U.S. patent application number 12/319615 was filed with the patent office on 2009-05-14 for disposable thermally insulated cup and blank therefor.
Invention is credited to Gerald J. Van Handel.
Application Number | 20090121007 12/319615 |
Document ID | / |
Family ID | 23186698 |
Filed Date | 2009-05-14 |
United States Patent
Application |
20090121007 |
Kind Code |
A1 |
Van Handel; Gerald J. |
May 14, 2009 |
Disposable thermally insulated cup and blank therefor
Abstract
A container blank comprises at least one substrate layer made of
disposable material and at least one film layer disposed
substantially over the substrate layer and having at least one
portion adapted to shrink away from the substrate layer upon
application of heat. The shrunk film layer portion is adapted to
thermally insulate the substrate layer located substantially behind
the shrunk film layer portion.
Inventors: |
Van Handel; Gerald J.;
(Neenah, WI) |
Correspondence
Address: |
PATENT GROUP GA030-43;GEORGIA-PACIFIC LLC
133 PEACHTREE STREET, N.E.
ATLANTA
GA
30303-1847
US
|
Family ID: |
23186698 |
Appl. No.: |
12/319615 |
Filed: |
January 9, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11613834 |
Dec 20, 2006 |
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12319615 |
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10797949 |
Mar 10, 2004 |
7464856 |
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11613834 |
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Current U.S.
Class: |
229/403 |
Current CPC
Class: |
B29C 61/02 20130101;
B32B 37/0076 20130101; Y10S 493/907 20130101; B31B 2105/001
20170801; B32B 37/1292 20130101; B65D 81/3869 20130101; B32B 37/153
20130101; B32B 2439/02 20130101; B32B 2317/12 20130101; Y10T
428/1303 20150115; Y10T 428/1328 20150115; Y10T 428/2481 20150115;
B32B 2307/736 20130101; B29L 2031/7132 20130101 |
Class at
Publication: |
229/403 |
International
Class: |
B65D 3/00 20060101
B65D003/00 |
Claims
1. A beverage container, comprising: (a) a sidewall having an outer
surface and an inner surface as well as one or more perforations to
allow air intrusion; and (b) at least one air pocket formed on said
inner surface by at least one strip of shrink film being coupled to
said inner surface in at least one pattern and adapted to pull away
from said inner surface of said sidewall according to said at least
one pattern upon application of heat sufficient to form said at
least one air pocket, said at least one air pocket thermally
insulating a portion of said outer surface located directly behind
said at least one air pocket.
2. The container according to claim 1, wherein the shrink film is
secured to the inner surface of said sidewall with a plurality of
generally parallel equally spaced seal lines extending from the
lower portion of the sidewall to the upper portion thereof such
that the shrunk film provides a plurality of generally parallel,
generally vertically oriented thermally insulating air pockets
extending from the lower portion of the sidewall of the container
to the upper portion of the sidewall of the container.
3. The container according to claim 1, wherein the shrink film is
secured to the inner surface of said sidewall with a plurality of
generally criss-crossing seal lines defining a diamond-like pattern
extending from the lower portion of the sidewall to the upper
portion thereof such that the shrunk film provides a plurality of
thermally insulating air pockets on both the lower portion of the
sidewall of the container and the upper portion of the sidewall of
the container.
4. The container according to claim 1, wherein the shrink film
layer is secured to the inner surface of said sidewall with a
plurality of generally equally spaced seal points on both the lower
portion of the sidewall and the upper portion thereof such that the
shrunk film provides a plurality of thermally insulating air
pockets on both the lower portion of the sidewall of the container
and the upper portion of the sidewall of the container.
5. The container according to claim 4, wherein the shrink film
layer is secured to the inner surface of said sidewall with a
plurality of generally equally spaced seal points arranged in a
square pattern.
6. The container according to claim 1, wherein the shrink film
layer is secured to the inner surface of said sidewall with a
plurality of generally parallel equally spaced seal lines extending
across the lower portion of the sidewall and the upper portion
thereof such that the shrunk film provides a plurality of generally
parallel, generally horizontally oriented thermally insulating air
pockets extending circumferentially around the sidewall of the
container on both the upper and lower portions of the sidewall of
the container.
7. A beverage container, comprising: (a) a sidewall extending
between a closed bottom and an open top, said sidewall having an
outer surface, an inner surface, and a substantially elongated seam
area defined between said closed bottom and said open top as well
as one or more perforations to allow air intrusion; and (b) at
least one substantially horizontal air pocket formed on said inner
surface by at least one strip of shrink film being coupled to said
inner surface in at least one pattern and adapted to pull away from
said inner surface of said sidewall according to said at least one
pattern upon application of heat at a temperature range sufficient
to form said at least one substantially horizontal air pocket, said
at least one substantially horizontal air pocket adapted to cover
said substantially elongated seam area and to thermally insulate a
portion of said outer surface located directly behind said at least
one substantially horizontal air pocket.
8. A beverage container, comprising: (a) a sidewall extending
between a closed bottom and an open top, said sidewall having an
outer surface, an inner surface, and a substantially elongated seam
area defined between said closed bottom and said open top as well
as one or more perforations to allow air intrusion; and (b) at
least one substantially horizontal air pocket formed on said inner
surface by at least one strip of shrink film being coupled to said
inner surface in at least one pattern and adapted to pull away from
said inner surface of said sidewall according to said at least one
pattern upon application of heat sufficient to form said at least
one substantially horizontal air pocket, said at least one
substantially horizontal air pocket adapted to thermally insulate a
portion of said outer surface located directly behind said at least
one substantially horizontal air pocket except for said
substantially elongated seam area.
9. The beverage container of claim 8, wherein heat is applied at a
temperature range of about 180.degree.-190.degree. F.
10. A container blank, comprising: (a) a substrate layer made of a
disposable material suitable for forming a sidewall of a container,
wherein the substrate layer has an interior and an exterior as well
as one or more perforations to allow air intrusion; (b) a shrink
film layer having upper and lower portions corresponding to their
relative positions on the sidewall of the container, secured to the
interior of the substrate layer on both the upper and lower
portions of the shrink film layer, wherein the shrink film layer is
adapted to shrink away from the substrate layer upon application of
heat thereto, thereby providing a shrunk film layer secured to the
interior of the substrate layer on both the upper and lower
portions of the shrink film layer after heat is applied to the
shrink film layer; and whereby the shrunk film layer provides at
least one thermal insulating pocket between the substrate layer and
the shrunk film layer and wherein the shrunk film layer is secured
at both its upper and lower portions to the container sidewall.
11. The container blank of claim 10, wherein the shrink film is
capable of automatically pulling away from the interior of the
substrate layer at a temperature range of about
180.degree.-190.degree. F.
12. The container blank according to claim 10, wherein the shrink
film layer is a biaxially oriented shrink film.
13. The container blank according to claim 10, wherein the shrink
film layer is a uniaxially oriented shrink film.
14. The container blank according to claim 10, wherein the shrink
film layer is secured to the inner surface of the substrate layer
by a method selected from the group consisting of extrusion
coating, rotary heat sealing, and adhesive lamination.
15. The container blank according to claim 10, wherein the shrink
film layer is secured to the interior of the substrate layer with a
plurality of generally parallel equally spaced seal lines extending
from the lower portion of the shrink film layer to the upper
portion thereof such that the shrunk film provides a plurality of
generally parallel, generally vertically oriented thermally
insulating air pockets extending from the lower portion of the
sidewall of a container made from the blank to the upper portion of
the sidewall of the container made from the blank.
16. The container blank according to claim 10, wherein the shrink
film layer is secured to the interior of the substrate layer with a
plurality of generally criss-crossing seal lines defining a
diamond-like pattern extending from the lower portion of the shrink
film layer to the upper portion thereof such that the shrunk film
provides a plurality of thermally insulating air pockets on both
the lower portion of the sidewall of a container made from the
blank and the upper portion of the sidewall of the container made
from the blank.
17. The container blank according to claim 10, wherein the shrink
film layer is secured to the interior of the substrate layer with a
plurality of generally equally spaced seal points on both the lower
portion of the shrink film layer and the upper portion thereof such
that the shrunk film provides a plurality of thermally insulating
air pockets on both the lower portion of the sidewall of a
container made from the blank and the upper portion of the sidewall
of the container made from the blank.
18. The container blank of claim 17, wherein the shrink film layer
is secured to the interior of the container blank with a plurality
of generally equally spaced seal points arranged in a square
pattern.
19. The container blank according to claim 10, wherein the shrink
film layer is secured to the interior of the substrate layer with a
plurality of generally parallel equally spaced seal lines extending
across the lower portion of the shrink film layer and the upper
portion thereof such that the shrunk film provides a plurality of
generally parallel, generally horizontally oriented thermally
insulating air pockets extending circumferentially around the
sidewall of a container made from the blank on both the upper and
lower portions of the sidewall of the container made from the
blank.
Description
RELATED APPLICATIONS
[0001] This application is a continuation under 37 C.F.R.
.sctn.1.53 (b)(1) of co-pending U.S. patent application Ser. No.
11/613,834 which was a continuation of U.S. patent application Ser.
No. 10/797,949, now U.S. Pat. No. 7,464,856, which claims the
benefit of issued U.S. Pat. No. 6,729,534, which is a continuation
of issued U.S. Pat. No. 6,536,657, which claims the benefit of U.S.
Provisional Patent Application Ser. No. 60/306,757, filed Jul. 20,
2001, by the same inventor and having common Assignee, the contents
of the prior pending application, three patents, and Provisional
application are incorporated herein in their entirety by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to container blanks
and more particularly to a blank for a disposable thermally
insulated container such as a paper cup.
BACKGROUND OF THE INVENTION
[0003] Disposable paper cups with heat insulating capability are a
desirable and widely used commodity. These types of cups are
designed for hot liquid contents such as hot coffee/tea/chocolate
and tend to maintain the liquid contents' temperature by preventing
undesirable heat transfer from the hot liquid contents inside the
cup to the cup holder's hand holding the cup. These cups may also
be used for cold liquid contents in which case the insulated walls
of the cup help maintain the cold liquid contents' temperature by
preventing undesirable heat transfer from the cup holder's hand to
the cold liquid contents.
[0004] Thermally insulated cups come in various known
configurations. For example, an insulated cup is disclosed in
Amberg et al. (U.S. Pat. No. 3,737,093) which uses a plastic cup
placed within a paper cup to create air space therebetween for
thermal insulation purposes. Another insulated cup is disclosed by
Iioka (U.S. Pat. No. 4,435,344) which coats a paper cup with a
thermoplastic synthetic resin film which is subsequently heated to
form a foamed insulating layer. Neale et al. (U.S. Pat. No.
5,952,068) deals with a cup insulation layer formed from syntactic
foam, a type of foam which incorporates insulating particles held
in place by a binder. The insulating particles may contain an air
space.
[0005] None of the known insulated cups, however, is an effective
thermal insulator. Furthermore, none of the known insulated cups
can be manufactured at low cost on a wide scale due to complexity
of fabrication, high cost of materials, and the like.
SUMMARY OF THE INVENTION
[0006] The present invention is generally directed to a container
blank comprising at least one substrate layer made of disposable
material and at least one film layer disposed substantially over
the substrate layer and having at least one portion adapted to
shrink away from the substrate layer upon application of heat. The
shrunk film layer portion is adapted to thermally insulate the
substrate layer located substantially behind the shrunk film layer
portion.
[0007] These and other aspects of the present invention will become
apparent from a review of the accompanying drawings and the
following detailed description of the preferred embodiments of the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention is generally shown by way of example in the
accompanying drawings in which:
[0009] FIG. 1A is a side plan view of a first disposable insulated
cup blank comprising shrink film which is pattern adhered to a
paperboard substrate in a first sealing pattern in accordance with
the present invention;
[0010] FIG. 1B is a partially cut away front perspective view of a
disposable insulated cup formed from the blank of FIG. 1A in
accordance with the present invention;
[0011] FIG. 1C is a cross sectional view taken along line 1C-1C of
FIG. 1B;
[0012] FIG. 2A is a plan view of a second disposable insulated cup
blank comprising shrink film which is pattern adhered to a
paperboard substrate in a second sealing pattern in accordance with
the present invention;
[0013] FIG. 2B is a partially cut away front perspective view of a
disposable insulated cup formed from the blank of FIG. 2A in
accordance with the present invention;
[0014] FIG. 2C is a cross sectional view taken along line 2C-2C of
FIG. 2B;
[0015] FIG. 3A is a plan view of a third disposable insulated cup
blank comprising shrink film which is pattern adhered to a
paperboard substrate in a third sealing pattern in accordance with
the present invention;
[0016] FIG. 3B is a partially cut away front perspective view of a
disposable insulated cup formed from the blank of FIG. 3A in
accordance with the present invention;
[0017] FIG. 3C is a cross sectional view taken along line 3C-3C of
FIG. 3B;
[0018] FIG. 4A is a plan view of a fourth disposable insulated cup
blank comprising shrink film which is pattern adhered to a
paperboard substrate in a fourth sealing pattern in accordance with
the present invention;
[0019] FIG. 4B is a partially cut away front perspective view of a
disposable insulated cup formed from the blank of FIG. 4A in
accordance with the present invention;
[0020] FIG. 4C is a cross sectional view taken along line 4C-4C of
FIG. 4B;
[0021] FIG. 4D is a partially cut away front perspective view of a
disposable insulated cup formed from the blank of FIG. 4A in
accordance with an alternative embodiment of the present
invention;
[0022] FIG. 4E is a partially cut away front perspective view of a
disposable insulated cup formed from a modified blank of FIG. 4A in
accordance with another alternative embodiment of the present
invention;
[0023] FIG. 4F is a partially cut away front perspective view of a
disposable insulated cup formed from the modified blank of FIG. 4E
in accordance with yet another alternative embodiment of the
present invention;
[0024] FIG. 5 is side perspective view of a roller used in
accordance with the present invention;
[0025] FIG. 6 is a schematic representation of a rotary heat
sealing process in accordance with one embodiment of the present
invention;
[0026] FIG. 7 is a schematic representation of an adhesive
lamination process in accordance with another embodiment of the
present invention; and
[0027] FIG. 8 is a schematic representation of an extrusion coating
process in accordance with yet another embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Hereinafter, some preferred embodiments of the present
invention will be described in detail with reference to the related
drawings of FIGS. 1-8. Additional embodiments, features and/or
advantages of the invention will become apparent from the ensuing
description or may be learned by the practice of the invention.
[0029] In the Figures, the drawings are not to scale and reference
numerals indicate the various features of the invention, like
numerals referring to like features throughout both the drawings
and the description.
[0030] The following description includes the best mode presently
contemplated for carrying out the invention. This description is
not to be taken in a limiting sense, but is made merely for the
purpose of describing the general principles of the invention.
[0031] In accordance with a preferred embodiment of the present
invention and as generally shown in FIGS. 1A-1C, an elongated cup
blank 14 (FIG. 1A) used to form a disposable thermally insulated
cup 15 (FIG. 1B) is constructed from a paperboard substrate 20
having a strip of heat-activated shrink film 22 pattern-adhered to
one side along a plurality of generally vertical seal lines 24.
Heat-activated shrink film suitable for practicing the present
invention may be of the uniaxial or biaxial shrink film type which
is available commercially from shrink film manufacturers such as
DuPont.RTM. Corp. of Wilmington, Del. One example of a biaxial
shrink film is DuPont.RTM. CLYSAR ABL.RTM. industrial shrink film.
A uniaxial shrink film may be produced, for example, using an
extrusion coating technique described hereinbelow in reference to
FIG. 8.
[0032] In general, biaxial shrink films are preferred for
performance reasons. However, uniaxial shrink films provide
satisfactory performance and are generally easier to apply in
extrusion laminating and coating processes. The generally flat
vertical sealing band pattern depicted in FIG. 1A extends between
what will be an open cup top 16 (FIG. 1B) and a closed cup bottom
18 (FIG. 1B) of disposable thermally insulated cup 15. In one
example, seal lines 24 may be spaced apart by about one inch with a
seal line thickness of about one-sixteenth of an inch. Other seal
line configurations may be utilized provided such other
configurations do not depart from the intended purpose of the
present invention.
[0033] Elongated cup blank 14 has (opposing) side edges 21, 23
(FIG. 1A) which are sealed together along a generally elongated
seam 19 (FIGS. 1B-1C) to form disposable cup 15 (FIG. 1B) with the
pattern adhered shrink film 22 remaining on the interior side of
the cup. The exterior side of cup 15 may have decorative graphics
(not shown). The formed cup is then, preferably, run through an
oven at sufficiently high temperature and for a period of time
enough to cause heat-activated film 22 to sufficiently shrink, or
pull away from paperboard substrate 20 (between seal lines 24) so
as to form outwardly (away from the interior side of the cup)
bulging and generally vertical air pockets 30 (FIGS. 1B-1C) which
continuously run from bottom 18 to top 16 (of cup 15) over seam 19
and thermally insulate the entire exterior side of cup 15 from hot
liquid contents such as hot coffee, tea or the like. Actual amount
of shrinkage would also depend on film thickness. In general, care
should be exercised to pick a gauge of heat-activated shrink film
which would form pocket walls that do not easily puncture during
normal use.
[0034] A person skilled in the art would readily recognize that
thermally insulated disposable cup 15 of FIG. 1B may also be used
to insulate a cup holder's hand from ice-cold contents, e.g.
ice-cold soda, water, and the like.
[0035] In accordance with another preferred embodiment of the
present invention and as generally shown in FIGS. 2A-2C, an
elongated cup blank 34 (FIG. 2A) used to form a disposable
thermally insulated cup 35 (FIG. 2B) is constructed from a
paperboard substrate 39 having heat-activated shrink film 42
adhered to one side along a plurality of generally criss-crossing
seal lines 44. The sealing pattern depicted in FIG. 2A extends
between what will be an open cup top 36 (FIG. 2B) and a closed cup
bottom 38 (FIG. 2B) of disposable thermally insulated cup 35. In
one example, criss-crossing seal lines 44 may form generally flat
one-inch square or diamond-like pattern (FIG. 2A) with a seal line
thickness of about one-sixteenth of an inch.
[0036] Elongated cup blank 34 includes side edges 31, 33 (FIG. 2A)
which are sealed together along a generally elongated seam 37
(FIGS. 2B-2C) to form disposable cup 35 (FIG. 2B) with the pattern
adhered shrink film 42 remaining on the interior side of the cup.
The exterior side of cup 35 may have decorative graphics (not
shown). The formed cup is then, preferably, run through an oven at
sufficiently high temperature and for a period of time enough to
cause heat-activated film 42 to sufficiently shrink, or pull away
from paperboard substrate 39 (between seal lines 44) so as to form
outwardly (away from the interior side of the cup) bulging air
pockets 40 (FIGS. 2B-2C) which generally run from bottom 38 to top
36 (of cup 35) over seam 37 and thermally insulate the entire
exterior side of cup 35 from hot liquid contents such as hot
coffee, tea or the like. The newly formed thermally insulated
disposable cup 35 may also be used to insulate a cup holder's hand
from ice-cold contents.
[0037] In accordance with yet another preferred embodiment of the
present invention and as generally shown in FIGS. 3A-3C, an
elongated cup blank 49 (FIG. 3A) used to form a disposable
thermally insulated cup 55 (FIG. 3B) is constructed from a
paperboard substrate 59 having heat-activated shrink film 52
adhered to one side via a plurality of seal spots or dots 54. The
spot sealing pattern depicted in FIG. 3A extends between what will
be an open cup top 56 (FIG. 3B) and a closed cup bottom 58 (FIG.
3B) of disposable thermally insulated cup 55. In one example, seal
spots 54 may form a generally flat 3/4-inch square pattern (FIG.
3A).
[0038] Elongated cup blank 49 includes side edges 51, 53 (FIG. 3A)
which are sealed together along a generally elongated seam 57
(FIGS. 3B-3C) to form disposable cup 55 (FIG. 3B) with the pattern
adhered shrink film 52 remaining on the interior side of the cup.
The exterior side of cup 55 may have decorative graphics (not
shown). The formed cup is then, preferably, run through an oven at
sufficiently high temperature and for a period of time enough to
cause heat-activated film 52 to sufficiently shrink, or pull away
from paperboard substrate 59 (between seal spots 54) so as to form
outwardly (away from the interior side of the cup) bulging air
pockets 60 (FIGS. 3B-3C) which generally run from bottom 58 to top
56 (of cup 55) over seam 57 and thermally insulate the entire
exterior side of cup 55 from hot liquid contents. The newly formed
thermally insulated disposable cup 55 may also be used to insulate
a cup holder's hand from ice-cold contents.
[0039] In accordance with still another preferred embodiment of the
present invention and as generally shown in FIGS. 4A-4C, an
elongated cup blank 61 (FIG. 4A) used to form a disposable
thermally insulated cup 65 (FIG. 4B) is constructed from a
paperboard substrate 69 having heat-activated shrink film 62
adhered to one side along a plurality of generally horizontal seal
lines 64. The sealing pattern depicted in FIG. 4A extends between
what will be an open cup top 66 (FIG. 4B) and a closed cup bottom
68 (FIG. 4B) of disposable thermally insulated cup 65. In one
example, generally horizontal seal lines 64 may be spaced apart by
about one inch forming generally flat, elongated and parallel
horizontal bands 63 (FIG. 4A) with a seal line thickness of about
one-sixteenth of an inch.
[0040] Elongated cup blank 61 includes side edges 67, 74 (FIG. 4A)
which are sealed together along a generally elongated seam 70
(FIGS. 4B-4C) to form disposable cup 65 (FIG. 4B) with the pattern
adhered shrink film 62 remaining on the interior side of the cup.
The exterior side of cup 65 may have decorative graphics (not
shown). The formed cup is then, preferably, run through an oven at
sufficiently high temperature and for a period of time enough to
cause heat-activated film 62 to sufficiently shrink, or pull away
from paperboard substrate 69 (between seal lines 64) so as to form
outwardly (away from the interior side of the cup) bulging and
generally horizontal air pockets 72 (FIGS. 4B-4C) which run along
the interior of the cup from bottom 68 to top 66 (of cup 65) over
seam 70 and thermally insulate the entire exterior side of cup 65
from hot liquid contents such as hot coffee, tea or the like. The
newly formed thermally insulated disposable cup 65 may also be used
to insulate a cup holder's hand from ice-cold contents.
[0041] In accordance with an alternative embodiment of the present
invention and as generally illustrated in FIG. 4D, an elongated cup
blank (not shown) comprising a paperboard substrate 82 having
heat-activated shrink film 84 adhered to one side along a plurality
of generally horizontal seal lines 86 is used to form a disposable
thermally insulated cup 80 (FIG. 4D). The horizontal sealing
pattern depicted in FIG. 4D preferably extends between an open cup
top 88 and a closed cup bottom 90. In one example, generally
horizontal seal lines 86 may be spaced apart by about one inch so
as to form generally flat, elongated and parallel horizontal bands
92.
[0042] The opposite side edges of the cup blank are sealed together
along a generally elongated seam 94 (FIG. 4D) to form disposable
cup 80 with the pattern adhered shrink film 84 remaining on the
interior side of the cup. The exterior side of cup 80 may have
decorative graphics (not shown). The formed cup is then,
preferably, run through an oven at sufficiently high temperature
and for a period of time enough to cause heat-activated film 84 to
sufficiently shrink, or pull away from paperboard substrate 82
(between seal lines 86) so as to form outwardly (away from the
interior side of the cup) bulging and generally horizontal
thermally insulating air pockets 96 (FIG. 4D).
[0043] As generally depicted in FIG. 4D, thermally insulating air
pockets 96, preferably, run in the vertical direction along the
interior of the cup from cup bottom 90 to cup top 88. In the
horizontal direction, thermally insulating air pockets 96,
preferably, run continuously along the interior of the cup on each
side of elongated interior seam area 95 (which includes centrally
seam 94), i.e. thermally insulating the entire exterior side of cup
80 except for the elongated exterior side area directly behind
elongated interior seam area 95 (not shown). In this case, the
disposable cup user should avoid touching the exterior side of
disposable cup 80 in the area directly behind elongated interior
seam area 95 as this area is not thermally insulated.
[0044] FIG. 4F shows a disposable cup 100 which is similar in
construction to cup 80 of FIG. 4D except that cup 100 has been
provided with a single generally horizontal thermally insulating
air pocket 102. Insulating air pocket 102 is preferably wider than
its corresponding middle insulating air pocket 96 of FIG. 4D to
provide greater insulation area and is adhered generally centrally
to the interior surface of cup 100 on each side of an elongated
interior seam area 106 (which includes centrally a seam 108).
Horizontal air pocket 102 only provides thermal insulation coverage
for the exterior surface of cup 100 located behind it with the
exception of the elongated exterior side area located directly
behind seam area 106 (not shown). Therefore, the disposable cup
user should avoid touching the exterior surface of disposable cup
100 in any areas not covered by horizontal thermally insulating air
pocket 102 as such areas are not thermally insulated.
[0045] FIG. 4E depicts a disposable cup 110 which is similar in
construction to disposable cup 100 of FIG. 4F except that cup 110
has been been provided with a single generally horizontal thermally
insulating air pocket 112 which provides greater thermal insulation
coverage. Specifically, insulating air pocket 112 is attached
generally centrally to the interior surface of cup 110 over a seam
114 so as to provide continuous thermal insulation coverage over
the corresponding exterior surface area of the cup (not shown). The
disposable cup user should avoid, however, touching exterior
surface areas (of disposable cup 110) located directly above and
below the thermal insulation area provided by horizontal air pocket
112 as such areas are not thermally insulated.
[0046] In one test conducted by Applicant, a 75 gauge DuPont.RTM.
CLYSAR LLG.RTM. polyethylene shrink film, which is similar to
DuPont.RTM. CLYSAR ABL.RTM. industrial shrink film, and a
paperboard stock of basis weight of about 143 lb/3000 sq. ft. and
thickness of about 0.0128 inch were used as starting materials for
forming the disposable thermally insulated cup of the present
invention. Paperboard stock of this type may be purchased from
Georgia-Pacific Corporation of Atlanta, Ga., which manufactures the
stock at its Naheola mill. The CLYSAR LLG.RTM. shrink film was
heat-sealed to the Naheola paperboard stock using an impulse heat
sealer which can be a VERTROD CORP.RTM. MODEL 20A.RTM., 1200-watt,
heat sealer. A heat setting of "6" was used. The resulting
disposable cup blank has a generally horizontal seal pattern, as
shown in FIG. 4A. The straight side edges of the disposable cup
blank were then brought together in an overlapping configuration
and sealed on a bench fixture. The bench fixture holds the blank in
a conical configuration while the seam area is heated and then
clamps the seal, holding it in place until cooled. The seal areas
were heated with a Wagner.RTM. model HT1000, 1200 watt, heat gun.
The truncated cone (without top curl or bottom) was placed in a
forced air oven at about 260.degree. F. for about 10 seconds to
force the film to shrink or pull away from the paperboard so as to
produce the desired thermal insulating pockets. Five-second and
thirty-second oven tests at the same temperature were also
conducted. However, the five-second oven test resulted in
insufficient film shrinkage, while the thirty-second oven test
resulted in cone distortion due to excessive film shrinkage. Best
results were achieved with an oven residence time of about 10
seconds. A silicone RTV sealant was used to seal the bottom of the
cup in place. The cup bottom may also be heat-sealed into place.
The cup bottom material used was paperboard stock of basis weight
of about 120 lb/3000 sq. ft. and thickness of about 0.0113 inch.
The paperboard was extrusion coated with about 20 lb/3000 sq. ft.
of low density polyethylene (LDPE). Top curl was added later in the
process.
[0047] The above-described novel disposable thermally insulated cup
may be mass produced using several commercial sealing methods such
as, for example, rotary heat sealing (FIG. 6), adhesive lamination
(FIG. 7), and extrusion coating (FIG. 8). All three methods employ
a roller 120 comprising a solid generally cylindrical body 122
having a plurality of generally raised, cup blank-shaped regions
123 on its outer surface, and a shaft 124, as generally illustrated
in FIG. 5. Raised, cup blank-shaped regions 123 are generally
oriented in rows in a back/forth pattern to minimize material
usage. The resultant pattern requires that so-called scroll
(zig-zag) slitting be used later in the manufacturing process. The
cup blank-shaped regions may come in a single pattern or in a
variety of patterns and are raised for printing, heat sealing, or
for applying pressure during extrusion coating. Specifically, the
raised patterns on cylindrical body 122 are used to form the
various seal lines, seal spots described hereinabove.
[0048] As generally depicted in FIG. 6, a moving shrink film 126
and a moving paperboard stock 128 are brought together in the nip
formed by heated roller 120 and a pressure roller 130. Heated
roller 120 and pressure roller 130 heat-seal shrink film 126 onto
paperboard stock 128 in the various patterns of FIGS. 1A, 2A, 3A,
4A producing a web of heat-sealed patterns 132 from which elongated
cup blanks will be cut (FIG. 6).
[0049] The adhesive lamination technique generally shown in FIG. 7
uses roller 120 essentially as a flexographic printing or
application roller to apply adhesive 134 to shrink film 136 which
rides around a roller 138. Adhesive 134, which is contained in a
pan 133, is applied to application roller 120 via a conventional
anilox roller 121 which is in rotational contact with application
roller 120. Anilox roller 121, which is dipped to a certain extent
in adhesive pan 133, picks up adhesive 134 for transfer to
application roller 120. A blade 135 is also provided, as generally
shown in FIG. 7, to automatically scrape away excess adhesive from
anilox roller 121 during operation. The shrink film with the
applied adhesive is then laminated to a moving paperboard stock 140
in the nip formed by film roller 138 and a pressure roller 142 in
the various patterns of FIGS. 1A, 2A, 3A, 4A producing a web of
adhesively sealed patterns 144 from which elongated cup blanks will
be cut (FIG. 7).
[0050] The extrusion coating technique of FIG. 8 uses roller 120 as
an impression roller. Specifically, an extrusion die 146 applies a
continuous stream of polymer melt 148 to a moving paperboard stock
150 in the nip formed by impression roller 120 and a chill roll 152
(FIG. 8). Chill roll 152 turns polymer 148 from liquid form to a
film at the same time as the polymer is being adhered to moving
paperboard stock 150 by impression roller 120 in the various
patterns of FIGS. 1A, 2A, 3A, 4A producing a pattern-adhered web
154 from which elongated cup blanks will be cut (FIG. 8).
[0051] Alternatively, a heated mandrel having at least one undercut
section and raised ridges (not shown) may be used to heat-seal
shrink film onto the paperboard stock. The resulting cup blank may
include, for example, a single centrally located insulating band
which can be used to form disposable thermally insulated cup 100 of
FIG. 4F. In this regard, a mandrel heated to about 240.degree. F.
was used by Applicant to produce a prototype disposable thermally
insulated cup of the type shown in FIG. 4F.
[0052] In general, the following manufacturing steps may be used to
produce the novel disposable thermally insulated cup. Step 1
involves printing or decorating one side of the paperboard stock,
this side will be used to form exterior cup sides. Step 2 deals
with pattern-adhering of the shrink film onto the opposite side of
the paperboard stock to produce a pattern-sealed web using one of
the above-described techniques, i.e. extrusion coating, rotary heat
sealing, or adhesive lamination. This side will be used to form the
interior cup sides. The end result is a roll of paperboard stock
with pattern-adhered film which is then taken to a slitter. The
slitter cuts the paperboard stock/pattern-adhered film roll into
narrower rolls corresponding to the width needed to cut a series of
cup blanks (Step 3). The slit rolls are then placed one at a time
on a cup-making machine which forms the entire cup, i.e. cuts the
cup blanks from the rolls, seals the side seams, attaches cup
bottoms, and applies top curls (Step 4). Step 5 includes placing
the formed cups in an oven at sufficiently high temperature and for
a period of time enough to cause the pattern-adhered film to
sufficiently shrink, or pull away from the paperboard stock so as
to form the thermally insulating air pockets described hereinabove
and shown, for example in FIGS. 1B, 2B, 3B, 4B, and 4D-4F. After
that the thermally insulated disposable cups are taken out of the
oven and cooled at ambient (room) temperature (Step 6). The cooled
thermally insulated disposable cups are then shipped to customers
or stored by the manufacturer for future shipment (step 7).
[0053] In accordance with another preferred embodiment of the
present invention, above-described steps 5-6 may be avoided
entirely if the film used in above-described pattern-adhering step
2 is capable of automatically shrinking or pulling away from the
interior paperboard wall of the cup at a temperature range of about
180.degree.-190.degree. F. so as to form thermally insulating air
pockets, i.e. after the pouring of a hot liquid such as hot coffee,
tea, or the like. Hot coffee temperature, for example, is generally
in the same range, i.e., 180.degree.-190.degree. F. In this regard,
the following two experiments were performed by Applicant to prove
that hot liquids can be used to effect shrinking of such
heat-shrinkable films on the interior of disposable cups.
[0054] A DuPont.RTM. Clysar ABL.RTM. 200 shrink film was sealed
with a Vertrod.RTM. impulse heat sealer to the top and bottom of a
cup blank which was polyethylene (PE) coated on both sides. The cup
blank was then heat-sealed into a truncated cone into which a
bottom was sealed with RTV (room temperature vulcanizing) silicone.
The truncated cone was not top curled. Thereafter, water at about
190.degree. F. was poured into the conical shell. It was
subsequently found that the film had shrunk only if it contained a
pinhole or if it had been intentionally pre-slit. In the areas
where there was no break in the film, partial vacuum had developed
which prevented the film from shrinking or pulling away from the
interior wall of the conical shell. The pre-applied PE coating on
the two sides of the cup blank prevented air intrusion between the
shrink film and the interior (PE-coated) wall of the conical shell.
To alleviate the partial vacuum problem, a series of pinholes were
punched through the cup blank (to allow air intrusion) prior to
heat-sealing the shrink film to the paperboard stock and the
experiment was repeated. This time the pattern-adhered film shrunk
sufficiently (after the pouring of hot water) to automatically form
the desired thermally insulating air pockets.
[0055] A person skilled in the art would recognize that other types
of shrink films capable of performing at other hot liquid
temperature ranges may be utilized to achieve the above results
provided such other types of shrink film do not depart from the
intended purpose of the present invention. A person skilled in the
art would also recognize that the above results may be achieved
using uncoated paperboard stock or paperboard stock that is coated
only on one side with PE. Other configurations and/or modifications
may be used, providing no departure from the scope and spirit of
the invention occurs.
[0056] A disposable cup with a pattern-adhered insulating shrink
film interior capable of automatically shrinking, or pulling away
from the interior wall of the cup after pouring a hot liquid so as
to form thermally insulating air pockets would only be suitable for
insulating a cup holder's hand from hot contents. Pouring of cold
liquids in such a cup would not trigger any film shrinkage and
should, therefore, be avoided. In general, the manufacture of such
disposable cups, i.e. cups that are capable of automatic
heat-insulation, should be preferred from a manufacturer's point of
view due to reduced cost of manufacture (above-described steps 5-6
being omitted) which would translate into a reduced overall cost,
and reduced overall volume of nested or stacked cups which can be
advantageous for storage and/or shipping purposes.
[0057] A person skilled in the art should recognize that the
above-described novel disposable cup provides improved thermal
insulation capability over known disposable insulated cups. The
novel disposable cup also exhibits no tendency to soften (i.e.,
deform) under hot liquid contents as, for example, conventional
foam cups tend to do. Moreover, the novel disposable cup may be
manufactured with higher quality graphics (decoration) on its
exterior side compared to known disposable cups which tend to have
a so-called "blistered" outer surface which distorts somewhat the
applied graphics. The above-described novel disposable thermally
insulated cup manufacturing process may be employed in any field or
application where effective thermal insulation capability is
required. An alternative application may include cushioning
capability for packaging, and the like.
[0058] While the present invention has been described in detail
with regards to the preferred embodiments, it should also be
appreciated that various modifications and variations may be made
without departing from the scope or spirit of the invention. It is
important to note that practicing the invention is not limited to
the applications described hereinabove. Many other applications
and/or alterations may be utilized provided that such other
applications and/or alterations do not depart from the intended
purpose of the present invention.
[0059] It should further be appreciated by a person skilled in the
art that features illustrated or described as part of one
embodiment can be used in another embodiment to provide yet another
embodiment such that the features are not limited to the specific
embodiments described above. Thus, it is intended that the present
invention cover all such modifications, embodiments and variations
as long as such modifications, embodiments and variations come
within the scope of the appended claims and their equivalents.
* * * * *