Title of Invention	A RECLOSABLE FASTENER
Abstract	A reclosable fastener (10) comprising a male/female closure between a pair of opposed base members (18) has a single flange (16) for attachment of the closure to a web or film (34) on one only of the two base members. The fastener is attached initially to the film (34) by the single flange and then the fastener is additionally attached to the film (34) by heat and pressure applied in the region of attachment ribs (30) on the base members and each base member has means to attach the fastener additionally to the web or film.

Title of Invention

A RECLOSABLE FASTENER

Abstract

A reclosable fastener (10) comprising a male/female closure between a pair of opposed base members (18) has a single flange (16) for attachment of the closure to a web or film (34) on one only of the two base members. The fastener is attached initially to the film (34) by the single flange and then the fastener is additionally attached to the film (34) by heat and pressure applied in the region of attachment ribs (30) on the base members and each base member has means to attach the fastener additionally to the web or film.

Full Text	A RECLOSABLE FASTNER Field of the invention This invention relates to reclosable fasteners, otherwise known as zippers, for plastics bags and other containers, and is particularly concerned with zippers intended to be applied to a film or web using cross-web techniques. Background of the invention When a zipper strip is applied to a film or web, heat and pressure are applied to effect the welding of the zipper to a film or web from which the bag or other container is to be made. In order to secure the zipper to the film or web, the zipper is conventionally provided with a plurality of flanges on the two interengageable members which together make up the fastener. The most common practice is to provide four flanges, two on each member, in order to seal these flanges to the film or web material on each side of the zipper. However, some zippers are provided with only three flanges, and some with only two. Sealing at the flanges is effected in order to keep heat and pressure away from the vulnerable male/female closure elements. However, it is a problem with such multi flanged zippers that they tend to be bulky and do not easily deflect when used in cross-web procedures. Summary of the invention It is an object of the present invention to overcome this problem, by providing a zipper which is less bulky. Accordingly the present invention provides for a reclosable fastener comprising a male/female closure between a pair of opposed base members, wherein a single flange for attachment of the closure to a web or film is provided on one only of the two base members and each base member has means to attach the fastener additionally to the web or film. The single flange is used to attach the zipper initially to the web or film for subsequent sealing/welding of the zipper to the web or film in the region of the base members, by whatever means is appropriate. Brief description of the/drawing In order that the invention may be more fully understood, one presently preferred embodiment of zipper in accordance with the invention will now be described by way of example and with reference to the accompanying drawing which is a schematic cross-sectional view through the zipper. Description of the preferred embodiment Referring to the drawing, there is shown a zipper, indicated generally at 10, comprising a first element 12 and a second element 14. The two elements 12 and 14 are generally the same as each other, apart from the fact that element 12 is provided with a single elongate flange 16. Each element 12, 14 comprises a base member or body portion 18 with two upstanding legs 20 which terminate in hooks 22 . The respective hooks 22 of the two elements 12 and 14 are interengageable to make the reclosable fastener. Each element 12, 14 also comprises an upstanding support post 24 at one margin. The support post 24 is slightly longer than the hooked legs 20, 2 2 so that it extends slightly beyond the tops of the legs. The upper end surface 26 of each post 24 is tapered to provide an angled contact surface. Facing each support post 24, on the opposing element, there is provided a heel portion 28, again at the margin. The surface of each heel portion 28 facing the respective post 24 is shaped, i.e. angled, to be complementary to the angled contact surface 26. As can be seen from the drawing, with this arrangement, the respective posts and heels nest with one another to provide a. shape-locking configuration which tends to resist squashing or outward bending under vertical loads. The angled contact surfaces are able to absorb the welding pressure and maintain their linear integrity/ thus preventing the hooked legs 20, 22 from being squashed or distorted. In order to reduce the effects of the welding heat, each of the closure elements 12 and 14 is provided with a pair of ribs 30 on the outside face remote from the legs 20. The respective ribs 3 0 are provided again at the margins of the closure, in alignment with the posts 24 and heel portions 28. The ribs 3 0 are provided by a thickening of the material of which each of the two elements is composed. Because of the additional bulk provided by the ribs 30, they also contribute to the resistance of the closure to deformation due to pressure. On each rib 30 there is provided a layer 32 of a material which is a high-performance sealing/welding material or blend of materials, such as EVA for example. This facilitates the welding of the zipper to the adjacent web or film 34. The layers 32 are co-extruded with the closure elements 12 and 14. The single long flange 16 which is part of element 12 is arranged to face the inside of the bag or container. This single flange 16 is used for initial attachment to the film or web 34 as the zipper is applied to the web by a cross-web technique. The provision of a single long flange provides increased internal strength to the bag by altering the angle at which the load in the bag acts against the zipper closure. The flange 16 is attached to the web or film 34 by the application of heat and pressure from a sealing jaw or jaws (not shown). The flange 16 could be provided on its surface adjacent to the web or film 34 with material to facilitate the attachment of the flange to the web or film. Although the invention has been described above in relation to a particular design of zipper, it is to be understood that the invention is not to be regarded as limited to this particular design of zipper, but can be applied to zippers of other designs and having ether configurations. WE CLAIM : 1. A rcclosablc fastener comprising a male/female closure between a pair of opposed base members, wherein a single flange for attachment of the closure to a web or film is provided on one only of the two base members and each base member has means to attach the fastener additionally to the w7eb or film. 2. A reclosable fastener as claimed in claim 1, in which the means for additional attachment comprise ribs on the base members, the ribs being arranged to be attached to the web or film. 3. A reclosable fastener as claimed in claim 2, in which the ribs are positioned at the margins of the respective base members. 4. A reclosable fastener as claimed in claim 2 or 3, in which a layer of sealant material is co- extruded on to each rib. 5. A reclosable fastener substantially as hereinbefore described with reference to the accompanying drawings. A reclosable fastener (10) comprising a male/female closure between a pair of opposed base members (18) has a single flange (16) for attachment of the closure to a web or film (34) on one only of the two base members. The fastener is attached initially to the film (34) by the single flange and then the fastener is additionally attached to the film (34) by heat and pressure applied in the region of attachment ribs (30) on the base members and each base member has means to attach the fastener additionally to the web or film.

Full Text

A RECLOSABLE FASTNER
Field of the invention
This invention relates to reclosable fasteners, otherwise known as zippers, for plastics bags
and other containers, and is particularly concerned with zippers intended to be applied to a film or
web using cross-web techniques.
Background of the invention
When a zipper strip is applied to a film or web, heat and pressure are applied to effect the
welding of the zipper to a film or web from which the bag or other container is to be made.
In order to secure the zipper to the film or web, the zipper is conventionally provided with a
plurality of flanges on the two interengageable members which together make up the fastener. The
most common practice is to provide four flanges, two on each member, in order to seal these flanges
to the film or web material on each side of the zipper. However, some zippers are provided with only
three flanges, and some with only two. Sealing at the flanges is effected in order to keep heat and
pressure away from the vulnerable male/female closure elements. However, it is a problem with such
multi flanged zippers that they tend to be bulky and do not easily deflect when used in cross-web
procedures.
Summary of the invention
It is an object of the present invention to overcome this problem, by providing a zipper which
is less bulky.
Accordingly the present invention provides for a reclosable fastener comprising a
male/female closure between a pair of opposed base members, wherein a single flange for attachment
of the closure to a web or film is provided on one only of the two base members and each base
member has means to attach the fastener additionally to the web or film.
The single flange is used to attach the zipper initially
to the web or film for subsequent sealing/welding of the
zipper to the web or film in the region of the base members,
by whatever means is appropriate.
Brief description of the/drawing
In order that the invention may be more fully understood,
one presently preferred embodiment of zipper in accordance
with the invention will now be described by way of example and
with reference to the accompanying drawing which is a
schematic cross-sectional view through the zipper.
Description of the preferred embodiment
Referring to the drawing, there is shown a zipper,
indicated generally at 10, comprising a first element 12 and
a second element 14. The two elements 12 and 14 are generally
the same as each other, apart from the fact that element 12
is provided with a single elongate flange 16. Each element
12, 14 comprises a base member or body portion 18 with two
upstanding legs 20 which terminate in hooks 22 . The
respective hooks 22 of the two elements 12 and 14 are
interengageable to make the reclosable fastener.
Each element 12, 14 also comprises an upstanding support
post 24 at one margin. The support post 24 is slightly longer
than the hooked legs 20, 2 2 so that it extends slightly beyond
the tops of the legs. The upper end surface 26 of each post
24 is tapered to provide an angled contact surface. Facing
each support post 24, on the opposing element, there is
provided a heel portion 28, again at the margin. The surface
of each heel portion 28 facing the respective post 24 is
shaped, i.e. angled, to be complementary to the angled contact
surface 26. As can be seen from the drawing, with this
arrangement, the respective posts and heels nest with one
another to provide a. shape-locking configuration which tends
to resist squashing or outward bending under vertical loads.
The angled contact surfaces are able to absorb the welding
pressure and maintain their linear integrity/ thus preventing
the hooked legs 20, 22 from being squashed or distorted.
In order to reduce the effects of the welding heat, each
of the closure elements 12 and 14 is provided with a pair of
ribs 30 on the outside face remote from the legs 20. The
respective ribs 3 0 are provided again at the margins of the
closure, in alignment with the posts 24 and heel portions 28.
The ribs 3 0 are provided by a thickening of the material of
which each of the two elements is composed. Because of the
additional bulk provided by the ribs 30, they also contribute
to the resistance of the closure to deformation due to
pressure. On each rib 30 there is provided a layer 32 of a
material which is a high-performance sealing/welding material
or blend of materials, such as EVA for example. This
facilitates the welding of the zipper to the adjacent web or
film 34. The layers 32 are co-extruded with the closure
elements 12 and 14.
The single long flange 16 which is part of element 12 is
arranged to face the inside of the bag or container. This
single flange 16 is used for initial attachment to the film
or web 34 as the zipper is applied to the web by a cross-web
technique. The provision of a single long flange provides
increased internal strength to the bag by altering the angle
at which the load in the bag acts against the zipper closure.
The flange 16 is attached to the web or film 34 by the
application of heat and pressure from a sealing jaw or jaws
(not shown). The flange 16 could be provided on its surface
adjacent to the web or film 34 with material to facilitate the
attachment of the flange to the web or film.
Although the invention has been described above in
relation to a particular design of zipper, it is to be
understood that the invention is not to be regarded as limited
to this particular design of zipper, but can be applied to
zippers of other designs and having ether configurations.
WE CLAIM :
1. A rcclosablc fastener comprising a male/female closure between a pair of opposed base
members, wherein a single flange for attachment of the closure to a web or film is provided on one
only of the two base members and each base member has means to attach the fastener additionally to
the w7eb or film.
2. A reclosable fastener as claimed in claim 1, in which the means for additional attachment
comprise ribs on the base members, the ribs being arranged to be attached to the web or film.
3. A reclosable fastener as claimed in claim 2, in which the ribs are positioned at the margins of
the respective base members.
4. A reclosable fastener as claimed in claim 2 or 3, in which a layer of sealant material is co-
extruded on to each rib.
5. A reclosable fastener substantially as hereinbefore described with reference to the
accompanying drawings.
A reclosable fastener (10) comprising a male/female closure between a pair of opposed base
members (18) has a single flange (16) for attachment of the closure to a web or film (34) on one only
of the two base members. The fastener is attached initially to the film (34) by the single flange and
then the fastener is additionally attached to the film (34) by heat and pressure applied in the region of
attachment ribs (30) on the base members and each base member has means to attach the fastener
additionally to the web or film.

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Patent Number

225250

Indian Patent Application Number

IN/PCT/2002/00397/KOL

PG Journal Number

45/2008

Publication Date

07-Nov-2008

Grant Date

05-Nov-2008

Date of Filing

26-Mar-2002

Name of Patentee

SUPREME PLASTICS HOLDINGS LIMITED. ,

Applicant Address

SUPREME HOUSE 300 REGENTS PARK ROAD, FINCHLEY, LONDON N3 2TL

Inventors:

#	Inventor's Name	Inventor's Address
1	OFFA-JONES, MARTIN JOHN CHARLES	4 FOURACRE DRIVE, SLEIGHTS, WHITBY, NORTH YORKSHIRE YO22 5HE

PCT International Classification Number

B65D 33/25

PCT International Application Number

PCT/GB2001/02976

PCT International Filing date

2001-07-05

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	0016894.8	2000-07-11	U.K.