U.S. patent application number 10/979682 was filed with the patent office on 2006-05-04 for blister package for adhesive compositions.
Invention is credited to Van R. Foster, Jeffrey Jay Grote, John A. Jones.
Application Number | 20060091037 10/979682 |
Document ID | / |
Family ID | 36260559 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060091037 |
Kind Code |
A1 |
Grote; Jeffrey Jay ; et
al. |
May 4, 2006 |
Blister package for adhesive compositions
Abstract
There is disclosed a novel sandwich blister package for adhesive
composition products and similar articles which generally
experience short shelf lives due to exposure to air, vapors, and
other environmental elements. The package comprises a plastic film
blister having heat-formed cavities which contain the product; and
a laminated blister card superimposed upon and sealed to the
plastic film blister to form an air, water, and vapor-proof blister
package assembly of a predetermined size and shape that
significantly extends shelf life of the adhesive composition
product.
Inventors: |
Grote; Jeffrey Jay;
(Columbus, OH) ; Jones; John A.; (Columbus,
OH) ; Foster; Van R.; (Westerville, OH) |
Correspondence
Address: |
JEFFREY JAY GROTE
351 FALLIS RD.
COLUMBUS
OH
43214
US
|
Family ID: |
36260559 |
Appl. No.: |
10/979682 |
Filed: |
November 2, 2004 |
Current U.S.
Class: |
206/471 ;
206/461 |
Current CPC
Class: |
B65D 75/36 20130101 |
Class at
Publication: |
206/471 ;
206/461 |
International
Class: |
B65D 73/00 20060101
B65D073/00 |
Claims
1. A blister package for an adhesive composition product, said
package comprising: a blister card portion including a base layer
and a foil layer laminated onto the base layer, the foil layer
being of sufficient thickness to serve as an effective barrier to
substantially prevent the transmission of air and moisture through
the blister card; and a blister portion having a substantially flat
perimeter edge, said blister portion including at least one cavity
containing an adhesive composition product packaged in a primary
container; and the blister card portion and the blister portion
mated and sealed together to form a substantially airtight and
water-resistant package.
2. A blister package according to claim 1 wherein the blister is
comprised of a thin sheet of plastic material, and wherein the at
least one cavity is formed in the blister prior to placing the
product in the at least one cavity.
3. A blister package according to claim 2, wherein the thin sheet
of plastic material is comprised of polyvinyl chloride,
polyvinylidine chloride, polyethylene, polypropylene, polyolefin,
fluoroplastics, and combinations thereof.
4. The blister package according to claim 3, wherein the thin sheet
of plastic material is between about 0.005 inches and about 0.008
inches in thickness.
5. A blister package according to claim 1 wherein foil layer is
comprised of material selected from the group consisting of
aluminum, tin.
6. A blister package according to claim 5, wherein the thickness of
the foil layer is in the range of from about 0.003 to about 0.005
inches.
7. A blister package according to claim 5, wherein the blister card
further includes a sealing layer disposed on the exposed surface of
the foil layer.
8. A blister package according to claim 7, wherein the sealing
layer is disposed on at least the portion of the exposed surface of
the foil layer that corresponds to the substantially flat perimeter
edge of the blister when the blister and blister card are
assembled.
9. A blister package according to claim 7, wherein the sealing
layer is disposed on the entire exposed surface of the foil
layer.
10. The blister package of claim 7 wherein the sealing layer is
comprised of a heat-sealable plastic.
11. The blister package of claim 7 wherein the sealing layer is
comprised of an adhesive material.
12. The blister package of claim 10 wherein the heat sealable
plastic comprises polyethylene.
13. A blister package according to claim 1 wherein said foil layer
further includes graphics superimposed on the exposed surface of
the foil layer, and wherein said blister is comprised of
transparent material such that the graphics superimposed on the
exposed surface of the foil layer are visible through the
blister.
14. A blister package according to claim 1 wherein the adhesive
composition product is selected from the group consisting of round
glue sticks and wide glue sticks.
15. A blister package for an adhesive stick material, said package
comprising: a blister card portion including a base layer and a
foil layer laminated onto the base layer, the foil layer being
comprised of aluminum of sufficient thickness to serve as an
effective barrier to substantially prevent the transmission of air
and moisture through the blister card; a blister portion comprised
of a transparent plastic material and having a substantially flat
perimeter edge, said blister portion including at least one cavity
containing an adhesive composition packaged in a primary container;
and the blister card portion and the blister portion mated and
sealed together by a sealing layer disposed between the
substantially flat perimeter edge of the blister and the foil layer
to form a substantially airtight and water-resistant package.
16. A method of significantly prolonging the useful shelf life of
an adhesive glue stick composition packaged in a primary container,
the method comprised of the steps of Providing a sheet of
heat-formable plastic material; Forming the sheet of heat-formable
plastic material so as to create at least one cavity portion
surrounded by a substantially flat perimeter edge portion;
Providing an adhesive composition product packaged in a primary
container; Placing the product into the at least one cavity;
Providing a blister card portion, the blister card portion
comprised of a base layer having a substantially flat perimeter
portion, a foil layer laminated over at least the substantially
flat perimeter portion of the blister card; Superimposing the
blister card over the blister so that the substantially flat
perimeter edge portion of the blister is mated to the foil layer
overlying substantially flat perimeter portion of the blister card;
and Sealing the blister to the blister card to produce a
substantially airtight secondary package that substantially
increases the shelf life of the product.
17. The method of claim 16, wherein the step of providing an
adhesive composition packaged in a primary container includes
providing a glue stick packaged in a primary plastic dispensing
container.
18. The method of claim 16, wherein the step of sealing includes
providing a sealing layer disposed over the exposed surface of the
foil layer.
19. The method of claim 18, wherein the step of providing a sealing
layer includes providing a heat-sealable plastic material comprised
of polyethylene.
20. The method of claim 19, wherein the step of providing a sealing
layer includes providing an adhesive composition suited for
permanently bonding the foil layer to the blister.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to packaging for storing and
displaying glue sticks and other adhesive composition products, and
more particularly to blister card packaging for storing and
displaying such products while significantly increasing shelf life
and product stability.
BACKGROUND OF THE INVENTION
[0002] Many adhesive products are provided in primary containers
formed of plastics in order to provide a relatively stable,
durable, and user-friendly package. In the case of glue sticks, the
primary package is generally cylindrical, having a circular
horizontal cross-sectional geometry ("round" glue sticks). More
recently, glue sticks have been sold using a primary package having
a horizontal cross-section that is generally oval or ovaloid. Such
oval or ovaloid packages are often referred to as "wide" glue
sticks since they impart a wider tip to the dispensed glue stick or
other adhesive composition contained in the package. In the
particular case of glue sticks, there exist both round cylindrical
and wide stick primary plastic packaging that includes a lower
closed portion having means for advancing the product out of an
opposite dispensing opening, and a cap for covering the dispensing
opening. In either case, the primary dispensing package is
customarily made of high-density polyethylene ("HDPE").
[0003] With the development of wide stick packaging, it has been
found that the shelf life of the wide stick product is shorter than
for round glue sticks. It is believed that the wide stick
containers more readily permit the passing of air to the adhesive
product before, during, and after use of the product. Passing air
to the product results in undesirable aging of the product, and
eventually deteriorates the product to the point that desirable
properties such as adhesion and ease of application are lost.
Additionally, some adhesive compositions are hygroscopic making it
necessary to protect them from moisture degradation so that they
retain their usefulness over prolonged periods; i.e. shelf life
stability, until they are consumed.
[0004] For the above reasons, it is desirable to prolong the shelf
life of glue sticks, whether round or wide, as well as other
adhesive compositions packaged in primary packaging that is
susceptible to leakage and exposure to air.
[0005] It is further desirable to provide secondary packaging that
protects the adhesive composition from exposure to air, gas and
moisture due to failure of the primary packaging.
SUMMARY OF THE INVENTION
[0006] It has now been found that the shortcomings of the existing
primary packaging for glue sticks and similar adhesive composition
consumer products can be overcome by the novel sandwich blister
package of the present invention. In general, the sandwich blister
package of this invention comprises a plastic film blister having
at least one heat-formed cavity, and a laminated blister card
having a base layer and a foil layer overlying at least a portion
of the base layer. Optionally, a sealing material forming a sealing
layer is overlaying at least a portion of the foil layer, the
sealing layer disposed so as to receive and securely seal the
blister against the foil layer. Preferably, the laminated blister
card has a base layer of paperboard or corrugated paper, a foil
layer comprising aluminum, and a sealing layer comprising
polyethylene. In another embodiment, the foil layer includes
graphics superimposed upon and sealed to the foil.
[0007] The invention further includes methods of using the plastic
film sandwich blister package of the invention as a secondary
package to reduce the loss of moisture from the adhesive
composition resulting from the exposure of the primary container
and its adhesive contents to air. As secondary benefit is that the
blister isolates the primary package and contents from exposure to
environmental conditions such as vapor humidity and liquid water.
By isolating the product in a substantially airtight package, the
present invention will significantly lengthen the useful shelf life
of the product. In addition, the present invention provides a
superior secondary package for display of the product for retail
sale.
[0008] The plastic materials that can be used for the plastic film
portion of the blister package of the invention are those which are
resilient, heat formable and heat sealable such as polyvinyl
chloride (PVC), polyvinylidine chloride, polyethylene,
polypropylene, polyolefin, fluoroplastics, and combinations
thereof. In one embodiment, PVC films having a thickness of from
between about 005 inches to about 0.008 inches provide the desired
packaging and processing properties for use in the sandwich blister
package of the invention and are commercially available.
Additionally, PVC films can be readily heated to form the cavities
for receiving and retaining product, retain the integrity of the
formed cavities after cooling, and are heat sealable.
[0009] The metal foil used in the foil layer of the invention
generally has a thickness of from about between 0.003 to about
0.005 inches, and is also commercially available. The preferred
type of metal foil is aluminum, although foils of other metals, as
well as foil having multiple layers that include plastics or other
reinforcing materials, may be used.
[0010] The sealing layer overlaying the foil layer is comprised of
a plastic or adhesive that is compatible with sealing to the
blister. Where the blister is PVC, the preferred method of sealing
is heat sealing, and accordingly, the sealing layer material
includes PVC, polyethylene, or combinations thereof. The sealing
material must provide a seal strong enough to cause a fiber tear of
the paperboard when removed from the blister card. Preferably, the
sealing layer applied to the foil layer is typically about 0.002 to
about 0.020 inches thick.
[0011] Conventional packaging apparatus can be used to produce the
sandwich blister package of the invention which generally comprises
feeding a sheet of PVC plastic film over a heating plate having a
plurality of spaced apertures formed therein; concurrently applying
heat and vacuum to the PVC plastic sheet while it is held over the
heating plate to vacuum form a plurality of spaced cavities in the
PVC plastic sheet; advancing the PVC plastic sheet and filling the
cavities with product; superimposing a sheet of blister card
material comprising a base layer, a foil layer, and a sealing layer
over the filled cavities; bonding the PVC plastic blister sheet to
the sealing layer of the blister card, cutting the thusly bonded
members to obtain separate blister cards of pre-set sizes, each
containing a pre-determined quantity of product.
[0012] Other features and advantages of the present invention will
be apparent from the following more detailed description of the
preferred embodiment, taken in conjunction with the accompanying
drawings which illustrate, by way of example, the principles of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The blister package of the invention and a method for
producing it will become more clear from the ensuing description
when considered together with the accompanying drawing wherein like
reference numerals identify like parts and wherein:
[0014] FIG. 1 is an exploded side elevation illustrating the
elements of a single unit of the sandwich blister package of the
invention;
[0015] FIG. 2 is a side elevation of the single unit sandwich
blister package of FIG. 1;
[0016] FIG. 3 is a side cross-sectional view of the single unit
blister package of FIG. 1 taken along line 3-3 of FIG. 2;
[0017] FIG. 4 is a top plan view of another embodiment of the
sandwich blister package of the invention, showing a foil layer
having text superimposed thereon; and
[0018] FIG. 5 is a side perspective view of the single unit blister
card of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0019] In order to accomplish the objects of the invention, the
present invention provides a secondary package that provides an
airtight enclosure for an adhesive product that is contained in a
primary package. As shown in the preferred embodiment illustrated
in FIG. 1, the secondary package 10 is comprised of a plastic
blister 12, and a blister card 20. The blister card 20 includes at
least a base layer 22, a foil layer 24 overlaying at least a
portion of the base layer 22, and a sealing layer 26 overlaying at
least a portion of the foil layer 24. The secondary package 10 is
assembled as a sandwich wherein the blister 12 includes a cavity
that generally corresponds to the size and shape of a product 30
such as an adhesive composition pre-packaged in a primary
container. The blister 12 includes one or more cavities formed in
the blister 12, and a substantially flat perimeter portion 14
disposed for receiving and sealing against the blister card 20 to
form a moisture/vapor/gas impervious secondary package. When the
blister package 10 is fully assembled and sealed, the product 30 is
thus protected from moisture/vapor/gas degradation until the
blister package 10 is unsealed to remove the product 30 to be
consumed.
[0020] As shown in FIGS. 1-5, the preferred embodiment of the
blister package 10 is a moisture/vapor/gas impervious blister
package 10 that comprises a blister 12 formed from a sheet of
plastic material such as polyvinylchloride ("PVC"), nylon, or other
resilient plastic. The blister 12 may be formed by any known means,
but is preferably formed by heating PVC film in a blister-forming
packaging machine as further described herein. The blister 12 is
configured so as to closely conform to the shape and size of an
adhesive composition product 13, so as to minimize air content of
the assembled package.
[0021] The blister card 20 is comprised of at least a base layer 22
and a foil layer 24. The card 20 is preferably a three-ply card
comprising a lower base layer 22, a laminated foil layer 24
overlaying at least a portion of the base layer 22, and a sealing
layer 26 overlaying at least a portion of the foil layer 24.
[0022] The foil layer 24 is preferably comprised of a foil metal
such as aluminum, tin, or combinations thereof. Alternatively, the
foil layer can include a plastic or resin such as polyester,
whether in combination with a metal foil or in place of the metal
foil. The foil layer 24 is preferably between about 0.01
millimeters and 0.02 millimeters thick. Such thin foils are known
to be easily punctured and have a tendency to easily tear.
Therefore, securely laminating the foil layer 24 to the base layer
22 helps to strengthen the foil layer so as to provide a continuous
foil barrier on the top surface of the base layer material.
Optionally, the foil layer 24 may be comprised of a second layer of
a material laminated to the foil, wherein the second layer is a
material that is tear-resistant and impervious to air. PVC,
polyethylene, and polyester for example, can be used for this
purpose, although other plastics will be known to those skilled in
the art. In any case, the foil layer 24 imparts the desired
moisture/vapor/gas barrier protection and is the layer overlaying
the blister card base layer 22.
[0023] The sealing layer 26 is preferably comprised of a
heat-sealable plastic composition such as polyethylene, PVC, or
other known heat-sealable plastic that is compatible with the
flexible plastic film of the blister 12 and the foil layer 24 to
form a permanent bond with both the blister 12 and the foil layer
24. The sealing layer 24 is preferably applied to the foil layer 22
early in the packaging process since the resilient nature of the
sealing layer 26 protects the aluminum foil ply and can prevent it
from being torn or punctured during packaging.
[0024] FIG. 1 shows an exploded view of a single unit sandwich
blister package of the invention. The package comprises a PVC
plastic blister 12 having a cavity heat formed therein for
receiving and retaining a product 13. A sealing layer 26 is
superimposed upon and bonded to the top foil layer 24 of a blister
card having a base layer 22, the base layer 22 and foil layer 24
laminated to form a blister card 20.
[0025] FIG. 2 shows the assembled sandwich blister package of FIG.
1, wherein the substantially flat perimeter edges of the blister 12
have been heat sealed to the foil layer 24 of the blister card by
heating the sealing layer 26 so that it bonds to the blister 12 and
to the foil layer 24. FIG. 3 shows a close-up side cross-sectional
view of the assembled, heat-sealed blister package 10 of FIG. 2.
Fog. 5 shows another side perspective view of the assembled
package.
[0026] As shown in FIG. 4, the assembled package of FIG. 2 can
include graphics and text superimposed onto the foil layer 24 to
form a package that is suitable for display without further
modification. Graphics may include product names, ingredients,
trademarks, and any other desirable artwork and text.
[0027] The preset invention further includes an assembly line
method that can be used to continuously produce completed blister
packages of the invention. PVC film for the blister is continuously
supplied in sheet form from a roll of PVC film and led over a hot
plate having a plurality of spaced apertures. The hot plate is kept
at a temperature sufficient to heat the PVC sheet 10 so that it
becomes softened and heat formable. When the PVC sheet has reached
a softened, heat formable state (usually within about 2 seconds to
about 6 seconds) vacuum is applied by conventional means to draw
the softened PVC sheet film down into apertures to thereby form the
cavities in the PVC sheet. The PVC sheet is then fed beneath a
product supply means such as a product hopper where a product, such
as a glue stick in a PVC primary package is deposited into each
cavity. Sufficient distance from the cavity forming operation and
the hopper is provided so that the cavities formed have time to
cool, set and become integral. Usually, the cavities are set and
cooled to maintain an integral self-supporting shape within about 2
seconds to about 6 seconds.
[0028] Downstream from hopper, a blister card comprised of a base
layer, a foil layer laminated to the base layer, and a sealing
layer overlaying the foil layer is provided to be superimposed over
the PVC sheet carrying the product in the formed cavities. The
blister card is then heat sealed to the PVC sheet 10 such as by
means of heat sealing platen to obtain a sealed blister secondary
package assembly. Conventional knife blades and other cutting means
can then be used to cut the blister package assembly into
individual blister cards of pre-set sizes. The fully assembled
blister cards are then fed to downstream stations for packaging
into bulk containers or tertiary packages such as display
cases.
EXAMPLES
[0029] The inventors were able to evaluate a series of experimental
blister packages, designated herein as the "S series" and the "L
series". The samples each included an Elmer's round glue stick in
its primary HDPE package, but with the cap removed, packaged into a
secondary blister package. Each blister package included a glue
stick laid on a blister card, with a plastic blister overlaying the
glue stick and sealed to the blister card using a polyethylene
sealing ring as the sealing layer. Each blister and card assembly
was than heat sealed at temperatures of between about 240 to 300
degrees Fahrenheit for sufficient dwell time to activate the
sealing layer and create an airtight and durable seal between the
blister card and the blister.
[0030] Each "S" series blister card included a paperboard backing
having a 0.003 to 0.005 inch thick foil layer of aluminum foil on
the exposed (top surface for contacting the product and plastic
blister.
[0031] By contrast, each "L" series package included a plastic
blister overlay of the same composition as the "S" series, and
paperboard backing identical to that of the "L" series, save for
the absence of the foil top layer.
[0032] Each series of packages was then placed in a 50 degree
Celcius oven for 2 weeks to measure the total package weight loss.
The results are listed in the tables below. The displayed weight
loss is a total weight loss that includes the entire package and
product and therefore is not limited to the product
itself--however, given the identical package components save for
the foil lacking in the "L" series, the majority of the weight loss
can indeed be attributed to moisture and volatiles loss from the
product. Calculated percentage weight loss for the glue stick
itself would therefore, of course, be much greater.
[0033] To clearly compare the results, the inventors have provided
a ratio of the two weight loss values to measure the performance
impact of the different foil metal layer. The "L" series, which
lacked the foil layer, lost 11.77%, nearly four times (4.times.) as
much weight (presumably mostly water) than the "S" series (2.83%).
TABLE-US-00001 S Series Initial Aged Wt (g) Weight (g) Difference
(g) (%) S-1 71.17 69.48 1.69 2.37 S-2 70.95 69.16 1.79 2.52 S-3
71.09 67.54 3.55 4.99 S-4 70.93 68.95 1.98 2.79 S-5 71.20 69.61
1.59 2.23 S-6 71.25 69.58 1.67 2.34 S-7 71.30 69.45 1.85 2.59
Average loss (%) = 2.83%
[0034] TABLE-US-00002 L Series Initial Aged Wt (g) Weight (g)
Difference (%) L-1 72.98 65.01 7.97 10.92 L-2 72.79 64.08 8.74
12.01 L-3 72.53 64.28 8.25 11.37 L-4 72.08 63.09 8.99 12.47 L-5
72.29 63.55 8.74 12.09 L-6 72.06 63.42 8.64 11.99 L-7 72.51 64.12
8.39 11.57 Average loss (%) = 11.77%
[0035] The ratio of "L" average weight loss to "S" average weight
loss as approximately 4.16:1. Clearly, the foil layer constitutes a
significant improvement over the current secondary blister
packaging for glue sticks. It is fully expected that further
testing will show that the blister package of the preset invention
will significantly improve the useful shelf life of the packaged
glue stick products and similar adhesive composition products, and
may triple the current shelf life of such products where the
primary cause of product degradation is by moisture loss.
[0036] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *