U.S. patent application number 11/195582 was filed with the patent office on 2006-12-28 for polymeric container.
This patent application is currently assigned to Paper Machinery Corporation. Invention is credited to James J. Fritz, Michael F. Hansen, Craig N. Johnson, Gary L. Johnson.
Application Number | 20060289609 11/195582 |
Document ID | / |
Family ID | 37566138 |
Filed Date | 2006-12-28 |
United States Patent
Application |
20060289609 |
Kind Code |
A1 |
Fritz; James J. ; et
al. |
December 28, 2006 |
Polymeric container
Abstract
A container has a bottom formed from polymeric material having a
floor and a skirt projecting from the floor and a sidewall formed
from polymeric material having opposite sides joined to one another
and a lower end joined to the skirt so as to form an interior
having a mouth, wherein the mouth has a dimension not less than the
floor.
Inventors: |
Fritz; James J.; (West Bend,
WI) ; Hansen; Michael F.; (Mequon, WI) ;
Johnson; Craig N.; (Germantown, WI) ; Johnson; Gary
L.; (Delafield, WI) |
Correspondence
Address: |
FOLEY & LARDNER LLP
777 EAST WISCONSIN AVENUE
MILWAUKEE
WI
53202-5306
US
|
Assignee: |
Paper Machinery Corporation
|
Family ID: |
37566138 |
Appl. No.: |
11/195582 |
Filed: |
August 2, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60598550 |
Aug 2, 2004 |
|
|
|
60628640 |
Nov 17, 2004 |
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Current U.S.
Class: |
229/4.5 ;
229/400 |
Current CPC
Class: |
B65D 1/265 20130101;
B65D 1/40 20130101 |
Class at
Publication: |
229/004.5 ;
229/400 |
International
Class: |
B65D 3/00 20060101
B65D003/00 |
Claims
1. A container comprising: a bottom formed from a polymeric
material having a floor and a skirt projecting from the floor; and
a sidewall formed from a polymeric material having opposite sides
joined to one another and a lower end joined to the skirt so as to
form an interior having a mouth, the mouth having a dimension not
less than the floor.
2. The container of claim 1, wherein the skirt has an edge and
wherein the lower end of the sidewall wraps about the edge.
3. The container of claim 1, wherein at least one of the bottom and
the sidewall is formed from polypropylene.
4. The container of claim 1, wherein at least one of the bottom and
the sidewall includes a layer of recycled polypropylene material
sandwiched between two layers of virgin polypropylene material.
5. The container of claim 1, wherein the container has an interior,
wherein at least one of the bottom and the sidewall has an inner
layer of virgin polymeric material adjacent the interior and a
layer of recycled polymeric material adjacent an exterior to the
layer of virgin polymeric material.
6. The container of claim 5, wherein the inner layer of virgin
polymeric material has a minimum thickness of at least about 0.001
inches.
7. The container of claim 6, wherein the inner layer of virgin
polymeric material has a maximum thickness of no greater than 0.040
inches.
8. The container of claim 5, wherein the inner layer of virgin
polymeric material has a maximum thickness of no greater than 0.040
inches.
9. The container of claim 5, wherein the layer of recycled
polymeric material has a minimum thickness of 0.005 inches.
10. The container of claim 5, wherein the layer of recycled
polymeric material has a maximum thickness of no greater than 0.040
inches.
11. The container of claim 5 including an outer layer of polymeric
material adjacent an exterior to the layer of recycled polymeric
material.
12. The container of claim 11, wherein the outer layer of virgin
polymeric material has a minimum thickness of no greater than 0.001
inches.
13. The container of claim 12, wherein the outer layer of virgin
polymeric material has a maximum thickness of no greater than 0.040
inches.
14. The container of claim 11, wherein the outer layer of virgin
polymeric material has a maximum thickness of no greater than 0.040
inches.
15. The container of claim 1, wherein the sidewall has a maximum
thickness of no greater than 0.040 inches.
16. The container of claim 1, wherein the sidewall has a minimum
thickness of at least 0.007 inches.
17. The container of claim 5, wherein at least one of the layers
includes a filler material.
18. The container of claim 17, wherein the filler material
comprises talc.
19. The container of claim 1, wherein at least one of the bottom
and the sidewall includes a filler material.
20. The container of claim 1, wherein the skirt includes a
plurality of inwardly extending notches.
21. The container of claim 20, wherein the notches are
V-shaped.
22. The container of claim 21, wherein the notches have an outer
most radial width of between about 0.2 inches and 0.3 inches.
23. The container of claim 21, wherein the ends of the notches are
spaced between 0.1 inches and 0.125 inches from the floor.
24. The container of claim 20, wherein the notches are equally
spaced about an entire perimeter of the skirt.
25. The container of claim 20 including at least 10 notches.
26. The container of claim 20, wherein the bottom includes a
circular score at a junction of the floor and the skirt.
27. The container of claim 26, wherein the bottom has a thickness
and wherein the circumferential score has a depth of at least
one-half the thickness.
28. The container of claim 1, wherein the bottom has a plurality of
inwardly extending scores.
29. The container of claim 28, wherein the plurality of scores
extend from an edge of the skirt to the floor.
30. The container of claim 28, wherein the plurality of scores are
uniformly spaced along an entirety of the skirt.
31. The container of claim 1, wherein the skirt includes a
plurality of inwardly extending slits.
32. The container of claim 31, wherein the slits extend at least
two-thirds of a radial width of the skirt.
33. The container of claim 31, wherein the slits are uniformly
spaced along an entirety of the skirt.
34. The container of claim 1, wherein the skirt is fused to the
sidewall.
35. The container of claim 1, wherein the bottom is formed entirely
from at least one polymeric material.
36. The container of claim 1, wherein the sidewall includes
printing on an outer surface.
37. A container comprising: a bottom having a floor and a skirt;
and a sidewall having opposite side ends joined to one another and
a lower end joined to the skirt to form a container interior,
wherein at least one of the bottom and sidewall includes an inner
layer of virgin polymeric material adjacent the interior and a
layer of recycled polymeric material exterior to the layer of
virgin polymeric material.
38. The container of claim 37, wherein at least one of the bottom
and the sidewall is formed from polypropylene.
39. The container of claim 37 including an outer layer of virgin
polymeric material adjacent to the layer of recycled polymeric
material.
40. A container comprising: a bottom formed substantially from a
polymeric material and having a floor and a skirt; and a sidewall
formed substantially from a polymeric material having opposite
sides joined to one another and a lower end joined to the skirt,
wherein the skirt includes a plurality of resiliency lessening
treatments.
41. The container of claim 40, wherein the resiliency lessening
treatments comprise notches.
42. The container of claim 41, wherein the notches are
V-shaped.
43. The container of claim 41, wherein ends of the notches are
spaced between about 0.1 inches and about 0.125 inches from the
floor.
44. The container of claim 41, wherein the notches are equally
spaced about the entire perimeter of the skirt.
45. The container of claim 41, wherein the bottom includes a
circular score at a junction of the floor and the skirt.
46. The container of claim 45, wherein the bottom has a thickness
and wherein the circumferential score has a depth of at least
one-half of the thickness.
47. The container of claim 40, wherein the resiliency lessening
treatments comprise slits.
48. The container of claim 40, wherein the resiliency lessening
treatments comprise scores.
49. The container of claim 40, wherein at least one of the bottom
and the sidewall includes a layer of virgin polymeric material.
50. The container of claim 40, wherein the floor extends in a first
plane and wherein the sidewall extends in a second plane
perpendicular to the first plane.
51. A method for forming a container, the method comprising:
forming a substantially planar bottom blank from a first sheet
formed substantially from at least one polymeric material; forming
a circumferential score in the bottom blank, the score separating
the bottom blankblank into a floor and a skirt; bending the skirt
relative to the floor; forming a substantially planar sidewall
blank from a second sheet formed substantially from at least one
polymeric material; joining opposite sides of the sidewall blank;
and joining a lower end of the sidewall blank to the skirt such
that the floor extends in a first plane and such that the sidewall
extends in a second plane perpendicular to the first plane.
52. The method of claim 51 including treating the skirt at a
plurality of spaced locations to weaken resiliency of the at least
one polymeric material.
53. The method of claim 52, wherein treating includes scoring the
skirt.
54. The method of claim 52, wherein treating includes slitting the
skirt.
55. The method of claim 52, wherein treating includes notching the
skirt.
56. The method of claim 51 including wrapping the lower end of the
sidewall about an edge of the skirt.
57. The method of claim 51 including fusing the lower end of the
sidewall to the skirt.
58. The method of claim 51, wherein the sheet includes a first
layer of virgin polymeric material and a second layer of recycled
polymeric material and wherein the method includes positioning the
virgin polymeric material adjacent an interior of the cylinder.
59. A method for forming a container, the method comprising:
forming a substantially planar bottom blank from a first sheet
formed substantially from at least one polymeric material; forming
a circumferential score in the bottom blank, the score separating
the bottom blank into a floor and a skirt; bending the skirt
relative to the floor; forming a substantially planar sidewall
blank from a second sheet formed substantially from at least one
polymeric material; joining opposite sides of the sidewall blank;
and joining a lower end of the sidewall blank to the skirt, wherein
at least one of the first sheet and the second sheet includes a
first layer of virgin polymeric material and a second layer of
recycled polymeric material and wherein the method further includes
positioning the virgin polymeric material adjacent an interior of
the container.
60. A method for forming a container, the method comprising:
forming a substantially planar bottom blank from a sheet formed
substantially from at least one polymeric material; forming a
circumferential score in the bottom blank the score separating the
bottom blank into a floor and a skirt; bending the skirt relative
to the floor; forming a substantially planar sidewall blank from a
sheet formed substantially from at least one polymeric material;
joining opposite sides of the sidewall blank; and joining a lower
end of the sidewall blank to the skirt, the additional step of
treating the skirt at a plurality of spaced locations to weaken
resiliency of the at least one polymeric material.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims priority to co-pending U.S.
Provisional Patent Application Ser. No. 60/598,550, filed on Aug.
2, 2004, by Fritz et al., entitled POLYMERIC CONTAINER, from which
priority is claimed under 35 U.S.C. .sctn.119(e), the full
disclosure of which, in its entirety, is hereby incorporated by
reference.
BACKGROUND
[0002] Paperboard containers have been in use for many years.
Despite their popularity, paperboard containers are not well suited
for containing items that require either a moisture vapor barrier
or a gas barrier.
[0003] Polymeric or plastic containers are better suited for
containing substances that require a moisture vapor or gas barrier.
Thermoforming such plastic containers requires the containers to
have a tapered sidewall. In many instances, a true straight wall
may be desired and is not achievable with thermoforming. Injection
molding can be made straight wall, but is expensive and does not
achieve high barrier requirements. Thermoforming requires an
excessive amount of plastic material to accommodate the stretching
and deformation of the plastic material during thermoforming.
Moreover, the stretching or deformation of the plastic material
during thermoforming prevents the printing of labels, data or
images directly on the plastic material prior to the plastic
material being shaped into a 3-dimensional container. Printing
directly upon the plastic material after it has been shaped into a
3-dimensional container is costly and is limited in the quality of
the image produced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a sectional view of one example of a container
according to one example embodiment.
[0005] FIG. 2 is a top plan view of one example of a sheet 60 from
which a sidewall blank is provided according to one example
embodiment.
[0006] FIG. 3 is a sectional view of the sidewall blank of FIG. 2
according to one example embodiment.
[0007] FIG. 4 is a top plan view of a bottom blank from which a
bottom may be formed according to one example embodiment.
[0008] FIG. 5 is a sectional view of the bottom blank of FIG. 4
according to one example embodiment.
[0009] FIG. 6 is a sectional view of another embodiment of the cup
of FIG. 1 according to an example embodiment.
[0010] FIG. 7 is a top plan view of one example of a sheet from
which one embodiment of a bottom blank may be provided according to
one example embodiment.
[0011] FIG. 8 is a top plan view of another sheet from which
another embodiment of a bottom blank may be provided according to
one example embodiment.
[0012] FIG. 9 is a top plan view of another sheet from which
another embodiment of a bottom blank may be provided according to
one example embodiment.
[0013] FIG. 10 is a side elevational view of another embodiment of
the cup of FIG. 1 according to one example embodiment.
[0014] FIG. 11 is a fragmentary sectional view of the cup of FIG.
10 according to one example embodiment.
[0015] FIG. 12 is a top plan view of a sidewall blank from which
the cup of FIG. 10 may be formed according to one example
embodiment.
[0016] FIG. 13 is a side elevational view of another embodiment of
the cup of FIG. 1 according to one example embodiment.
[0017] FIG. 14 is a fragmentary sectional view of the cup of FIG.
13 according to one example embodiment.
[0018] FIG. 15 is a top plan view of a sidewall blank from which
the cup of FIG. 13 may be formed according to one example
embodiment.
[0019] FIG. 16 is a top plan view of a sheet from which a bottom
blank may be provided for forming the cup of FIG. 13 according to
one example embodiment.
[0020] FIG. 17 is a top plan view of a machine for forming a cup
according to one example embodiment.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0021] FIG. 1 is a sectional view of a container 10 according to
one exemplary embodiment. Container 10 includes bottom 12 and
sidewall 16. Bottom 12 includes floor 18 and skirt 20. Skirt 20
projects from floor 18. Skirt 20 and floor 18 are integrally formed
as part of a single unitary body. In particular, both floor 18 and
skirt 20 of bottom 12 are substantially formed from at least one
plastic or polymeric material.
[0022] Sidewall 16 comprises a panel substantially formed from at
least one polymeric material. For purposes of this disclosure, the
phrase "formed substantially from at least one polymeric material"
means that a member, panel or structure is formed from one or more
layers of plastic or polymeric material such that main structural
support or a majority of the thickness of the member is provided by
the plastic or polymeric material. In particular embodiments, the
plastic or polymeric material may have disbursed or impregnated
filler materials. The one or more layers of plastic or polymeric
materials may also include much thinner layers of non-polymeric or
plastic materials wherein such layers have a de minimus or
insubstantial thickness such that the non-polymeric layer or layers
add little to the overall thickness of the member or do not
substantially increase the rigidity or strength of the member.
[0023] As shown by FIG. 1, sidewall 16 has a pair of opposite ends
22, 24 which are joined to one another. In the particular example
shown, ends 22 and 24 overlap one another. Sidewall 16 further
includes a lower end 26 which wraps about edge 28 of skirt 20. As a
result, lower end 26 of sidewall 16 cooperates with skirt 20 of
bottom 12 to form a 3-ply wall below floor 18. In the particular
example shown, ends 22, 24 are joined to one another by heating and
melting the exterior plastic or polymeric materials of sidewall 16
such that overlapping portions of ends 22 and 24 are fused to one
another to form a substantially moisture impermeable and gas
impermeable seal when sidewall 16 is formed from appropriate
materials. Examples of materials that may be used to provide an
effective moisture vapor transfer barrier include polypropylene and
low density polyethylene. An example of a material that may be used
to provide an effective gas or oxygen transfer barrier is ethylene
vinyl alcohol (EVOH). In a similar fashion, polymeric surfaces 32,
34 and 36 of lower end 28 of sidewall 16, as well as surfaces 38
and 40 of skirt 20 of bottom 12 are heated so as to fuse skirt 20
to lower end 28 of sidewall 16. The heating of such surfaces may be
achieved by radiant heat, convection heat or by generating friction
such as by ultrasonic welding. Skirt 20 and end 28 as well as ends
22 and 24 may be joined with glue. Like the junction between ends
22 and 24, the junction between bottom 18 and sidewall 16 forms a
substantially moisture impermeable and gas impermeable seal.
[0024] As further shown by FIG. 1, sidewall 16 includes an upper
end 44 which is curled or rolled for up to 270 degrees to provide
the mouth 46 of container 10 with a smooth surface. In the
particular example shown, upper end 44 is curled utilizing a push
in curl in which ends 44 are pushed towards bottom 18 to form the
noted curl. Alternatively, ends 44 may be formed by multiple push
in curls or spin curls.
[0025] Bottom 12 and sidewall 16, when joined, form container 10
which has interior 48. Like containers formed from thermoformed or
injection molded plastic, container 10 provides an interior 48 well
suited for containing liquids or other contents which require a
moisture or gas impermeable barrier. Although not shown, container
10 may additionally be provided with a lid or cover. Unlike
polymeric containers formed by thermoforming or injection molding,
container 10 does not require stretching or deformation of those
exterior portions 50 of sidewall 16 that extend generally above
floor 18. In addition, the fabrication of container 10 does not
require that portion 50 be subjected to extreme heat. As a result,
at least portions 50 of sidewall 16 may be made from a thinner
panel, requiring less material. In addition, portions 50 of
sidewall 16 may be configured so as to extend along axes or planes
52 which are substantially perpendicular to the plane 54 of floor
18 of bottom 12, providing container 10 with a true straight
sidewall. Moreover, portions 50 of sidewall 16 may have text and/or
images preprinted directly upon the surface of sidewall 16 prior to
ends 22, 24 being joined to one another and prior to sidewall 16
being converted from a generally flat 2-dimensional panel to a
3-dimensional structure as part of container 10. Such printing may
be achieved with less chance of printing becoming distorted during
the formation of container 10.
[0026] FIGS. 2-5 illustrate examples of materials from which bottom
12 and sidewall 16 may be formed. FIG. 2 is a top plan view of a
sheet 60 from which a sidewall blank 62 is formed. FIG. 3 is a
sectional view of the sidewall 62. In one embodiment, sidewall
blank 62 is cut from sheet 60. According to one particular method,
sidewall blank 62 is stamped from sheet 60 and is generally
2-dimensional. As shown by FIG. 3, sidewall blank 62 includes three
substantially coextensive layers 64, 66 and 68. In one embodiment,
layers 64, 66 and 68 are coextruded with one another. In another
embodiment, layers 64, 66 and 68 are laminated to one another.
Layer 64 generally comprises a layer of a recycled polymer. In one
embodiment, layer 64 comprises recycled polypropylene. Layer 64 is
sandwiched between layers 66 and 68. In other embodiments, one of
layers 66 and 68 may be omitted. Although not shown, additional
binding or tie layers may be added as needed.
[0027] Layer 66 comprises a layer substantially formed of a virgin
polymer. In one embodiment, layer 66 is formed from virgin
polypropylene. Because layer 66 is formed from virgin
polypropylene, the surfaces of layer 66 may be positioned along
interior 48 of container 10 (shown in FIG. 1) where it may come in
contact with the content of container 10 such as a food or
beverage.
[0028] Layer 68 comprises a layer of a virgin polymer. In the
particular example shown, layer 68 comprises a layer of virgin
polypropylene. Because layer 68 is formed from a virgin polymer,
layer 68 may be located along an exterior of sidewall 16 where it
may come into contact with food or beverages, a person's hand or
other surfaces for which contact with layer 64 would be
undesirable. Layer 66 and 68 cooperate with one another to
substantially cover and seal off the recycled polymer of layer
64.
[0029] Because sheet 60 and sidewall blank 62 formed from it
include layer 64 of a recycled polymer, sidewall blank 62 and the
resulting container 10 may be less expensively formed. In addition,
sidewall blank 62 and the resulting container 10 are more
environmentally friendly in that at least a portion is formed
utilizing the recycled polymer rather than being formed entirely
from virgin polymer. The reduced cost and environmental benefit
achieved by using a recycled polymer is further enhanced with the
configuration of container 10. In particular, because container 10
is formed utilizing a two-piece construction, neither bottom 12 nor
sidewall 16 need to be substantially deformed or stretched as would
otherwise be required in a thermoforming process. Because neither
bottom 12 nor sidewall 16 is substantially stretched or thinned
during the formation of container 10, layers 66 and 68 of the
virgin polymer may be made thinner with a lesser risk of layer 64
becoming exposed. Because layers 66 and 68 may be made thinner,
less virgin polymer and a greater amount of recycled polymer may be
utilized, lessening the cost and increasing the environmental
friendliness of container 10.
[0030] In the particular example shown, layer 64 has a minimum
thickness of at least 0.005 inches and a maximum thickness of no
greater than 0.040 inches. Layer 66 has a minimum thickness of at
least about 0.001 inches and a maximum thickness of no greater than
0.040 inches. Layer 68 has a minimum thickness of at least about
0.001 inches and a maximum thickness of no greater 0.040 inches. In
the particular example illustrated, layers 64, 66 and 68 are each
additionally provided with a filler material which is impregnated
or disbursed throughout the one or more polymers. In one
embodiment, the filler material comprises talc. The talc filler
material lessens the resiliency or memory of the polymeric material
forming layers 64, 66 and 68. In other embodiments, less than all
the layers 64, 66 and 68 may be provided with a filler material. In
still other embodiments, layers 64, 66 and 68 may each omit any
filler material. In still other embodiments, sidewall 16 may be
formed from a single layer (such as formed out of a homopolymer
material) of a polymeric material with or without a filler material
disbursed throughout.
[0031] FIG. 4 is a top plan view of a sheet 80 from which a bottom
blank 82 is formed. FIG. 5 is an enlarged sectional view of bottom
blank 82. Sheet 80 is generally a planar 2-dimensional structure
from which bottom blank 82 is formed. In one embodiment, bottom
blank 82 is cut from sheet 80. In the particular example shown,
bottom blank 82 is stamped from sheet 80.
[0032] As shown by FIG. 5, bottom blank 82 includes three
substantially coextensive layers 84, 86 and 88. In one embodiment,
bottom blank 82 is cut from sheet 80. According to one particular
method bottom blank 82 is stamped from sheet 80 and is generally
2-dimensional. As shown by FIG. 5, bottom blank 82 includes three
substantially coextensive layers 84, 86 and 88. In one embodiment,
layers 84, 86 and 88 are coextruded with one another. In another
embodiment, layers 84, 86 and 88 are laminated to one another.
Layer 84 generally comprises a layer of a recycled polymer. In one
embodiment, layer 84 comprises recycled polypropylene. Layer 84 is
sandwiched between layers 86 and 88. In other embodiments, one of
layers 66 and 68 may be omitted.
[0033] Layer 86 comprises a layer substantially formed of a virgin
polymer. In one embodiment, layer 86 is formed from virgin
polypropylene. Because layer 66 is formed from virgin
polypropylene, the surfaces of layer 66 may be positioned along
interior 48 of container 10 (shown in FIG. 1) where it may come in
contact with the content of container 10 such as a food or
beverage.
[0034] Layer 88 comprises a layer of a virgin polymer. In the
particular example shown, layer 88 comprises a layer of virgin
polypropylene. Because layer 88 is formed from a virgin polymer,
layer 88 may be located along an exterior of sidewall 16 where it
may come into contact with food or beverages, a person's hand or
other surfaces for which contact with layer 84 would be
undesirable. Layer 86 and 88 cooperate with one another to
substantially cover and seal off the recycled polymer of layer
84.
[0035] Because sheet 80 and sidewall blank 62 formed from it
include layer 84 of a recycled polymer, sidewall blank 62 and the
resulting container 10 may be less expensively formed. In addition,
sidewall blank 62 and the resulting container 10 are more
environmentally friendly in that at least a portion is formed
utilizing the recycled polymer rather than being formed entirely
from virgin polymer. The reduced cost and environmental benefit
achieved by using a recycled polymer is further enhanced with the
configuration of container 10. In particular, because container 10
is formed utilizing a two-piece construction, neither bottom 12 nor
sidewall 16 need to be substantially deformed or stretched as would
otherwise be required in a thermoforming process. Because sidewall
16 is not substantially stretched or thinned during the formation
of container 10, layers 86 and 88 of the virgin polymer may be made
thinner with a lesser risk of layer 84 becoming exposed. Because
layers 66 and 68 may be made thinner, less virgin polymer and a
greater amount of recycled polymer may be utilized, lessening the
cost and increasing the environmental friendliness of container
10.
[0036] In the particular example shown, layer 84 has a minimum
thickness of at least 0.005 inches and a maximum thickness of no
greater than 0.040 inches. Layer 86 has a minimum thickness of at
least about 0.001 inches and a maximum thickness of no greater than
0.040 inches. Layer 88 has a minimum thickness of at least about
0.001 inches and a maximum thickness of no greater 0.040 inches. In
the particular example illustrated, layers 84, 86 and 88 are each
additionally provided with a filler material which is impregnated
or disbursed throughout the one or more polymers. In one
embodiment, the filler material comprises talc. The talc filler
material lessens the resiliency or memory of the polymeric material
forming layers 84, 86 and 88. In other embodiments, less than all
the layers 84, 86 and 88 may be provided with a filler material. In
still other embodiments, layers 84, 86 and 88 may each omit any
filler material. In still other embodiments, sidewall 16 may be
formed from a single layer (such as formed out of a homopolymer
material) of a polymeric material with or without a filler material
disbursed throughout.
[0037] As further shown by FIGS. 4 and 5, bottom blank 82
additionally includes a circumferential score 90. Score 90 extends
partly into or partly through the thickness of bottom blank 82.
Circumferential score 90 facilitates the bending or other
deformation of a perimeter portion of blank 82 along score 90 to
form floor 18 and skirt 20. Although score 90 is illustrated as
being continuous, score 90 may alternatively intermittently extend
circumferentially along and substantially parallel to an edge
perimeter of bottom blank 82. Although the edge perimeter of bottom
blank 82 as well as score 90 are illustrated as being substantially
circular, bottom blank 82 and score 90 may have other shapes and
configurations depending upon the desired shape of container 10.
For example, bottom 82 may alternatively be square or rectangular
in shape with generally rounded corners. In other embodiments,
bottom blank 82 may be oval. In such embodiments, the joining of
ends 22 and 24 of sidewall 16 (shown in FIG. 1) and the joining of
lower end 28 of sidewall 16 to bottom blank 82 would result in a
container having a non-circular or non-cylindrical interior.
[0038] The formation of container 10 is generally as follows.
Initially, sidewall blank 62 and bottom blank 82 are formed from
sheets 60 and 80 which are formed from at least one polymeric
material, respectively. Either before or after bottom link 82 is
separated from sheet 80, scores 90 are formed which extend between
floor 18 and skirt 20. Skirt 20 is bent or otherwise deformed
relative to floor 18. Skirt 20 is joined to lower end 28 of
sidewall blank 62 while ends 22 and 24 of sidewall blank 62 are
joined to one another. In the embodiment in which sheet 60 and
sheet 80 include a layer of recycled of polymer and an adjacent
layer of virgin polymer, sidewall blank 62 and bottom blank 82 are
positioned so as to position the layer of virgin polymer adjacent
to an interior of the resulting container. Printing upon sidewall
blank 62 is done before sidewall blank 62 is joined to bottom blank
82 and while sidewall blank 62 is in a generally 2-dimensional
form. In the particular example shown, lower end 28 and/or skirt 20
are heated, ultrasonically welded, adhered with a hot melt or glue
or otherwise treated so as to fuse, weld or otherwise join lower
end 28 to skirt 20. In one particular embodiment, lower end 28 is
wrapped about skirt 20. Although sidewall blank 62 is configured so
as to form a substantially straight sidewall which extends along
axes or in an arcuate plane substantially perpendicular to the
plane in which floor 18 extends, sidewall blank 62 may
alternatively be configured so as to form an outwardly tapered
sidewall with respect to the plane in which floor 18 extends.
[0039] FIG. 6 is a sectional view of container 110, another
embodiment of container 10 shown in FIG. 1. Container 110 is
similar to container 10 except that lower end 26 of sidewall 16
does not wrap about end 28 of skirt 20 of bottom 12. Rather,
surface 38 of skirt 20 and surface 32 of lower end 26 of sidewall
16 are sealed to one another. In one embodiment, the sealing is
achieved by melting the polymer material of surfaces 32 and 38 to
fuse the surfaces together, and to have melted polymer floor into
gaps caused by the convolute forming process. In another
embodiment, the fusion may be achieved by ultrasonic welding or
adhesives.
[0040] In contrast to paperboard, plastic or polymeric materials
have a much greater elasticity or shape memory. Moreover, plastic
or polymeric material does not compress like paperboard. As a
result, during bending of skirt 20 away from floor 18, portions of
skirt 20 may overlap one another and build up. With paperboard
material, the paper compresses. Due to its shape, memory or
elasticity, the polymeric material of skirt 20 does not easily
compress which may result in the formation of gaps between
sidewalls 16 and skirt 20. These gaps present leakage issues and
forming issues.
[0041] FIGS. 7-9 illustrate techniques for treating skirt 20 of
bottom 12 (or of bottom blank 82) to lessen the resiliency or shape
memory of skirt 20 and to reduce the likelihood of a potential leak
causing gaps between skirt 20 and sidewall 16 (or sidewall blank
62). FIG. 7 is a top plan view of bottom blank 182 formed from
sheet 80 described above with respect to FIG. 4. As noted above,
sheet 80 includes three layers 84, 86 and 88 (shown in FIG. 5). In
other embodiments, sheet 80 may alternatively comprise a single of
polymeric material or a homopolymer plastic sheet. One or more
layers 84, 86, 88 or an alternative homopolymer plastic sheet may
additionally include an organic filler, such as talc. Like sidewall
16, bottom 12 (formed from bottom blank 82 or blank 182) may be
opaque, translucent or clear.
[0042] Bottom blank 182 has a generally circular perimeter edge 192
and an inwardly spaced circumferential score 190. Score 190 extends
partially into the thickness or caliber of bottom blank 182 to
separate bottom blank 182 into floor 18 and skirt 20. In one
particular embodiment, score 190 has a depth of one-half the
thickness or caliber of bottom blank 182. In the particular
embodiment, score 190 continuously extends circumferentially about
a center of bottom blank 182 and is inwardly spaced from outer edge
192 by a minimum distance of at least 0.100 inches. In other
embodiments, both outer edge 192 and score 190 may have shapes
other than circles. For example outer edge 192 and score 190 may
alternatively be oval, square or rectangular. In square and
rectangular embodiments, the corners are rounded.
[0043] As shown by FIG. 7, skirt 20 of bottom blank 182 is
additionally treated at a plurality of spaced locations to weaken
the resiliency of one or more polymeric materials from which bottom
blank 182 is formed. In the embodiment shown in FIG. 7, skirt 20 is
treated by scoring. In particular, skirt 20 includes a plurality of
uniformly or equally spaced scores 196. Scores 196 have a depth of
at least one-third of the thickness or caliber of bottom blank 182.
In the particular example shown, bottom blank 182 has a caliber
thickness of 0.020 inches and scores have a depth of approximately
0.010 inches. Scores 196 extend from edge 192 to circumferential
score 190. In the particular example shown, each score 190 has a
length of at least 0.100 inches and nominally of about 0.375
inches. Scores 196 weaken the resilient nature or shape memory of
the polymeric material of skirt 20 to facilitate bending of skirt
20 relative to floor 18 and to facilitate better securement of
skirt 20 to sidewall 16.
[0044] FIG. 8 is a top plan view illustrating bottom blank 282
formed from sheet 80. Bottom blank 282 is similar to bottom blank
182 except that skirt 20 of bottom blank 282 is treated at a
plurality of spaced locations with slits 296 in lieu of scores 196.
Slits 296 comprise cuts which extend inwardly from outer edge 192
and which extend completely through the thickness or caliber of
bottom blank 282. Slits 296 extend inwardly from outer edge 192 and
have terminal ends 298 spaced from circumferential score 190. Slits
296 have a length such that terminal ends 298 are spaced from
circumferential score 190 by at least 0.1 inches. In one
embodiment, slits 296 have a length of approximately two-thirds of
the bottom depth BD (FIG. 1). In other embodiments, slits 282 may
have other lengths such that ends 298 are spaced from score 190 by
other distances. A number of slits 296 as well as the uniform
spacing of slits 296 is determined based upon the radial difference
between outer edge 192 and circumferential score 190. In the
particular example shown, slits 296 are evenly spaced from one
another about the circumference.
[0045] Slits 296 weaken the resilient nature or shape of memory of
skirt 20 to facilitate bending or deformation of skirt 20 relative
to floor 18. Slits 296 further facilitate the joining of skirts 20
to sidewall 16. As compared to scores 196, slits 296 are relatively
better at weakening the resilient nature of skirt 20, enabling
easier and more reliable joining of skirt 20 to sidewall 16,
improved heating and reducing the potential for leakage between
bottom 12 and sidewall 16.
[0046] FIG. 9 is a top plan view illustrating bottom blank 382
formed from sheet 80. Bottom blank 382 is substantially similar to
bottom blank 182 except that skirt 20 of bottom blank 382 is
treated at a plurality of spaced locations to weaken the shape
memory or resilient nature of the polymeric material of skirt 20 by
notching in lieu of scoring. In particular, skirt 20 includes a
plurality of inwardly extending notches 396. Notches 396 are
different than scores 196 and slits 296 in that notches 396 are
formed by removal of material from skirt 20. Because material is
removed, notches 396 better minimize overlapping or pleating of
skirt 20 when it is bent or deformed relative to floor 18 as
compared to scores 196 or slits 296. By reducing pleating of skirt
20, notches 396 reduce the likelihood of leaks occurring between
skirt 20 and sidewall 16 (shown in FIG. 1). Notches 396 further
enable bottom blank 382 to be more easily formed into floor 12 and
joined to sidewall 16.
[0047] As shown by FIG. 9, notches 396 are uniformly spaced about
the entirety of skirt 20. The spacing and the quantity of notches
396 is determined based upon the radial distance between outer edge
192 and score 190. In the particular example shown, notches 396
have a radial length of approximately two-thirds of the bottom
depth BD (FIG. 1). Notches 396 extend inwardly from outer edge 192
towards score 190. In the particular example shown, notches 192 are
generally V-shaped. Because notches 396 are V-shaped, notches 396
better reduce shape memory of skirt 20. In other embodiments,
notches 396 may have other shapes. In the particular example shown,
notches 396 have end points 398 which terminate prior to reaching
score 190. In the particular example shown, end points 398 are
spaced from score 190 by a minimum radial distance of 0.1 inches
and a maximum radial distance of 0.125 inches. In the embodiment
shown, each notch 396 has a radial depth of about 0.02 inches and
0.03 inches.
[0048] Overall, containers 10 and 110 provide several advantages
over typical paperboard containers and conventional thermoformed or
injection molded polymeric containers. Unlike paperboard
containers, containers 10 and 110 provide reliable moisture and gas
impermeable sealed containers capable of containing foods and other
content which are sensitive to moisture or gas. Unlike thermoformed
polymeric containers, containers 10 and 110 enables the mouth of
the container the same size as the opposite floor of the container.
Containers 10 and 110 facilitate the preprinting of information or
images upon the outer surface of sidewall 16 above floor 18 while
sidewall 16 is in a 2-dimensional state with less distortion during
the completion of the formation of the container. Containers 10 and
110 further facilitate thinner walled containers, the greater use
of recycled polymeric materials and the conservation of virgin
polymeric material due, in part, to sidewall 16 not being stretched
or deformed to form the container. Containers 10 and 110, when
having bottom 12 formed from bottom blank 182, 282 or 382 are
easier to manufacture and are less likely to have leaks along the
juncture of bottom 12 and sidewall 16.
[0049] Although containers 10 and 110 are each illustrated as
having mouths 46 which have the same diameter as the opposite floor
18, containers 10 and 110 may alternatively have various other
configurations. For example, containers 10 and 110 may have
outwardly tapered sidewalls 16. FIGS. 10-13 illustrate container
410, another embodiment of container 10 (shown in FIG. 1).
Container 410 is substantially similar to container 10 except that
container 410 has outwardly tapering sidewalls 416. Those remaining
components of container 410 which correspond to container 10 are
numbered similarly. FIG. 13 illustrates sidewall 416 after it has
been cut or formed from sheet 60 (described above). Sidewall 416 is
joined to bottom 12 in a similar manner to that of the joining of
sidewall 16 to bottom 12.
[0050] Although containers 10 and 110 are illustrated as being
substantially imperforate along sidewall 16 and bottom 12,
containers 10 and 110 may alternatively be perforate. FIGS. 13-16
illustrate container 510, another embodiment of container 10.
Container 510 is similar to container 410 except that container 510
includes a perforated bottom 512 and sidewall 516 in lieu of bottom
12 and sidewall 416 of container 410. According to one embodiment,
bottom 512 is formed from sheet 80 described above. In other
embodiments, bottom 512 may be formed from sheets of other
materials. As compared to bottom 12, bottom 512 additionally
includes cutouts or notches 596 and perforations 598. Notches 596
minimize overlapping or pleating of skirt 20 when it is bent or
deformed relative to floor 18. As a result, cutouts 96 reduce the
likelihood of leaks occurring between skirt 20 and sidewall 516.
Cutouts 596 further enable bottom blank 582 to be more easily
formed into bottom 512 and joined to sidewall 516.
[0051] Perforations 598 constitute openings extending through floor
18 of bottom 512. Perforations 598 facilitate the escape of
moisture from the interior of container 510 and the in-flow of
external air into container 510. As a result, container 510 is well
suited for containing soil, plants or other similar contents.
[0052] Sidewall 516 is similar to sidewall 416 except that sidewall
516 includes notches 602. Notches 602 have a sufficient depth or
dimension so as to facilitate wrapping of sidewall 516 and bending
of the lower end of sidewall 16 about skirt 20 of bottom 512 while
minimizing overlapping of portions of sidewall 16 to reduce leakage
potential. In other embodiments, notches 602 may be omitted.
[0053] Containers 10, 110, 410 and 510 may be formed using a
variety of different machines. FIG. 17 illustrates a floor plan of
one example of a machine 610 configured to form container 10,
container 410 or container 510. In particular, the machine shown is
configured to perform the above-described steps. Machine 610
generally includes mandrel turret 612, rimming turret 614, transfer
turret 616, bottom maker 618, bottom preheat station 620, sidewall
heater 622, blank or roll feed 624, bottom heat station 626, bottom
in-curl station 628, rimming stations 630 and cup discharge 640.
Bottom maker 618 forms bottom 12. In one embodiment, bottom maker
618 additionally includes hole puncher 632 for forming perforations
598 (shown in FIG. 16) when a cup such as cup 510 is being formed.
In other embodiments, hole puncher 632 may be omitted.
[0054] Bottoms 12 formed by bottom maker 16 are carried by mandrel
turret 612 to preheat station 620 where bottoms 12 are preheated
prior to bonding of sidewall such as sidewall 16 thereto.
Sidewalls, such as sidewalls 16, are formed by blank or feed roll
616 supplying sidewall blanks to transfer turret 624 which
transfers the sidewalls to sidewall heater 622 and subsequently
into position with respect to bottoms 12, where sidewalls 16 are
wrapped about bottoms 12 and the sides of sidewall 16 are bonded to
one another. Thereafter, mandrel turret 612 transfers the bottom
sidewall assembly to bottom heat station which further secures
bottom 12 to sidewall 16.
[0055] Mandrel turret 612 subsequently transfers the assembly to
bottom in-curl station 628 where the lower end of sidewall 16 is
curled about skirt 20. Once the lower end of sidewall 16 is curled
about skirt 20 of bottom 12, the partially formed cup is
transferred to rimming turret 614. In other embodiments where
sidewall 16 is not curled or in-curled about skirt 20 of bottom 12,
bottom in-curl station 628 may be omitted.
[0056] Rimming turret 614 transfers the cup to each of rimming
station 630 which curl a top of sidewall 16. After the top of
sidewall 16 has been curled, the finished cup is discharged at a
cup discharge 614. FIG. 17 illustrates just one example of a
machine for forming any one of cups 10, 110, 410 and 510. Other
machines may also be utilized to form such cups.
[0057] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize that changes may be made in form and detail without
departing from the spirit and scope of the invention. For example,
although different preferred embodiments may have been described as
including one or more features providing one or more benefits, it
is contemplated that the described features may be interchanged
with one another or alternatively be combined with one another in
the described preferred embodiments or in other alternative
embodiments. Because the technology of the present invention is
relatively complex, not all changes in the technology are
foreseeable. The present invention described with reference to the
preferred embodiments and set forth in the following claims is
manifestly intended to be as broad as possible. For example, unless
specifically otherwise noted, the claims reciting a single
particular element also encompass a plurality of such particular
elements.
* * * * *