U.S. patent application number 14/167994 was filed with the patent office on 2014-07-31 for high-clarity, cast polypropylene produce pouch and method.
The applicant listed for this patent is Dupak, Inc.. Invention is credited to Philip Beach, Duke X. W. Yu.
Application Number | 20140212068 14/167994 |
Document ID | / |
Family ID | 51223034 |
Filed Date | 2014-07-31 |
United States Patent
Application |
20140212068 |
Kind Code |
A1 |
Yu; Duke X. W. ; et
al. |
July 31, 2014 |
High-Clarity, Cast Polypropylene Produce Pouch and Method
Abstract
A high-clarity, cast polypropylene produce pouch with first and
second sidewalls and a bottom panel joined to form a pouch wherein
the first and second sidewalls and the bottom panel are formed from
cast polypropylene. The bottom panel can be a bottom gusset panel.
The first and second sidewalls and the bottom gusset panel can have
edges joined by side welding or heat sealing. Zipper or slide
closures can close the first and second sidewalls. A method for
forming a high-clarity, cast polypropylene produce pouch comprises
creating a polypropylene (PP) resin, passing the polypropylene (PP)
resin through a cast extruding machine and extruding molten
polypropylene (PP) to produced extruded polypropylene (PP), rolling
the extruded polypropylene (PP) in a cooling roller, and applying a
surface-modifying corona treatment to the extruded polypropylene
(PP).
Inventors: |
Yu; Duke X. W.;
(Mississauga, CA) ; Beach; Philip; (Southbury,
CT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dupak, Inc. |
Mississauga |
|
CA |
|
|
Family ID: |
51223034 |
Appl. No.: |
14/167994 |
Filed: |
January 29, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61758099 |
Jan 29, 2013 |
|
|
|
Current U.S.
Class: |
383/7 ;
156/244.13; 383/104; 383/105; 383/107; 383/120; 383/42; 383/64 |
Current CPC
Class: |
B65D 33/01 20130101;
B65D 33/2591 20130101; B65D 33/08 20130101; B65D 31/005 20130101;
B65D 75/008 20130101 |
Class at
Publication: |
383/7 ; 383/105;
383/120; 383/107; 383/42; 383/64; 383/104; 156/244.13 |
International
Class: |
B65D 75/00 20060101
B65D075/00; B65D 33/25 20060101 B65D033/25; B65D 33/08 20060101
B65D033/08; B65D 33/00 20060101 B65D033/00 |
Claims
1. A high-clarity, cast polypropylene (PP) produce pouch
comprising: a pouch with first and second sidewalls wherein the
first and second sidewalls have edges that joined to form a pouch;
wherein the first and second sidewalls are formed from cast
polypropylene (PP) film.
2. The high-clarity, cast polypropylene (PP) produce pouch of claim
1 further comprising a bottom gusset panel joined to the first and
second sidewalls.
3. The high-clarity, cast polypropylene (PP) produce pouch of claim
2 wherein the first and second sidewalls and the bottom gusset
panel have edges that are joined by side welding.
4. The high-clarity, cast polypropylene (PP) produce pouch of claim
2 wherein the first and second sidewalls and the bottom gusset
panel have edges that are joined by heat sealing.
5. The high-clarity, cast polypropylene (PP) produce pouch of claim
1 wherein the produce pouch has a mouth defined by edges of the
first and second sidewalls and further comprising a closure
mechanism for selectively joining the first and second sidewalls to
close the mouth.
6. The high-clarity, cast polypropylene (PP) produce pouch of claim
5 wherein the closure mechanism comprises a zipper closure.
7. The high-clarity, cast polypropylene (PP) produce pouch of claim
5 wherein the closure mechanism comprises a slide closure and a
slider for adjusting the slide closure between open and closed
configurations.
8. (canceled)
9. The high-clarity, cast polypropylene (PP) produce pouch of claim
2 wherein each of the first and second sidewalls has a body portion
with a rectangular upper section and a tapered lower section and
wherein the bottom gusset panel has a rectangular main section and
pointed ends that taper at angles corresponding to the tapered
lower sections of the first and second sidewalls whereby, when the
produce pouch is in an open configuration, the bottom gusset panel
establishes a foot for enabling the produce pouch to be disposed in
a free-standing position.
10. The high-clarity, cast polypropylene (PP) produce pouch of
claim 1 further comprising a plurality of through-holes in each of
the first and second sidewalls.
11. The high-clarity, cast polypropylene (PP) produce pouch of
claim 2 further comprising a handle formed by handle portions
disposed through the first and second sidewalls.
12. The high-clarity, cast polypropylene (PP) produce pouch of
claim 11 wherein the produce pouch has a mouth defined by edges of
the first and second sidewalls and further comprising a closure
mechanism for selectively joining the first and second sidewalls to
close the mouth wherein the handle is disposed proximal to the
closure mechanism relative to the bottom gusset panel.
13. The high-clarity, cast polypropylene (PP) produce pouch of
claim 11 wherein the produce pouch has a mouth defined by edges of
the first and second sidewalls and further comprising a closure
mechanism for selectively joining the first and second sidewalls to
close the mouth wherein the handle is disposed distal to the
closure mechanism relative to the bottom gusset panel.
14. A method for forming a high-clarity, cast polypropylene (PP)
produce pouch with first and second sidewalls formed from cast
polypropylene (PP) film, the method comprising the following steps:
providing a molten polypropylene (PP) resin blend; passing the
molten polypropylene (PP) resin blend through a cast extruding
machine and extruding the molten polypropylene (PP) resin blend to
produce extruded polypropylene (PP); rolling the extruded
polypropylene (PP) in a cooling roller; providing a curing time;
slitting the extruded polypropylene (PP); and joining portions of
the extruded polypropylene (PP) to form a cast polypropylene (PP)
produce pouch with first and second sidewalls.
15. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the step of passing the
polypropylene (PP) resin blend through a cast extruding machine is
carried out at a temperature of 225-235.degree. C. (or
437-455.degree. F.).
16. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 further comprising applying a
surface-modifying corona treatment to the extruded polypropylene
(PP).
17. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the polypropylene (PP) resin
blend includes an anti-blocking agent.
18. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the polypropylene (PP) resin
blend includes a slipping agent
19. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the polypropylene (PP) resin
blend includes an antistatic agent.
20. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the polypropylene (PP) resin
blend includes a nucleating agent.
21. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 therein the polypropylene (PP) resin
blend includes a propylene carrier elastomer.
22. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 further comprising the step of rolling
the extruded polypropylene (PP) in a secondary cooling roller.
23. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the step of joining portions of
the extruded polypropylene (PP) to form a cast polypropylene (PP)
produce pouch with first and second sidewalls comprises heat
sealing the portions of extruded polypropylene (PP).
24. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the step of joining portions of
the extruded polypropylene (PP) to form a cast polypropylene (PP)
produce pouch with first and second sidewalls comprises side
welding the portions of extruded polypropylene (PP).
25. The method for forming a high-clarity, cast polypropylene (PP)
produce pouch of claim 14 wherein the step of providing a curing
time comprises providing an approximately 72-hour curing time.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to flexible
containers. More particularly, disclosed herein is a flexible,
self-standing produce pouch of high-clarity, cast polypropylene
film for containing loose produce, particularly fruits and
vegetables.
BACKGROUND OF THE INVENTION
[0002] Prior art bags or pouches for fruits, vegetables, and other
produce are often crafted from an extruded tube of thermoplastic
film. The thermoplastic film is assembled by heat sealing and
processed to yield a finished pouch. Processing steps commonly
include hole punching, perforating, and potentially further
manufacturing steps designed to produce a specified pouch. Pouches
are commonly crafted with rectangular or tapered shapes. Some
pouches have zipper or slide closures with engaging male and female
strips that can be selectively engaged to seal the mouth of the
pouch. Other pouches are designed for being tied or fastened in a
closed configuration. Pouches can incorporate handles and can be
vented to help preserve freshness and to permit rinsing.
[0003] Produce pouches are commonly formed from coextruded and
blown high and low density polyethylene, polyester, or
polypropylene film, which may be laminated. The manufacturing
process typically includes the step of sealing a bag by applying
enough heat to the surface of the bag to melt the material and
cause it to adhere to itself.
[0004] To heat seal bags manufactured from coextruded polyethylene,
the packaging industry developed a heat sealing mechanism under
which a filament generates sufficient heat to reach the melting
point of the material. The inside layer of material must melt while
the outer layers must be cooled so that they do not melt and cause
the bag to lose its shape. Cooling can be achieved by, for example,
blasts of cold air following the application of heat.
[0005] To avoid the manufacturing problems associated with heat
sealing coextruded polyethylene, the packaging industry has used
laminated film. Laminated film consists of layers of different
material that are brought together. The layers may consist of such
materials as polyethylene, polyester, paper, foil and
polypropylene. The outside layer of laminated film can be a heat
resistant material, such as polyester, or can be coated for heat
resistance. The use of laminated film and high temperature jaws for
heat sealing streamlines the manufacturing process. However, the
laminated film is approximately three times the cost of coextruded
polyethylene.
[0006] The prior art has also recognized that it is desirable to
have produce bags or pouches that are capable of standing up when
filled. Self-standing bags are desirable for a number of reasons.
For example, a principal display panel can then be caused to face
consumers. Further, arranging the bags in a standing position takes
less space, can prevent damage and loss to the contained goods, and
can be more attractive to consumers.
[0007] It is further known that retail produce merchandisers now
seek high-clarity packaging for many commodities, including grapes,
cherries, and other loose fruit and vegetable products.
High-clarity pouches give a consumer a greater ability to view the
contained goods and can increase the perceived cleanliness and
quality of the fruit, vegetable, or other produce contained by the
pouch. However, although desirable, high-clarity packaging can
entail increased production costs. Of course, produce growers and
shippers desire cost-effective packaging. Moreover, existing
high-clarity constructions often do not tolerate changes in
temperature well and suffer losses in clarity, strength, and
durability, all quite undesirable to produce growers, shippers,
sellers, and consumers.
[0008] Accordingly, it will be recognized that a high-clarity
packaging solution that is innovative in construction while
remaining efficient in cost and demonstrating an ability to
tolerate temperature variations with limited or no loss in
performance would represent a useful advance in the art of produce
packaging.
SUMMARY OF THE INVENTION
[0009] With a knowledge of the present state of the art, the
present inventors set forth with the basic object of providing a
pouch for produce and other goods that provides a high-clarity
packaging solution.
[0010] A further object of embodiments of the invention is to
provide a produce pouch with high-clarity characteristics that
better tolerates temperature variations.
[0011] An additional object of the invention is to provide a
produce pouch that can be manufactured and sold with cost
efficiency.
[0012] Still another object of embodiments of the invention is to
provide a high-clarity produce pouch that is capable of being
self-standing when retaining goods.
[0013] These and further objects and advantages of the present
invention will become obvious not only to one who reviews the
present specification and drawings but also to those who have an
opportunity to experience an embodiment of the high-clarity, cast
produce pouch disclosed herein in operation. However, it will be
appreciated that, although the accomplishment of each of the
foregoing objects in a single embodiment of the invention may be
possible and indeed preferred, not all embodiments will seek or
need to accomplish each and every potential advantage and function.
Nonetheless, all such embodiments should be considered within the
scope of the present invention.
[0014] One will appreciate that the foregoing discussion broadly
outlines the more important goals and features of the invention to
enable a better understanding of the detailed description that
follows and to instill a better appreciation of the inventors'
contribution to the art. Before any particular embodiment or aspect
thereof is explained in detail, it must be made clear that the
following details of construction and illustrations of inventive
concepts are mere examples of the many possible manifestations of
the invention.
BRIEF DESCRIPTION OF DRAWINGS
[0015] In the accompanying drawing figures:
[0016] FIG. 1 is a perspective view of a high-clarity, cast produce
pouch pursuant to the present invention in a standing
configuration;
[0017] FIG. 2 is a view in front elevation of the high-clarity,
cast produce pouch of FIG. 1 in a collapsed configuration;
[0018] FIG. 3 is a view in front elevation of a plurality of
high-clarity, cast produce pouches as disclosed herein joined
together by fasteners passed through their retaining strips;
[0019] FIG. 4 is a view in left side elevation of the high-clarity,
cast produce pouch of FIG. 1 with the bottom gusset expanded and
the pouch in a standing disposition;
[0020] FIG. 5 is a top plan view of the high-clarity, cast produce
pouch of FIG. 1 in an open configuration;
[0021] FIG. 6 is a bottom plan view of the high-clarity, cast
produce pouch of FIG. 1 in an open configuration;
[0022] FIG. 7 is a top plan view of the high-clarity, cast produce
pouch of FIG. 7 in an open configuration during production;
[0023] FIG. 8 is a perspective view of an alternative high-clarity,
cast produce pouch pursuant to the present invention in a standing
configuration;
[0024] FIG. 9 is a perspective view of a further alternative
embodiment of the high-clarity, cast produce pouch in a standing
configuration;
[0025] FIG. 10 is a view in front elevation of the high-clarity,
cast produce pouch of FIG. 9 in a collapsed configuration;
[0026] FIG. 11 is a view in front elevation of a plurality of
high-clarity, cast produce pouches as disclosed herein joined
together by fasteners passed through their retaining strips;
[0027] FIG. 12 is a view left side elevation of the high-clarity,
cast produce pouch of FIG. 1 with the bottom gusset expanded and
the pouch in a standing disposition;
[0028] FIG. 13 is a top plan view of the high-clarity, cast produce
pouch of FIG. 1 in an open configuration;
[0029] FIG. 14 is a bottom plan view of the high-clarity, cast
produce pouch of FIG. 1 in an open configuration;
[0030] FIG. 15 is a top plan view of the high-clarity, cast produce
pouch of FIG. 7 in an open configuration during production;
[0031] FIG. 16 is a perspective view of another embodiment of the
high-clarity, cast produce pouch in a standing configuration;
[0032] FIG. 17 is a top plan view of an embodiment of the
high-clarity, cast produce pouch with side welds in an open
configuration during production;
[0033] FIG. 18 is a top plan view of a further embodiment of the
high-clarity, cast produce pouch with side welds in an open
configuration during production;
[0034] FIG. 19 is a top plan view of another embodiment of the
high-clarity, cast produce pouch in an open configuration during
production wherein a handle is disposed below the closure
mechanism;
[0035] FIG. 20 is a top plan view of still another embodiment of
the high-clarity, cast produce pouch in an open configuration
during production wherein a handle is disposed above the closure
mechanism; and
[0036] FIG. 21 is a flow chart of a production process for produce
pouches according to the invention disclosed herein.
[0037] The various notes, dimensions, and details on the drawings
are incorporated herein by reference but should not be interpreted
as limiting the invention in any manner.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0038] The produce pouch disclosed herein is subject to a wide
variety of embodiments. However, to ensure that one skilled in the
art will be able to understand and, in appropriate cases, practice
the present invention, certain preferred embodiments of the broader
invention revealed herein are described below and shown in the
accompanying drawing figures.
[0039] Turning more particularly to the drawings, a produce pouch
according to the present invention is indicated generally at 10 in
FIGS. 1 through 7. There, the produce pouch 10 has a first sidewall
12, a second sidewall 14 joined along its outboard, lateral edges
to the first sidewall 12 to form side seams 20, and a bottom gusset
panel 16 joined at its ends by bottom seams 22 and at its
longitudinal edges to the first and second sidewalls 12 and 14.
[0040] As best seen perhaps in FIG. 7 where the pouch 10 is
depicted in an open configuration prior to formation of the seams
20 and 22, the first and second sidewalls 12 and 14 and the bottom
gusset panel 16 can be integrally formed with the first sidewall
12, the bottom gusset panel 16, and the second sidewall 14 disposed
in series. The first and second sidewalls 12 and 14 have body
portions that are generally mirror images, each with a rectangular
upper section and a tapered lower section. The bottom gusset panel
16 has a rectangular main section and pointed ends that taper at
angles corresponding to the tapering of the lower sections of the
first and second sidewalls 12 and 14. The sidewalls 12 and 14 and
the bottom gusset panel 16 can be joined to form the overall pouch
10 by, for example, heat sealing to create the side and bottom
seams 20 and 22.
[0041] When the produce pouch 10 is in an open configuration as
depicted in FIGS. 1 and 4 through 6, the bottom gusset panel 16
achieves a somewhat flattened configuration such that the panel 16
acts as a foot for enabling the produce pouch 10 to be disposed in
a free-standing position. Prior to being filled with produce, the
pouch 10 can be disposed in a flat configuration with the bottom
gusset panel 16 folded longitudinally into a facing
relationship.
[0042] The produce pouch 10 has a mouth defined by the upper edges
of the first and second sidewalls 12 and 14. The mouth can be
selectively closed by use of a zipper closure 18. As seen, for
example, in FIG. 7, the zipper closure 18 is formed by strips 18A
and 18B that traverse substantially the entire length of the
respective sidewall 12 and 14. The strips 18A and 18B have mating,
self-retaining profiles. The male and female profiles of the strips
18A and 18B can be connected to close the pouch 10 by pinching and
sliding across the strips 18A and 18B along the length of the top
edges of the first and second sidewalk 12 and 14, and the strips
18A and 18B can be separated to open the mouth of the pouch 10 as
is necessary to insert or remove produce.
[0043] To permit air and liquid flow within and through the open
inner volume defined by the first and second sidewalls 12 and 14
and the bottom gusset panel 16, a plurality of vents 30 can be
spaced over the sidewalk 12 and 14 and the bottom gusset panel 16.
In this example, the vents 30 comprise round through-holes, but it
will be recognized that other shapes would be readily possible. In
the depicted embodiment, however, vents 30 are not disposed over
predetermined portions of the first and second sidewalk 12 and 14
such as upper and central segments thereof, to permit the
application and display of display material 32.
[0044] Of course, the locations and content of the display material
32 can vary irnfinitely and can include, for instance, branding,
product information, and pricing codes. Display material 32 can be
centrally disposed on one or both sidewalk 12 and 14, on the bottom
gusset panel 16, and potentially above the closure mechanism.
[0045] Still further, a handle 24 can be cut through each of the
first and second sidewalk 12 and 14 in aligned locations, such as
adjacent to the upper edges thereof In this example, the handle 24
is disposed below the zipper closure 18, but it could be disposed
above the zipper closure 18 as shown and described hereinbelow. As
seen in FIG. 7, a handle 24A can be formed in the first sidewall
12, and a handle 24B can be formed in the second sidewall 14.
[0046] With further reference to FIG. 3, produce pouches 10 as
taught herein can be initially provided with a retaining strip 26
that has a plurality of retaining apertures 28 longitudinally
spaced therealong. A fastener 36, such as a simple twist tie, can
be passed through each of the aligned apertures 28 in a plurality
of produce pouches 10 to retain the pouches 10 prior to separation
and filling. The retaining strip 26 can be removable thereby to
permit a separation of the retaining strip 26 from the remainder of
a given pouch 10 and a separation of that pouch 10 from the
remaining pouches 10. In this example, as best seen in FIG. 3, the
retaining strip 26 is detachably connected to the upper edge of the
first panel 12 by a line of perforations 34. With that, the
retaining strip 26 can be selectively torn away.
[0047] The first and second sidewalk 12 and 14 and the bottom
gusset panel 16 are preferably formed as cast polypropylene (PP),
which has been found by the present inventors toy provide a
plurality of improved performance characteristics carrying forth
the goals of the invention. By way of example and not limitation,
cast polypropylene permits the sidewalk 12 and 14, the bottom
gusset panel 16, and the produce pouch 10 in general to exhibit
high clarity, good durability, and desired improvements in
performance despite fluctuations in temperature. Moreover, the cast
polypropylene sidewalls 12 and 14 and bottom gusset panel 16
exhibit high resistance to chemical caustics and solutes and are
reusable as necessary.
[0048] An alternative produce pouch 10 pursuant to the invention
disclosed herein is depicted in FIGS. 8 through 15. The produce
pouch 10 again has a first sidewall 12, a second sidewall 14 joined
along its outboard, lateral edges to the first sidewall 12 to form
side seams 20, and a bottom gusset panel 16 joined at its ends by
bottom seams 22 and at its longitudinal edges to the first and
second sidewalls 12 and 14. The first and second sidewalk 12 and 14
and the bottom gusset panel 16 are again preferably formed as cast
polypropylene (PP) due to its improved performance characteristics
as discussed previously.
[0049] As shown in FIG. 15 where the pouch 10 is depicted in an
open configuration prior to formation of the seams 20 and 22, the
first and second sidewalls 12 and 14 and the bottom gusset panel 16
can again be integrally formed with the first sidewall 12, the
bottom gusset panel 16, and the second sidewall 14 disposed in
series. As before, the first and second sidewalls 12 and 14 have
body portions that are generally mirror images, each with a
rectangular upper section and a tapered lower section. The bottom
gusset panel 16 has a rectangular main section and pointed ends
that taper at angles corresponding to the tapering of the lower
sections of the first and second sidewalls 12 and 14. The sidewalls
12 and 14 and the bottom gusset panel 16 can be joined to form the
overall pouch 10 by, for example, heat sealing to create the side
and bottom seams 20 and 22.
[0050] When the produce pouch 10 is in an open configuration as
depicted in FIGS. 9, 12, and 13, the bottom gusset panel 16
achieves a somewhat flattened configuration such that the panel 16
acts as a foot for enabling the produce pouch 10 to be disposed in
a free-standing position. Prior to being filled with produce, the
pouch 10 can be disposed in a flat configuration with the bottom
gusset panel 16 folded longitudinally into a facing
relationship.
[0051] As in the embodiment of FIGS. 1 through 7, the produce pouch
10 has a mouth defined by the upper edges of the first and second
sidewalls 12 and 14. The mouth can be selectively closed by use of
a slide closure 38. As seen, for example, in FIG. 15, the slide
closure 38 is formed by strips 38A and 38B that traverse
substantially the entire length of the respective sidewall 12 and
14. The strips 38A and 38B have mating, self-retaining profiles.
The male and female profiles of the strips 38A and 38B can be
connected to dose the pouch 10 by sliding a slider member 40 along
the strips 38A and 38B, and the pouch 10 can be opened by sliding
the slider member 40 in an opposite direction.
[0052] A plurality of vents 30 are again spaced over the sidewalls
12 and 14 and, the bottom gusset panel 16 to permit air and liquid
flow within and through the open inner volume defined by the first
and second sidewalls 12 and 14 and the bottom gusset panel 16. As
before, the vents 30 comprise round through-holes. Vents 30 are not
disposed over predetermined portions of the first and second
sidewalls 12 and 14, such as upper and central segments thereof, to
permit the application and display of display material 32.
[0053] Again looking to FIG. 11, produce pouches 10 as taught
herein can be initially provided with a retaining strip 26 that has
a plurality of retaining apertures 28 longitudinally spaced
therealong. A fastener 36 can be passed through each of the aligned
apertures 28 in a plurality of produce pouches 10 to retain the
pouches 10 prior to filling. The retaining strip 26 can be
removable thereby to permit a separation of the retaining strip 26
from the remainder of a given pouch 10 and a separation of that
pouch 10 from the remaining pouches 10. Here, the retaining strip
26 is again detachably connected to the upper edge of the first
panel 12 by a line of perforations 34 so that the retaining strip
26 can be selectively torn away.
[0054] While the produce pouch illustrated in FIGS. 8 through 15 is
depicted without a handle 24, it will be appreciated that a handle
24 could readily be incorporated. Indeed, a handle 24 could readily
be disposed above or below the closure mechanism whether the
closure mechanism comprises a slide closure 38 with a slider member
40 as illustrated in the current embodiment, a zipper closure 18 as
in the embodiment of FIGS. 1 through 7, or any other closure
mechanism. In theory, a handle 24 could be disposed above the
closure mechanism, and a handle 24 could be disposed below the
closure mechanism. For instance, in the embodiments of the produce
pouch 10 illustrated in FIGS. 16 and 19, a handle 24, which is
formed by handle portions 24A and 24B, is disposed below the
closure mechanism, formed in this case by a slider member 40 in
combination with a slide closure 38 formed by the strips 38A and
38B. In the embodiment of FIG. 20 where the produce pouch 10 is
depicted in a pre-assembly open configuration, handle portions 24A
and 24B are disposed distal to the closure mechanism formed by the
slide closure 38 and the slider member 40 such that the handle 24
so formed is above the closure mechanism in the completed pouch
10.
[0055] Further embodiments of the produce pouch 10 are contemplated
as in FIG. 17 and FIG. 18, which depicts just one-half of a produce
pouch 10, where the pouch 10 again has a first sidewall 12, a
second sidewall 14 for being joined along its outboard, lateral
edges to the first sidewall 12 to form side seams, and a bottom
gusset panel 16 joined at its ends to form bottom seams and at its
longitudinal edges to the first and second sidewalls 12 and 14.
Here, however, the side and bottom seams are formed by side welds
42 for joining the sidewalls 12 and 14 and the bottom gusset panel
16 to form the completed produce pouch 10. The illustrated side
weld construction for the produce pouch 10 thus forms a bag with
welded side seals and a folded and welded bottom. As the
die-cutting forms of FIGS. 17 and 18 illustrate, the width of the
side welds 42 can vary within the scope of the invention. For
instance, as shown in FIG. 17, the side welds 42 could be 10 mm
(approx. 0.4 inches) wide. As shown in FIG. 18, the side welds 42
could be narrower, such as 6 mm (approx. 0.24 inches) wide. The
connections between the bottom gusset panel 16 and the first and
second sidewalls 12 and 14 can be formed integrally as during the
initial extrusion or other formation of the sidewalls 12 and 14 and
the bottom gusset panel 16.
[0056] As noted previously, the first and second sidewalls 12 and
14 and the bottom gusset panel 16 are preferably formed as cast
polypropylene (PP). As contemplated hereunder, the production
process can proceed as shown schematically in FIG. 21. First, a
resin blend can be created. The resin blend can be processed at an
elevated temperature, such as 225-235.degree. C. (or 437-455
.degree. F.). The preferred resin used hereunder can have additives
and agents added, including one or more of an anti-blocking agent,
a slipping agent, an antistatic agent, a nucleating agent, and a
propylene carrier elastomer. This presently preferred resin formula
seeks to achieve, among other things, longer shelf life of the
polypropylene (PP) film, including during prolonged low-temperature
storage of produce.
[0057] The resin blend so formed can be passed through a cast
extruding machine prior to undergoing molten plastic extrusion in
an extruding step in the cast extruding machine and/or in a
secondary extruding machine. The resulting product can then pass
through a primary cooling roller, potentially followed by a
secondary cooling roller. Gauge control can be undertaken to
measure and confirm thickness and other parameters of the cooled
and rolled product. A surface-modifying corona treatment can then
be applied to the material, such as by use of a low temperature
corona discharge plasma, to achieve desired surface energy
characteristics of the polypropylene (PP) material. The resulting
product can then be trimmed, wound, slit, and packed with the for
sidewalls 12 and 14 and the bottom gusset panel 16 joined, such as
by heat sealing, side welding, or any other effective practice. A
72-hour curing time can be provided prior to slitting. Printing can
be applied as appropriate and may be done with high temperature ink
where necessary. It will be understood that the processing time for
the material will depend on, among other things, machine capacity.
In one practice of the invention, for example, the full processing
capacity is 22,000 pounds per 24 hour period.
[0058] With certain details and embodiments of the present
invention for high-clarity, cast produce pouch 10 disclosed, it
will be appreciated by one skilled in the art that numerous changes
and additions could be made thereto without deviating from the
spirit or scope of the invention. This is particularly true when
one bears in mind that the presently preferred embodiments merely
exemplify the broader invention revealed herein. Accordingly, it
will be clear that those with certain major features of the
invention in mind could craft embodiments that incorporate those
major features while not incorporating all of the features included
in the preferred embodiments.
[0059] Therefore, the following claims are intended to define the
scope of protection to be afforded to the inventor. Those claims
shall be deemed to include equivalent constructions insofar as they
do not depart from the spirit and scope of the invention. It must
be further noted that a plurality of the following claims may
express certain elements as means for performing a specific
function, at times without the recital of structure or material. As
the law demands, these claims shall be construed to cover not only
the corresponding structure and material expressly described in
this specification but also all equivalents thereof that might be
now known or hereafter discovered.
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