U.S. patent application number 13/770028 was filed with the patent office on 2013-07-25 for paperboard-based beverage container.
This patent application is currently assigned to MeadWestvaco Corporation. The applicant listed for this patent is MeadWestvaco Corporation. Invention is credited to Sven S. ARENANDER, Vladislav A. BABINSKY, Teresa KRUG, Dobbie C. NEWMAN.
Application Number | 20130190154 13/770028 |
Document ID | / |
Family ID | 42632182 |
Filed Date | 2013-07-25 |
United States Patent
Application |
20130190154 |
Kind Code |
A1 |
BABINSKY; Vladislav A. ; et
al. |
July 25, 2013 |
PAPERBOARD-BASED BEVERAGE CONTAINER
Abstract
A container including at least one wall that defines an internal
volume and an opening into the internal volume, the wall defining
an internal surface and an external surface and being formed as a
layered structure that includes a first layer, a second layer that
includes paperboard and defines the external surface, and an
adhesive layer disposed between the first layer and the second
layer, wherein at most 0.15 grams of surface condensation forms on
the wall per 300 square centimeters of the external surface during
a 20-minute interval, the 20-minute interval beginning upon filling
75 percent of the internal volume with a liquid maintained at a
temperature of about 32.degree. F. while the filled container is
exposed to an ambient temperature of about 73.degree. F. and about
50 percent relative humidity.
Inventors: |
BABINSKY; Vladislav A.;
(Midlothian, VA) ; ARENANDER; Sven S.; (Richmond,
VA) ; NEWMAN; Dobbie C.; (Glen Allen, VA) ;
KRUG; Teresa; (Henrico, VA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MeadWestvaco Corporation; |
Richmond |
VA |
US |
|
|
Assignee: |
MeadWestvaco Corporation
Richmond
VA
|
Family ID: |
42632182 |
Appl. No.: |
13/770028 |
Filed: |
February 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13318380 |
Nov 1, 2011 |
8389079 |
|
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PCT/US2010/033658 |
May 5, 2010 |
|
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13770028 |
|
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61175569 |
May 5, 2009 |
|
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61287990 |
Dec 18, 2009 |
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Current U.S.
Class: |
493/114 |
Current CPC
Class: |
B32B 2266/025 20130101;
B32B 2439/70 20130101; Y10T 428/249953 20150401; B32B 2255/12
20130101; Y10T 428/13 20150115; Y10T 428/1352 20150115; B32B
2260/046 20130101; Y10T 428/1393 20150115; Y10T 428/31975 20150401;
Y10T 428/1303 20150115; B32B 27/302 20130101; B32B 2266/0228
20130101; B32B 2260/025 20130101; Y10T 428/31895 20150401; Y10T
428/2495 20150115; Y10T 428/253 20150115; Y10T 156/10 20150115;
Y10T 428/31902 20150401; B32B 27/18 20130101; B32B 29/002 20130101;
B32B 2307/7163 20130101; B65D 81/3874 20130101; B32B 27/205
20130101; Y10T 428/249962 20150401; B32B 29/007 20130101; B32B
2270/00 20130101; B32B 27/10 20130101; B32B 2266/0242 20130101;
B32B 2264/06 20130101; B32B 2307/7246 20130101; B32B 23/06
20130101; Y10T 428/31982 20150401; Y10T 428/249974 20150401; B65D
3/06 20130101; B32B 2307/304 20130101; Y10T 428/31703 20150401;
Y10T 428/24851 20150115; B32B 2266/0207 20130101; Y10T 428/31993
20150401; B31B 50/62 20170801; B32B 9/06 20130101; B32B 5/16
20130101; Y10T 428/31899 20150401; Y10T 428/31996 20150401; B32B
3/26 20130101; B32B 27/22 20130101; B32B 29/04 20130101; B32B
2262/06 20130101; B32B 9/02 20130101; B32B 27/32 20130101; Y10T
428/26 20150115; B32B 29/005 20130101; B32B 29/02 20130101; B32B
5/20 20130101; B32B 2255/26 20130101; B32B 15/12 20130101; B32B
27/306 20130101; B65D 3/28 20130101 |
Class at
Publication: |
493/114 |
International
Class: |
B31B 1/62 20060101
B31B001/62 |
Claims
1. A method for making a beverage container comprising the steps
of: providing a first layer of paperboard and a second layer of
paperboard; positioning an adhesive material between said first
layer and said second layer to form a layered structure, said
adhesive material having a pseudoplasticity index in the range of
about 0.3 to about 0.5; shaping said layered structure to define an
internal volume and an opening into said internal volume, said
layered structure having an internal surface and an external
surface; and drying said adhesive material.
2. The method of claim 1 wherein said second layer has an average
porosity of 20 to 1000 Gurley units.
3. The method of claim 1 wherein said second layer has an average
porosity of 20 to 150 Gurley units.
4. The method of claim 1 wherein said adhesive material is provided
as a foam.
5. The method of claim 4 wherein 10 to 60 percent of said foam is
comprised of open voids.
6. The method of claim 1 wherein said adhesive material includes
sawdust and a binder.
7. The method of claim 6 wherein said sawdust has an average
particle size of at least 100 microns.
8. The method of claim 6 wherein said sawdust has an average
particle size of at least 1000 microns.
9. The method of claim 6 wherein said binder comprises latex.
10. The method of claim 6 wherein said binder comprises starch.
11. The method of claim 1 wherein said adhesive material comprises
2 to 70 percent by weight filler and 8 to 70 percent by weight
organic binder.
12. The method of claim 11 wherein said filler comprises an organic
filler.
13. The method of claim 12 wherein said organic filler is selected
from the group consisting of sawdust, ground wood, cellulose pulp,
pearl starch, gluten feed, corn seed skin, kenaf core and
combinations thereof.
14. The method of claim 12 wherein said organic filler comprises a
hard organic filler.
15. The method of claim 11 wherein said adhesive material further
comprises 1 to 15 percent by weight sodium silicate.
16. The method of claim 11 wherein said adhesive material further
comprises 0.5 to 10 percent by weight plasticizer.
17. The method of claim 11 wherein said adhesive material has an
equilibrium moisture content of about 10 to 15 percent by
weight.
18. The method of claim 1 wherein said adhesive material forms an
adhesive layer between said first layer and said second layer, and
wherein said adhesive layer has a thickness of 0.05 to 5
millimeters.
19. The method of claim 1 wherein said second layer includes an
inner surface and an outer surface, said outer surface defining
said external surface, and wherein inner surface has a first
Hercules sizing and said outer surface has a second Hercules
sizing, said second Hercules sizing being greater than said first
Hercules sizing.
20. The method of claim 1 wherein said adhesive material comprises
organic filler and organic binder.
21. The method of claim 1 wherein said adhesive material spaces
said first layer at least 0.5 millimeters away from said second
layer.
22. A method for making a beverage container comprising the steps
of: providing a first layer of paperboard and a second layer of
paperboard; positioning an adhesive material between said first
layer and said second layer to form a layered structure, said
adhesive material having a pseudoplasticity index in the range of
about 0.3 to about 0.5; shaping said layered structure to define an
internal volume and an opening into said internal volume, said
layered structure having an internal surface and an external
surface; and drying said adhesive material, wherein at most 0.15
grams of condensation forms on said external surface per 300 square
centimeters of said external surface during a 20-minute interval,
said 20-minute interval beginning upon filling 75 percent of said
internal volume with a liquid maintained at a temperature of about
32.degree. F. while said filled container is exposed to an ambient
temperature of about 73.degree. F. and about 50 percent relative
humidity.
Description
PRIORITY
[0001] This application is a divisional of U.S. Ser. No. 13/318,380
filed on Nov. 1, 2011, now U.S. Pat. No. 8,389,079, which is a
continuation of International Application PCT/US10/33658 filed on
May 5, 2010 which claims priority from U.S. Ser. No. 61/175,569
filed on May 5, 2009 and U.S. Ser. No. 61/287,990 filed on Dec. 18,
2009; the entire contents of these application are incorporated
herein by reference in their respective entireties.
FIELD
[0002] This application relates to paperboard-based beverage
containers, such as beverage cups, and, more particularly, to
insulated paperboard-based beverage containers and, even more
particularly, to insulated paperboard-based beverage containers
that reduce or eliminate condensate formation.
BACKGROUND
[0003] Beverage containers, such as beverage cups, are used to hold
various beverages, including cold beverages, such as soda and iced
tea, and hot beverages, such as coffee and tea. Cold beverages are
typically served with ice and, due to humidity in the ambient air,
result in the formation of water droplets (i.e., condensation) on
the external surface of the beverage container. Such condensation
inhibits the user's ability to securely grip the beverage
container, which may result in accidental spillage, particularly
when the beverage is being consumed while operating a motor
vehicle. Furthermore, the formation of condensation on the external
surface of beverage containers may result in the undesirable
pooling of condensate on the surface supporting the beverage
container, thereby potentially damaging the surface.
[0004] Accordingly, those skilled in the art continue to innovate
in the field of beverage containers.
SUMMARY
[0005] In one aspect, the disclosed method for making a beverage
container may include the steps of (1) providing a first layer of
paperboard and a second layer of paperboard, (2) positioning an
adhesive material between the first and second layers to form a
layered structure, the adhesive material having a pseudoplasticity
index in the range of about 0.3 to about 0.5, (3) shaping the
layered structure to define an internal volume and an opening into
the internal volume, the layered structure having an internal
surface and an external surface, and (4) drying the adhesive
material.
[0006] In yet another aspect, the disclosed method for making a
beverage container may include the steps of (1) providing a first
layer of paperboard and a second layer of paperboard, (2)
positioning an adhesive material between the first and second
layers to form a layered structure, the adhesive material having a
pseudoplasticity index in the range of about 0.3 to about 0.5, (3)
shaping the layered structure to define an internal volume and an
opening into the internal volume, the layered structure having an
internal surface and an external surface, and (4) drying the
adhesive material, wherein at most 0.15 grams of surface
condensation forms on the external surface per 300 square
centimeters of the external surface during a 20-minute interval,
the 20-minute interval beginning upon filling 75 percent of the
internal volume with a liquid maintained at a temperature of about
32.degree. F. while the filled container is exposed to an ambient
temperature of about 73.degree. F. and about 50 percent relative
humidity.
[0007] Other aspects of the disclosed paperboard-based beverage
container will become apparent from the following description, the
accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front elevational view, in section, of one
aspect of the disclosed paperboard-based beverage container;
[0009] FIG. 2 is a cross-sectional view of a portion of the side
wall of the beverage container of FIG. 1;
[0010] FIG. 3 is a cross-sectional view of a portion of a side wall
of a beverage container in accordance with one alternative aspect
of the disclosure;
[0011] FIG. 4 is a graphical illustration of condensate formation
versus time on a beverage container in accordance with one aspect
of the disclosure;
[0012] FIG. 5 is a graphical illustration of condensate formation
versus time on a beverage container having an embossed external
surface in accordance with another aspect of the disclosure;
[0013] FIG. 6 is a graphical illustration of condensate formation
versus time on a beverage container having a wood-containing outer
layer in accordance with yet another aspect of the disclosure;
and
[0014] FIG. 7 is a graphical illustration of compression force
versus condensate formation on the beverage container of FIG.
5.
DETAILED DESCRIPTION
[0015] Referring to FIG. 1, one aspect of the disclosed
paperboard-based beverage container, generally designated 10, may
be formed as a cup, such as a 12-ounce, 16-ounce, 21-ounce or
24-ounce disposable take-out cup. The beverage container 10 may
include a frustoconical side wall 12 having an upper end portion 14
and a lower end portion 16, and a bottom wall 18 connected to the
lower end portion 16 to define an internal volume 20 within the
beverage container 10. The upper end portion 14 of the side wall 12
may define an opening 22 into the internal volume 20. Optionally,
the upper end portion 14 of the side wall 12 may additionally
include a lip 23 for securing a lid (not shown) or the like to the
beverage container 10.
[0016] Those skilled in the art will appreciate that the disclosed
beverage container 10 may be formed in various shapes and sizes,
and may be formed with fewer or more walls than the side and bottom
walls 12, 18 discussed above, without departing from the scope of
the present disclosure.
[0017] As shown in FIG. 2, the side wall 12 may be formed as a
layered structure having a first layer 24, a second layer 26 and an
adhesive layer 28. The first layer 24 may include an inner surface
30 and an outer surface 32, wherein the inner surface 30 of the
first layer 24 may define (or may be proximate) the interior
surface 34 of the beverage container 10. The second layer 26 may
include an inner surface 36 and an outer surface 38, wherein the
outer surface 38 of the second layer 26 may define the external
surface 40 of the beverage container 10.
[0018] In one aspect, the adhesive layer 28 may be positioned
between the first and second layers 24, 26 such that the adhesive
layer 28 is connected to both the outer surface 32 of the first
layer 24 and the inner surface 36 of the second layer 26. In
another aspect, optional additional layers (not shown) may be
positioned between the first layer 24 and the adhesive layer 28,
such that the adhesive layer 28 may be connected to the inner
surface 36 of the second layer 26 and the outer surface (not shown)
of one of the optional additional layers.
[0019] As shown in FIG. 3, in one optional aspect, the inner
surface 30 of the first layer 24 may be coated with a moisture
barrier layer 42, thereby rendering the interior surface 34 of the
side wall 12 of the beverage container 10 resistant to moisture
penetration when the internal volume 20 of the beverage container
10 is filled with a beverage (not shown). For example, the moisture
barrier layer 42 may be (or may include) a layer of polyethylene
that has been laminated, extrusion coated or otherwise connected
(e.g., adhesives) to the inner surface 30 of the first layer 24.
Other moisture barrier materials useful in the moisture barrier
layer 42 are known in the art and commercially available.
[0020] The first layer 24 may be a sheet of material capable of
being shaped into the side wall 12. The first layer 24 may have a
thickness T.sub.1 and rigidity sufficient to impart the beverage
container 10 with sufficient structural integrity to maintain the
desired shape of the beverage container 10 when a beverage is
received in the internal volume 20. For example, the first layer 24
may be formed from a recyclable material, such as paperboard, or
from a polymeric material, such as polycarbonate or polyethylene
terephthalate, and may have a thickness of at least about 6 points,
such as about 8 to about 24 points.
[0021] The second layer 26 may be formed from a sheet of
paperboard, which may be bleached or unbleached, and which may have
a basis weight of at least about 85 pounds per 3000 square feet and
a thickness T.sub.2 of at least about 6 points. For example, the
second layer 26 may be formed from paperboard, such as linerboard
or solid bleached sulfate (SBS), having a basis weight ranging from
about 180 to about 270 pounds per 3000 square feet and a thickness
T.sub.2 ranging from about 8 to 36 points.
[0022] At this point, those skilled in the art will appreciate that
the paperboard used to form the second layer 26 may include various
components and optional additives in addition to cellulosic fibers.
For example, the second layer 26 may optionally include one or more
of the following: binders, fillers, organic pigments, inorganic
pigments, hollow plastic pigments, expandable microspheres and
bulking agents, such as chemical bulking agents.
[0023] In one optional aspect, the paperboard used to form the
second layer 26 may include ground wood particles dispersed
therein. Without being limited to any particular theory, it is
believed that the ground wood particles in the second layer 26
encourage the absorption of condensation that is formed on the
external surface 40 into the second layer 26 and the adhesive layer
28.
[0024] In another optional aspect, the outer surface 38 of the
second layer 26 may be textured to improve the gripping ability of
the external surface 40 of the beverage container 10, as well as
the moisture absorbing properties of the container 10. One
technique for texturing the outer surface 38 includes embossing the
outer surface 38. While a skilled artisan can perceive various
texture patterns, examples of useful texture/embossing patterns
include checkered patterns, consecutive horizontal lines,
consecutive vertical lines, and consecutive lines disposed at a
non-right angle relative to the vertical axis of the beverage
container 10.
[0025] Thus, those skilled in the art will appreciate that the
external surface 40 of the container 10 may have various features,
shapes, contours and configurations without departing from the
scope of the present disclosure.
[0026] The second layer 26 may be engineered to maximize the
transfer of moisture (i.e., condensation) forming on the external
surface 40 of the side wall 12 into the second layer 26 and the
adhesive layer 28 of the side wall 12. For example, the surface
sizing and the porosity of both the inner and outer surfaces 36, 38
of the second layer 26 may be engineered to maximize moisture
(i.e., condensation) absorption and minimize the negative effects
of condensate formation.
[0027] In one particular aspect, the surface sizing of the inner
and outer surfaces 36, 38 of the second layer 26 may be controlled
such that the inner surface 36 has a Hercules sizing that is less
than the Hercules sizing of the outer surface 38. For example, the
surface sizing of the inner and outer surfaces 36, 38 of the second
layer 26 may be controlled such that the inner surface 36 has a
sizing in the range from about 30 to about 80 Hercules units, while
the outer surface 38 has a sizing in the range from about 100 to
about 150 Hercules units.
[0028] In another particular aspect, the porosities of the inner
and outer surfaces 36, 38 of the second layer 26 may be controlled
such that the inner surface 36 has a Gurley porosity that is less
than the Gurley porosity of the outer surface 38 (i.e., greater
pore volume on the inner surface 36 and on the outer surface 38).
For example, the porosities of the inner and outer surfaces 36, 38
of the second layer 26 may be controlled such that the inner
surface 36 has a porosity of about 20 Gurley units (400 cc test),
while the outer surface 38 has a porosity of about 40 Gurley units
(400 cc test).
[0029] At this point, those skilled in the art will appreciate that
surface sizing may be controlled using various sizing agents, such
as alkyl ketene dimer. Furthermore, those skilled in the art will
appreciate that other properties pertaining to moisture absorption,
such as porosity, can be achieved by modifying the paperboard
making process, such as modifying the selection of the forming,
pressing and drying fabrics.
[0030] Accordingly, by modifying the surface sizing and porosity of
both the inner and outer surfaces 36, 38 of the second layer 26,
the rate of moisture absorption can be controlled. For example,
moisture absorption rates of 0.02 to 0.1 g/cm.sup.2/min at the
outer surface 38 and 0.03 to 0.2 g/cm.sup.2/min at the inner
surface 36 may be achieved.
[0031] As noted above, the outer surface 38 of the second layer 26
may be embossed, thereby providing additional surface area for
condensate absorption. For example, the topography of the embossed
surface may be configured such that the area of finger contact with
the embossed surface is 20 percent of the total surface of the
container 10 under fingers. The shape of the embossed recesses may
be designed in such a way that the porosity on the picks of the
embossed structure is 30 percent greater than in the valleys of the
embossed structure. The increased porosity may occur because of a
designed concentration of stresses in the peak areas of the
embossed structure, while a greater curvature of the picks results
in lower porosity of the pick area.
[0032] The adhesive layer 28 may be a layer of thermally insulative
material that couples the second layer 26 to the underlying layer
(e.g., the first layer 24). The thickness T.sub.A of the adhesive
layer 26 may range from about 0.05 millimeters to about 5
millimeters. Of course, those skilled in the art will appreciate
that a greater thickness T.sub.A may be used when greater
insulation is desired.
[0033] The adhesive layer 28 may be deemed thermally insulating if
it has an insulative R-value per unit of thickness that is greater
than the insulative R-value per unit of thickness of the second
layer 26. For example, the ratio of the insulative R-value per unit
of thickness of the adhesive layer 28 to the insulative R-value per
unit thickness of the second layer 26 may be at least about 1.25:1,
such as 1.5:1, 2:1 or even 3:1.
[0034] The adhesive layer 28 may cover all, or only a portion, of
the inner surface 36 of the second layer 26. As one example, the
adhesive layer 28 may cover about 20 to about 100 percent of the
surface area of the inner surface 36 of the second layer 26. As
another example, the adhesive layer 28 may cover about 20 to about
80 percent of the surface area of the inner surface 36 of the
second layer 26. As yet another example, the adhesive layer 28 may
cover about 40 to about 60 percent of the surface area of the inner
surface 36 of the second layer 26. As yet another example, the
adhesive layer 28 may cover about 50 percent of the surface area of
the inner surface 36 of the second layer 26.
[0035] When the adhesive layer 28 covers less than all of the inner
surface 36 of the second layer 26, the adhesive layer 28 may be
applied to the inner surface 36 either randomly or in various
patterns. Those skilled in the art will appreciate that certain
patterns, such as vertical strips (either straight or wavy), may
increase the overall structural integrity of the beverage container
10.
[0036] In one aspect, the adhesive layer 28 may be formed as a
composite material that includes an organic binder and a filler.
The organic binder may comprise 15 to 70 percent by weight of the
adhesive layer 28 and the filler may comprise 2 to 70 percent by
weight of the adhesive layer 28.
[0037] The organic binder of the composite adhesive layer 28 may be
any material, mixture or dispersion capable of bonding the second
layer 26 to the underlying layer (e.g., the first layer 24). The
organic binder may also have insulative properties. Examples of
suitable organic binders include latexes, such as styrene-butadiene
latex and acrylic latex, starch, such as ungelatinized starch,
polyvinyl alcohol, polyvinyl acetate, and mixtures and combinations
thereof.
[0038] The filler of the composite adhesive layer 28 may be an
organic filler, an inorganic filler, or a combination of organic
and inorganic fillers. Organic fillers include hard organic fillers
and soft organic fillers. Examples of suitable hard organic fillers
include sawdust and ground wood. Examples of suitable soft organic
fillers include cellulose pulp, pearl starch, synthetic fiber
(e.g., rayon fiber), gluten feed, corn seed skin, and kenaf core (a
plant material). Examples of suitable inorganic fillers include
calcium carbonate, clay, pearlite, ceramic particles, gypsum and
plaster. For example, organic filler may comprise 2 to 70 percent
by weight of the composite adhesive layer 28 and inorganic filler
may comprise 0 to 30 percent by weight of the composite adhesive
layer 28.
[0039] All or a portion of the filler may have a relatively high
particle size (e.g., 500 microns or more). The use of high particle
size filler material may increase the thickness T.sub.A of the
adhesive layer 28, thereby acting as a spacer that improves the
insulative properties of the adhesive layer 28. For example, the
adhesive layer 28 may be formed as a composite material that
includes an organic binder and a hard organic filler, such as
sawdust, that has an average particle size of at least 500 microns,
such as about 1000 to about 2000 microns.
[0040] In one particular aspect, the adhesive layer 28 may be a
foam. The foam may be formed by mechanically whipping the
components of the adhesive layer 28 prior to application.
Optionally, a foam forming agent may be included in the adhesive
layer formulation to promote foam formation. As one example, 10 to
60 percent of the foam of the adhesive layer 28 may be open voids,
thereby facilitating the absorption of moisture from the external
surface 40 of the beverage container 10. As another example, 10 to
30 percent of the foam of the adhesive layer 28 may be open
voids.
[0041] In another particular aspect, the adhesive layer 28 may be
formed from a binder-filler formulation, as described herein,
wherein the formulation has a pseudoplasticity index in the range
of 0.3 to 0.5. Such a range provides the adhesive layer 28 with a
sufficient minimum thickness T.sub.A, while preserving the ability
to apply the formulation at a low viscosity. For example, the
formulation may have a low shear viscosity in the range of 2,000 to
50,000 centipoises and a high shear viscosity in the range of 100
to 5,000 centipoises.
[0042] As one option, the adhesive layer 28 may additionally
include a plasticizer. The plasticizer may comprise 0.5 to 10
percent by weight of the composite adhesive layer 28. Examples of
suitable plasticizers include sorbitol, Emtal emulsified fatty
acids and glycerine.
[0043] As another option, the adhesive layer 28 may additionally
include a sodium silicate, which may act as a filler, but is
believed to aid in binding and curing of the binder by rapidly
increasing viscosity of the binder during the drying process. The
sodium silicate may comprise 0 to 15 percent by weight of the
adhesive layer 28, such as about 1 to about 5 percent by weight of
the adhesive layer 28.
[0044] Those skilled in the art will appreciate that, after initial
processing, the adhesive layer 28 may maintain an equilibrium
moisture content of about 10 to 15 percent by weight.
[0045] At this point, those skilled in the art will appreciate that
the material that forms the adhesive layer may be formulated to be
biodegradable.
EXAMPLES
Examples 1-4
[0046] Four sample composite adhesive materials (Nos. 1-4) suitable
for forming the adhesive layer 28 were prepared. The formulations
are provided in Table 1.
TABLE-US-00001 TABLE 1 Parts by Weight Material No. 1 No. 2 No. 3
No. 4 Component sawdust 15 15 15 15 FILLER sodium silicate 2 2
BINDER calcium carbonate 0 20 15 15 FILLER clay @40% 0 20 15 15
FILLER latex SBR @40% 20 20 20 75 BINDER starch modified 30 30 15
15 pearl starch 20 20 20 100 BINDER polyvinyl alcohol 0 5 10 10
BINDER sorbitol 5 2 0 PLASTICIZER Emtal emulsified fatty 5 5 5 5
PLASTICIZER acids@40% glycerine 0 0 5 5 PLASTICIZER Safoam FPN3 1 1
1 1 FOAMING AGENT Triton 100 0.5 0.5 0.5 SURFACTANT pearlite 1 3
FILLER cellulosic insulation 0 0 2 2 FILLER (recycled
newsprint)
[0047] Formulation Nos. 1-4 were mechanically whipped to form a
foam having a pseudoplasticity index in the range of about 0.3 to
about 0.5.
[0048] Additional formulations for forming the adhesive layer 28,
as well as methods suitable for forming the side wall 12, are
disclosed in U.S. Ser. No. 61/175,569 filed on May 5, 2009, the
entire contents of which are incorporated herein by reference.
Example 5
[0049] A 21-ounce beverage cup was constructed having a side wall
and a bottom wall. The side wall was prepared as described above
using adhesive formulation No. 1 (Example 1, above) sandwiched
between a first, inner layer of SBS paperboard having a basis
weight of 180 pounds per 3000 square feet and a thickness of 16
points and a second, outer layer of SBS paperboard having a basis
weight of 150 pounds per 3000 square feet and a thickness of 14
points. The adhesive formulation covered about 100 percent of the
inner surface of the second layer and resulted in an adhesive layer
having a thickness of about 0.5 millimeters. The first layer had an
inner surface coated with a 1 mil layer of polyethylene. The
external surface of the cup had a surface area of 300 square
centimeters.
[0050] The cup was positioned in a controlled atmosphere that was
maintained at an ambient temperature of about 73.degree. F. and
about 50 percent relative humidity. With the cup in the controlled
atmosphere, 15.75 ounces of an ice-water mixture was added to the
cup and a timer was activated. Every twenty minutes for two hours,
the accumulated surface condensation was wiped away from the
external surface of the cup with a new absorbent cloth and the mass
of the condensate collected on the cloth was determined (i.e., mass
of cloth after wiping minus mass of cloth before wiping). The
results are plotted in FIG. 4 as the "Example 5" data points,
wherein each data point is indicative of the amount of surface
condensation collected during a 20 minute period.
[0051] As used herein, "surface condensation" refers to
condensation that forms on the external surface of a container, and
that is capable of being wiped away from the external surface of
the container. Surface condensation generally does not include
condensation that has formed on or inside the external surface of a
container, and that has been absorbed by the container in a manner
the prevents or inhibits one's ability to wipe away the
condensation. However, it should be appreciate that while wiping
away surface condensation from the external surface, a certain
negligible amount of internal condensation may also be collected
due to, for example, capillary action.
[0052] For comparison, the same condensate formation test was also
performed on a clear polyethylene terephthalate plastic cup
("Clear"), a single-ply paperboard cup coated on both sides with
polyethylene ("Control"), a PERFECT TOUCH brand cup ("Perfect
touch") made from polymeric foam available from Georgia Pacific, an
INSULAIR brand cup ("Insulair") available from Insulair, Inc. of
Veralis, Calif, and a cup formed from SYTROFOAM ("Styrofoam"). All
comparison cups also had an external surface area of about 300
square centimeters. The comparative results are also plotted in
FIG. 4.
Example 6
[0053] A 21-ounce beverage cup was constructed and tested in the
manner described above in Example 5, except that the external
surface of the cup was embossed with a checkered pattern. The
results are plotted in FIG. 5 as the "Example 6" data points,
together with the same comparative results shown in FIG. 4.
Example 7
[0054] A 21-ounce beverage cup was constructed and tested in the
manner described above in connection with Example 5, except that
the second, outer layer included ground wood particles with
particle sizes ranging from about 100 to about 1000 microns,
thereby resulting in a board having a basis weight of about 180
pounds per 3000 square feet. The test results are plotted in FIG. 6
as the "Example 7" data points, together with the same comparative
results shown in FIGS. 4 and 5.
Example 8
[0055] The 21-ounce beverage cup Example 6 was tested for
compression strength, both before the introduction of the ice-water
mixture and immediately after two hours with the ice-water mixture.
The compression force was measured at 5 percent deformation with
the cup in a horizontal configuration (i.e., perpendicular to the
vertical axis of the cup) using an INSTRON brand compression
testing machine, available from Illinois Tool Works, Inc. of
Glenview, Ill. The results are provided in Table 2 and are plotted
in FIG. 7 (the "Example 8" data points) versus total condensate
formation after 2 hours with the ice-water mixture.
TABLE-US-00002 TABLE 2 Initial After 2 Hours With Ice Water
Compression Compression Condensate Sample Strength (lbs.) Strength
(lbs.) Formation (g) Double Wall 9.00 3.83 0.20 Solo Two Ply 3.95
1.35 0.24 Perfect Touch 3.15 2.10 2.10 Insulair 2.65 1.70 1.90
Control 0.34 0.31 3.00
[0056] For comparison, the same compression strength test was
performed on the Perfect Touch, Insulair and Control cups used for
comparison in Examples 5-7, as well as on a large two-ply cup
("Solo Two Ply") sold under the SOLO brand name by the Solo Cup
Company of Chicago, Ill. The results of the comparative tests are
also provided in FIG. 7.
[0057] Accordingly, beverage containers formed in accordance with
the present disclosure exhibit surprisingly low surface
condensation formation, similar to STYROFOAM cups, but may be
biodegradable, unlike STYROFOAM cups. Furthermore, beverage
containers formed in accordance with the present disclosure
maintain significantly high compression force (e.g., greater than
2.5 pounds), even after holding a cold beverage for 2 hours.
[0058] Although various aspects of the disclosed paperboard-based
beverage container have been shown and described, modifications may
occur to those skilled in the art upon reading the specification.
The present application includes such modifications and is limited
only by the scope of the claims.
* * * * *