Note: Descriptions are shown in the official language in which they were submitted.
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METHODS FOR FOIL STAMPING PARTS HAVING ASYMMETRICAL EDGES
FIELD OF THE INVENTION
The present invention is directed to methods for foil stamping parts that have
asymmetrical edges, wherein the foil is a decorative or protective coating.
BACKGROUND OF THE INVENTION
Foil stamping on parts for decorative or protective purposes is known. Foil
for decorating
and protecting parts is also known. The foil is typically a thin, multi-layer
sheet or ribbon. The
layers typically comprise a thin film carrier, a volatile release substance, a
colorant or protective
coating, a metal layer, and an adhesive. But prior machines and methods of
using these machines
are typically used on flat, symmetrical surface. For example, it is know how
to cover cylindrical
and frusta conical part by simply rolling a mated mandrel over them. The foil
is fed between the
part and the mandrel and adheres evenly to the part. But these systems do not
work parts with
asymmetrical geometry as the mandrel cannot maintain constant contact with the
asymmetrical
part.
Moreover complex shapes can be foil stamped by creating a stamp that is the
negative
image of the part to be stamped. While virtually any shape can be stamped in
this manner there
is one inherent drawback to this process. The foil is flat and when stamped
onto a complex shape
it necessarily must stretch and fold over onto itself resulting into uneven
coverage. Accordingly,
there are geometrical limitations to this type of foil stamping.
Soft, deformable stamps are also used to press foil or a label onto an
asymmetrical
surface. Soda bottles are often labeled in this manner. But these soft,
deformable stamp pads
suffer from the same defects as discussed above. When a flat foil is pressed
onto a curved
surface it must conform to the surface by folding and stretching. This
invariably leads to uneven
coverage.
There exists a need for apparatuses and methods that overcome these and other
problems
associated with prior methods and apparatuses. More specifically there exists
a need for an
apparatus that can apply a thin decorative or protective film on the surface
of a part wherein the
part has an asymmetrical portion to it.
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SUMMARY OF THE INVENTION
The present invention is directed to a method for coating a part comprising an
asymmetrical edge comprising the steps of: attaching the part to a part
holder; placing a film
between the part and a mandrel; rolling the part over the mandrel such that
the asymmetrical edge
of the part contact the film; and, moving one or both of the mandrel and the
part holder in an
angular relationship to one another as the angle of the part's asymmetrical
edge changes. Further
there is provided a film dispenser and a film retriever which move co-
operatively in at least two
dimensions with respect to the part holder. The film can have a first edge and
a second edge, and
wherein the film is a decorative coating, a protective coating or combinations
of these. The film
is preferably a multi-layered film comprising a carrier, a release compound, a
metallic foil and an
adhesive.
The present invention provides methods that can coat parts with asymmetrical
edges with
a decorative or protective foil in a fast, economical, method that results in
a uniform coating.
The present methods do not suffer from prior methods and apparatuses that
stretched or pulled
the foil over irregularly shaped parts causing visible striations in the foil.
The ability to coat
irregularly shaped parts gives designers substantial new freedom in design.
Not only can new
part shapes be produced and decorated or protected, but the addition of
different surfaces allow
for multiple decorations on one part. These and other benefits of the present
invention will be
apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly
claiming the present invention, it is believed the same will be better
understood from the
following description taken in conjunction with the accompanying drawings in
which:
FIG. 1 is a cross sectional view of a part having an asymmetrical edge;
FIG. 2 is a cross sectional view of a part having an asymmetrical edge;
FIG. 3 is a mandrel, part and part holder of the prior art;
FIG. 4 is a mandrel, part, and part holder according to the present invention;
FIG. 5 is an apparatus according to the present invention;
FIG. 6 is a jar having a lid with an asymmetrical edge according to the
present invention;
FIG. 7 is a lid having an asymmetrical edge that is decorated differently than
the
remaining surfaces of the lid according to the present invention;
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FIG. 8 is a clear over cap having an asymmetrical edge according to the
present
invention;
FIG. 9 is a jar with a pump and a clear over cap with an asymmetrical edge
according to
the present invention; and,
FIG. 10 is a jar with a pump having an asymmetrical edge according to the
present
invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention may be understood more readily by reference to the
following
detailed description of illustrative and preferred embodiments. It is to be
understood that the
scope of the claims is not limited to the specific ingredients, methods,
conditions, devices, or
parameters described herein, and that the terminology used herein is not
intended to be limiting
of the claimed invention. Also, as used in the specification, including the
appended claims, the
singular forms "a," "an," and "the" include the plural, and reference to a
particular numerical
value includes at least that particular value, unless the context clearly
dictates otherwise. When a
range of values is expressed, another embodiment includes from the one
particular value and/or
to the other particular value. Similarly, when values are expressed as
approximations, by use of
the antecedent basis "about," it will be understood that the particular values
form another
embodiment. All ranges are inclusive and combinable.
As used herein, a "part" can be a container, for example, a bottle, jar, over
pack, and the
like, a lid, for example, a container cap, an over cap, and the like, a
consumer product, for
example, a razor, a tooth brush, a powered brush, a skin care device, a pump,
an electric razor,
an appliance, and the like. Parts can be made from any of the known plastics
and other
polymeric compositions, naturally occurring compounds like rubber, metals, and
other materials
of construction know to those skilled in the art. Likewise, parts can be
manufactured be methods
known to those skilled in the art. Molding and high gloss molding are
preferred examples of part
manufacture, while stamping, thermo forming and the like are also acceptable
methods of
forming the parts of the present invention.
As used herein "a part having an asymmetrical edge" is best defined by
reference to
Figures 1 and 2. Figure 1 is a cross sectional view of a generally circular
lid 22 for a jar, bottle or
the like according to the present invention. More specifically, in Figure 1,
lid 22 has a top edge
12 a first angled edge 14 and a second angled edge 16. Lid 22 further
comprises side wall 18,
threads 20, and bottom 24. A line 19 drawn parallel to bottom 24 is
intersected by line 21 drawn
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parallel to first angled edge 14 to form angle [3. Likewise, a line 23 drawn
parallel to second
angled edge 16 intersects line 19 to form angle a. Therefore, to determine if
a part has an
asymmetrical edge, vertical cross sections are taken through the center of the
part and a and 13 are
calculated. A part has an asymmetrical edge when at least one vertical cross
section through the
center of the part results in a is not equal to [3. Preferably a is not equal
to 13 by at least 30, more
preferably at least about 50, and even more preferably at least about 100. It
is understood that
either a or 13 can equal 90 . This will occur when there is no angled edge
(that is, when top edge
12 meets side wall 18 directly), but if the other angle is greater than or
less than 90 , then there is
an asymmetrical edge, albeit on only a portion of the part.
Turning now to Figure 2, which is a cross sectional view of a generally
circular lid 32 for
a jar, bottle or the like according to the present invention. More
specifically, in Figure 2, lid 32
has a top edge 42 a first angled edge 34 and a second angled edge 36. Lid 32
further comprises
side wall 38, threads 40, and bottom 44. First angled edge 34 and second
angled edge 36 are
concave and convex, respectively. Figure 2 illustrates that none of the edges
of the present
invention need be flat. Angles a' and p' can still be calculated as discussed
above. Angle p' can
be measured by using the exterior intersection point 31 of first angled edge
34 and side wall 38
and exterior intersection point 33 between first angled edge 34 and top edge
42. A line 49 drawn
parallel to bottom 44 is intersected by line 51 drawn through exterior
intersection point 31 and 33
to form angle p'. Likewise, a line 53 drawn through exterior intersection
points 35 and 37
intersects line 49 to form angle a'.
As used herein the term "film" is generically used to describe any thin sheet
like material
that has multiple layers, at least one of the layers being deposited on the
part. The deposited
layer can be a protective, decorative coating or the like. Metal, color,
labels, decals, prints,
plastics and many more materials can be applied to the parts of the present
invention by films.
Exemplary films that may be suitable for use in the present invention are
shown and described in,
for example, US Patent Application 2009/0286054, published November 19, 2009
to Meiki, et
al., US Patent Application 2008/0063863, published March 13, 2008, to Colella,
et al., and US
Patent 7,410, 551, issued August 12, 2008, to Bethune.
While different films can be used for different end results, a typical film
will include a
carrier, a release compound, the deposited layer and an adhesive. The carrier
holds the layer to
be deposited and after deposition the carrier can be retrieved, for example
taken up by the film
retriever. The carrier is often a thin sheet of plastic or other inexpensive
material that can
withstand the heat, pressure, or both of the deposition process. The release
compound is
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typically a liquid, gel, or semi-solid material that allows the carrier to
pull away easily from the
deposited layer without taking any of the deposited layer with it. Preferably
the release
compound is volatile such that when the carrier is pulled away, the release
compound simply
evaporates. Alternatively, a non-volatile release compound can be washed or
wiped off in a post
5 deposition step.
The deposited layer can be any number of materials and can itself encompass
multiple
layers. A thin layer of vacuum metalized metal is a popular choice for both
decoration and
protection. Often a color layer will be added to the metal layer. Metal films
can be produced by
other methods as well and can be as thick or thin as the desired outcome
requires. Obviously,
thinner deposited layers will be more economical and have greater flexibility,
but thicker layers
will be more durable and show less deviation in color when deposited. Finally,
the adhesive
simply serves to adhere the deposited layer to the part. Adhesives are well
known to the art, and
they can be activated by temperature, pressure, an activating compound or all
of these. In the
case of a fast setting epoxy, the part may be coated with one chemical of the
epoxy, with the
other being on the film. When the film contacts the part a reaction occurs and
the adhesive layer
is formed. In most cases the adhesive is simply activated by the pressure and
or heat between the
mandrel and the part. Necessarily, the carrier side of the film is in contact
with the mandrel,
while the adhesive and deposited layer side of the film is in contact with the
part.
Turning now to Figure 3 which is a prior foil stamping operation shown to
highlight the
differences and advantages of the present invention. In Figure 3 there is a
rotatable mandrel 60
attached to mandrel holder 61. Part 63 is shown held in place by part holder
66. Part 63 has a
flat side wall 65 that rotates in the opposite direction as mandrel 60. Film
62 is fed between
mandrel 60 and the flat side wall 65 of part 63 and is in contact with both.
As can be seen, the
angle between mandrel 60 and part 63 never changes. This allows film 62 to
move laterally only
without ever being twisted or forced to move outside of one plane of motion.
This configuration
puts minimal, to no stress on the film and generally results in good coverage.
This system is
known to work on symmetrical frusta conical parts as well. This simplistic
system, however,
does not work for parts that have asymmetrical edges.
Figure 4 illustrates a schematic representation of an apparatus for coating a
part
comprising an asymmetrical edge according to the present invention. Apparatus
69 has a
mandrel 70 that rotates and is attached to a mandrel holder 71. Part holder 76
holds part 73
which has asymmetrical edge 80. Film 72 is disposed between mandrel 70 and
part 73. Part 73
rotates in the opposite direction as mandrel 70. As will be explained in
further detail, one or both
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of mandrel 70 and part holder 76 move in an angular relationship to the other.
In Figure 4 part
holder 76 rests on plate 81 which is attached to mandrel holder 71 via hinge
82. This is just one
way of accomplishing the necessary angular motion of the present invention.
The mandrel and
part holder need not be connected, as those skilled in the art will appreciate
that the angular
movement can be controlled remotely by a computer controlling the part holder,
the mandrel or
both in a preprogrammed manner, for example with servo motors, pneumatic
motors and the like.
Mandrels suitable for use in the present invention can be frusta conical in
shape (see, for
example mandrel 69, Figure 4), cylindrical (see, for example mandrel 102,
Figure 5), or other
generally symmetrical shape. Likewise, the mandrel can be solid or deformable.
By deformable
it is meant that the mandrel can conform to an irregular shape, for example
concave or convex.
A deformable mandrel would be used to coat, for example, the first and second
angled edges, 34
and 36 respectively, of part 32, Figure 2. Deformable mandrels are useful when
coating part with
raised or lowered indicia, for example when a product name, Trade Mark, or
logo are molded
directly into the part to be decorated.
Figure 5 is a slightly more detailed schematic of an apparatus 90 of the
present invention.
Part 92 is shown having asymmetrical edge 94, side wall 96 and top edge 98,
and is attached to
part holder 100. Mandrel 102 is shown attached to mandrel holder 104 and also
shown is mandrel
heater 106. Mandrel heater 106 is used when the adhesive layer of the film is
heat activated, it is
not required for pressure sensitive adhesive, epoxies and the like. Film 108
is shown attached to
film dispenser 110 and film retriever 112. Film 108 is shown a roll, but in
its simplest form film
108 has a first edge 114 attached to film dispenser 110 and a second edge 116
attached to film
retriever 112. As shown, mandrel 102 and mandrel holder 104 rotate, while part
92 and part
holder 100 rotate in the opposite direction. Film dispenser 110 and film
retriever 112 can also
rotate to feed film 108 between mandrel 102 and part 92. Film dispenser 110
and film retriever
112 can rotate continuously or they can rotate only between the processing of
each part, i.e.
indexing. Moreover, a new sheet of film can be loaded between film dispenser
110 and film
retriever 112 for each part processed, in this case film dispenser 110 and
film retriever 112 need
not rotate.
As shown in Figure 5, film dispenser 110 and film retriever 112 should have
the freedom
to move about axes 111 and 113. If they move only side to side or only up and
down about axes
111 and 113 this would be considered two dimensional movement. If they can
move both up and
down and sided to side about axes 111 and 113 this is movement in three
dimensions. While not
wanting to be pound by any one theory, it is known that as the angle of the
asymmetrical edge
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changes around the circumference of the part, and the part holder (or mandrel,
or both) are
moved to correct for this change of angle, stress is placed on the film. This
stress is not
experienced when coating a flat part or even a frusta conical part because the
angle between the
film, the mandrel and the part never changes.
As used herein "move cooperatively" is intended to mean that at least one of
the film
dispenser or film retriever moves in two dimensions to account for the
changing angle of the
mandrel and part having an asymmetrical edge. Preferably both the film
dispenser and the film
retriever move in two dimensions, more preferably at least one of the film
dispenser or film
retriever moves in three dimensions and even more preferably both of the film
dispenser and film
retriever move in three dimensions. How the film dispenser and film retriever
move to relieve
stress on the film during the film application process depends on the geometry
of each individual
part. It is understood that the intent and purpose of the present invention is
to deal with parts
having edges that change in angle at least once during the film application
process, but the degree
of change, and number of changes will vary by part. As a general principle,
however, the present
apparatuses keep the surface area of the mandrel generally parallel to the
edge of the part being
coated, and it is best to feed the film such that it enters the space between
the mandrel and the
part reasonably flat, that is, without twisting. Likewise, if the film is
indexed (not being fed
continuously) it can still be manipulated to keep it in a generally flat and
parallel relationship to
the mandrel and part edge interface. Using this general precept, those skilled
in the art will be
able to program the movements of the film dispenser, film retriever, or both
to each individual
asymmetrical part configuration. Methods of movement of a mechanical device
such as the film
dispenser and film retriever of the present invention will be known to those
skilled in the art.
Pneumatic motors, servo motors and like can be used to move the film dispenser
and film
retriever while computer assisted controllers can coordinate the movement with
the changing
angles of the mandrel and part holder.
SYSTEMS
The apparatus of the present invention can be a standalone operation or it can
be used in a
system with known components, that is, as one module in a system comprising at
least two
modules. Other modules for use with the modular apparatus of the present
invention include, but
are not limited to, an apparatus for coating a part that has symmetrical
edges, an apparatus for
applying labels or decals, an apparatuses with a deformable mandrel for
coating non-planar
surfaces, and the like. In a system of the present invention the part is moved
from one module to
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the next in a predetermined sequence until the desired level of decoration or
protection for the
part is achieved.
Benefits of a modular system include, but are not limited to: many different
decorative or
protective coating can be applied to a single part without changing the film
between each step;
the individual coating steps can be staged to provide the best looking and
most efficient overlap
between coating of each step; and, it allows layering of films, decal, labels
and the like in a flow
through operation. By way of exemplifying the benefits of the systems claimed
herein, Figure 6
shows part 120 which is a lid for ajar or bottle. Part 120 has an angled edge
122, flat side wall
124, and top edge 126 which is a concave surface. As shown all three edges
have a different
decorative coating and there is label, 128 placed over the decorative surface
on concave top edge
126. Part 120 can be decorated and labeled in four steps at one station
comprising one apparatus
by changing the decorative material four times. This inefficient process can
be eliminated by
using a four module system according to the present invention.
METHODS OF USE
A method for coating a part that comprises an asymmetrical edge comprising the
steps of,
placing a film over the asymmetrical edge of the part and then rolling the
part over a mandrel
with the film sandwiched there between. In this method, one or both of the
mandrel and the part
holder move in an angular relationship to one another. While the asymmetrical
edge changes
angle it is preferred that the film change orientation as well. To accomplish
this it is preferred
that the edges of the film be held by a film dispenser and a film retriever
which move
cooperatively to align the film with the changing angle of the asymmetrical
edge of the part being
coated. The manner of movement to achieve proper film alignment is discussed
above.
PARTS
The parts of the present invention can be, for example, selected from the
group consisting
of, a bottle, a jar, an over cap, a pump, a lid, a consumer product and
mixtures thereof. Examples
of consumer products include, but are not limited to, a razor, a tooth brush,
a powered brush, a
skin care device, an electric razor, an appliance, and the like. Parts can be
made from any of the
known plastics and other polymeric compositions, naturally occurring compounds
like rubber,
metals, and other materials of construction know to those skilled in the art.
Likewise, parts can
be manufactured be methods known to those skilled in the art. Molding and high
gloss molding
are preferred examples of part manufacture, while stamping, thermo forming and
the like are also
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acceptable methods of forming the parts of the present invention. The
asymmetrical edge can be
molded into the part, it can be physically stamped, chemically etched, cut, or
ground onto the
part, or made in any other manner known to the art.
Additionally, the parts of the present invention have an asymmetrical edge
that is coated
with a thin film as described herein. Figures 7-10 show exemplary, and non-
limiting parts of the
present invention. Figure 7 shows jar 130 having lid 132 with asymmetrical
edge 133 that has
been decorated with thin film 134. In this example, the part according the
present invention is lid
132. Jar 130 could also be a part according to the invention if it had an
asymmetrical edge that
was decorated. Figure 8 illustrates a clear plastic over cap 140, having
asymmetrical edge 143
with a thin film decorative coating 144. As will be apparent those skilled in
the art, over caps are
typically used to protect or conceal a pump or the like. Figure 9 shows jar
150 with clear over
cap 152 which has an asymmetrical edge 154 with thin film decoration 153.
Moreover, pump
156 is shown under over cap 152. Pump 156 has asymmetrical edge 158 with a
film protective
coating 157. Jar 160 and pump 162 are shown in Figure 10 and jar 160 has an
asymmetrical edge
164 with protective film coating 163. The parts illustrated in Figures 7-10
are exemplary only
and those skilled in the art will appreciate the myriad of parts and consumers
products that can
implement this unique technology.
'fhe citation of any document is not an admission that it is prior art with
respect to any invention disclosed or claimed herein or that it alone, or in
any combination with
any other reference or references, teaches, suggests or discloses any such
invention.
The scope of the claims should not be limited by the preferred embodiments set
forth
in the examples, but should be given the broadest interpretation consistant
with the
description as a whole.
