U.S. patent application number 11/098853 was filed with the patent office on 2005-10-27 for insulating cup wrapper and insulated container formed with wrapper.
This patent application is currently assigned to Insulair, Inc.. Invention is credited to Sadlier, Claus E..
Application Number | 20050236468 11/098853 |
Document ID | / |
Family ID | 35135451 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050236468 |
Kind Code |
A1 |
Sadlier, Claus E. |
October 27, 2005 |
Insulating cup wrapper and insulated container formed with
wrapper
Abstract
A thermally insulated cup is formed from a single-walled paper
or plastic inner cup and an insulating outer wrapper. The
insulating outer wrapper comprises a paper base sheet or outer
sidewall blank, optionally printed on one side, and a corrugated
paper or foamed plastic insulating insert. The insulating insert is
similar in shape to the outer sidewall blank but smaller in size.
The insert is glued in a centered position to the non-printed side
of the sidewall blank to form a two-layered insulating wrapper.
Less than 20% of the area of the insert is glued to the base sheet.
Specifically, no glue is applied to the area adjacent to the cut
side edges of the insert, and as such these edges are not attached
to the base sheet. The wrapper is then wrapped around the single
walled inner cup. The side edges of the base sheet of the wrapper
overlap and are sealed directly together to form a side seam. The
side seam is itself adhesively secured to the side wall of the
inner cup. The side edges of the insert do not come between the
seal between the side seam of the base sheet and the inner cup. The
wrapper can also be adhered to the inner cup by one or more beads
of cold glue (paste adhesive) or a thin layer of polyethylene (or
similar heat sealing material) can be pre-applied to the inside cut
edges of the base sheet. This is then heat-activated immediately
prior to wrapping the wrapper around the inner cup, and pressing
the overlapping side seam to the sidewall of the inner cup to
simultaneously glue the side seam together, and to glue the
insulating wrapper to the side wall of the cup.
Inventors: |
Sadlier, Claus E.;
(Pleasanton, CA) |
Correspondence
Address: |
David Pressman
#1402
1070 Green St.
San Francisco
CA
94133-5418
US
|
Assignee: |
Insulair, Inc.
Vernalis
CA
|
Family ID: |
35135451 |
Appl. No.: |
11/098853 |
Filed: |
April 4, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11098853 |
Apr 4, 2005 |
|
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10831411 |
Apr 22, 2004 |
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Current U.S.
Class: |
229/403 ;
229/4.5 |
Current CPC
Class: |
B65D 81/3865
20130101 |
Class at
Publication: |
229/403 ;
229/004.5 |
International
Class: |
B65D 003/00 |
Claims
1. A thermally insulated cup wrapper, comprising: an outer base
sheet having a plurality of boundary edges and a corresponding
plurality of edge portions adjacent said boundary edges,
respectively, an insert sheet having a plurality of edges, at least
one of said outer base sheet and said insert sheet being made of
insulating material to provide an insulating layer, said insert
sheet being adhered to one side of said outer base sheet to form a
thermally insulated cup wrapper, said insert sheet being smaller in
size than said outer base sheet and being positioned on said outer
base sheet so that said plurality of edge portions of said outer
base sheet extend beyond said edges of said insert sheet, whereby
said thermally insulated cup wrapper can be wrapped around and
adhered to a single wall cup to form a thermally insulated cup.
2. The thermally insulated cup wrapper of claim 1 wherein said
insert sheet is made of insulating material.
3. The thermally insulated cup wrapper of claim 2 wherein said
insert sheet is made of a material selected from the class
consisting of corrugated material and foamed plastic.
4. The thermally insulated cup wrapper of claim 1 wherein said base
sheet and said insert sheet each have a generally rectangular shape
with four bounding cut edges, two of said edges being opposite side
edges that are oriented at an acute angle to each other, the other
two of said edges being opposite top and bottom edges that are
curved and are oriented concentrically to each other.
5. The thermally insulated cup wrapper of claim 1 wherein said base
sheet and said insert sheet are made of paper.
6. The thermally insulated cup wrapper of claim 1 wherein said
insert sheet is coated with reflective material on at least one
side thereof.
7. The thermally insulated cup wrapper of claim 1 wherein said
insert sheet is made of insulating material selected from the class
consisting of corrugated material and foamed plastic, said base
sheet and said insert sheet each have four bounding cut edges, two
of said edges being opposite side edges that are oriented at an
acute angle to each other, the other two of said edges being
opposite top and bottom edges that are curved and are oriented
concentrically to each other and said base sheet and said insert
sheet are made of paper.
8. The thermally insulated cup wrapper of claim 1, further
including a cup having a bottom and a side wall, said thermally
insulated cup wrapper being wrapped around and adhered to said
cup.
9. A thermally insulated container, comprising: a cup having a side
wall, said side wall having an inside and an outside surface, a
thermally insulated cup wrapper being wrapped around and adhered to
said outside surface of said side wall of said cup, said cup
wrapper comprising a plurality of layers comprising an outer base
sheet and an insert sheet, said outer base sheet having a plurality
of boundary edges and a corresponding plurality of edge portions
adjacent said boundary edges, respectively, said insert sheet
having a plurality of edges, at least one of said base sheet and
said insert sheet being an insulating layer, said insert sheet
being adhered to one side of said outer base sheet, said insert
sheet being smaller in size than said outer base sheet and being
positioned on said outer base sheet so that said plurality of edge
portions of said outer base sheet extend beyond said edges of said
insert sheet.
10. The thermally insulated cup wrapper of claim 9 wherein said
insert sheet is made of said insulating material.
11. The thermally insulated cup wrapper of claim 10 wherein said
insulating material is selected from the class consisting of
corrugated material and foamed plastic.
12. The thermally insulated cup wrapper of claim 9 wherein said
base sheet and said insert sheet are made of paper.
13. The thermally insulated cup wrapper of claim 12, further
including a coating of reflective material on at least one side of
said insert sheet.
14. The thermally insulated cup wrapper of claim 9 wherein said
base sheet and said insert sheet each have four bounding cut edges,
two of said edges being opposite side edges that are oriented at an
acute angle to each other, the other two of said edges being
opposite top and bottom edges that are curved and are oriented
concentrically to each other.
15. The thermally insulated cup wrapper of claim 9 wherein said
insert sheet is made of insulating material selected from the class
consisting of corrugated material and foamed plastic, said base
sheet and said insert sheet each having four bounding cut edges,
two of said edges being opposite side edges that are oriented at an
acute angle to each other, the other two of said edges being
opposite top and bottom edges that are curved and are oriented
concentrically to each other and said base sheet and said insert
sheet are made of paper.
16. A method of forming a thermally insulated container,
comprising; providing an outer base sheet having a plurality of
boundary edges and a corresponding plurality of edge portions
adjacent said boundary edges, respectively, providing an insert
sheet having a plurality of edges, at least one of said outer base
sheet and said insert sheet being made of insulating material to
provide an insulating layer, adhering said insert sheet to one side
of said outer base sheet to form a thermally insulated cup wrapper,
making said insert sheet being smaller in size that said outer base
sheet and positioning said insert sheet on said outer base sheet so
that said plurality of edge portions of said outer base sheet
extend beyond said edges of said insert sheet, providing a cup
having a closed bottom and a side wall, wrapping said thermally
insulated cup wrapper around said side wall of said cup and
adhering said thermally insulated cup wrapper to said side
wall,
17. The method of claim 16 wherein said insert sheet is made of
said insulating material, said insulating material being selected
from the class consisting of corrugated material and foamed
plastic, said base sheet and said insert sheet each having four cut
edges, two of said edges being opposite side edges that are
oriented at an acute angle to each other, the other two of said
edges being opposite top and bottom edges that are curved and are
oriented concentrically to each other, and said base sheet and said
insert sheet are made of paper.
18. A cup made by the method of claim 16.
19. The thermally insulated cup wrapper of claim 16 wherein said
insert sheet is made of said insulating material.
20. The thermally insulated cup wrapper of claim 19 wherein said
insulating material is selected from the class consisting of
corrugated material and foamed plastic.
21. The thermally insulated cup wrapper of claim 16 wherein said
base sheet and said insert sheet each have a generally rectangular
shape with four bounding cut edges, two of said edges being
opposite side edges that are oriented at an acute angle to each
other, the other two of said edges being opposite top and bottom
edges that are curved and are oriented concentrically to each
other.
22. The thermally insulated cup wrapper of claim 16 wherein said
cup is made substantially from plastic material.
23. A thermally insulated container, comprising: a cup having a
side wall, an insulating wrapper wrapped around said side wall of
said cup, said insulating wrapper being comprised of a base sheet
and an insulating insert sheet, said base sheet and said insulating
insert sheet each having cut side edges, said insulating insert
sheet having a smaller surface area than said base sheet, said
insulating insert sheet being adhered to said base sheet such that
said cut side edges of said base sheet extend beyond said cut side
edges of said insert sheet, and at least one area adjacent said cut
side edges of said insert sheet is free of said base sheet, said
cut side edges of said base sheet being overlapped and sealed
directly to each other to form a side seam, and said base sheet
being adhesively attached to said side wall of said cup.
24. The thermally insulated cup of claim 23 wherein said insulating
insert sheet is made of a material selected from the class
consisting of corrugated material and foamed plastic.
25. The thermally insulated cup of claim 23 wherein less than 20%
of the area of said insert sheet is adhesively attached to said
base sheet.
26. The thermally insulated cup of claim 23 wherein said cup is
made from substantially plastic material.
27. The thermally insulated cup of claim 23 wherein said cup is
made from substantially paper material.
Description
BACKGROUND--CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of my application
Ser. No. 10/831,411, filed 22 Apr. 2004, now abandoned.
BACKGROUND--FIELD OF INVENTION
[0002] This invention relates generally to insulating disposable
cups and containers, specifically to insulating wrappers, methods
for producing insulating wrappers, and methods for making insulated
containers with insulating wrappers.
BACKGROUND--PRIOR ART
[0003] Many types of cups and containers are available, each with a
specific set of characteristics relating to print quality,
rigidity, insulation, biodegradability, recyclability, clarity,
permeability, microwavability, and shelf life, among other
characteristics. Many types of cups have desirable features and
benefits in one or more areas, but undesirable features in other
areas.
[0004] E.g., cups made from expanded polystyrene (EPS), well known
in the art, are excellent thermal insulators and maintain the
temperature of a drink, whether hot or cold, for a long period of
time. They also provide a barrier between the hot or cold
temperature of the product and the user's hand. However EPS cups
are generally considered environmentally unfriendly because they
are not biodegradable. As a result, their use has been banned in
some municipalities. Also, in order to print EPS cups a slow and
costly off-line printing process must be used because the cups must
be printed after they have been formed, and their relatively rough
surface does not permit high-resolution printing.
[0005] Standard single-wall paper containers, also well known in
the art, are generally considered to be more environmentally
friendly than EPS cups, but they have poor insulating qualities. As
such, many coffee shops resort to double cupping, which is the
practice of serving a hot beverage in two stacked single-wall paper
cups in order to provide some level of insulation. This is a very
expensive and wasteful. Alternatively, designers have provided a
number of cup sleeves which are wrapped around a single wall paper
cup to provide insulation to keep drinks hot and hands comfortable;
see, e.g., U.S. Pat. No. 5,205,473 to Coffin (1993), U.S. Pat. No.
5,794,843 to Sanchez (1998), and U.S. Pat. No. 6,277,454 to Neale
et al (2001). One of the shortcomings of cup sleeves is that they
must be assembled and/or placed onto the cup when the beverage is
served. This requires extra labor and slows the speed of service.
Also the need for cups and sleeves require additional and
simultaneous purchasing, additional storage space, and additional
inventory management. Cup sleeves also have a tendency to fall off
of the cups, do not conveniently fit in all vehicle cup holders,
and cover the graphics printed on the cup.
[0006] Single-wall plastic cups made from materials such as
polyethylene terephthalate (PET), polystyrene (PS), polypropylene
(PP), and high density polyethylene (HDPE) are well known in the
art, and are formed through either thermoforming or injection
molding processes. Plastic cups are aesthetically pleasing and can
be made with high barrier properties to offer longer shelf life to
the products that they contain. A barrier material called EVOH can
also be added to provide a better oxygen barrier. A cup made from a
thick layer of HDPE will provide a significant moisture barrier.
Plastic cups made with both HDPE and EVOH are resistant to both
moisture and oxygen to provide extended shelf life to the products
they contain. Some types of plastic cups, such as those made from
polypropylene, are resistant to high levels of heat and as such are
microwavable. Also, plastic cups do not have a seam area, which
makes them relatively leak proof. However plastic cups must be
printed off-line after the cup is formed, which is an expensive
process and limits the graphic capabilities. Another problem is
that these cups are poor thermal insulators. They will loose their
heat or cool very quickly, and are uncomfortable to carry when
holding hot or cold contents. Another deficiency is that their
sidewall rigidity strength is poor.
[0007] Multi-layered paper cups have been designed to provide
thermal insulation and increased strength. U.S. Pat. No. 3,908,523
to Shikaya (1975), U.S. Pat. No. 5,205,473 to Coffin (1993), U.S.
Pat. No. 5,547,124 to Mueller (1996), U.S. Pat. No. 5,685,480 Choi
(1997), U.S. Pat. No. 5,769,311 Morita et al. (1998), U.S. Pat. No.
5,775,577 Titus (1998), U.S. Pat. No. 6,039,682 Dees et al. (2000)
and U.S. Pat. No. 6,253,995 Blok et al. (2001) all show
multilayered cups with at least three layers, which include some
form of an inner cup made from paper and an outer cover or wrapper
to provide insulation. The wrapper comprises a multi-ply sheet
consisting of at least one base sheet, and at least one corrugated
or embossed sheet adhered to the base sheet. Although thermally
insulated and strong, these cups are expensive to manufacture
because the corrugated or embossed sheet must be adhered to cover
the entire surface of the base sheet through a lamination process.
This is a process whereby adhesive, such as hot melt or heated
polyethylene, or a paste adhesive such as a starch based cold glue,
is applied either to the surface of the embossed sheet and/or the
base sheet and the two sheets are pressed together forming a
multi-ply insulating sheet. The wrapper is then cut out (a process
called blanking) of this multi-ply sheet and wrapped around and
adhered to an inner cup. The process of laminating the sheets
together is expensive and wasteful. There is a significant amount
of value-added multi-ply sheet trim scrap which is wasted when
blanking the wrapper. There is also a significant amount of
adhesive used to secure the embossed sheet across the entire
surface of the base sheet, which is typically done along all of the
tips of the corrugations or embossments. The printing process is
expensive because either the base sheet must be printed prior to
laminating, which causes significant registration and distortion
issues after the sheets are laminated together, or the multi-ply
sheet is printed after the sheets are laminated, which is difficult
because of the thickness and stiffness of the multiply sheet and
the excess compressibility of the sheet. In any event, it is very
difficult to offer high quality printing at a cost effective price
on these types of insulated cups. Finally it is difficult to wrap
or bend the multi-ply laminated wrapper around an inner cup because
of the limited flexibility of thick laminated paperboard.
[0008] The insulated cups of U.S. Pat. No. 5,660,326 to Varano and
Sadlier (the present inventor) (1997), and U.S. Pat. No. 6,085,970
to Sadlier (2000) have overcome these deficiencies. These cups have
gained widespread acceptance in the market and many millions have
been sold throughout the world. Although the cups of these two
patents are major improvements, I have discovered that both the
cups and their manufacturing processes can be improved even
further. Since the inner cup and the outer layer are made from a
continuous blank, these two parts are made from the same material.
This is disadvantageous since the inner layer must be made from
expensive polyethylene coated board for waterproofing and thus the
outer layer must also be made from this same expensive material.
Also, since the inner and outer layers are made from the same
blank, the entire blank, rather than just the outer portion of the
blank, must be passed through a printing press, which is a
relatively expensive processing operation. The sidewall blank must
also be folded in order to form the inner and outer layers of the
cup from the same elongated blank. The process of folding the blank
is an expensive additional step which requires precise
registration.
OBJECTS AND ADVANTAGES
[0009] Accordingly, several objects and advantages of the invention
are to provide an improved cup that has (a) improved thermal
insulating properties and rigidity. Also it can (b) be made of less
costly materials, (c) be made more leak resistant, (d) extend the
shelf life of the drink it contains, (e) be microwaved, (f) be made
with recycled materials, (g) be made from the most economical
materials for each part to save costs, (h) be printed more
economically, (i) be made without folding, and (j) be assembled at
very rapid speed with high-speed fabrication machinery. Further
objects and advantages will be apparent from a consideration of the
ensuing description and accompanying drawings.
SUMMARY
[0010] In accordance with one embodiment of the invention, a
thermally insulated container is formed from a single-walled paper
or plastic inner cup and an insulating outer wrapper. The
insulating outer wrapper comprises a paper base sheet or outer
sidewall blank, optionally printed on one side, and a corrugated
paper insert. The corrugated insert is similar in shape to the
outer sidewall blank but its size is smaller than that of the
sidewall blank. The insert is glued in a centered position of the
non-printed side of the sidewall blank to form a two-layered
insulating wrapper. The two-layered wrapper is then wrapped around
a single walled inner cup, which is positioned on a forming mandrel
for support, with the corrugated insert portion to the inside and
the printed side of the blank to the outside. The side edges of the
wrapper overlap and are sealed together to form a side seam. The
side seam is itself adhesively secured to the inner cup. The
manufacturer can use other methods to adhere the inner cup to the
wrapper. E.g., they can use one or more beads of cold glue (paste
adhesive). Also they can pre-apply a thin layer of polyethylene (or
similar heat sealing material) to the inside cut edges of the
sidewall blank. This is then heat-activated--immediately prior to
wrapping the wrapper around the inner cup, and pressing the
overlapping side seam to the sidewall of the inner cup to glue it
in place.
DRAWINGS--FIGURES
[0011] FIG. 1 is a perspective view of a prior-art plain
single-walled paper or plastic cup.
[0012] FIG. 2 is a plan view of a flat paper base sheet used in an
outer wrapper according to the invention.
[0013] FIG. 3A is a plan view of a corrugated paper insert which is
attached to the base sheet.
[0014] FIG. 3B is an edge view of the corrugated paper insert of
FIG. 3A.
[0015] FIG. 4A is a view of an outer wrapper consisting of an
assembly of the base sheet and corrugated insert.
[0016] FIG. 4B is an edge view of the outer wrapper.
[0017] FIG. 5 is a perspective view of the outer wrapper being
wrapped around a cup.
[0018] FIG. 6A is an elevational view of the wrapped cup and FIG.
6B is a sectional view taken as indicated by lines 6B-6B in FIG.
6A.
[0019] FIG. 7 is a perspective view of the outer wrapper being
wrapped around a cup with a foamed plastic insert.
DRAWINGS--REFERENCE NUMERALS
[0020] 10 side wall
[0021] 10R upper rim
[0022] 10B bottom
[0023] 12 base sheet
[0024] 12G glue spot
[0025] 14 corrugated insert
[0026] 14F foamed plastic insert
DETAILED DESCRIPTION--FIG. 1--PRIOR-ART CUP
[0027] FIG. 1 shows a view from below of a prior-art paper or
plastic cup. The cup comprises a sidewall 10 an upper rim 10R, and
a bottom 10B, and is made of a single wall of plastic or
plastic-coated paper. As a result it has poor insulating qualities.
Thus if it contains a hot beverage (not shown) the heat will pass
through the cup and heat or burn the fingers of anyone who holds
it. The cup could be made of an insulating material, such expanded
polystyrene (EPS), a foam like thick material, but EPS cups are
generally considered environmentally deleterious because they are
not biodegradable and thus their use has been banned in some areas.
Also manufacturers find it difficult to print trademarks and other
messages on them. The cup can be doubled, but this is an expensive
and wasteful practice. A cup sleeve could be slid over the cup, but
this requires additional labor, time, storage, and inventory
management, and sleeves have a tendency to fall off of the cups, do
not conveniently fit in all cup holders, and cover any graphics
printed on the cup. Multi-layered cups have been provided, but
these have numerous disadvantages, as noted above.
[0028] If made from paper, the cup is preferably made from solid
bleach sulfite (SBS) paperboard which is coated on at least one
side with polyethylene or any other suitable water proof material.
The process of making such a single-walled paper cup is well-known
in the art. It has a vertical side seam (not shown) that runs from
the bottom to the top of the cup. Different material combinations
and thicknesses can be used to achieve certain properties. For
example, if an insulated cup with a long shelf life is required,
the paper cup can be coated with a layer of foil on the inside.
Foil provides a great moisture and oxygen barrier to preserve the
contents of the liquid within. Alternatively, different
thermoplastic barrier materials can be coated onto the paper. E.g.,
HDPE and EVOH provide moisture and oxygen barriers, respectively.
If more sidewall strength is required, the paper can be made
thicker. If the insulated cup is to be microwaved a waterproof
material with a high melting point, such as medium to high density
polyethylene, can be used.
[0029] If made from plastic, the cup will not have a side seam, and
can be formed from any of a number of materials, or combination of
materials, such as PET, PP, PS, and/or HDPE. The process of making
single wall plastic cups from a thermoforming or injection molding
process is well known. Different material combinations and
thicknesses can be used to achieve certain properties. For example,
if an insulated cup with a long shelf life is required, the plastic
cup can be made from a combination of HDPE and EVOH. The HDPE
provides a moisture barrier which increases with the thickness of
the material, and the EVOH provides an oxygen barrier. If a
microwavable container is required, HDPE or polypropylene can be
used, both of which are resistant to high levels of heat.
INSULATING OUTER WRAPPER--FIGS. 2 TO 4
[0030] In accordance with the invention, I provide an insulating
outer wrapper for use with the cup of FIG. 1. The wrapper comprises
a base sheet or layer 12 (FIG. 2) and an insert, sheet, or layer 14
(FIGS. 3A and 3B) which is attached to the base sheet. Both sheets
have the same shape, which is generally rectangular with four
bounding edges. Two of the edges are opposite side edges that are
oriented at an acute angle to each other, while the other two of
the edges are opposite top and bottom edges that are curved and are
oriented concentrically to each other. Layer 14 has corrugations or
other multiple distortions so as to cause it to be thicker than the
basic thickness of its material, thereby significantly increasing
its insulating properties and creating an insulating layer.
[0031] Presently for base sheet 12 I prefer to use Solid Bleach
Sulfite (SBS) paper, 0.20 mm to 0.50 mm thick. The base sheet is
cut or blanked from a larger starting sheet or roll (not shown) and
has a cut edge along the top and bottom arcs, and along each side.
If the finished cup is to bear a trademark and/or other printing,
base sheet 12 should be printed prior to being blanked from the
larger starting sheet or roll. The base sheet can be clay-coated in
well-known fashion on the print side to improve the smoothness and
brightness of the printing surface.
[0032] Corrugated insert 14 is formed by passing a flat sheet of
paper (preferably plate stock paperboard or linerboard which is
0.15 mm to 0.50 mm thick, and optionally coated with a layer of
reflective material such as metallized film or foil as indicated)
through an embossing or corrugating die (not shown), and then cut
to size in well-known fashion. Similar to the base sheet, the
corrugated insert has a cut edge along the top and bottom arcs, and
along each side. I prefer to form the corrugations with a pitch
(spacing between tops of adjacent ribs) of between 2.5 mm to 7.6
mm. The depths of the corrugations are 0.5 mm inch to 1.27 mm.
Insert 14 is about 30% smaller in area than that of base sheet 12.
Due to the smaller size of the insert, if it is not precisely
centered on the base sheet as often happens with high-speed
assembling machinery, the insulating outer wrapper will still be
useable since the base sheet will still extend beyond the edges of
the insert.
[0033] Base sheet 12 and corrugated insert 14 are adhered together
(FIGS. 4A and 4B) to form an insulating outer wrapper or assembly
by placing a small amount of glue 12G in a central area of, and
centered on, the base sheet, and attaching the insert. If the
insert material has a reflective coating on one side, the
reflective side would be positioned to face away from the base
sheet. Preferably less than 20% of the area of the insert is
adhesively attached to the base sheet. Note that since the insert
sheet is smaller than the base sheet, edge portions of the base
sheet extend beyond the edges of the insert. I presently prefer to
use hot melt adhesive because of its fast set time. Alternatively
the adhesive can be placed on the corrugated insert. As a further
alternative, several glue spots can be used in a central area of
the base sheet to provide more stability to the insert as it is
attached with high speed machinery. Unlike the prior art corrugated
cups, it is not necessary to use a large volume of glue to adhere
each of the tips of the corrugations to the base sheet as mentioned
above I prefer to glue less than 20% of the area of the corrugated
insert to the base sheet. In particular, no glue is applied to the
area adjacent to the cut side edges of the insert, and as such
these edges are free. The overall thickness of the finished
insulating outer wrapper, indicated in FIG. 4B, is between 1 mm to
2 mm thick.
CONTAINER WITH INSULATING OUTER WRAPPER--FIGS. 5 AND 6
[0034] As shown in FIG. 5, the insulating outer wrapper or assembly
of base sheet 12 and corrugated insert 14 is assembled to the
outside of cup 10 of FIG. 1 by placing the cup on a mandrel (not
shown) and wrapping the insulating outer wrapper around the cup.
This can be done by well-known automated machinery. When the outer
wrapper is wrapped or curled in the manner shown in FIG. 5, the
right and left cut side ends of the inner or upper layer (insert
14) will tend to migrate outwardly on the outer or lower layer
(base sheet 12). If the two layers were glued over their entire
area, curling the assembly would tend to kink the insert, tear the
base layer, or pull the glued joint apart. Since insert 14 is not
attached to base sheet 12 along the side edges, these edges can
migrate freely and such undesirable results will not occur.
[0035] When the insulating outer wrapper is fully wrapped around
the cup as shown in FIGS. 6A and 6B, the free cut edges of base
layer 12 overlap and are glued together. This is done in any of a
number of ways. Preferably one or more beads of paste adhesive or
hot melt adhesive are applied to the overlapping edges of the base
sheet and then pressed together. Alternatively a layer of
heat-activated adhesive, such as polyethylene, can be pre-applied
to the area adjacent the cut edges of the base sheet and then heat
activated to seal the edges when they are overlapped and pressed
together. The insulating outer wrapper is itself adhered to the cup
side wall along the wrapper's vertical side seam area through a
similar means of applying paste adhesive, hot melt adhesive, or a
pre-applied heat-activated polyethylene layer to the inside surface
of the side seam, which is then attached directly to the cup.
[0036] The resultant insulated container of FIGS. 6A and 6B can
contain a hot beverage, yet can be held with one's bare hands. Very
little glue is needed since only a vertical strip of the wrapper
(along the side seam) and the cup are glued. Note that the
overlapping edges of base layer 12 are in contact with each other
and with cup 10. The cut edges of corrugated insert 14 do not come
between the overlapping side seam of base sheet 12 and cup 10 since
the corrugated insert is shorter than base sheet 12. Thus it does
not interfere with the gluing of base sheet 12 to cup 10. Another
advantage of this is that it reduces the overall thickness of the
sidewall of finished insulated container. If standard corrugated
board were wrapped around a cup, there would be a double thickness
of the corrugated board at the overlapping side seam. This extra
thickness at the side seam would prevent the cups from nesting one
into one another. But by only having the base sheet overlap at the
side seam the overall thickness of the finished cup is not
increased. Additionally the manufacturer can glue the corrugated
insert, and thus the insulated wrapper, to cup 10 at one or more
circumferential locations around the cup for added stiffness and
strength.
[0037] I presently prefer to attach the insulating outer wrapper to
cup 10 about 1.6 mm down from rim 10R so as to leave a an exposed
area at the top of the cup directly under the rim, but the wrapper
can be attached directly under the rim, or spaced farther down. I
have designed the dimensions of the insulated wrapper such that it
does not cover the entire vertical length of the cup. It is spaced
up from the bottom of the cup by approximately 1.6 cm to leave that
area of the cup's base exposed. Alternatively it can be sized to
cover the entire outside of cup 10, except for rim 10R. The wrapper
could also be sized to mimic the look of a cup sleeve wrapped
around a cup, whereby the cup side wall would be exposed above and
below the wrapper. The wrapper should just be large enough to cover
and thus insulate any area which will be held by the user.
[0038] The outside of the container can be printed more easily
since only base layer 12 need be passed though the printer. While
cup 10 should be made of waterproof material (plastic or
plastic-coated paper), the outer insulating wrapper need not be
made of this expensive material since it does not contact the
liquid and is not part of cup 10.
CONTAINER WITH FOAMED PLASTIC INSERT--FIG. 7
[0039] In lieu of a corrugated paper insert 14 (FIGS. 3A to 5 and
6B), the insert can be made of a layer of foamed plastic 14F, as
shown in FIG. 7. Layer 14F preferably is made of foamed
polystyrene, but also can be made of foamed polyethylene, foamed
PET (sometimes called PETE), or any other closed or open cell
foamed plastic. A closed cell foam structure provides better
insulation than an open cell structure. Therefore I presently
prefer to use a closed cell foam material such as extruded foam
polystyrene. The blowing agent in the foam (such as CO.sub.2 or
Butane) can also be varied to effect the insulation. I prefer to
use a blowing agent that provides superior insulation. Layer 14F
preferably is 0.5 mm to 1.5 mm thick. The insulating qualities of
layer 14F are comparable and even better in some cases to those of
corrugated layer 14, yet it can be adhered to outer layer 12 and
curled in the same manner as layer 14.
CONCLUSION, RAMIFICATIONS, AND SCOPE
[0040] Accordingly the reader will see that, according to the
invention, I have provided a container with improved thermal
insulating properties and rigidity, and that also uses less costly
materials, is cheaper to make, is more leak resistant, extends the
shelf life of the liquid it holds, is microwavable, can be made
from a higher content of recycled content, can be made from the
most economical materials for each part to save costs, does not
require folding, and can be printed more economically. Wrapping the
insulated wrapper around a single wall plastic cup will provide an
insulated cup that, depending upon the plastic material of the
inner cup, can be leak proof, have extended shelf life, be
microwavable, provide rigidity to the plastic cup, provide better
graphics to the plastic cup, and will be potentially be less
expensive than wrapping it around a single wall paper cup
(depending upon the type of plastic material and thickness used).
Due to the overlap of the base layer, the insulating layer does not
interfere with the gluing of the base layer to itself or to the
cup.
[0041] While the above description contains many specificities,
these should not be construed as limitations on the scope of the
invention, but as exemplifications of the presently preferred
embodiments thereof. Many other ramifications and variations are
possible within the teachings of the invention. For example,
although not necessary, the insulating insert, and thus the
insulated wrapper, can also be adhesively attached to the sidewall
of the inner cup in one or more locations, as this will provide
more rigidity to the finished cup. The insulating outer wrapper can
be wrapped into a cylinder and glued in this configuration,
whereafter the cup is then inserted into the wrapper. In lieu of
corrugations, the insert can be embossed with dimples, horizontal
corrugations, cruciform embosses, etc. As mentioned, the insert
sheet can be optionally coated with a reflective material, such as
foil or metallized film, which would be positioned to reflect
radiant heat back toward the inner cup. Also base sheet 12 (as well
as or in lieu of insert 14) can be embossed, corrugated, or made
from foamed plastic in order to provide the outside of the cup
wrapper with a textured look and feel and additional insulation
properties. The wrapper can also be adhered to the inner cup by one
or more beads of cold glue (paste adhesive) or a thin layer of
polyethylene (or similar heat sealing material) can be pre-applied
to the cut side edges of the base sheet. This is then
heat-activated immediately prior to wrapping the wrapper around the
inner cup, and pressing the overlapping side seam to the sidewall
of the inner cup to glue it in place. Since the inner cup and the
insulated wrapper can be made from different material, the base
sheet and/or corrugated insert can be made from recycled paper,
including clay-coated recycled paper for an improved printing
surface. The cup can be used to contain hot or cold solids as well
as liquids. The base sheet and the insulating insert can have
different shapes. E.g., if the cup is not tapered, the opposite
edges of the sheet and insert can be parallel.
[0042] Thus the scope of the invention should be determined by the
appended claims and their legal equivalents, and not by the
examples given.
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