U.S. patent application number 12/291297 was filed with the patent office on 2009-03-12 for high burst closure assembly for large packages.
This patent application is currently assigned to ILLINOIS TOOL WORKS INC.. Invention is credited to David J. Anzini, Steven Ausnit, Rusty Koenigkramer.
Application Number | 20090067761 12/291297 |
Document ID | / |
Family ID | 41278268 |
Filed Date | 2009-03-12 |
United States Patent
Application |
20090067761 |
Kind Code |
A1 |
Koenigkramer; Rusty ; et
al. |
March 12, 2009 |
High burst closure assembly for large packages
Abstract
The present disclosure relates to a high burst closure which
allows for bottom filling of packages, such as large bags, and
further provides increased resistance to damage from the dropping
or shock loading of the filled package. This is achieved by
providing profiles that combine an upper portion of one profile and
its related flange, so as to form a juncture above a peel seal
joining one profile to the other, so that external forces on a
package or bag from bottom filling or shock loading are directed
toward the juncture thereby causing a shear force against the peel
seal or other frangible connection, thereby increasing the
resistance of the package to external forces.
Inventors: |
Koenigkramer; Rusty;
(Nanuet, NY) ; Anzini; David J.; (Middletown,
NY) ; Ausnit; Steven; (New York, NY) |
Correspondence
Address: |
DAY PITNEY LLP;ACCOUNT: ILLINOIS TOOL WORKS INC.
7 TIMES SQUARE
NEW YORK
NY
10036-7311
US
|
Assignee: |
ILLINOIS TOOL WORKS INC.
|
Family ID: |
41278268 |
Appl. No.: |
12/291297 |
Filed: |
November 7, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11728477 |
Mar 26, 2007 |
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12291297 |
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60839447 |
Aug 23, 2006 |
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Current U.S.
Class: |
383/210.1 |
Current CPC
Class: |
B31B 70/8132 20170801;
B65D 33/2508 20130101; B65D 33/2591 20130101 |
Class at
Publication: |
383/210.1 |
International
Class: |
B65D 65/26 20060101
B65D065/26 |
Claims
1. A closure for a package, including: a first profile with a first
upper portion and a first flange, further including an interior
flange with a first end and a second end, the first end being
attached to an interior of the first upper portion; a second
profile with a second upper portion and a second flange; and a
separable connection connecting the second end of the interior
flange and a generally central area of the second profile, wherein
the separable connection is more resistant to a shear force than to
a peeling force.
2. The closure of claim 1 wherein a load on the first and second
flanges applies a shear force to the separable connection.
3. The closure of claim 2 wherein the separable connection is a
first peel seal.
4. The closure of claim 1 wherein a load on the first and second
flanges is redirected away from the separable connection to a
location above the separable connection.
5. The closure of claim 1 wherein the first and second upper
portions are sealed together by a hard seal.
6. The closure of claim 5 wherein the first and second upper
portions include respective first and second lines of weakness.
7. The closure of claim 6 wherein the first and second lines of
weakness are perforated lines.
8. The closure of claim 6 wherein the first and second lines of
weakness are scored lines.
9. The closure of claim 1 wherein the first and second upper
portions are joined by a second peel seal.
10. The closure of claim 1 wherein the second profile is made from
a single sheet of web material.
11. The closure of claim 1 wherein the first and second flanges are
attached to an exterior of respective first and second package
walls.
12. The closure of claim 1 wherein the first and second flanges are
attached to an interior of respective first and second package
walls.
13. The closure of claim 1 further including an extension extending
from one of the first and second flanges, the extension including
an aperture thereby serving as a handle.
14. A closure for a package, including: a first profile with a
first upper portion and a first flange, the first upper portion
having an upper end and a lower end, wherein the first flange is
connected to a generally central area of the first upper portion; a
second profile with a second upper portion and a second flange, the
second upper portion having an upper end; and a separable
connection connecting the lower end of the first upper portion and
a generally central area of the second profile, wherein the
separable connection is more resistant to a shear force than to a
peeling force.
15. The closure of claim 14 wherein a load on the first and second
flanges applies a shear force to the separable connection.
16. The closure of claim 15 wherein the separable connection is a
first peel seal.
17. The closure of claim 14 wherein a load on the first and second
flanges is redirected away from the separable connection to a
location above the separable connection.
18. The closure of claim 14 wherein the upper ends of the first and
second upper portions are sealed together by a hard seal.
19. The closure of claim 18 wherein the first and second upper
portions include respective first and second lines of weakness.
20. The closure of claim 19 wherein the first and second lines of
weakness are perforated lines.
21. The closure of claim 19 wherein the first and second lines of
weakness are scored lines.
22. The closure of claim 14 wherein the upper ends of the first and
second upper portions are joined by a second peel seal.
23. The closure of claim 14 wherein the second profile is made from
a single sheet of web material.
24. The closure of claim 14 wherein the first and second flanges
are attached to an exterior of respective first and second package
walls.
25. The closure of claim 14 wherein the first and second flanges
are attached to an interior of respective first and second package
walls.
26. The closure of claim 14 further including an extension
extending from one of the first and second flanges, the extension
including an aperture thereby serving as a handle.
27. A closure for a package, including: a first profile with a
first upper portion and a first flange formed from a single sheet
of web, wherein the single sheet is folded below the first upper
portion and connected to a generally central area of the first
upper portion thereby forming a second fold and the first flange; a
second profile with a second upper portion and a second flange; and
a separable connection connecting the first upper portion and a
generally central area of the second profile, wherein the separable
connection is more resistant to a shear force than to a peeling
force.
28. The closure of claim 27 wherein a load on the first and second
flanges applies a shear force to the separable connection.
29. The closure of claim 28 wherein the separable connection is a
first peel seal.
30. The closure of claim 27 wherein a load on the first and second
flanges is redirected away from the separable connection to a
location above the separable connection.
31. The closure of claim 27 wherein the first and second upper
portions are sealed together by a hard seal.
32. The closure of claim 31 wherein the first and second upper
portions include respective first and second lines of weakness.
33. The closure of claim 32 wherein the first and second lines of
weakness are perforated lines.
34. The closure of claim 32 wherein the first and second lines of
weakness are scored lines.
35. The closure of claim 27 wherein the first and second upper
portions are joined by a second peel seal.
36. The closure of claim 27 wherein the second profile is made from
a single sheet of web material.
37. The closure of claim 27 wherein the first and second flanges
are attached to an exterior of respective first and second package
walls.
38. The closure of claim 27 wherein the first and second flanges
are attached to an interior of respective first and second package
walls.
39. The closure of claim 27 further including an extension
extending from one of the first and second flanges, the extension
including an aperture thereby serving as a handle.
40. The closure of claim 1 wherein at least a portion of the first
flange is formed by at least a portion of a bag wall.
41. The closure of claim 14 wherein at least a portion of the first
flange is formed by at least a portion of a bag wall.
42. The closure of claim 1 wherein the interior flange and the
first upper portion are integral with each other.
43. The closure of claim 1 wherein the interior flange and the
first upper portion are joined by a hard seal.
44. The closure of claim 1 wherein at least one of the first and
second upper portions are extended and include a handle-sized
aperture therein.
45. The closure of claim 14 wherein at least one of the first and
second upper portions includes a handle-sized aperture therein.
46. The closure of claim 27 wherein at least one of the first and
second upper portions includes a handle-sized aperture therein.
47. The closure of claim 27 wherein the first flange is formed by a
portion of a bag wall.
48. The closure of claim 14 wherein the first flange is sealed to
the generally central area of the first upper portion.
49. The closure of claim 14 wherein the first flange is integral
with the generally central area of the first upper portion.
50. The closure of claim 27 wherein the single sheet is folded
below the first upper portion and sealed to a generally central
area of the first upper portion.
Description
[0001] This application is a continuation-in-part of application
Ser. No. 11/728,477 filed Mar. 26, 2007 entitled "High Burst Zipper
Assembly for Large Reclosable Packages" which claims priority under
35 U.S.C. .sctn.119(e) from provisional application Ser. No.
60/839,447, filed on Aug. 23, 2006, entitled "High Burst Slider
Zipper for Large Bags and Method of Manufacture", the contents of
which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to closure assemblies for
packages which are large bags, particularly closure assemblies
which achieve high burst strengths while allowing an easy-to-open
configuration, and the methods for manufacture thereof.
[0004] 2. Description of the Prior Art
[0005] Large packages, bags or pouches, such as those used for pet
food, charcoal, cat litter and similar items are typically filled
and sealed shut. These packages may be formed by form fill and seal
(FFS) or by other methods. Prior attempts to incorporate an easy to
use closure mechanism have been unsatisfactory due to the unique
requirements of a large bag with a relatively heavy load. In
particular, filling from the bottom places all of the load on the
closure during filling. This load can cause the closure mechanism
to fail and open. Similarly, dropping a filled bag onto a pallet or
similar rough handling during transportation, as well as exposing a
bag to elevated temperatures during transportation, can cause the
closure mechanism to fail.
[0006] The prior art has addressed these deficiencies by folding
over the end of the package, particularly a multi-wall package,
using an expensive label as tape thereby allowing successful
filling and transport. Similarly, the prior art has addressed these
deficiencies by using a liner peel seal below the zipper and a
solid tear line in the zipper flange to provide a fill and
transport system that does not rupture and spill the contents.
However, these methods have slow rates of production, as well as
increased costs of production, and frequently do not result in a
satisfactory product for the consumer.
[0007] Some further examples of the prior art which are not
entirely satisfactory are found in U.S. Pat. No. 6,979,482 entitled
"Multiwall Bag with Zipper and Fin" issued on Dec. 27, 2005 to
Hartzell et al. and U.S. Pat. No. 7,090,904 entitled "Enhanced
Slider Zipper Multiwall Bag and Associated Methods" issued On Aug.
15, 2006 to Hartzell et al.
[0008] Typical prior tamper-evident zipper assemblies are disclosed
in U.S. Pat. No. 6,354,738 entitled "Tamper Evident Reclosable
Plastic Bag" issued on Mar. 12, 2002 to Buckman et al.; U.S. Pat.
No. 4,647,063 entitled "Reclosable Bag with Laminated Liner and
Method" issued on Jan. 13, 1987 to Sullivan; and U.S. Pat. No.
5,509,735 entitled "Closure Arrangement Having a Peelable Seal"
issued on Apr. 23, 1996 to May.
OBJECTS AND SUMMARY OF THE INVENTION
[0009] It is therefore an object of the present invention to
provide a closure assembly for packages, particularly large bags,
formed by form fill and seal or other methods, which provides for
high burst strength in bottom filling or top filling
configurations, to allow the bags to withstand dropping or shock
loading without the closure mechanism bursting open, while allowing
for an easy to open configuration.
[0010] It is therefore a further object of the present invention to
provide such a closure assembly without significant increases in
manufacturing and related costs.
[0011] It is therefore a still further object of the present
invention to provide a method of manufacture for a product
achieving the above objects.
[0012] These and other objects are attained by providing a closure
assembly for packages, particularly large bags, with a first
profile with a first upper separating portion, a first flange, and
an interior flange, and a second profile with a second upper
separating portion and a second flange. A peel seal is formed
between the lower end of the interior flange and a generally
central portion of the second profile. This causes the external
forces on a bag from bottom filling or shock loading (or forces
from within the bag, typically created when the bag is dropped on
its top or side) to be directed towards the junction of the
interior flange and the first upper portion, thereby redirecting
the peel seal from a peel position to a shear position. As the
force required to separate a peel seal in a shear position is
several times greater than the force required to separate the peel
seal in a peelable position, the load-bearing capacity of the
package or bag is increased to meet the requirements previously
mentioned.
[0013] These and other objects are similarly obtained by providing
a closure assembly for a package, particularly large bags, wherein
one of the flanges is provided in two segments in a
T-configuration, with the intersection of the two segments being
above the peel seal.
[0014] These and other objects are similarly obtained by providing
a closure assembly for a reclosable package, particularly large
bags, with a flange connected to the profile above the peel
seal.
DESCRIPTION OF THE DRAWINGS
[0015] Further objects and advantages of the invention will become
apparent from the following description and from the accompanying
drawings, wherein:
[0016] FIG. 1 is a plan view, partially in phantom, of a typical
reclosable package incorporating the zipper assembly of the present
invention.
[0017] FIG. 2 is a cross-sectional view along the upper portion of
plane 2-2 of FIG. 1, showing the cross section of the zipper
assembly of the present invention.
[0018] FIG. 3 is a cross-sectional view along the upper portion of
plane 2-2 of FIG. 1, showing the cross section of an alternative
embodiment of the zipper assembly of the present invention.
Additionally, an alternative area of detail is shown with a
variation of the alternative embodiment.
[0019] FIG. 4 is a cross-sectional view along the upper portion of
plane 2-2 of FIG. 1, showing a cross section of a portion of the
package or bag in an unstressed configuration.
[0020] FIG. 5 is a cross-sectional view along the upper portion of
plane 2-2 of FIG. 1, showing a cross section of a portion of the
package or bag when an internal load (i.e., a force from within the
package or bag) is applied thereto.
[0021] FIG. 6 is a cross-sectional view of the upper portion of
plane 2-2 of FIG. 1, showing a cross section of a portion of the
package or bag and further showing the resultant forces on the
zipper assembly when an internal load is applied to the package or
bag.
[0022] FIG. 7 is a cross-sectional view of a first alternative
embodiment of the zipper.
[0023] FIG. 8 is a cross-sectional view of a second alternative
embodiment of the zipper.
[0024] FIG. 9 is a cross-sectional view of a third alternative
embodiment of the zipper showing the use of reinforcing ribs on one
profile.
[0025] FIG. 10 is a cross-sectional view of a fourth alternative
embodiment of the zipper showing a tamper-evident removable
hood.
[0026] FIG. 11 is a cross-sectional view of a fifth alternative
embodiment of the zipper, which substitutes a secondary zipper-type
assembly for the peel seal.
[0027] FIG. 12 is a cross-sectional view of the fifth alternative
embodiment of the zipper, shown in a loaded position thereby
putting the secondary zipper-type assembly into a shear
configuration.
[0028] FIG. 13 is a cross-sectional view of the zipper profile,
prior to attachment to the package or bag walls, and further prior
to the stomping of the ends and the insertion of the sliders.
[0029] FIG. 14 is a perspective view of the zipper profile, prior
to attachment to the package or bag walls, and further prior to the
stomping of the ends and the insertion of the sliders.
[0030] FIG. 15 is a plan view of the vacuum device used to spread
the flanges of the zipper prior to the adhesive insertion step.
[0031] FIG. 16 is a cross-sectional view of glue or similar
adhesive being inserted onto the interior of the flanges of the
zipper.
[0032] FIG. 17 is a schematic of the processing of the packages or
bags after the zipper has been attached.
[0033] FIGS. 17A and 17B are alternative plan views of the sealing
of the flange ends of FIG. 17.
[0034] FIG. 18 is a plan view of the reclosable package or bag with
the zipper attached thereto.
[0035] FIG. 19 illustrates a first alternative for manufacturing
the zipper.
[0036] FIG. 20 illustrates a second alternative for manufacturing
the zipper.
[0037] FIG. 21 illustrates a third alternative for manufacturing
the zipper.
[0038] FIG. 22 is a cross-sectional view of a first alternative
top-filling embodiment of the zipper.
[0039] FIG. 23 is a perspective view of the walls of the package,
with strips of polyethylene, in preparation for the second
alternative top-filling embodiment of the zipper, as shown in FIG.
24.
[0040] FIG. 24 is a cross-sectional view showing the second
alternative top-filling embodiment of the zipper attached to the
package walls.
[0041] FIG. 25 is a cross-sectional view showing the third
alternative top-filling embodiment of the zipper attached to the
package walls.
[0042] FIG. 26 is a cross-sectional view showing the fourth
alternative top-filling embodiment of the zipper attached to the
package walls.
[0043] FIG. 27 is a cross-sectional view of a first embodiment of a
high burst closure without a zipper.
[0044] FIG. 28 is a cross-sectional view of a second embodiment of
a high burst closure without a zipper.
[0045] FIG. 29 is a cross-sectional view of a third embodiment of a
high burst closure without a zipper.
[0046] FIG. 30 is a cross-sectional view of a first variation of
the attachment of a high burst closure to package or bag walls.
[0047] FIG. 31 is a cross-sectional view of a second variation of
the attachment of a high burst closure to package or bag walls.
[0048] FIG. 32 is a cross-sectional view of a third variation of
the attachment of a high burst closure to package or bag walls.
[0049] FIG. 33 is a cross-sectional view of a fourth variation of
the attachment of a high burst closure to package or bag walls.
[0050] FIG. 34 is a cross-sectional view of a high burst closure,
including a handle structure as a bag wall extension or similar
structure.
[0051] FIG. 35 is an alternative cross-sectional view of a high
burst closure, including a handle structure.
[0052] FIG. 36 is an alternative cross-sectional view of a high
burst closure, including a handle structure implemented as a flange
extension.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] Referring now to the drawings in detail wherein like
numerals indicate like elements throughout the several views, one
sees that FIG. 1 is a perspective view of a typical reclosable
package 100, such as a large bag, which incorporates the zipper
assembly 10 of the present invention. Reclosable package 100 may be
formed by form fill and seal or by other methods. Reclosable
package 100 includes a front wall 102 and a rear wall 104. Front
and rear walls 102, 104 may be separate polymeric or multi-sheet
panels sealed together at edges 106, 108. Alternatively, front and
rear walls 102, 104 may be provided as a single tube with or
without a lap seal in the longitudinal direction. Front and rear
walls 102, 104 may be formed from virtually any substrate in the
packaging art--laminate films, plain polyethylene or polypropylene
films, multi-wall paper, and polypropylene woven layer bags or any
combination or hybrid thereof. Additionally, gussets (not shown)
may be provided between front and rear walls 102, 104 at edges 106,
108, or similarly at bottom 110.
[0054] Bottom 110 may be sealed shut, or folded over and then
glued. Reclosable package 100 is typically bottom filled, so that
the seal or glued fold may be formed after filling. However, other
methods of filling, such as top filling before the complete
application of zipper assembly 10, are equally applicable to the
present invention and are disclosed herein.
[0055] A longitudinal seal or seam 111, which can be a lap or fin
seal or seam, may optionally be formed in a generally central
longitudinal location on rear wall 104 and is shown in phantom on
FIG. 1.
[0056] Mouth 112 is formed at the top of the reclosable package 100
of FIG. 1, and is reclosably sealed by zipper assembly 10.
[0057] As shown in FIGS. 1 and 2, zipper assembly 10 is formed from
polymeric materials and includes first profile 12, second profile
14 and optional slider 15 (see FIG. 1). First profile 12 includes
first interlocking element 16 and first flange 18. Similarly,
second profile 14 includes second interlocking element 20 and
second flange 22. Optional slider 15 is mounted on first and second
profiles 12, 14 and operates in a conventional manner by
interlocking first and second interlocking elements 16, 20 of
respective first and second profiles 12, 14 when moved in a closing
direction and separating first and second interlocking elements 16,
20 of respective first and second profiles 12, 14 when moved in an
opening direction.
[0058] Peel seal 24 is formed between central locations of first
and second flanges 18, 22. Peel seal 24 may be replaced by other
frangible (and therefore tamper-evident) seals, or even a rip-cord
(either supplementing or substituting for the peel seal 24). Peel
seal 24 is more resistant to shear forces than to peeling forces.
Peel seal 24, or any substitutes therefor, particularly when loaded
in a shear configuration, is typically sufficiently strong to
support the loads required by bottom filling. Peel seal 24 is
typically pre-activated, but may be activated at the time of
package or bag conversion. Additionally, first flange 18 in FIG. 2
includes upward fold 26 immediately or proximately below peel seal
24. First flange 18 continues upward from upward fold 26 to
downward fold 28, wherein hard seal 30 is formed between a portion
of first flange 18 above peel seal 24. This configuration can be
considered to divide first flange 18 into three portions--first
portion 34 which extends from first interlocking element 20 to
upward fold 26, second portion 36 which extends from upward fold 26
to downward fold 28, and third portion 38 extends from downward
fold 28 to first distal end 40 thereby providing an area for
sealing, gluing, or otherwise securing to front wall 102 of package
100. Likewise, second flange 22 extends from second interlocking
element 20, past peel seal 24, to second distal end 42 thereby
providing an area for sealing, gluing, or otherwise securing to
rear wall 104 of package 100. As shown in FIGS. 1, 4, 5 and 6,
first and second flanges 18, 22 are typically sealed, glued or
otherwise secured to the upper exterior surfaces of front and rear
walls 102, 104. However, some embodiments may seal, glue or
otherwise secure first and second flanges 18, 22 to upper interior
surfaces of respective front and rear walls 102, 104.
[0059] In the alternative embodiment of FIG. 3, second portion 36
of first flange 18 is omitted, so that first and third portions 34,
38 are separate sheets or segments of web. Third portion 38 is
joined to a generally central location of first portion 34 by hard
seal 30. Alternatively, hard seal 30 can be omitted if first and
third portions 34, 38 are formed integrally and simultaneously by
extrusion, as shown in the alternative area of detail of FIG.
3.
[0060] In the configuration of either embodiment, as shown in FIGS.
5 and 6, the external forces on package 100 from bottom filling or
shock loading (or forces from within the bag) are directed toward
hard seal 30 (which is above the peel seal 24) and redirected so as
to cause a shear force on peel seal 24. As a peel seal is much more
resistant to a shear force than a conventional peeling force, the
resistance of package 100 to external or internal forces is greatly
increased.
[0061] FIGS. 7 and 8 disclose embodiments, wherein first flange 18
is relatively short, extending from profile 16 and terminating
upwardly adjacent to gap 25. First flange 18 is sealed or otherwise
joined to extension segment 46 at point 50. Second flange 22
includes proximal segment 21 which extends from profile 20. Second
flange 22 further includes distal segment 23 which is joined to
proximal segment 21 at fold 44 wherein a line of weakness, such as
a perforated or scored line, is provided in order to provide
additional tamper evidence after opening. Distal segment 23 extends
upwardly from fold 44 and terminates downwardly adjacent to gap 25.
Second flange 22 is sealed or otherwise joined to extension segment
48 at point 52 and distal segment 23 is sealed or otherwise joined
to first extension segment at point 54 and adjacent to peel seal
24. The connections at points 50, 52, 54 are typically formed by
heat sealing. Peel seal 24 is further formed between faces (or
facing portions) of proximal segment 21 and distal segment 23.
[0062] Extension segments 46, 48 are typically formed with nominal
6 mil film, but those skilled in the art will recognize a range of
equivalents after review of this disclosure. Extension segments 46,
48 are joined, typically by adhesive, to front and rear walls 102,
104, respectively. The embodiment of FIG. 7 differs from that of
FIG. 8 in that the extension segment 48 of FIG. 8 includes fold 56
between inner portion 57 and outer portion 59. Inner portion 57 is
sealed to second flange 22 at point 52 while outer portion 59
descends past flanges 18, 22.
[0063] The alternative embodiment of FIG. 9 includes reinforcing
ribs 60 on flange 22 to increase the stiffness of flange 22. The
alternative embodiment of FIG. 10 (based on the construction of
FIG. 3) includes tamper-evident header 62 formed of film enclosing
zipper assembly 10. Tamper-evident header 62 includes lines of
weakness 64, 66, typically formed by a perforated or scored line,
in order to provide access to zipper assembly 10.
[0064] The alternative embodiment of FIG. 11 (unloaded) and FIG. 12
(loaded) substitutes the separable connection of secondary zipper
27 for the separable connection of peel seal 24 of the previous
embodiments. Secondary zipper 27 includes first interlocking
profile 29 attached or sealed to first flange 18 and second
interlocking profile 31 attached or sealed to second flange 22. As
shown in FIG. 12, the loaded configuration, or other forces from
within the package 100, causes a shear force to be applied to
secondary zipper 27. Secondary zipper 27, similar to peel seal 24,
resists a shear force to a much greater extent than a peeling force
thereby increasing the strength of the resulting package when in
the loaded configuration of FIG. 12. The possibility of the
substitution of the secondary zipper 27 for the peel seal 24 is
envisioned for all of the disclosed embodiments of zipper assembly
10.
[0065] The manufacturing process of reclosable package or bag 100
is illustrated in FIGS. 13-18. A continuous length of interlocked
zipper profiles 12, 14 is illustrated in FIGS. 13 and 14 and is
typically provided from a spool 190 (see FIG. 17). The flanges 18,
22 of zipper profiles 12, 14 are then spread apart, typically by a
spreader apparatus 192 such as is illustrated in FIG. 15 (also see
FIG. 17) wherein the portion of flanges 18, 22 immediately below
the interlocked profiles 12, 14 is fed into the nip 200 between
rollers 202, 204. A portion of flanges 18, 22 extends therefrom and
is engaged by vacuum elements 206, 208. Vacuum elements 206, 208
spread the portions of flanges 18, 22 extending from rollers 202,
204 so that adhesive, typically a hot-melt reactive adhesive such
as a hot melt, cross-linkable adhesive (particularly, a hot melt
cross-linkable polyurethane reactive adhesive), can be applied or
otherwise placed by nozzle 210 onto the interior of flanges 18, 22
as shown in FIG. 16 (those skilled in the art will recognize that
some adhesives should be applied by a downwardly pointing nozzle
210 with the orientation of the flanges 18, 22 during adhesive
application changed in accordance therewith). Additionally,
optional plasma or corona discharge station 209 may change the
surface energy (described later in detail herein) of the flanges
18, 22 prior to application of adhesive. The flanges 18, 22 are
temporarily clamped by clamps 194 (see FIG. 17), or pressure
similarly applied, to the outside bag walls 102, 104 of successive
packages or bags 100 (typically supplied with an open bottom and
free of contents).
[0066] The adhesive layer is typically applied to flanges 18, 22 in
a path divergent or parallel to the bag supply so that the flanges
18, 22 are subsequently guided from the divergent or parallel path
to a position wherein the bag walls are captured within the flanges
18, 22.
[0067] Zipper 10 is stomped at stomp locations 68 at package-width
intervals, typically two stomps 68 at a time, by stomper 220 and
slider 15 is inserted therebetween by slider inserter 222 as shown
in FIG. 17. The laterally extending excess portions of the flanges
are heat sealed, glued, or ultrasonically bonded to each other by
bonding station 224.
[0068] FIG. 17A illustrates a possible configuration for the
flanges 18, 22 to be sealed to each other in an inverted T-shaped
area 400 below end stomp 68 between successive bags 100 by bonding
station 224. FIG. 17B illustrates a possible configuration for the
flanges 18, 22 to be glued to each other in rectangular area 402
between edges of successive bags 100 and below end stomp 68.
[0069] The zippers are then cut at cutting station 226 to achieve
the package 100 illustrated in FIG. 18 (with the phantom lines
illustrating a gusset between the front and rear walls). The
resulting packages or bags 100 are typically unfilled and have an
open bottom. Optional filling station 225 is illustrated prior to
cutting station 226. Optional filling station 225 may be top
filling (in which case, zippers such as illustrated in FIG. 22 or
24-26 may be used) or bottom filling (in which case, the packages
or bags are inverted and a bottom sealer is included with the
filling station 225). However, separate subsequent filling steps
may be performed at a different location to fill packages or bags
100 with contents and seal the bottom 110 of the package or bag
100.
[0070] Alternative embodiments may cut the zippers prior to the
application of the adhesive, may include pre-mounted sliders, or
sliders inserted and stomps formed prior to the gluing process.
Walls 102, 104 may be folded to form gussets prior to the securing
of the zipper assembly 10 thereto. Similarly, gussets may be
attached below or within the flanges 18, 22 by glue dots or similar
connection methods. To reinforce the gussets underneath the zipper
assembly 10, glue may be applied in between the inside faces of the
gussets or in between the outside faces of the gussets.
[0071] FIGS. 19, 20 and 21 illustrate variations in the formation
of the zipper assembly 10. FIG. 19 illustrates how first and second
sheets of web 300, 302 can be joined by peel seal 24, a fold 28
formed in second sheet of web 302 and then sealed to first and
second flanges 18, 22 thereby achieving a construction similar to
FIG. 2. Similarly, FIG. 20 illustrates first and second profiles
12, 14 being joined by peel seal 24 and first sheet of web 300
being slit into two pieces which are sealed to flanges 18, 22
thereby forming a construction similar to that illustrated in FIG.
3. In FIG. 21, a lower portion of first flange 18 is removed and
then resealed to an upper portion of first flange 18 thereby
likewise forming a construction similar to that illustrated in FIG.
3. Alternatively, first flange 18 can be folded to achieve the
construction of FIG. 2. Further alternatively, the T-shaped
configuration of first flange 18 can be achieved by simultaneous
extrusion of a single T-shaped flange.
[0072] With respect to the adhesive used by nozzle 210 to fasten
the zipper assembly 10 to the walls 102, 104 of package 100, it has
been found that hot melt, cross-linkable adhesives (such as hot
melt polyurethane reactive adhesive which are cross-linkable) have
been found to be superior to ordinary hot melt adhesives, both for
multi-wall paper and woven polypropylene walls. Likewise, this
adhesive has been found superior for the construction of all seams
of package or bag 100, including bottom seam 110 and longitudinal
seam 111. This was determined by tests in which the package 100 was
loaded with 2.5 times its rated load and hung upside down (that is,
with the load bearing on the zipper assembly 10) and placed in 140
degree Fahrenheit environment (which is representative of
temperatures which may be encountered during shipping) for
seventy-two hours. The package 100 was considered to have passed
this test if the package 100 maintained its integrity during this
period.
[0073] Likewise, this test can be performed for the same load (2.5
times rated load) and period (seventy-two hours) at negative 20
degrees Fahrenheit (-20.degree. F.) for simulation of cold
environments which may be encountered during transportation and
storage in some climates. The hot melt, cross-linkable adhesives
(such as hot melt polyurethane reactive adhesive which are
cross-linkable) have likewise been found to be superior under these
tests and can be applied to all seams of packages, with or without
a reclosable zipper.
[0074] Similarly, it has been found that pre-treatment of the
olefin structures of the walls 102, 104 (particularly if made from
woven polypropylene) and zipper flanges, typically by corona
discharge or plasma treatment of the walls and flanges, improves
the adhesion bond of the hot melt, cross-linkable adhesive (such as
hot melt cross-linkable polyurethane reactive adhesive) between the
walls and zipper flanges, particularly for film structures having a
non-polar surface energy of less than 40 dynes per square
centimeter.
[0075] Additionally, heat sealing may be effective in instances
wherein the bag surface includes resin binder type inks.
[0076] As shown in FIG. 22, in the first alternative top-filling
embodiment of zipper assembly 10, distal ends 40, 42 of respective
segment 38 and second flange 22 are attached to respective front
and rear walls 102, 104 prior to the attachment or sealing of
segment 38 to first flange 18. Segment 38 is typically a
polyethylene strip that is attached by glue to the bag wall prior
to the filling of the package or bag and by a heat seal to flange
18 after the package or bag is filled. This allows the package to
be filled with contents through the gap or opening 37 between
segment 38 and first flange 18 prior to the joining or sealing of
segment 38 to first flange 18. This top filling eliminates the
bottom filling typically associated with many of the other
disclosed embodiments.
[0077] As shown in FIG. 23, in the second alternative top-filling
embodiment of zipper assembly 10, polyethylene strips 103, 105 are
attached to the exterior of front and rear walls 102, 104
immediately adjacent to mouth 112. Extension segment 46 is
typically heat sealed or otherwise attached to polyethylene strip
103 prior to filling of the package 100 and extension segment 48 is
typically heat sealed or otherwise attached to polyethylene strip
105 after filling of the package 100 to reach the configuration
shown in FIG. 24. While FIG. 24, as well as FIG. 25, is illustrated
with the zipper assembly 10 of FIG. 7, other equivalent zipper
configurations could be substituted for this zipper assembly 10, as
would be recognized by those skilled in the art after review of
this disclosure.
[0078] FIG. 25 shows a third alternative top-filling embodiment of
zipper assembly 10, similar to that shown in FIG. 24, except that
extension segment 46 is glued to front wall 102, typically by hot
melt, cross-linkable adhesive (such as hot melt cross-linkable
polyurethane reactive adhesive) 107 prior to filling of the package
100, thereby obviating the need for polyethylene strip 103. After
filling of package 100 with contents, similar to the embodiment
shown in FIG. 23, extension segment 48 is heat sealed to
polyethylene strip 105 on rear wall 104.
[0079] FIG. 26 illustrates a zipper assembly 10, similar to that of
FIG. 3, wherein flange 22 and segment 38 are glued or otherwise
sealed or attached to front and rear walls 102, 104 prior to the
formation of peel seal 24. Peel seal 24 is formed and activated
thereby joining first and second flanges 18, 22 to each other after
the filling of package 100 with contents between first and second
interlocking elements 16, 20 as shown by arrow labeled as "fill".
This filling may be done by using the slider (see FIG. 1) to
separate the first and second interlocking elements 16, 20, filling
between first and second interlocking elements, and then using the
slider to interlock first and second interlocking elements 16,
20.
[0080] FIG. 27 is a cross-sectional view of a first embodiment of
high burst closure 11. High burst closure 11 includes first profile
12 and second profile 14. First profile 12 includes first upper
separating portion 17 and first flange 18, integral with each
other, formed from a single sheet of polymeric web or similar
material. First profile 12 further includes interior flange 19
integrally formed with upper separating portion 17 or attached by a
hard seal to the interior surface thereof. Second profile 14
includes second upper separating portion 21 and second flange 22.
First peel seal 24 is formed between the lower end of interior
flange 19 and a generally central portion of second profile 14.
Alternatives for closing first and second upper separating portions
17, 21 are shown in FIGS. 31 and 32. In this, as well as the other
embodiments of high burst closures, similar to the previously
disclosed zippered embodiments, loads on the package walls or
flanges cause a shear force on the peel seal, as shown in FIG. 12,
thereby increasing the load resistance of the closure and the
package in order to meet the required high burst strength.
[0081] FIG. 28 is a cross-sectional view of a second embodiment of
high burst closure 11. In this embodiment, the first profile 12 is
formed from a first upper separating portion 17 which extends to
first peel seal 24. First flange 18 is sealed to a generally
central portion of first upper separating portion 17. Again,
alternatives for closing first and second upper separating portions
17, 21 are shown in FIGS. 31 and 32.
[0082] FIG. 29 is a cross-sectional view of a third embodiment of
high burst closure 11. A single sheet of polymeric web or similar
material is used to form first profile 12. This sheet forms upper
separating portion 17 and is folded adjacent to a bottom of peel
seal 24 and is then sealed to a generally central exterior portion
of first upper separating portion 17, with the remaining portion of
the sheet forming first flange 18.
[0083] FIG. 30 is a cross-section view of the first embodiment of
the high burst closure of FIG. 27 (equally applicable to the
embodiments of FIGS. 28 and 29) with the exterior of first and
second flanges 18, 22 sealed to the interior of respective first
and second bag walls 102, 104. Alternatively, the interior of the
first and second flanges 18, 22 can be attached by adhesive or
other means to the exterior of bag walls 102, 104.
[0084] FIG. 31 is a cross-sectional view of the first embodiment of
the high burst closure of FIGS. 27 and 30 (equally applicable to
the embodiments of FIGS. 28 and 29) wherein second peel seal 31 is
added between first and second upper separating portions 17, 21 so
that first and second upper ends 17', 21' of respective first and
second upper separating portions 17, 21 protrude therefrom thereby
providing grips for the user to grasp and peel apart the first and
second peel seals 24, 31 in order to open closure 11.
[0085] FIG. 32 is a cross-sectional view of the first embodiment of
the high burst closure of FIGS. 27, 30 (equally applicable to the
embodiments of FIGS. 28 and 29) wherein the first and second upper
ends 17', 21' of respective first and second upper separating
portions 17, 21 are sealed together by hard seal 29. Furthermore,
first and second lines of weakness 33, 35 (typically formed by
perforated lines or scored lines) are formed in respective first
and second upper ends 17', 21' under hard seal 29 whereby a user
opens closure 11 by grasping an area proximate to hard seal 29 and
tearing along the first and second lines of weakness 33, 35 thereby
removing the resulting header-like portion of first and second
upper ends 17', 21' above the first and second lines of weakness
33, 35 thereby gaining access to first peel seal 24 which is opened
by the user by further separating first and second upper separating
portions 17, 21.
[0086] FIG. 33 is a cross-sectional view of an embodiment similar
to that of FIG. 28 wherein first wall 102 extends upwardly and is
sealed directly to the generally central portion of first upper
separating portion 17, thereby fulfilling the function of first
flange 18. Identical to the configuration of FIG. 32, first and
second upper separating portions 17, 21 are sealed together by hard
seal 29 and first and second lines of weakness 33, 35 are formed in
respective first and second upper ends 17', 21'. Alternately, a
second peel seal, as shown in FIG. 31, can replace hard seal 29, or
the first and second supper ends 17', 21' can remain unsealed as
shown in FIG. 30.
[0087] FIG. 34 is a cross-sectional view of an embodiment similar
to that of FIG. 31 wherein first flange 18 is sealed to first bag
wall 102 and first bag wall 102 extends above closure 11 and
includes aperture 37 which serves as a handle. In other words,
aperture 37 is formed in a portion of first bag wall 102 which
extends above first flange 18. Alternately, first bag wall 102 can
be integral with first flange 18 (i.e., first bag wall 102 sealed
directly to first upper separating portion 17 thereby eliminating
the need for a separate first flange 18) and a separate bag wall
extension is sealed to the exterior thereof and aperture 37 formed
in this separate bag wall extension.
[0088] FIG. 35 is a cross-sectional view of an embodiment similar
to that of FIG. 32 wherein first bag wall 102 extends above closure
11 and includes aperture 37 which serves as a handle. Furthermore,
second peel seal 31 is formed between first upper separating
portion 17' (proximate to hard seal 29) and first bag wall 102
(downwardly adjacent from aperture 37).
[0089] FIG. 36 is a cross-sectional view of an embodiment similar
to that of FIG. 32 wherein an extension 41 of upper separating
portion 17 is provided, with an aperture 43 serving as a handle.
This is equally application to upper separating portion 21, or both
upper separating portions 17, 21. Likewise, extension 41 may be
implemented in combination with, or in lieu of, the upward
extension of first wall 102 illustrated in FIG. 34 and the aperture
37 formed therein.
[0090] Those skilled in the art will recognize a broad range of
possible contents for the packages 100, including, but certainly
not limited to, charcoal, pet food, livestock or other animal food,
cat litter, fertilizer, seeds, plant bulbs, rock salt, and
foodstuffs.
[0091] Thus the several aforementioned objects and advantages are
most effectively attained. Although preferred embodiments of the
invention have been disclosed and described in detail herein, it
should be understood that this invention is in no sense limited
thereby and its scope is to be determined by that of the appended
claims.
* * * * *