NZ330422A - Web of thermoplastic material comprising spaced apart recloseable fasteners with interlocking profiles removable sealing means - Google Patents

Abstract

A reclosable plastic bag comprises a first sheet of plastic film material, a second sheet of plastic film material, joined to the first sheet at its entire perimeter and a reclosable fastener 1 of a kind having or including two self-interlocking profile strips 3, 4. Each profile strip 3, 4 is connected to an internal surface of one of the first or second sheets of plastic film in a position to overly an opening or region 7 capable of creating an opening in one of the first or second sheets of plastic film. A removable sealing means 10 overlies the entire opening or region 7 and is capable of creating an opening in one of the first or second sheets of plastic film on the exterior surface thereof.

Description

NEW ZEALAND PATENTS ACT, 1953 No: 330422 Date: 13 May 1998 COMPLETE SPECIFICATION "A Web with Re-Closeable Fastener Strip, Re-Closeable Packaging and/or Related Methods" We, AEP INDUSTRIES (NZ) LIMITED, a company duly incorporated under the laws of New Zealand of 100 Carbine Road, Mt Wellington, Auckland, New Zealand, do hereby declare this invention to be described in the following statement: INTEWECTUAL PROPEWOFFiCE OF N.Z. 1 3 MAY 1999 received The present invention relates to a web with re-closeable fastener strip, re-closeable packaging and/or related methods of sealing.

Existing re-closeable fastener strips and packaging which include such fastener strips are well known. Such existing strips are normally used to form part of packaging such as plastic bags and are normally located either at a distal end of a bag to define an openable mouth region at an edge, or are located within a panel of the packaging away from any of the edges. The development of such existing re-closeable strip fasteners and their applications in form-fill-seal machines is well documented in prior patent specifications. The discrete re-closeable fastener strip assemblies are normally produced from a continuous supply of material which has two longitudinal portions joined at self interlocking profiles. Discrete strips are usually separated from the feed of material by cutting in a transverse direction to the feed. Any regions of overlap of the two portions of the re-closeable fastener strip are usually heat sealed to each other at their distal ends. The formation of the re-closeable fastener strips may occur prior to their introduction to the machine to form the packaging or alternatively the source material for forming the re-closable fastener strip assemblies may form part of the machinery forming the packaging.

In the example where the known re-closeable fastener strip assemblies are located within a panel of the packaging away from any of the edges, the re-closeable fastener strip assembly is secured to the panel by heat or RF sealing or the like at the perimeter regions of each of the portions of the re-closeable fastener strip assembly. The current problem which exists in relation to the sealing of the perimeter of such closure means and packaging is that such perimeter sealing can not because of machine limitations extend across or at least terminate immediate to the self interlocking profiles. Indeed there is difficultly in achieving such perimeter heat sealing which extends sufficiently close to the self interlocking profiles to provide a moisture and/or oxygen tight closure for the packaging. The old packaging provided by the such known process results in the perimeter sealing of the re-closable fastening strip from leaving a gap at each end between such sealing and the self-interlocking profiles. Such gaps even when the self-interlocking profiles are engaged with each other leave sufficient room for moisture and/or oxygen and even fine food stuffs or the like to leak there through.

It is therefore an object of the present invention to provide a web with re-closeable fastener strip, re-closeable packaging and/or related methods of sealing which will at least overcome the abovementioned problems and/or provide the public with a useful choice.

Accordingly in a first aspect the present invention consists in a method for making reclosable bags comprising, providing a plurality of reclosable fasteners each with two self-interlocking profile strips and connecting them at bag length intervals to a rectangular sheet of film having two parallel side edges and a top and a bottom edge, each profile strip of each reclosable fastener being maintained in interlocked condition and each being connected to the same side of said film to overly an opening or region capable of creating an opening in said film, applying to the other side of said film a removable sealing means to overly the entire said opening or region capable of creating an opening in said film, overlapping said side edges of said film to form a tube to enclose said reclosable fasteners on the inside of said tube, said tube having a top edge and a bottom edge, sealing said overlapped side edges of said film, sealing said bottom edge of said tube, and sealing said tube said single bag length from said bottom edge to form a top edge of said bag to enclose a single reclosable fastener.

Preferably said reclosable fasteners are connected to said film normal to the sides of said sheet and wherein said width (side to side) of said film is more than twice that of the length of said reclosable fasteners.

Preferably said removable sealing means is releaseably secured to said film by an adhesive and/or peelable heat seal.

Preferably said removable sealing means is releaseably secured to said film at substantially the entire perimeter of said removable sealing means, save for a region which provides a tab to be grasped by a digit of a user.

Preferably said removable sealing means is releaseably secured to said film at substantially the entire surface located against said film, save for a region which provides a tab to be grasped by a digit of a user.

In a further aspect the present invention consists in an elongate (whether in a rolled or lie flat condition) web of thermoplastic material for the forming of plastic packaging by forming a tube from said web, sealing the longitudinal edges together and subsequent and sequential bag length separation of discrete packs from said elongate web, said elongate web comprising; a plurality of re-closeable fastener each spaced a bag length from an adjacent of said re-closeable fastener said re-closeable fasteners being of a kind each consisting of two substantially parallel thermoplastic strips having along their length self-interlocking profiles to engage said two substantially parallel thermoplastic strips in a partial overlap and engaged condition, said two substantially parallel thermoplastic strips of each said re-closeable fasteners each engaged on one major surface of the web of thermoplastic material overlying an elongate opening (whether an opening or a perforated openable region) of said thermoplastic material, a plurality of removable sealing means releaseably secured to the other said major surface of said web of thermoplastic material and each overlying a said opening.

Preferably said re-closeable fasteners are secured to a major surface of said web by heat and/or RF sealing.

Preferably said removable sealing means is a strip of thermoplastic material which overlies said opening, and is removably attached to said web by either releasable heat sealing and/or adhesive.

Preferably the removable sealing means is adhered to said thermoplastic material save for a region adapted to provide a tab or the like for the grasping and aid in removal of said removable sealing means.

In a further aspect a re-closeable plastic pack of a kind having an openable mouth region in a wall of said pack which is selectively openable by an elongate re-closeable fastener of a kind consisting of two substantially parallel thermoplastic elongate strips having self-interlocking elongate profiles to engage said two substantially parallel thermoplastic strips in a partial overlap and engageable condition, said two substantially parallel strips engaged to said thermoplastic material internally of said pack about said mouth region, a removable sealing means releaseably secured the outside of said pack and located to overlie said mouth region.

Preferably said removable sealing means is a strip of thermoplastic material, and is removably attached to said web by either releasable heat sealing and/or adhesive.

Preferably there is provided one said re-closeable fastener strip on an internal surface of said re-closeable pack.

In still a further aspect the present invention consists in a method for making a rectangular film material for the manufacture of reclosable bags formed by overlapping and sealing side edges of said film to form a tube, said tube having a top edge and a bottom edge, sealing said bottom edge of said tube, and sealing said tube said a bag length from said bottom edge to form a top edge of said bag said method comprising, providing a plurality of reclosable fasteners each with two self-interlocking profile strips and connecting them at bag length intervals to said rectangular sheet of film, each profile strip of each reclosable fastener being maintained in interlocked condition and each being connected to the same side of said film to overly an opening or region capable of creating an opening in said film, applying to the other side of said film a removable sealing means to overly the entire said opening or region capable of creating an opening in said film.

In even a further aspect the present invention consists in a reclosable plastic bag comprising, a first sheet of plastic film material, a second sheet of plastic film material, joined to said first sheet at its entire perimeter, a reclosable fastener of a kind having or including two self-interlocking profile strips each profile strip connected to an internal surface of one of said first or second sheets of plastic film in a position to overly an opening or region capable of creating an opening in one of the said first or second sheets of plastic film, a removable sealing means to overly the entire said opening or region capable of creating an opening in one of the said first or second sheets of plastic film on the exterior surface thereof.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

One preferred form of the present invention will now be described with reference to the accompanying drawings in which; Figure 1 is a plan view of a web of material (preferably thermoplastic material) which as a feed stock for the making of packaging, has associated therewith a plurality of the re-closeable fastener strips, Figure 2 is a perspective view of a packaging of the present invention in a lie flat condition which has been formed from for example the web of material as shown in figure 1, Figure 3 illustrates a perspective view of a packaging of the present invention having contents such as food products or the like where in the packaging is in a moisture and air tight sealed condition, Figure 4 is a planned view of a portion of the web of material of figure 1 prior to the re-closable fastener strip and sealing means having been applied, Figure 5 is a sectional view at section AA of figure 2 save for the sealing means, Figure 6 is a more detailed view of the region of the re-closeable fastener strip saved for the sealing means being illustrated, Figure 7 is a sectional view through section AA of figure 2 wherein the sealing means is also illustrated, Figure 8 is perspective view of a roll of web material having said removable sealing means attached, and Figure 9 is a perspective view of part of a package and shown in partial cross section the region at the re-closeable element and the removable sealing means.

In Figure 1 there is illustrated a web of material of undefined length on which re-closeable strip fasteners are located at preferably equally spaced intervals. The longitudinal direction of the web of material defines the mouth to bottom direction of packages made from the material of this nature. Hence the re-closeable strip fasteners are located at substantially bag length, top to bottom, intervals. The web of material is preferably of a thermoplastics material and its geometry and spacing of the re-closeable fastener strips are such as to provide re-closeable packaging of a desired shape. Such materials may for example be polyester, polypropylene, polyethylene or laminated arrangements thereof. It must be appreciated the present invention is not limited to such material choices as many alternative materials suitable for making packages utilising the present invention are suitable.

As illustrated in figure 2, the re-closeable packaging formable from the web of material of figure 1 has preferably the re-closeable fastener strip 1 located laterally to the general longitudinal direction of the web of material from which the packaging was formed.

The web of material is preferably provided to a packaging forming machine in a roll form. Alternative to the re-closeable fastener strip being located across the general longitudinal direction, such re-closeable fastener strips may be provided on the web of material to be substantially parallel with the general longitudinal direction.

The re-closeable packaging 2 of the present invention as shown in figure 2 is preferably rectangular in shape however it must be appreciated that this invention is not necessarily limited to such packaging being rectangular, square or the like and other geometric shapes are envisaged.

The re-closeable strip fastener forming part of the packaging or of the web to form such packaging consists of two strip portions 3,4 which have complementary self-interlocking profiles 5,6. With reference to figure 5 it can be seen that the self- interlocking profiles are engageable with each other to engage the portions 3 and 4 with each other. Many alternative profile shapes are known and as illustrated in figure 5 the preferred form is a double profile. The web or the packaging of the present invention is preferably provided with a mouth region 7 through which contents of the packaging may be removed or added. The mouth region of the present invention may be a slot (provided eg by the cutting of a portion of the web) or may alternatively be a perforate region (or any other like, one time openable region) such that a mouth region may be created by the breaking of the perforations.

The mouth region is made re-closeable by the re-closeable strip fastener 1.

As the re-closeable strip fastener is in its normal form provided and cut from a roll of supply material to provide a discrete fastener, the cross sectional shape of the re-closeable fastener strip 1 remains consistent.

The provision of a discrete re-closeable fastener strip from such a roll of material usually involves the cutting of an appropriate length diagonal across the general longitudinal direction of the strips, there after (whether it is in situ or prior to it being applied to a packaging), the heat sealing of the end regions such that the two portions 3, 4 are sealed together. This sealing takes place across the distal ends of the self-interlocking profiles 5,6, and or the remaining flange portions of each strip portion.

The re-closeable fastener strip of the present invention is made to overlie the mouth region 7 such that when the self-interlocking profiles 5,6 are separated from each other (ie open) access is gained to the interior of the packaging (or the packaging to be formed from the web). In that alternative of the present invention where the mouth region can be provided by severing the perforations or the like, access to the interior of the packaging will be gained once the perforations are severed.

In the preferred form as can be seen in figures 5 and 7 the re-closeable strip fastener is preferably located on the interior of a re-closeable packaging. Where the present invention is providing a web of material for the forming of packaging, the re-closeable fastener strip is preferably located on one side of such a web of material.

With reference to figure 6 the re-closeable fastener strip is sealed (either by adhesive, heat sealing, rf sealing, ultrasonic welding or the like) to a web of thermoplastic material such as to overlie the mouth region 7. The sealing region 8 is usually at or near the outer lying perimeter of each of the strip portions 3,4. Such sealing could be termed a "race track like seal". In the form of the invention shown in figure 6, the race track like seal is not continuous due to the in situ sealing of the re-closeable fastener strip to the web of material. As can be seen in figure 6 the seal 8 is discontinuous at regions adjacent the self-interlocking profiles 5,6. Such regions of discontinuity create gaps 9 through which material within the packing is able to flow. Furthermore such gaps are also an opening to oxygen/moisture and the like.

To this extent the packaging and/or web of the present invention is provided with a removable sealing means 10 which overlies at least the mouth region 7 of the packaging preferably on the side of the web opposite to which the re-closeable fastener strip is located. Such a removable sealing means 10 is provided to the packaging and/or the web of material to form the packaging to ensure that a package product is delivered to its end destination/use (eg two households or the like) without any of the contents having leaked and without there having been any moisture or oxygen leakage through the mouth region in/out of the packaging. The removable sealing means is preferably a strip and is preferably attached to the packaging to overlie the mouth region by a suitable adhesive and/or heat sealing. The method of adhesion may be applied to the entire removable sealing means such that it adheres on its entire surface to the plastic packaging and/or web of material or may alternatively be a peripheral like seal to ensure that such removable sealing means is peripherally sealed about the mouth region 7. In the preferred form however the removable sealing means is provided with adhesion on its entire surface save for a small portion which is to act as a tab or the like to aid in the removal of the removable sealing means once access to the contents of the packaging is desired. It also envisaged by the inventor of this invention that the removable sealing means may only be partly removable from the package. It may indeed be a flap which with the method of adhesion remains in contact and overlies the mouth region 7 but is removable from the mouth region in such a fashion as to provide a flap which remains partially secured to said web of material. The method of adhesion may then be such as to allow for the removable sealing means to reseal over the mouth region. In this alternative along with the re-closeable fastening strip, the package can be resealed to substantially the same condition.

In the version of the invention where the removable sealing means is attached to the web by adhesive, a suitable peelable adhesive may be used. Such a peelable adhesive needs to be selected to be suitable for the materials of both the removable sealing means and the web of material.

The removable sealing means maybe of any suitable plastics material or plies of plastics material which are for example co-extruded or laminated. Furthermore the removable sealing means may also be a paper/plastic laminate or the like.

The opening to the web of material as mentioned is preferably a perforated line which is severable. With reference to Figure 4 the line is preferably provided with an upstand region 11 which aids and assists in the severing of the perforated line by allowing a digit of a user of the bag to grasp this region. This upstand region 11 may itself also be perforated or may alternatively be a continuous cut in the web of material.

Claims (9)

WHAT WE CLAIM IS:

1. A method for making reclosable bags comprising, t /? ^ v providing a plurality of reclosable fasteners each with two self-interlocking profile strips and connecting them at bag length intervals to a rectangular sheet of film having two parallel side edges and a top and a bottom edge, each profile strip of each reclosable fastener being maintained in interlocked condition and each being connected to the same side of said film to overly an opening or region capable of creating an opening in said film, / -- applying to the other side of said film a removable sealing means to overly the entire said opening or region capable of creating an opening in said film, overlapping said side edges of said film to form a tube to enclose said reclosable fasteners on the inside of said tube, said tube having a top edge and a bottom edge, sealing said overlapped side edges of said film, sealing said bottom edge of said tube, and sealing said tube said single bag length from said bottom edge to form a top edge of said bag to enclose a single reclosable fastener.

2. A method for making reclosable bags as claimed in claim 1 wherein said reclosable fasteners are connected to said film normal to the sides of said sheet and wherein said width (side to side) of said film is more than twice that of the length of said reclosable fasteners

3. A method for making reclosable bags as claimed in claim 1 or 2 wherein said removable sealing means is releaseably secured to said film by an adhesive and/or peelable heat seal.

4. A method for making reclosable bags as claimed in any one of claims 1 to 3 wherein said removable sealing means is releaseably secured to said film at substantially the entire perimeter of said removable sealing means, save for a region which provides -12- sealing means is adhered to said thermoplastic material save for a region adapted to provide a tab or the like for the grasping and aid in removal of said removable sealing means. 10. A re-closeable plastic pack of a kind having an openable mouth region in a wall of said pack which is selectively openable by an elongate re-closeable fastener of a kind consisting of two substantially parallel thermoplastic elongate strips having self-interlocking elongate profiles to engage said two substantially parallel thermoplastic strips in a partial overlap and engageable condition, said two substantially parallel strips engaged to said thermoplastic material / internally of said pack about said mouth region, a removable sealing means releaseably secured the outside of said pack and located to overlie said mouth region. 11. A re-closeable plastic pack as claimed in claim 10 wherein said removable sealing means is a strip of thermoplastic material, and is removably attached to said web by either releasable heat sealing and/or adhesive. 12. A re-closeable plastic pack as claimed in claim 10 or 11 wherein there is provided one said re-closeable fastener strip on an internal surface of said re-closeable pack. 13. A method for making a rectangular film material for the manufacture of reclosable bags formed by overlapping and sealing side edges of said film to form a tube, said tube having a top edge and a bottom edge, sealing said bottom edge of said tube, and sealing said tube said a bag length from said bottom edge to form a top edge of said bag said method comprising, providing a plurality of reclosable fasteners each with two self-interlocking profile strips and connecting them at bag length intervals to said rectangular sheet of film, each profile strip of each reclosable fastener being maintained in interlocked condition and each being connected to the same side of said film to overly an opening or region capable -11 - a tab to be grasped by a digit of a user.

5. A method for making reclosable bags as claimed in anyone of claims 1 to 13 wherein said removable sealing means is releaseably secured to said film at substantially the entire surface located against said film, save for a region which provides a tab to be grasped by a digit of a user.

6. An elongate (whether in a rolled or lie flat condition) web of thermoplastic material for the forming of plastic packaging by forming a tube from said web, sealing the longitudinal edges together and subsequent and sequential bag length separation of discrete packs from said elongate web^ said elongate web comprising; ' I a plurality of re-closeable fastener each spaced a bag length from an adjacent of said re-closeable fastener said re-closeable fasteners being of a kind each consisting of two substantially parallel thermoplastic strips having along their length self-interlocking profiles to engage said two substantially parallel thermoplastic strips in a partial overlap and engaged condition, said two substantially parallel thermoplastic strips of each said re-closeable fasteners each engaged on one major surface of the web of thermoplastic material overlying an elongate opening (whether an opening or a perforated openable region) of said thermoplastic material, a plurality of removable sealing means releaseably secured to the other said major surface of said web of thermoplastic material and each overlying a said opening.

7. An elongate web as claimed in claim 6 wherein said re-closeable fasteners are secured to a major surface of said web by heat and/or RF sealing.

8. An elongate web as claimed in claim 6 or 7 wherein said removable sealing means is a strip of thermoplastic material which overlies said opening, and is removably attached to said web by either releasable heat sealing and/or adhesive.

9. An elongate web as claimed in anyone of claims 6 to 8 wherein the removable 4'id - 13 - of creating an opening in said film, applying to the other side of said film a removable sealing means to overly the entire said opening or region capable of creating an opening in said film. 14. A reclosable plastic bag comprising, a first sheet of plastic film material, a second sheet of plastic film material, joined to said first sheet at its entire perimeter, a reclosable fastener of a kind having or including two self-interlocking profile strips each profile strip connected to an internal surface of one of said first or second sheets of plastic film in a position to overly an opening or region capable of creating an opening in one of the said first or second sheets of plastic film, a removable sealing means to overly the entire said opening or region capable of creating an opening in one of the said first or second sheets of plastic film on the exterior surface thereof. INTELLECTUAL PROPERTY OFFICE OF N.Z. 1 3 MAY 1999 H:\library\patents\djj\ahb\386268.ahb RECEIVED