Note: Descriptions are shown in the official language in which they were submitted.
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CLOSURE DEVICE FOR A
RECLOSABLE POUCH
Related C~',a~e
[001] This application is a continuation-in-part of serial number 10/278,599,
filed
October 23, 2002, entitled "Closure Device for a Reclosable Pouch."
Technical Field
[002] The present invention relates to closures for reclosable pouches, and
more
particularly, to such closures wherein at least one flange is disposed on a
surface of the
bag adjacent a closure element.
Background Art
[003] A thermoplastic bag for the storage of items typically includes a
closure
mechanism comprising male and female closure elements or profiles attached to
bag walls.
In addition, thermoplastic bags are known having guide ribs disposed on one or
more
internal surfaces of the thermoplastic bag closely spaced and adjacent the
closure elements
of the bag to assist in aligning the male and female closure elements when
sealing the bag.
[004] Hugues et al., U. S. Patent No. 4,672,723 discloses a stabilized
reclosable extruded
plastic fastener. The fastener comprises a female profile on one wall of an
extruded film
material and a male profile on an opposite wall of the film material.
Alignment ribs are
spaced alongside and integral with a base area of the male profile to
facilitate alignment of
the male profile with the female profile during closing of the fastener.
[005] Fisher, U.S. Patent No. 4,736,496, owned by the assignee of the present
application, discloses a wide-traclc integral thermoplastic closure for a
reclosable
thermoplastic container. The closure includes ribs on either side of an
element of the
closure to assist in guiding a user's fingers during closure of the
thermoplastic container.
[006] Wirth et al., U.S. Patent No. 5,198,055 discloses two profile strips
wherein each
strip includes a reclosable element, preferably a rib element and a groove
element. Each
of the profile strips further include a flange element spaced on one side of
the profile strip
and a heat barrier means associated with an inside face or front side of each
flange
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element, wherein the heat barrier section includes a thickened portion of each
flange
element.
[007] Tilman, U. S. Patent No. 5,209,574 discloses a reclosable plastic bag
having a
sliderless zipper. The bag includes front and rear walls sealed along three
edges to form a
mouth or opening. Male and female profiles are attached to internal surfaces
of the front
and rear walls, respectively, wherein the male and female profiles are
engageable to close
the opening. Two ribs are provided on an outside surface of the front wall,
one on each
side of the male profile, to define a valley therebetween. Similarly, two
additional ribs are
formed on the outside surface of the rear wall, one on each side of female
profile, to define
a valley therebetween. The valleys act as finger guides for the user of the
bag.
[008] Dais et al. U.S. Patent No. 5,527,112 discloses an adhesive closure for
flexible
bags. During closure, the front wall and back wall are guided into adhesive
contact by an
aligning rib member. The aligning rib member further serves to provide tactile
feedback to
the user during closure.
[009] Tomic U.S. Patent No. 6,217,215 discloses a closure profile for flexible
bags. The
assembly includes a base strip, first and second closure members and a guide
post. The
guide post projects outwardly from the base strip and assists in aligning a
plurality of
opposing hooked profile elements into interlocking contact. The guide post
also aids in
holding the closure mechanism closed when the opposing hooked profile elements
are
fully engaged.
[010] Simonsen et al., U.S. Patent No. 5,017,021 discloses a closure member
having first
and second profile strips attached to the package at the package opening. A
male member
and at least one post member are formed on the first profile strip for
engaging an opposing
female mei'nber. The post member is positioned on the inboard 'side of the
profile strip
close to the male member resulting in added resistance to the disengagement of
the male
member to an opposing female member attached to the second profile strip.
[011] Scott et al., U.S. Patent No. 5,36,394 discloses a stabilizer wedge
zipper for
reclosable bags. The zipper includes male and female profiles wherein each of
the profiles
includes a stabilizer wedge on both sides thereof. The stabilizer wedges are
parallel to the
profiles and span the width of the bag in order to maintain a wide-traclc feel
as a user
closes a bag.
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[012] Johnson, U.S. Patent No. 5,577,305 discloses a fastener assembly for
reclosable
plastic containers. The assembly includes male and female base members each
having
male and female closure elements, respectively, and flanges attached thereto
having ribs
proximate the distal ends of the flanges. The ribs extending from the male
base member
are angled substantially perpendicular to the base and the ribs extending from
the female
base member are angled inwardly at approximately 70 degrees from the female
base
member. The position and orientation of the ribs increases the holding power
of the
female closure element when interlocked with the male closure element.
Summary of the Invention
[013] According to one aspect of the present invention, a closure for a pouch
having first
and second pouch walls, includes male and female closure elements disposed on
and
separate from the first and second pouch walls, respectively. The female
closure element
includes a female profile member and first and second flanges disposed on
either side of
and spaced apart from the female profile member.
[014] According to another aspect of the present invention, a reclosable
plastic container
includes first and second oppositely disposed pouch walls and male and female
closure
elements disposed on and separate from the first and second pouch walls,
respectively.
The female closure element includes a female profile member and first and
second flanges
disposed on either side of and spaced apart from the female profile member.
[O15] According to yet another aspect of the present invention, a zipper tape
includes
male and female closure elements disposed on and separate from the first and
second
pouch walls, respectively. The female closure element includes a female
profile member
and first and second flanges disposed on either side of and spaced apart from
the female
profile member.
[016] Other aspects and advantages of the present invention will become
apparent upon
consideration of the following detailed description and the attached drawings,
in which
like elements are assigned like reference numerals.
Brief Description of the Drawings
[017] FIG. 1 is an elevational view of a reclosable thermoplastic storage bag
according to
the present invention;
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[018] FIG. 2 is an enlarged, fragmentary, sectional view taken generally along
the lines
2-2 of FIG. 1;
[019] FIG. 3 is an enlarged sectional view similar to FIG. 2 illustrating bags
produced in
accordance with the present invention;
[020] FIGS. 4 and 5 are enlarged, fragmentary, sectional view similar to FIG.
2
illustrating further embodiments of the present invention;
[021] FIG. 6 is an enlarged, fragmentary, elevational view of a portion of
zipper tape
according to the present invention;
[022] FIG. 7 is an isometric view of an apparatus for producing bags of the
present
invention;
[023] FIG. 8 is an enlarged isometric view of the apparatus of FIG. 7;
[024] FIG. 9 is an enlarged end elevational view of the apparatus of FIGS. 7
and 8; and
[025] FIGS. 10-13 are bottom elevational views of extrusion die profile plates
that may
be used to produce female closure elements for thermoplastic storage bags of
the present
invention.
[026] FIG. 14 is an enlarged, fragmentary, sectional view illustrating a
further
embodiment taken generally along the lines 2-2 of FIG. 1.
[027] FIG. 15 is an enlarged sectional view similar to FIG. 14 illustrating
bags produced
in accordance with the present invention.
[028] FIGS. 16 and 17 are enlarged, fragmentary, sectional view similar to
FIG. 14
illustrating further embodiments of the present invention
Description of the Preferred Embodiments
[029] Refernng to FIG. 1, a reclosable pouch in the form of a thermoplastic
storage bag
20 comprises first and second body portions 22, 24 joined to one another to
form first and
second bag walls 26, 28. The first and second bag walls 26, 28 are joined at
first and
second side portions 30, 32, respectively, and at a bottom portion 34. An
opening 35 is
disposed at a top portion 36 of the bag 20. A closure mechanism 38 and two
lips 40 are
also disposed at the top portion 36 of the bag 20.
[030] Referring to FIGS. 2 and 3, female and male closure elements 42, 44 of
the closure
mechanism 38 are disposed on opposing inside surfaces 46, 48 of the first and
second
body portions 22, 24, respectively. The female element 42 comprises a base 62
with a C-
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shaped profile member 64 extending therefrom, wherein the female element 42 is
adapted
to receive the male element 44 when pressure is exerted on the closure
elements by a
user's fingers) during closing of the bag. According to a first embodiment,
the female
closure element 42 further comprises flanges 70 attached to each side of the
base 62 of the
female closure element 42 and extending outwardly towards the bottom 34 and
top 36
portions of the bag along the inside surface 46.
[031] The male closure element 44 comprises a base 58 integral with flanking
side
members 54 and 56 and an arrow-shaped profile member 60 that extends from the
base 58.
The side members 54 and 56 are of a sufficient size and proximity to the
profile member
60 such that the side members 54 and 56 move together with the member 60 when
the
members 60 and 64 are engaged and disengaged. The side members 54 and 56 also
have a
height less than the height of the profile member 60, and the members 54 and
56 extend
beyond tips 68 of the C-shaped profile member 64 when the profile member 60 is
engaged
with the C-shaped profile member 64. Thus, at such time, the tips 68 of the C-
shaped
profile member 64 reside between the side members 54 and 56 and the male
profile
member 60.
[032] The flanges 70 associated with the female closure element 42 include a
first
portion 72 and a second portion 74 having a thickness less than a thickness of
the first
portion 72. The second portion 74 is disposed adjacent the C-shaped profile
member 64
and connects the first portion 72 to the C-shaped profile member 64. The
second poution
74 has a thickness of between about 0.001 inch and about 0.005 inch and
preferably about
0.0018 inch. The first portion 72 has a thickness of between about 0.03 inch
and about
0.06 inch and preferably about 0.047 inch, wherein the first portion 72 has
either a
generally uniform thickness throughout a length thereof as seen in FIG. 2 or a
varying
thickness throughout a length thereof by adding ribs 77 to a surface 79
thereof as seen in
FIG. 3. The second portion 74, therefore, has a thickness about one-quarter
the thickness
of the first portion 72 and is not completely attached to the inside surface
46 adjacent the
C-shaped profile member 64, thereby creating a gap 76 between the second
portion 74 of
the flanges 70 and the inside surface 46. The C-shaped profile member 64 has a
thickness
between about 0.035 inch and 0.06 inch, preferably about 0.043 inch. The
flanges 70 are
colored the same color as the C-shaped profile member 64 and the base 62,
thereby
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providing a larger colored area to the closure mechanism 38 and providing a
wider area for
tactile feedback.
[033] If desired, one or more gripping ribs 75 may be disposed on the inside
surfaces 46,
48 of the bag 20 between the closure elements 42 and 44 and the top portion 36
of the bag
20 as seen in FIG. 2, wherein the gripping ribs 75 are integrally extruded
with the walls of
the bag. Any number of gripping ribs 75 can be used, although space is
necessary
between adjacent ribs in order to facilitate a gripping action with a user's
fingers. In a
preferred embodiment, about six or seven gripping ribs 75 are disposed on each
lip 40 of
the bag.
[034] In other embodiments, as seen in FIGS. 4 and 5, the female closure
element 42 and
the male closure element 44 may both have flanges 70 each having a first
portion 72 and a
second portion 74. Some or all of the second portions 74 may have a thickness
less than
that of the first portions 72 as seen in FIG. 4. Alternatively, some or all of
the second
portions 74 may have a thickness equal to that of the first portions 72 as
seen in FIG. 5.
[035] Another embodiment as shown in FIG. 6 comprises a zipper tape 78. The
zipper
tape 78 includes first and second thermoplastic strips 80, 82, wherein female
and male
closure elements 42, 44 are attached to or otherwise formed on the first and
second
thermoplastic strips 80, 82, respectively. The female closure element 42
further comprises
flanges 70 attached to each side of the base 62 of the female closure element
42 and
extending outwardly towards an upper portion 84 of the first strip 80 and a
lower portion
86 of the first strip 80. The zipper tape 78 may be attached to a folded
thermoplastic sheet
by any suitable conventional process and apparatus and the resulting structure
may be
severed and sealed at spaced locations to form individual bags.
[036] Reclosable thermoplastic storage bags as described herein can be
produced by any
conventional bag-making process, such as a cast post applied process, a cast
integral
process, a blown process, or any other process known in the art. An
alternative post
applied process can also be used such as seen in FIGS. 7 and 8. Referring to
such FIGS.,
the alternative post applied process utilizes an extrusion apparatus including
a first
extrusion slot die 88, a temperature-controlled driven casting roll 90, edge
pinning devices
or apparatus 92a, 92b, an air lcnife 94, second and third extrusion dies 96a,
96b (which,
together with the die 88, form the extrusion apparatus) and cooling apparatus
98a, 98b.
The extrusion die 88 receives molten thermoplastic from an extruder (not
shown) and
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deposits the thermoplastic in sheet fornz as a web 100 onto the casting roll
90. The
extrusion die 88 includes a slot opening (not shown) that forms thickened
areas 102, 104
at outside edge portions 106a, 106b of the resulting web 100 and a relatively
thinner
portion 108 intermediate the thickened areas 102, 104. The edge portions 106a,
106b are
pinned to the casting roll 90 by the edge pinning devices 92a 92b,
respectively. The web
100 is then pinned across the entire width thereof (i.e., as a whole) to the
casting roll 90 by
the air knife 94.
[037] After the web 100 is pinned to the casting roll 90, the male and female
closure
elements 42, 44 are formed on the web 100. Preferably, the extrusion dies 96a,
96b
receive molten thermoplastic from separate extruders and extrude the male and
female
closure elements 42, 44, respectively, onto the thickened areas 102, 104.
Alternatively,
the separate extrusion dies 96a, 96b may be replaced by a single extrusion die
having two
outlets at which the male and female closure elements 42, 44 are
simultaneously extruded
onto the thickened areas 102, 104. In any event, as seen in FIG. 7, the angle
of a face 110
of each die 96 is at least initially disposed substantially parallel to a
horizontal (as seen in
FIG. 9) radial line 111 extending from the center of the casting roll 90. The
position of the
die 96 (or each die 96a, 96b individually if separate dies are used) may then
be adjusted by
moving the die left, right, up, or down (all as seen in FIG. 9) or the die may
be tipped (i.e.,
anguharhy displaced) to adjust the angle of the die face 110 to obtain
desirable results. The
closure elements 42, 44 formed by the dies) 96 may exit the dies) 96 at a
point
coincident with a vertical tangent line 112 (FIG. 9) intersecting the surface
of the casting
roll 90 on the side of the casting roll 90 where the web 100 is first
deposited thereon.
Alternatively, the closure elements 42, 44 formed by the dies) 96 may exit the
dies) 96 at
a point displaced to the right or left (as seen in FIG. 9) of the tangent line
112. If the
extrudate exits the dies) 96 at a point displaced to the right of the line
112, some
provision must be made at the initiation of production to attach the extrudate
stream to the
casting roll 90. Thereafter, production may commence, (provided that the exit
of the
dies) 96 is not disposed too far to the right of the tangent line 112)
whereupon the melt
strength of the extrude stream carries the stream into contact with the roll
90.
[038] Once the molten thermoplastic from the dies) 96 has been deposited onto
the web
100, coolant is applied to the closure elements 42, 44 by the coolant
apparatus 98a, 98b to
bring the temperature thereof below the melting point of the thermoplastic
material
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forming the closure elements 42, 44 as quickly as possible. Preferably, the
coolant
comprises water or any other suitable cooling fluid and the coolant is applied
to the
material of the closure elements 42, 44 only after such material contacts the
material of the
web 100 so that adhesion thereto is optimized. The web 100 and the closure
elements 42,
44 are maintained in contact with the temperature-controlled casting roll 90
for a period of
time as the roll 90 is rotated so that the web 100 and closure elements 42, 44
are further
cooled. The casting roll 90 should be maintained at a temperature below the
melting point
of the thermoplastic materials) forming the web 100 and the closure elements
42, 44,
typically about 20-80 degrees C.
[039] Profile plates as seen in FIGS. 10-13 may be utilized in any suitable
process to
produce thermoplastic bags having a female closure element 42 with flanges 70
according
to the present invention. The profile plate 130 includes a base portion
aperture 132 to
create the base 62 of the female closure element 42 and the flanges 70,
wherein the base
portion aperture 132 can have horizontal end portions 134 as in FIGS. 10-13 or
upwaxdly
curving end portions 134 as in FIG. 13. Two profile portions apertures 136 are
disposed
symmetrically about a center 138 of the base portion aperture 132 of the
profile plate 130,
wherein each of the profile portions apertures 136 include a tip portion 139
and a leg
portion 142. The leg portion 142 of each of the profile portion apertures 136
may be
disposed perpendicular to the base portion aperture 132 as seen in FIG. 11, or
may be at a
slight angle outwardly with respect to a vertical axis as seen in FIGS. 10,
12, and 13. The
leg portion 142 of each profile portion aperture 136 may also be slightly
curved or arched
(not seen). Notches 140 may be created in the base portion aperture 132
adjacent the
profile portion apertures 136 to create the second, thinner portions 72,
wherein a thickness
of the notches 140 is about half a thickness of the base portion aperture 132
and the end
portions 134. The notches 140 reduce the interaction between the base 62 and
the flanges
70 during deposition of molten thermoplastic to form the female closure
element 42. This
reduction in interaction allows formation of the C-shaped profile member 64 in
a
substantially undeformed shape as compared with the shape produced when the
flanges 70
are not present. That is, if the notches 140 were not included in the profile
plate 130 as
seen in FIG. 10, the flanges 70 would be formed properly, but the C-shaped
profile
member 64 would tend to spread apart (i.e. would be formed with a greater
distance
between the tips 68 of the C-shaped profile member 64), thereby possibly
adversely
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affecting the engagement of the C-shaped profile member 64 with the arrow-
shaped
profile member 62. Proper formation of the female closure element 42 can be
attained
using no notches 140 as seen in FIG. 10, but the variability would be greater.
[040] Referring to FIG. 14, another embodiment of a closure mechanism 238 is
shown.
Male and female closure elements 242, 244 are disposed on opposing inside
surfaces 246,
248 of the first and second body portions 226, 228 respectively. The female
element 242
comprises a C-shaped profile member 264 extending therefrom, wherein the
female
element 242 is adapted to receive the male element 244 when pressure is
exerted on the
closure elements by a users) fingers during the closure of the bag.
[041] In the present embodiment, the female closure element 242 further
comprises pair
of flanges 271 disposed at a spaced apart distance L on either side of the
base 262 of the
female closure element 242. The distance L is preferably about 0.065 inches.
However,
the use of alternative values for the distance L are also considered to be
within the scope
of the invention. The flanges 271 extend outwardly towards the bottom and the
top
portions of the bag along the inside surface 246. Each of the flanges 271 has
a
substantially uniform thickness of between about 0.03 inch and about 0.06 inch
and
preferably about 0.047 inch. It should be noted however, that although flanges
of
substantially uniform thickness have been described, flanges have a non-
uniform
construction are also considered to be within the scope of the invention.
[042] The flanges 271 are preferably, but not necessarily, colored the same
color as the
C-shaped profile member 264 and the base 262, thereby providing a larger
colored area to
the closure mechanism 238 and providing a wider area for tactile feedback.
[043] The male closure element 244 comprises a base 258 integral with flanking
side
members 254 and 256 and an arrow-shaped profile member 260 that extends from
the base
258. The side members 254 and 256 are of a sufficient size and proximity to
the profile
member 260 such that the side members 254 and 256 move together with the
member 260
when the members 260 and 264 are engaged and disengaged. The side members 254
and
256 also have a height less than the height of the profile member 260, and the
members
254 and 256 extend beyond tips 268 of the C-shaped profile member 264 when the
profile
member 260 is engaged with the C-shaped profile member 264. Thus, at such
time, the
tips 268 of the C-shaped profile member 264 reside between the side members
254 and
256 and the male profile member 260.
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[044] If desired, one or more gripping ribs 275 may be disposed on the inside
surfaces
246, 248 between the closure elements 242 and 244 as seen in FIG. 14, wherein
the
gripping ribs 275 are integrally extruded with the walls of the bag. Any
number of
gripping ribs 275 can be used, although space is necessary between adjacent
ribs in order
to facilitate a gripping action with a user's forgers. In a preferred
embodiment, about six
or seven gripping ribs 275 are disposed on each lip 240 of the bag.
[045] In another embodiment, shown in FIG, 1 S, a number of ribs 277 may be
added to
the surface 279 of the flanges 271 flanking the C-shaped profile member 264
such that the
flanges 277 have a varying thickness throughout the length thereof.
[046] In a further embodiment, shown in FIG. 16, the male closure element 244
further
comprises pair of flanges 273 disposed at a spaced apart distance D on either
side of the
base 258. The distance D is preferably about 0.065 inches. However, the use of
alternative values for the distance D are also considered to be within the
scope of the
invention. The flanges 273 extend outwardly towards the bottom and the top
portions of
the bag along the inside surface 246. Each of the flanges 273 has a
substantially uniform
thickness of between about 0.03 inch and about 0.06 inch and preferably about
0.047 inch.
It should be noted however, that although flanges of substantially uniform
thickness have
been described, flanges have a non-uniform construction are also considered to
be within
the scope of the invention.
[047] The flanges 273 may be colored the same color as the male closure
element 244,
thereby providing a larger colored area to the closure mechanism 238 and
providing a
wider area for tactile feedback.
[048] In another embodiment, shown in FIG, 17, a number of ribs 281 may be
added to
the surface 283 of the flanges 273 flanking the base 258 of the male closure
element 244
such that the flanges 277 have a varying thickness throughout the length
thereof.
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Industrial Applicability
[049] Closure devices according to the present invention are particularly
useful for
resealable closures for thermoplastic bags or pouches. Such closure devices
include a
male and a female profiles wherein the female profile includes spaced apart
flange
portions extending along an inside surface of a bag or pouch wall. The flange
portions of
the female profile provide a wider surface for increased tactile confirmation
that closure
has been achieved.
[050] Numerous modifications will be apparent to those skilled in the art in
view of the
foregoing description. Accordingly, this description is to be construed as
illustrative only
and is presented for the purpose of enabling those skilled in the art to make
and use the
invention and to teach the best mode of carrying out same. The exclusive
rights to all
modifications which come within the scope of the appended claims are reserved.
