Note: Descriptions are shown in the official language in which they were submitted.
CA 02940187 2016-08-26
SYSTEMS AND PROCESSES FOR APPLYING SHRINK LABELS
Cross-Reference to Related Applications
[0001] The present application is a divisional application of CA
2,768,698 filed
July 27, 2010, and claims priority to U.S. Provisional Application No.
61/228,719 filed July 27,
2009; U.S. Provisional Application No. 61/299,165 filed January 28, 2010; and
U.S.
Provisional Application No. 61/296, 715 filed January 20, 2010.
Field of the Invention
[0002] The present invention relates to equipment and methods for
applying
shrink labels to a curved surface, and particularly to a compound curved
surface. The
present invention also relates to labeling processes and in particular,
applying pressure
sensitive heat shrink labels to containers. The present invention further
relates to
techniques for reducing label defects, improving label retention and label
adherence, and
improving aesthetics of an applied label. The invention is particularly
directed to application
of labels onto curved container surfaces and defect-free retention thereon.
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
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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. Direct screen printing is
another method for
applying indicia or other markings to 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.
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[0006] Other processes for applying pressure sensitive shrink labels are
known. In certain
applications, a label is applied onto a container, heated, and any resulting
defects then wiped to
minimize such defects. A potential problem exists with a separate heat and
wipe process with pressure
sensitive shrink labels where edge defects are initially formed and then
removed. Although the
formation of the edge defects typically occurs in the same general region of
the bottle, the defects are
not in the exact same spot, nor of the same size or occur in the same number.
These defects,
collectively referred to herein as "darts" can in certain instances, be shrunk
with heat. As these defects
shrink, the area of the label comprising the dart is reduced along with the
ink and print on top of the
label dart. The shrinkage of the dart will shrink the print as well cause
distortion of the print.
Depending on the size of the dart and print fidelity, the distortion might be
noticed and can in certain
cases, be significant. This distortion may limit the type or quality of print
in the shrink region of the
label. Therefore, avoiding the formation of darts entirely would be of great
benefit.
[0007] Accordingly, a need exists for a process in which a shrink label
could be applied to a
curved surface and particularly a compound curved surface without the
occurrence of darts or other
defects.
[0008] Labels are typically applied to containers or other receiving
surfaces by use of one or
more layers of adhesive on a face of the label, the container or receiving
surface, portions of label face,
container or surface, or combinations of these surfaces. Prior to or during
label application in which the
label is contacted with the receiving surface, heating is typically employed
to promote adherence of the
label. In certain labeling applications, the use of heat may be necessary such
as for operations utilizing
heat shrink materials or using heat activated adhesives.
[0009] However, currently known labeling processes using one or more
heating operations
have various drawbacks. For example, in processes in which labels and/or a
receiving substrate are
heated to some minimum temperature prior to or during label application, the
process line speed is
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often limited. This is due to the time required to heat the label and/or
substrate to the desired
temperature. Although many processes using a heating step prior to or
concurrently with labeling are
satisfactory, it would be beneficial to provide an alternative to such heating
operations so that the label
and/or substrate prior to label application, would not need to be heated or
heated to the same extent,
as currently known processes. By avoiding such heating operations, labeling
line speeds could be
increased.
[0010] Moreover, many label application processes utilize preheating
stages. These stages
typically include one or more heaters, conveyors, and sensing and control
systems, all of which are
costly, require installation and maintenance, and increase process complexity.
Accordingly, it would be
beneficial to eliminate such preheating stages.
[0011] Depending upon the label materials, their characteristics, and
the colors and
patterns appearing on the label, certain heating operations may induce non-
uniform physical changes or
other distortions in the label. For example, it is known that use of infrared
heaters may cause uneven
label shrinkage of heat shrink labels containing one or more regions of black
or other dark colored
regions. This is due to greater absorbance of infrared radiation by the black
colored regions and thus
greater heating as compared to lighter colored, translucent, or transparent
regions of the label.
Accordingly, it would be desirable to avoid these consequences while still
using heat shrink labels having
black or other dark regions.
[0012] Certain labeling equipment utilizes members that contact labels
during application.
These flexible members may serve to promote adherence of the label or to
"wipe" the label after initial
application. Typically, these members are formed from elastomers. Exposure to
heat or heat inducing
radiation may be detrimental to the elastomeric member. This in turn may
reduce the life of the
member or otherwise alter its flexibility or other desirable properties.
Therefore, it would be beneficial
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to avoid heating prior to or during labeling operations to thereby avoid
exposing such members to
damaging heat or heat-inducing radiation.
[0013] 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.
Summary of the Invention
[0014] The present invention provides advances in various phases of
labeling operations.
For purposes of describing the invention and its various embodiments, the
invention will be described in
terms of the following process phases. In a first process phase, a label is
contacted and applied to a
container by use of a flexible member. Alternatively, or in combination, one
or more regions of the label
are wiped or otherwise contacted by a moving member. And in a second process
phase, the labeled
containers are subjected to one or more post-heat operations.
[0015] 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 pressure sensitive shrink labels to
containers, and particularly containers
with compound curved surfaces, without the occurrence of darts or other
defects.
[0016] Regarding the first phase and using a flexible member, the
present invention
provides a label processor for contacting, and preferably concurrently heating
and contacting, a label to
a container. The processor comprises a rigid frame defining a first face and
an oppositely directed
second face. The frame defines an opening extending between the first and the
second faces. The label
processor further comprises 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
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the second face of the frame. The flexible member defines 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. The label processor may
optionally comprise a
heat source disposed within the interior hollow region of the flexible member
for heating the outer
surface of the flexible member.
[0017] In another aspect, the present invention provides a process for
applying a label to
an article. The process comprises providing a label processor including (i) a
rigid frame defining a first
face and an oppositely directed second face, and (ii) a flexible member
projecting outward from the
second face of the frame. The flexible member defines an outer surface for
heating and contacting a
label. The flexible member also defines an interior hollow region accessible
from the first face of the
frame. The process further comprises heating the outer surface of the flexible
member. The process
additionally comprises providing an article and a label at least partially
contacted thereto, wherein
portion(s) of the label contacting the article define attached region(s) and
portion(s) of label free from
contact with the article define unattached region(s). And, the process
comprises progressively
contacting the label with the heated outer surface of the flexible member such
that the flexible member
first contacts an attached region of the label and subsequently contacts and
heats an unattached region
to thereby fittingly apply the unattached region of the label to a complex
curved surface of the article.
[0018] In still another aspect, the present invention provides an
assembly for applying
labels to a collection of containers. The assembly comprises a collection of
label processors, each
processor including (i) a rigid frame defining a first face and an oppositely
directed second face, (ii) a
flexible member projecting outward from the second face of the frame, the
flexible member defining an
outer surface for heating and contacting a label, the flexible member defining
an interior hollow region
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accessible from the first face of the frame and (iii) a heat source disposed
within the interior hollow
region of each flexible member.
[0019] In still a further aspect, the present invention provides a label
processing system for
contacting a label to a container. The system comprises a label processor for
concurrently heating and
contacting a label to a container. The processor includes a rigid frame
defining a first face and an
oppositely directed second face. The frame also defines an opening extending
between the first and the
second faces. The label processor also includes 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 a label. The flexible member 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 system also
comprises at least one label for heating and contacting to a container by the
label processor.
[0020] The difficulties and drawbacks associated with previously known
labeling techniques
and associated equipment are overcome in the present systems and methods for
selectively applying a
label onto a moving container, and particularly a heat shrink label using
pressure sensitive adhesive in
which the label is initially partially contacted with the container so that
label flags are produced, which
can subsequently be fully adhered to the moving container.
[0021] Regarding the first phase and in the alternate strategy using a
wiping member, the
present invention provides an assembly for selectively contacting one or more
regions of a label to a
moving container. The assembly comprises a moveable frame, the frame including
at least one frame
member pivotally moveable about a pivot axis. The assembly also comprises a
wiper member engaged
to the frame member and moveable therewith, the wiper member including a
wiping element for
contacting a label. The assembly additionally comprises a cam follower member
affixed to the frame
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and moveable therewith. Movement of the cam follower corresponds to movement
of a container and
label to be contacted by the wiping element. The wiping element selectively
contacts the label to the
moving container.
[0022] In another aspect, the present invention provides a system for
partially applying a
label to a moving container. The system comprises a conveyor for transporting
containers equally
spaced and aligned thereon. The system also comprises a wiping assembly
disposed proximate to the
conveyor. The wiping assembly includes a moveable frame, the frame pivotally
moveable about a pivot
axis. The wiping assembly also includes a wiper member affixed to the frame
and positionable such that
the wiper member can be placed into contacting proximity with a container
transported by the conveyor
by selectively pivoting the frame. And, the wiping assembly additionally
includes a cam follower affixed
to the frame and operated such that movement of the conveyor results in
reciprocating pivotal
movement of the cam follower, the frame, and the wiper member. The cam
follower is configured such
that as a container on the conveyor is transported to the wiping assembly and
proximate therewith, the
wiper member is positioned so as to contact a label positioned between the
container and the wiper
and apply a force to the label to thereby further contact the label with the
container.
[0023] In another aspect, the present invention provides a labeling
system for producing a
labeled container. The system comprises a label dispenser adapted to
selectively position a label
alongside a moving container. The system also comprises a label for
administration by the label
dispenser. The system also comprises an assembly for selectively contacting
one or more regions of a
label positioned alongside a container by the label dispenser. The assembly
includes a moveable frame
which includes at least one frame member pivotally moveable about a pivot
axis. The assembly also
includes a wiper member engaged to the frame member and moveable therewith.
The wiper member
includes a wiping element for contacting the label. The assembly further
includes a cam follower affixed
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to the frame and moveable therewith. Movement of the cam follower corresponds
to movement of a
container, such that the wiping element selectively contacts the label onto
the moving container.
[0024] In yet another aspect, the present invention provides a method of
selectively
contacting a label to a moving container. The method comprises providing a
moveable frame assembly,
the frame including at least one frame member pivotally moveable about a pivot
axis. The method
further comprises affixing a wiper member to the frame. The method
additionally comprises positioning
the frame such that upon pivoting the frame about the pivot axis, the wiper
member is displaced
between (i) a first position in which the wiper member is in contacting
proximity of a path of the moving
container, and (ii) a second position in which the wiper member is spaced from
the path of the moving
container. The method further comprises providing a cam follower on the frame
assembly. The method
also comprises positioning the label between the container and the wiper
member. And, the method
also comprises configuring the cam follower and movement of the container such
that the frame is
pivoted so that when the moving container is alongside the wiper member, the
wiper member is
displaced to the first position so that the wiper member contacts the label to
the container.
[0025] The difficulties and drawbacks associated with previously known
processes and
systems are overcome in the present methods and systems for various post
treatment processes
involving applied labels and in particular, labels applied to containers using
pressure sensitive adhesives.
Implementation of the methods and use of the systems described herein can
reduce and in certain
applications, eliminate various preheating operations otherwise required in
labeling operations. The
methods and systems described herein provide defect-free labeled containers or
other substrates.
[0026] Regarding the second phase and in still another aspect, the
present invention
provides a method for preventing label post-defects. The method comprises
providing a substrate
having a polymeric label adhesively applied to the substrate. The method also
comprises immediately
after adhesive application of the label to the substrate, heating the label to
a temperature sufficient to
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relieve at least a portion of internal stresses within the polymeric label
material and thereby prevent
label post-defects.
[0027] In another aspect, the present invention provides a method for
improving label
retention after adhesive application of the label to a substrate. The method
comprises, immediately
after adhesive application of a label to a substrate, heating the label and
the adhesive to a temperature
of at least 30 C.
[0028] In another aspect, the present invention provides a method for
preventing label
defects in a label applied onto a container. The method comprises providing a
container having an
exterior surface and providing a label. The method also comprises adhesively
applying the label to the
exterior surface of the container by use of an effective amount of adhesive
disposed between the label
and the exterior surface of the container. And, the method further comprises
immediately after
application of the label to the surface, heating the applied label and the
adhesive to a temperature of at
least 30 C within a time period less than about 5 seconds.
[0029] In yet another aspect, the present invention provides a method
for reducing label
defects occurring after application of an adhesively applied label to an
exterior surface of a container.
The method comprises immediately after application of the label to the
exterior surface of the
container, heating the label and the adhesive to a temperature of from about
50 C to about 100 C
within a time period of less than about 5 seconds.
[0030] In still another aspect, the present invention provides a system
for reducing label
post-defects. The system comprises an assembly for adhesively applying a label
to a container. And, the
system comprises one or more heaters for heating the applied label immediately
after application to the
container. The heaters are capable of heating the applied label from ambient
to a temperature of from
about 30 C to about 150 C, within a time period of less than 5 seconds.
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[0031] 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
[0032] Figure 1 is an illustration of a representative container having
a compound curved
surface.
[0033] 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.
[0034] 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.
[0035] Figure 4 is a schematic perspective view of a preferred
embodiment flexible
member in accordance with the present invention.
[0036] Figure 5 is a side view of the flexible member shown in Figure 4.
[0037] Figure 6 is a front view of the flexible member shown in Figures
4 and 5.
[0038] 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.
[0039] Figure 8 is another front perspective view revealing an interior
region of the flexible
member, frame assembly, and enclosure depicted in Figure 7.
[0040] Figure 9 is a rear perspective view of the flexible member, frame
assembly, and
enclosure of Figures 7 and 8.
[0041] Figure 10 is a cross sectional view of the flexible member, frame
assembly, and
enclosure taken across line AA in Figure 9.
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[0042] Figure 11 is a front view of the preferred flexible member and
another preferred
embodiment frame assembly in accordance with the present invention.
[0043] Figure 12 is a perspective view of the preferred embodiment frame
assembly shown
in Figure 11 without the flexible member.
[0044] 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.
[0045] Figure 14 is a top view of the container and partially adhered
label depicted in
Figure 13.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] Figure 20 is a perspective view illustrating deformation of the
flexible member
resulting from contact with a container having a curved outer contour.
[0052] Figure 21 is a preferred assembly of flexible members and frame
assemblies for
concurrently applying multiple labels onto multiple containers.
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[0053] Figure 22 is a top elevational view of a preheating assembly for
use with the
assembly in Figure 21.
[0054] Figure 23 is a top elevational view of the assembly depicted in
Figure 21 with
additional components.
[0055] Figure 24 is a schematic front view of another preferred
embodiment flexible
member in accordance with the invention.
[0056] Figure 25 is a schematic front view of yet another preferred
embodiment flexible
member in accordance with the invention.
[0057] Figure 26 is a front view of representative guides corresponding
to the shape of a
container to be labeled.
[0058] Figure 27 is a perspective view of a preferred embodiment quick
change assembly
having a flexible member in accordance with the invention.
[0059] Figure 28 is a perspective view of a collection of quick change
assemblies according
to the invention.
[0060] Figure 29 is a front view of the collection of assemblies
depicted in Figure 28.
[0061] Figure 30 is a front view of a collection of quick change
assemblies, each using. a
different sized bladder.
[0062] Figure 31 is a perspective view of a representative container and
partially applied
label.
[0063] Figure 32 is a top planar view of the container and label
depicted in Figure 31.
[0064] Figure 33 is a perspective view of a preferred embodiment wiping
assembly in
accordance with the present invention.
[0065] Figure 34 is a perspective view of a preferred embodiment wiper
member used in
the wiping assembly of Figure 33.
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[0066] Figure 35 illustrates the preferred embodiment wiping assembly
applying regions of
a label to a container.
[0067] Figures 36 and 37 schematically illustrate a configuration of a
container and partially
contacted label.
[0068] Figures 38 and 39 schematically illustrate another configuration
of a container and
partially contacted label.
[0069] Figures 40 and 41 schematically illustrate another configuration
of a container and
partially contacted label.
[0070] Figures 42-44 and 46-49 schematically depict a preferred
embodiment process in
accordance with the present invention.
[0071] Figure 45 illustrates an undesirable state that can potentially
occur during a labeling
operation.
Detailed Description of the Embodiments
[0072] 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 described in
terms of applying labels
or films 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 shrink labels onto curved
container surfaces. And, the
invention is also particularly directed to applying labels such as shrink
labels onto compound curved
surfaces of various containers.
[0073] 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
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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.
Application of Label Using Flexible Members
[0074] 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.
[0075] 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
[0076] 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
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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.
[0077] 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.
[0078] 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
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.
[0079] 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.
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[0080] 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.
[0081] 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.
[0082] 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
17
CA 02940187 2016-08-26
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.
[0083] 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.
[0084] 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
18
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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 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.
[0085] 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.
[0086] 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.
[0087] 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.
19
CA 02940187 2016-08-26
[0088] 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.
[0089] 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 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.
[0090] 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
CA 02940187 2016-08-26
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.
[0091]
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 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
21
CA 02940187 2016-08-26
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.
[0092] 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.
[0093] 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.
[0094] More precisely called polymerized siloxanes or polysiloxanes,
silicones are mixed
inorganic-organic polymers with the chemical formula [R2S10],, 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.
[0095] In some cases, organic side groups can be used to link two or
more of these -Si-0-
backbones together. By varying the -51-0- 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.
[0096] A particularly preferred silicone for use in forming the flexible
member is a
commercially available silicone elastomer designated as Rhodorsir V-240.
Rhodorsir 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
22
CA 02940187 2016-08-26
(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:
[0097] Table 1 - Formulation of Rhodorsir
Component CAS Reg Number Percentage
Methylvinylpolysiloxane
Quartz (S102) 14808-60-7 15 - 40
Filler
Calcium Carbonate 471-34-1 1 - 5
Platinum Complex <0.1
[0098] 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).
[0099] For embodiments in which the flexible member is formed from a
silicone elastonner,
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.
[00100] 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
23
CA 02940187 2016-08-26
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 Rhodorse 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 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.
[00101] 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
[00102] 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.
[00103] 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
24
CA 02940187 2016-08-26
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.
[00104] 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.
[00105] 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.
[00106] 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
CA 02940187 2016-08-26
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.
[00107] 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.
[00108] 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.
[00109] 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 oriented rails upon which the guides can be selectively positioned
and engaged. The use of
26
CA 02940187 2016-08-26
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.
[00110] 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
necessary.
[00111] 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
27
CA 02940187 2016-08-26
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.
[00112] 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.
[00113] 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 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
[00114] 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,
28
CA 02940187 2016-08-26
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.
[00115] 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.
[00116] 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
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.
[00117] 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.
[00118] 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
29
CA 02940187 2016-08-26
the transverse (or cross) direction (TD) of about 138,000,000 N/nn 2 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.
[00119] 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.
[00120] 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.
[00121] 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 honnopolymer, 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, 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
CA 02940187 2016-08-26
wherein the first listed cyclic olefin is the major constituent of the
copolymer, and mixtures of any of
the foregoing olefin polymers.
[00122] 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.
[00123] 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 50 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.
[00124] 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.
[00125] 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
31
CA 02940187 2016-08-26
polytetrafluoroethylene powder. Anti-static agents useful in the present
invention include alkali metal
sulfonates, polyether-modified polydiorganosiloxanes, polyalkylphenylsiloxanes
and tertiary amines.
[00126] 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.
[00127] 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
[00128] 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, lnterscience
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.
[00129] 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.
[00130] 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
32
CA 02940187 2016-08-26
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.
[00131] 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.
[00132] 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
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).
The disclosures of these patents as they relate to acrylic adhesives are
hereby incorporated by
reference.
[00133] 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.
33
CA 02940187 2016-08-26
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%.
[00134] 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, and this patent is
hereby incorporated by a reference for its disclosure of such hot melt
adhesives that are described more
fully below.
[00135] 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), 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.
[00136] 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 copolymers. The latter rubbers may be obtained from the
corresponding
unsaturated polyalkylene moieties such as polybutadiene and polyisoprene by
hydrogenation thereof.
34
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[00137] 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, nnultiblock, 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.
[00138] 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.
[00139] 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.
CA 02940187 2016-08-26
[00140] 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.
[00141] 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-
methylstyrene, etc.
[00142] 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.
[00143] 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.
[00144] 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.
[00145] 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 (SIS), alpha-methylstyrene-
butadiene-alpha-
36
CA 02940187 2016-08-26
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.
[00146] 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.
[00147] 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.
[00148] 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
37
CA 02940187 2016-08-26
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).
[00149] 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 G1650
and Kraton G1652.
[00150] In another embodiment, the selectively hydrogenated block
copolymer is of the
formula: 13,(AB)0A, 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.
[00151] 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
38
CA 02940187 2016-08-26
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.
[00152] 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-dinnethy1-2,5-di(t-butylperoxy) hexane
by a melt reaction in a
twin screw extruder.
[00153] Examples of commercially available maleated selectively
hydrogenated copolymers
of styrene and butadiene include Kraton FG1901X, FG1921X, and FG1924X, often
referred to as
maleated 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.
[00154] 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.
[00155] 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
39
CA 02940187 2016-08-26
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.
[00156] 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 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 C9 (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.
[00157] 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 Irgafos
168 and lrganox 565 available from Ciba-Geigy, Hawthorne, N.Y. Cutting agents
such as waxes and
surfactants also may be included in the adhesives.
CA 02940187 2016-08-26
[00158] 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.
[00159] 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.
[00160] 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.
[00161] 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
41
CA 02940187 2016-08-26
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.
[00162] 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.
[00163] 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.
[00164] 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
42
CA 02940187 2016-08-26
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).
[00165] 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.
[00166] 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.
[00167] 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 nnethacrylic 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
43
CA 02940187 2016-08-26
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.
[00168] 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
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.
[00169] 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.
44
CA 02940187 2016-08-26
[00170] The protective layer may comprise polyolefins, thermoplastic
polymers of ethylene
and propylene, polyesters, polyurethanes, polyacryls, polymethacryls, epoxy,
vinyl acetate
homopolymers, co- or terpolymers, iononners, and mixtures thereof.
[00171] 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-tetrannethy1-4-
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.
[00172] 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
lrganox 1010, lrganox 1076 or lrgafos 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.
[00173] 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
CA 02940187 2016-08-26
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
[00174] 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 art 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
46
CA 02940187 2016-08-26
occurs, i.e. progressively outward from a central location, is believed to be
a significant factor in the
resulting defect-free label application.
[00175] 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 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.
[00176] 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/m2. It is to be appreciated
however that the present
invention includes the use of label application forces greater than or lesser
than these amounts.
[00177] 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
47
CA 02940187 2016-08-26
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.
[00178] 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.
[00179] 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
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.
[00180] 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
48
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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.
[00181] 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
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.
49
CA 02940187 2016-08-26
[00182] 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
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.
[00183] 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.
[00184] 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
CA 02940187 2016-08-26
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
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.
[00185]
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
51
CA 02940187 2016-08-26
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.
[00186] 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 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.
[00187] 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
52
CA 02940187 2016-08-26
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.
[00188] 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.
[00189] 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.
[00190] 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 the outer surface of the flexible member 30. The optional apertures 91
may serve to promote
53
CA 02940187 2016-08-26
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.
[00191] 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.
[00192] 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.
[00193] 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.
[00194] 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
54
CA 02940187 2016-08-26
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.
[00195]
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 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 affixnnent 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
CA 02940187 2016-08-26
secondary guides 170 to limit further deformation outward by the sidewalls 34
of the flexible member
30.
[00196] 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.
[00197] 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 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.
56
CA 02940187 2016-08-26
[00198] 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 distalnnost 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.
[00199] 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 the 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/nn2. 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.
[00200] 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
57
CA 02940187 2016-08-26
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 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.
[00201] 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.
[00202] 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,
58
CA 02940187 2016-08-26
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
Y2 towards the targeted containers on the conveyor 240. Movement of each set
220, 230 continues as
contact occurs 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 Y1 direction that the beam
begins to move in the X1direction in preparation for the next set of targeted
containers.
[00203] 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.
[00204] 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
59
CA 02940187 2016-08-26
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.
[00205] 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
the labels are heated, depends upon numerous factors including for example the
heat shrink activation
temperature of the labels.
[00206] 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.
CA 02940187 2016-08-26
[00207] 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.
[00208] 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.
[002091 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
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shown in Figure 26. The guides 662 are each preferably shaped or contoured to
match, follow, or
generally 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.
[00210] 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.
[00211] 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.
[00212] Figures 28 and 29 illustrate a plurality of quick change systems
700 collectively
referred to as a labeling group 800. Figure 28 is a perspective view and
Figure 29 is a front elevational
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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 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.
[002131 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
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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.
[00214] 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
[00215] 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 described herein have particular significance in labeling
operations using heat shrink
labels and pressure sensitive adhesives.
[00216] 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.
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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."
[00217] 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.
[00218] The present invention provides systems and 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.
[00219] 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.
CA 02940187 2016-08-26
[00220] 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.
[00221] 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.
[00222] 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
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CA 02940187 2016-08-26
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 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.
[00223] 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.
[00224] 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
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CA 02940187 2016-08-26
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.
[00225] 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 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
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CA 02940187 2016-08-26
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.
[00226] 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.
[00227] 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
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CA 02940187 2016-08-26
movement of 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.
[00228] 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 one 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
CA 02940187 2016-08-26
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
amount C1, 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
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CA 02940187 2016-08-26
prior to subjecting a container and partially attached label to a heated
flexible member for heat
shrinking and final label adherence to the container.
[00229] 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.
[00230] 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.
[00231] 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
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CA 02940187 2016-08-26
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.
[00232] 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.
[00233] 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.
[00234] 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
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CA 02940187 2016-08-26
preferred 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.
[00235]
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
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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.
[00236] 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 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.
[00237] 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,
CA 02940187 2016-08-26
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.
[00238] 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.
[00239] 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 91015 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.
[00240] 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 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.
[00241] 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,
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CA 02940187 2016-08-26
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.
[00242] 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.
[00243] 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.
[00244] 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.
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CA 02940187 2016-08-26
[00245] 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 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.
[00246] 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.
[00247] 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
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CA 02940187 2016-08-26
the pivot axis such that the wiper member is displaced or moved away from the
path of the moving
container.
[00248] 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.
[00249] 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.
[00250] 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
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CA 02940187 2016-08-26
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.
[00251] 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
[00252] 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 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
CA 02940187 2016-08-26
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.
[00253] 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.
[00254] 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.
[00255] 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".
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CA 02940187 2016-08-26
[00256] 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 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
[00257] 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.
[00258] 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,
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CA 02940187 2016-08-26
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.
[00259] 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 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.
[00260] 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
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CA 02940187 2016-08-26
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.
[00261] 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.
[00262] 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
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CA 02940187 2016-08-26
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
[00263] 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
CA 02940187 2016-08-26
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
as infrared (IR) sensors to conveniently and accurately measure the
temperature of the label during and
after the heating operation.
Examples
[00264] 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.
[00265] 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 100 C 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.
[00266] 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.
[00267] 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,
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CA 02940187 2016-08-26
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.
[00268] Additional details associated with applying pressure sensitive
labels,
and particularly pressure sensitive shrink labels, are provided in WO
2008/124581; US
2009/0038736; and US 2009/0038737.
[00269] Many other benefits will no doubt become apparent from future
application and development of this technology.
[00270] 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 scope
of the appended claims.
87
