
[00284] Additional details associated with heat transfer labeling
technology are provided in US Patent
4,610,744; US Patent 6,698,958; US Patent Application Publication
2008/0185093; US Patent Application
Publication 2007/0275319; US Patent Application Publication 2007/0009732; US
Patent Application
Publication 2005/0100689; International Publication WO 2004/050262;
International Publication WO
2005/069256; US Patent 7,758,938; US Patent 6,756,095; International
Publication WO 2002/055295;
Page 67
CA 02750143 2016-08-31
US Patent 6,228,486; US Patent 6,461,722; International Publication WO
2000/20199; International
Publication WO 2000/23330; US Patent 6,796,352; International Publication WO
2002/12071; US Patent
Publication 2007/0281137; and International Publication WO 2007/142970.
[00285] Many other benefits will no doubt become apparent from future
application and
development of this technology.
[00286]
[00287] As described hereinabove, the present invention solves many
problems associated with
previous type devices and methods. However, it will be appreciated that
various changes in the details,
materials and arrangements of parts or operations, which have been herein
described and illustrated in
order to explain the nature of the invention, may be made by those skilled in
the art without departing
from the principle and scope of the invention, as expressed in the appended
claims.
Page 68
