U.S. patent application number 12/612111 was filed with the patent office on 2010-05-06 for insulated double-walled disposable plastic cup.
This patent application is currently assigned to The Coca-Cola Company. Invention is credited to Qiuchen Peter Zhang, Liguo Zhao.
Application Number | 20100108693 12/612111 |
Document ID | / |
Family ID | 42130173 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100108693 |
Kind Code |
A1 |
Zhang; Qiuchen Peter ; et
al. |
May 6, 2010 |
INSULATED DOUBLE-WALLED DISPOSABLE PLASTIC CUP
Abstract
A thermally insulated double-walled disposable plastic container
includes a container body having an inner cup and outer cup fixedly
separated by an insulating space. The thermally insulated
double-walled disposable plastic container is open at the top and
enclosed at the bottom. The insulating space includes a gas for
providing thermal insulation. A preferred gas is air. Preferred
methods for making the insulated disposable double-walled plastic
container includes blow-molding, thermoforming or injecting molding
an inner cup and outer cup then fixedly connecting the inner cup
and outer cup to define an insulation space there between.
Inventors: |
Zhang; Qiuchen Peter;
(Alpharetta, GA) ; Zhao; Liguo; (Holland,
OH) |
Correspondence
Address: |
THE COCA-COLA COMPANY;PATENT & TECHNOLOGY DEPT--NAT 19
P. O. BOX 1734
ATLANTA
GA
30301
US
|
Assignee: |
The Coca-Cola Company
Atlanta
GA
|
Family ID: |
42130173 |
Appl. No.: |
12/612111 |
Filed: |
November 4, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61111096 |
Nov 4, 2008 |
|
|
|
Current U.S.
Class: |
220/592.2 ;
156/145; 220/62.11 |
Current CPC
Class: |
B65D 81/3869 20130101;
B65D 1/265 20130101 |
Class at
Publication: |
220/592.2 ;
220/62.11; 156/145 |
International
Class: |
B65D 3/22 20060101
B65D003/22; B65D 81/38 20060101 B65D081/38; B65D 8/04 20060101
B65D008/04 |
Claims
1. A thermally insulated disposable plastic container, comprising:
i. a plastic outside wall having a thickness of about 0.005 to
about 0.030 inches; ii. a plastic inside wall having a thickness of
about 0.001 to about 0.012 inches iii. an insulation layer
sandwiched between said plastic outside wall and said plastic
inside wall; and iv. a plastic base closure connected to a bottom
portion of said plastic outside wall and said plastic inside wall,
whereby said plastic outside wall and said plastic inside wall
cooperate to define a an insulation layer having a thickness of
about 0.025 to about 0.250 inches there between for providing
thermal insulation for any material disposed within said container
and wherein said insulation layer comprises a gas.
2. The container of claim 1, wherein said gas comprises air,
nitrogen, pentane, hydrocarbon gas or combinations thereof.
3. The container of claim 1, wherein at least said plastic outside
wall and said plastic inside wall have a transparency value of from
about 80 to 100%.
4. The container of claim 1, wherein at least said plastic outside
wall and said plastic inside wall are translucent.
5. The container of claim 1, wherein said plastic outside wall and
said plastic inside wall are attached by a process comprising
welding, ultrasonic welding, chemical adhesives, rim rolling, snap
fit sealing or a combination thereof.
6. The container of claim 1, further comprising one or more
circular horizontal ribs, rectangular vertical ribs or a
combination thereof formed between the said plastic inside wall and
said plastic outside wall.
7. The container of claim 1, wherein said plastic base closure is
double-walled and is defined by said plastic inside wall and said
plastic outside wall.
8. A double-walled disposable cup comprising an outer cup and an
inner cup formed of a polymer based material, said inner cup and
said outer cup coming together near or at an upper rim of said cup
to form an annular space there between, wherein said inner cup has
a wall thickness of from about 0.001 to about 0.012 inches, said
outer cup has a wall thickness of about 0.005 to about 0.030 inches
and said annular space is about 0.025 to about 0.250 inches
wide.
9. The double-walled cup of claim 8 wherein at least one of said
inner cup or said outer cup is tapered toward the other in a
section of the cup below where said inner cup and said outer cup
come together.
10. The double-walled cup of claim 8 wherein said inner cup and
said outer cup are substantially parallel before coming together
near said upper rim of said cup.
11. The double-walled cup of claim 8 wherein said inner cup and
said outer cup form said rim of said cup.
12. The double-walled cup of claim 11 wherein the inner cup and
outer cup both have an overhang rim that are rolled together to
form a unitary curled rim for said cup.
13. The double-walled cup of claim 8 wherein an upper section of
said outside cup near said rim comprises at least one locking
protrusion for engaging an upper section of said inside cup near
said rim, whereby said at least one locking protrusion slopes
inwardly and downwardly of said upper section of said outside cup
to provide an engagement section for said inner cup; and wherein a
section of said inner cup is formed to extend above and over the
top of the outer cup and further extending downwardly to engage
said at least one locking protrusion of the outer cup via an inner
protrusion of said inner cup that slopes inwardly and downwardly to
engage and seal with the at least one locking protrusion.
14. The double-walled cup of claim 13, wherein an upper section of
said outside cup near said rim further comprises a second locking
protrusions for engaging a lid.
15. The double-walled cup of claim 8 wherein both said inner cup
and said outer cup are transparent or translucent.
16. The double-walled cup of claim 8, wherein said polymer based
material comprises polypropylene, polyethylene terephthalate,
polylactic acid, polystyrene or a combination thereof.
17. The double-walled cup of claim 8, wherein said annular space is
divided into at least four equal parts having at least two
double-walled portions.
18. The double-walled cup of claim 17, wherein said at least four
equal parts alternate between double-walled and single walled
sections.
19. A method of forming a double-walled disposable plastic cup
comprising the steps of: i. forming an outer cup having a wall
thickness of about 0.005 to about 0.030 inches ii. forming an inner
cup having a wall thickness of from about 0.001 to about 0.012
inches iii. fixedly attaching said inner cup and said outer cup
together near or at an upper rim of said cup and forming a space
comprising a gas between said inner cup and said outer cup, wherein
said space is about 0.025 to about 0.250 inches thick.
20. The method of claim 19, wherein said step of forming said outer
cup comprises blow molding an outer bottle from a thermoplastic
polymer and trimming said outer bottle to form said outer cup; or
said step of forming said inner cup comprises blow molding an inner
bottle from a thermoplastic polymer and trimming said inner bottle
to form said inner cup.
21. The method of claim 19, wherein said step of fixedly attaching
said inner cup and said outer cup comprises welding, ultrasonic
welding, chemical adhesion, rim rolling, snap fit sealing or a
combination thereof.
22. The method of claim 19, wherein at least said step of forming
said outer cup or forming said inner cup comprises
thermoforming.
23. The method of claim 20, wherein at least one of said step of
forming said outer cup or forming said inner cup comprises
injection molding and wherein at least one of said step of forming
said outer cup or forming said inner cup comprises a blow molding
process.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to disposable
plastic containers, and more particularly to thermally insulated
disposable plastic containers. More specifically, the present
invention relates to double-walled thermally insulated disposable
plastic containers.
BACKGROUND OF THE INVENTION
[0002] The production and use of thermally insulated disposable
containers, such as cups, are well known and highly desirable.
Thermally insulated disposable cups are generally useful for both
hot and cold beverages. They are designed to maintain the beverage
temperature by preventing undesirable heat transfer via the
beverage inside the cup to/from the atmosphere or cup holder's
hand. Currently available thermally insulated disposable cups are
generally made from paper, polymeric materials or combinations
thereof.
[0003] Paper-based materials are generally favored for disposable
cups, because of low cost and high volume production capability.
However, paper-based materials generally do not have good barrier
properties to liquids. Disposable cups made from such paper-based
materials, have a tendency to decompose due to liquid penetration
into the paper material, which can cause the cup to loose its
structure and become soggy or leak. Furthermore, cups made from
paper-based materials generally do not provide adequate thermal
insulation and have limited product visibility.
[0004] There have been many attempts to provide improved thermal
insulation to paper-based disposable cups. U.S. Pat. No. 5,226,585
to Varano discloses a double-walled disposable cup made from
paper-based materials, which has a smooth walled inner cup and an
outer wrap with inwardly directed ribs being useful to maintain a
gap between the walls to provide thermal insulation. However, these
cups are difficult and expensive to manufacture. They also tend to
exhibit liquid barrier problems, which compromise the structural
integrity of the cup.
[0005] U.S. Pat. No. 5,145,107 to Silver et al. teaches a
double-walled thermal insulated disposable paper cup having an
inner wall connected to an outer wall at the lip and at the base of
the cup. The walls have different tapers which define an air pocket
between the two walls. The air pocket is meant to provide thermal
insulation. However, as with currently available paper-based
disposable cups, structural integrity and product visibility remain
a disadvantage.
[0006] Polymeric materials, such as polypropylene, polyethylene
terephthalate (PET) based polyesters and polystyrenes have been
widely used as container materials for disposable containers
because of their improved mechanical and barrier properties. They
also provide for product visibility. Numerous methods of producing
disposable plastic beverage bottles and cups are disclosed in the
prior art. However, containers made from such plastic materials do
not provide adequate thermal insulation. Foamed polystyrene cups
provide adequate insulation but are not good for recyclability and
don't provide transparency.
[0007] Accordingly, there is a need for a disposable container that
provides excellent thermal insulation and barrier properties and is
recyclable. It would also be desirable to see the inside of the
container from the sides of the container, thereby having better
visibility of the product contained therein. In paper based or
foamed polystyrene containers, in order to see the contents inside,
it is necessary to look through an opening, for example by removing
a lid, which could result in spills or additional heat transfer via
the opening. Accordingly, it would be desirable to provide a
transparent thermally insulated disposable plastic container.
SUMMARY OF THE INVENTION
[0008] The present invention relates to a thermally insulated
double-walled disposable container made from polymeric materials
useful for containing hot or cold products and liquids. Thermally
insulated double-walled disposable containers in accordance with
the invention provide recyclability, enhanced container structural
integrity and improved insulation. In addition, a container in
accordance with the invention may be transparent. Conventional
methods may be used to manufacture a thermally insulated
double-walled disposable container in accordance with the
invention. The manufacturing of the containers are cost
effective.
[0009] In an aspect of the invention, a thermally insulated
double-walled disposable plastic container includes a container
body having an inner cup and outer cup fixedly separated by a
space. The thermally insulated double-walled disposable plastic
container is open at the top and enclosed at the bottom. The space
includes a gas for providing thermal insulation. A preferred gas is
air. Preferred methods for making the insulated double-walled
disposable plastic container includes blow-molding, thermoforming
or injecting molding an inner cup and outer cup then fixedly
connecting the inner cup and outer cup to define an insulation
space there between.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross-sectional view of one embodiment of a
container in accordance with the invention.
[0011] FIG. 1A is an enlarged view of a wall connection in
accordance with the invention.
[0012] FIG. 1B is an enlarged view of an alternate wall connection
in accordance with the invention.
[0013] FIG. 1C is an enlarged view of a yet another alternate wall
connection in accordance with the invention.
[0014] FIG. 2 is a cross-sectional view of a tapered walled
container in accordance with the invention.
[0015] FIG. 2A is an enlarged view of a wall connection of a
tapered walled container of the invention.
[0016] FIG. 2B is an enlarged view of alternate wall connection of
a tapered walled container of the invention.
[0017] FIG. 2C is an enlarged view of a yet another alternate wall
connection of a tapered walled container of the invention.
[0018] FIG. 3 is a top view of a container divided into four equal
parts having two double-walled portions in accordance with the
invention.
[0019] FIG. 4 is a top view of a container divided into six equal
parts having three double-walled portions in accordance with the
invention.
[0020] FIG. 5 is a perspective view of horizontal ribs between
walls of a container of the invention
[0021] FIG. 6 is a perspective view of vertical ribs between walls
of a container of the invention.
[0022] FIG. 7 is a perspective view of one embodiment of a
container with both horizontal and vertical ribs between the
walls.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0023] The present invention provides a thermally insulated
double-walled disposable plastic container having excellent
insulation properties, recyclability, and optionally transparency.
As used herein the term "plastic" refers to a wide range of
synthetic or semi-synthetic polymerization products, composed of
organic condensation or addition polymers and may contain other
substances, including bio materials and recycled content, to
improve performance or reduce costs. "Disposable" as used herein is
meant to describe articles that are most often discarded after one
use. "Double-walled" as used herein refers to a structure that
includes an inside wall, an outside wall, and a space defined
between the inside wall and outside wall. The term "insulated or
insulating" as used here in refers generally to the prevention of
reduction of heat transfer from conducting bodies. The term
"insulated double-walled disposable plastic container" may
alternatively be referred to as `container` for convenience. As
used herein the terms inside wall and inside cup generally refer to
the same structure and outside wall and outside cup generally refer
to the same structure where the container is a cup, and
respectively may be used interchangeably.
[0024] Referring now to FIG. 1, there is shown a container 100. In
one embodiment of the invention, the container 100 is preferably a
double-walled disposable plastic cup. The container 100 includes an
inside wall or cup 102 and an outside wall or cup 104. The inside
wall or cup 102 and the outside wall or cup 104 are fixedly
separated by an insulation space 106 between them, and joined at an
upper section of the container to enclose the insulation space 106.
The container 100 includes an interior space 110 for containing
food or beverages. The inside wall or cup 102 and the outside wall
or cup 104 may be any suitable shape, but in a preferred embodiment
are frusto-conical in shape with an opening at the top and a base
section 108 for providing a closed end. In an embodiment of the
invention, the base section 108 is also double-walled. A
double-walled base section 108 preferably comprises an inwardly
extending protrusion 130 that connects the inside wall or cup 102
and an outside wall or cup 104 to help provide an even distribution
of gas or air in the insulation space 106. In another embodiment of
the invention, the base section 108 may be single-walled (not
shown). "Single-walled" as used herein refers to a structure that
includes only a single layer or a structure that does not have an
insulating layer. As shown, the inside wall or cup 102 and outside
wall or cup 104 may be formed parallel to each other or any
suitable design, including but not limited to tapered. In an
embodiment of the invention, vertical ribs are welded on the inside
wall or cup 102 and the outside wall or cup 104 for additional
strength.
[0025] The inside wall or cup 102, the outside wall or cup 104 and
the base section 108 may be formed of any suitable plastic.
Preferred plastics include polypropylene (PP), polyethylene
terephthalate (PET), polylactic acid (PLA), polystyrene (PS) or
combinations thereof. It is also preferred that the plastic be food
grade plastic.
[0026] Insulation space 106 preferably comprises a gas. Any
suitable gas may be used. It is preferred that such gas provides
insulation properties equal to or better than air. Preferred gases
include air, nitrogen, and hydrocarbon gases such as pentane or
combinations thereof.
[0027] In accordance with an embodiment of the invention,
preferably, the outside wall or cup 104 is preferably of from about
0.005 to 0.030 inches in thickness and more preferably of from
about 0.010 to 0.020 inches in thickness; and the inside wall or
cup 102 is preferably of from about of 0.001 to 0.012 inches in
thickness and more preferably about 0.005 to 0.010. The space 106
between the inside wall 102 and the outside wall 104 is preferably
between 0.025 and 0.250 inches, more preferably, between 0.100 and
0.200 inches and even more preferably, between 0.130 and 0.150
inches.
[0028] In one embodiment of the invention, the container 100 is
transparent. In this embodiment it is preferred that at least the
inside wall or cup 102 and the outside wall or cup 104 are
transparent. The inside wall or cup 102 and the outside wall or cup
104 are preferably formed from any suitable food grade plastic
having transparent properties and a transparency value of 80 to
100%. While it is to be understood that the base section 108 also
may be transparent, it is not required by the invention.
[0029] In one embodiment of the invention, the container 100 is
translucent. In this embodiment it is preferred that at least the
inside wall 102 and the outside wall 104 are translucent. The
inside wall 102 and the outside wall 104 are preferably formed from
any suitable food grade plastics having translucent properties.
While it is to be understood that the base section 108 also may be
translucent, it is not required by the invention. The container may
be any suitable color and it is also envisioned that the container
may be opaque.
[0030] The container 100 may be of any suitable size. In an
embodiment of the invention, the container 100 can also be of the
size and shape of a commonly used take-out container to store food
or beverages. The take-out container may be of any shape, without
limitation, such as a box-type container. In an embodiment of the
invention, the container can be put in a microwave or freezer. In
various embodiments, the container may have a length larger than
the height. In a preferred embodiment of the invention, the base
preferably is double-walled.
[0031] In an embodiment, wherein the container 100 is a cup, the
cup may be of any suitable size. For example, the cup can be made
in sizes generally used in restaurants and coffee shops, including
but not limited to 12, 16, 20, 21, 22, 32 and 44 oz cups.
[0032] The inside wall or cup 102 and outside wall or cup 104 may
be joined or connected by any suitable techniques. A person skilled
in the art would appreciate that various chemical or mechanical
techniques may be used to join inside wall or cup 102 and outside
wall or cup 104 such as, without limitation, welding, ultrasonic
welding, adhesive sealants, rim rolling or snap fitting sealing
engagement. FIG. 1A is an enlarged view of a preferred wall
connection 113 by welding or using an adhesive sealant. FIG. 1B is
an enlarged view of a preferred wall connection, wherein the inside
wall or cup 102 and outside wall or cup 104 both have an overhang
rim that are rolled together by a conventional rim rolling process
to form a curled overturned rim 112. The upper rim or periphery 114
of the inside wall or cup 102 is curled over the curl of the
outside wall or cup 104. Such double curling also enhances the
rigidity of the container 100.
[0033] FIG. 1C is an enlarged view of yet another preferred wall
connection technique for a substantially parallel walled container
100, whereby a snap fitting sealing engagement forms a wall sealing
engagement 113' that fixedly attaches the outside wall 104 and
inside wall 102. The snap fitting sealing engagement is
advantageous particularly in the case where a lid 120 may be used
in connection with the container 100. In a preferred embodiment,
the outside wall 104 is preferably provided with at least two
locking protrusions 116 and 118 for engaging the inside wall 102
and a lid 120, respectively. Preferably, a first outside wall
locking protrusion 116 slopes inwardly and downwardly from a top
section of the outside wall 104 to provide an engagement section
for the inside wall 102. The inside wall 102 is substantially
parallel to the outside wall and extends above and over the top of
the outside wall 104, further extending downwardly to engage an
inside wall locking protrusion 116 of the outside wall 104 via an
inside wall inner protrusion 117 that slopes inwardly and
downwardly to engage and seal with the first outside wall locking
protrusion 116. A second outside wall locking protrusion 118 slopes
outwardly and downwardly below the first outside wall protrusion
116 to provide an engagement section for the lid 120. The lid 120
preferably extends below the first outside wall locking protrusion
116 and has a lid locking protrusion 119 that slopes inwardly to
engage the second outside wall locking protrusion 118 and seal the
lid to the cup.
[0034] In another embodiment of the invention, shown in FIG. 2, the
top section of the outside wall or cup 204 and the inside wall or
cup 202 have a difference in taper. Any suitable angle may be used
for the taper. As with the previous embodiment, the inside wall or
cup 202 and outside wall or cup 204 may be connected by any
suitable techniques. In a double-walled base embodiment, there is
provided a centering ring 230 that connects the walls or the
container to create a concentric gas gap and even distribution of
gas between the outside wall or cup 204 and the inside wall or cup
202.
[0035] FIG. 2A is an enlarged view of a cut-out section of a
preferred wall or cup connection 213 formed by welding or gluing.
The outside wall or cup 204 of the inside wall or cup 202 is sealed
via an adhesive or welded in any suitable section of the container
from the upper end of the taper to an outwardly extending lip or
bend of the outside wall 204. The upper rim or periphery 214 of the
inside wall or cup 202 is preferably formed over and welded to the
lip or bend 212 of the outside wall or cup 204.
[0036] FIG. 2B is an enlarged view of a preferred tapered walled
connection, where at a suitable point after the taper whereby the
inside wall or cup 202 and outside wall or cup 204 meet, the
overhang from both the inside wall or cup 202 and outside wall or
cup 204 are rolled together by a conventional rim rolling process
to form a curled overturned rim 212.
[0037] FIG. 2C is an enlarged view of yet another preferred wall
connection technique for a tapered wall container 200, whereby a
snap fitting sealing engagement forms a wall sealing engagement
213' that fixedly attaches the outside wall or cup 204 and inside
wall or cup 202. The snap fitting sealing engagement is
advantageous particularly in the case where a lid 220 may be used
in connection with the container 200. In a preferred embodiment,
the outside wall or cup 204 is preferably provided with at least
two locking protrusions 216 and 218 for engaging the inside wall or
cup 202 and a lid 220, respectively. Preferably, a first outside
wall locking protrusion section 216 having an interior surface that
slopes inwardly and downwardly from a top section of the outside
wall or cup 204 to provide a clasp section for the inside wall 202
having a contact point 221 for a flat outer surface of the inside
wall or cup 202 and an inside wall inner protrusion 217 to pinch
the first outside wall locking protrusion section 216. The inside
wall or cup 202 tapers toward the outside wall or cup 204 at any
suitable position below the first outside wall locking protrusion
section and extends above and over the top of the outside wall or
cup 204, further extending downwardly to engage an flat outer
surface of the first outside wall locking protrusion section 216
via the inside wall inner protrusion 217 that slopes inwardly and
downwardly to pinch the first outside wall locking protrusion
section 216. A second outside wall locking protrusion 218 slopes
outwardly and downwardly below the first outside wall protrusion
section 216 to provide an engagement section for the lid 220. The
lid 220 preferably extends below the first outside wall locking
protrusion section 216 and has a lid locking protrusion 219 that
slopes inwardly to engage the second outside wall locking
protrusion 218 and seal the lid 220 to the container.
[0038] In various embodiments of the invention, the double wall is
provided only to a portion of the container. The container may be
divided into double-walled and single-walled portions. For example,
the container may be divided into four parts out of which two are
double-walled. FIG. 3 is a top view of the container 300 in an
embodiment of the invention. The circumference of container 300 is
divided into four equal parts having two double-walled portions. In
a preferred embodiment, two alternate parts 302a, and 302b are
double-walled while the other two 304a and 304b are single walled.
FIG. 4 is a top view of the container 400 in an embodiment of the
invention. The circumference of container 400 is divided into six
equal parts having three double-walled portions. In a preferred
embodiment, three alternate parts 402a, 402b, and 402c are
double-walled while the other three 404a, 404b, and 404c, are
single walled.
[0039] In an embodiment of the invention shown in FIG. 5, the
container 500 has horizontal ribs 506 between the inside wall or
cup 502 and the outside wall or cup 504. The horizontal ribs 506
are circular in shape and divide the annular region between the
inside wall or cup 502 and the outside wall or cup 504 into number
of horizontal sub-regions. The horizontal ribs 506 reduce
convection heat loss by blocking air circulation between
sub-regions. As a result, the horizontal ribs 506 enhance the
thermal insulation performance of the container 500. In an
embodiment of the invention, the horizontal ribs 506 are preferably
about 8 mm apart. The horizontal rib thickness is preferably
between about 0.001 inch and about 0.010 inch.
[0040] In another embodiment shown in FIG. 6, the container 600 has
vertical ribs 606 between the inside wall or cup 602 and the
outside wall or cup 604. The vertical ribs 606 are rectangular in
shape and divide the annular region between the inside wall or cup
602 and the outside wall or cup 604 into number of vertical
sub-regions. The vertical ribs 606 reduce convection heat loss by
blocking air circulation between sub-regions. As a result, the
vertical ribs 606 enhance thermal insulation performance of the
container 600. In an embodiment of the invention, the vertical ribs
606 are preferably about 8 mm apart. The vertical rib thickness is
preferably between about 0.001 inch and about 0.010 inch.
[0041] In yet another embodiment shown in FIG. 7, the container 700
has both horizontal ribs 706 and vertical ribs 708 that form grids
between the inside wall or cup 702 and the outside wall or cup 704.
The grids are preferably square or rectangular. The horizontal ribs
706 and the vertical ribs 708 reduce convection heat loss by
blocking air circulation between grids. As a result, the horizontal
ribs 706 and the vertical ribs 708 enhance thermal insulation
performance of the container 700. In an embodiment of the
invention, the grids are of square shape and are preferably about 8
mm by 8 mm. The thickness of the grids is preferably between about
0.001 inch and about 0.010 inch.
[0042] A double-walled disposable plastic container in accordance
with the invention may be formed by any suitable means. In
accordance with another embodiment of the invention the container
may be manufactured by conventional blow molding and trimming
techniques. Generally a bottle is first formed by a conventional
blow molding process. Then the top portion and the body of the
bottle are separated into two pieces by a trimming process. The
resultant body portion forms a cup. Any thermoplastic polymer can
be used to prepare the perform, for example, polypropylene (PP),
polyethylene terephthalate (PET), polylactic acid (PLA),
polystyrene (PS) or combinations thereof. It is also preferred that
the plastic be food grade plastic. Preferred products are
polypropylene (PP), polyethylene terephthalate (PET). In yet
another embodiment of the invention, the inside and outside walls
or cups are formed by a thermoforming process.
[0043] Injection molding is also a process that may be used to form
a container in accordance with the invention. For example, both the
inner wall or cup and the outer wall or cup may be formed by
injection molding the walls or cups and then joining the walls or
cups together by the means described above. The inner wall or cup
and outer wall or cup may also be made separately on different
molding machines or made on the same machine at different
locations. It should also be understood that one or more of the
wall forming processes described herein may be used alone or in
combination. For example, in accordance with one embodiment of the
invention, the outside wall or cup may be injection molded to
provide rigidity having a thickness in the range of about 0.005
inch to about 0.020 inch and the inside wall or cup may be blown
and trimmed to have a thickness preferably in the range of about
0.001 inch to about 0.010 inch.
[0044] It should be apparent that the foregoing relates only to the
preferred embodiments of the present application and that numerous
changes and modifications may be made herein by one of ordinary
skill in the art without departing from the general sprit and scope
of the invention as defined by the following claims and equivalents
thereof.
* * * * *