WO1997019857A2

WO1997019857A2 - A method of forming a recloseable bag and/or a recloseable bag

Info

Publication number: WO1997019857A2
Application number: PCT/NZ1996/000132
Authority: WO
Inventors: John Charles Welton Hogg; Arthur Graydon Gillingham; Rodney Ernest Sullivan; Neill Peter Gillespie
Original assignee: Minigrip Flexible Packaging Limited
Priority date: 1995-11-30
Filing date: 1996-11-28
Publication date: 1997-06-05
Also published as: WO1997019857A3; AU7713496A

Abstract

The invention comprises a method of forming a recloseable bag comprising the steps of providing a tape or tapes or strip or strips such as a reclosure tape (10) in the form of an elongated base member having thereon substantially parallel spaced apart elongated co-operating closure members (12, 13) and providing packaging material in the form of a sheet of flexible material (4). The reclosure tape (10) and the packaging material (4) are engaged so that the longitudinal axes of the reclosure tape (10) and the packaging material are substantially parallel; and the packaging material (4) with the reclosure tape (10) attached is then formed into individual bags, each bag having the reclosure tape (10) thereon. The attachment is made in the preferred form on form fill packaging apparatus (2).

Description

A Method of Forming a Recloseable Bag and/or a Recloseable Bag

A method of forming a recloseable bag using recloseable tape and/or a recloseable bag formed by that method.

Background of the Invention

There is a continuing need to develop effective methods of attaching reclosure elements to bags, particularly plastic bags, although the invention can be used with other types of bags if required. The reclosure element should be able to be fixed simply and securely and in particular minimise the possibility of leakages in the constructed bag. It would also be desirable to provide a method of fitting the reclose elements to machinery that is pre-existing for forming bags. One particular area where this would be desirable would be in the area of vertical form and fill packaging equipment.

Object

It is therefore an object of the present invention to provide a method of forming a bag and/or a bag which will go some distance towards meeting the foregoing requirements in a simple yet effective manner or which will at least provide the public with a useful choice.

Summary of the Invention

Accordingly in one aspect the invention consists in a method of forming a recloseable bag comprising the steps of; providing a tape or tapes or strip or strips comprising an elongated base member;

providing packaging material in the form of a sheet of flexible material;

engaging said tape or tapes or strip or strips and said packaging material so that the longitudinal axes of said tape or tapes or strip or strips and the packaging material are substantially parallel; and

forming the packaging material into individual bags, each bag having the tape or tapes or strip or strips thereon.

Preferably the method further includes filling the bag at least before the bag and tape or tapes or strip or strips are separated from the following packaging material and following reclosure tape.

Preferably said bags are formed on form fill apparatus.

Preferably the tube of the form fill apparatus is used as an anvil against which the tape or tapes or strip or strips is applied to the material.

Alternatively the tape or tapes or strip or strips is applied to the material before the material reaches the form fill tube.

Preferably the material is lapped about the tube and the tape or tapes or strip or strips is applied at one of 90°, 180° or 270° from the lapped position.

Preferably the tape or tapes or strip or strips include re-closure elements.

Preferably the co-operating closure members are inter-engaged before the tape is engaged with the packaging material so that in cross section the tape has an adhered section at each side edge of the tape and an unadhered section between the adhered sections. Preferably the packaging material is provided with a line of perforations or line of weakened material and the tape is positioned so that the line of perforations or line of weakened material is positioned adjacent the unadhered part of the tape.

In a further aspect the invention may broadly be said to consist in a package when formed by a method according to any one of the preceding paragraphs.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

Brief Description of the Drawings

One preferred form of the invention will now be described with reference to the accompanying drawings in which,

Figure 1: is a diagrammatic representation of one form of the method of the invention,

Figure 2: is a diagrammatic representation of an altemative embodiment of the invention,

Figure 3: is a cross section through part of a bag or package formed according to the methods of figures 1 or 2,

Figure 4: is a diagrammatic cross sectional view of the method at

AA in figure 1 or BB in figure 2, and

Figs 5, 6 and 7: are diagrammatic cross sectional views of altemative embodiments of the invention. Modes for Carrying Out The Invention

Referring to the drawings form and fill apparatus such as vertical form fill apparatus is provided for forming and filling bags, for example, plastic bags such as the bag indicated at 1. The vertical form fill apparatus, as is standard, provides a vertical tube 2 through which the material to be packaged is deposited in the direction of arrow 3 and flexible packaging material such as sheet plastics material 4 drawn from a roll (not shown) is provided and formed about the tube 2 into a tubular form. The edges 5 and 6 of the packaging material are in the embodiment shown lapped as at 7 but other connection methods can be used.

The bags are therefore initially in the form of a tube and are sealed and cut by standard reciprocating sealing plates 8 again substantially in the known manner.

A tape or tapes or strip or strips are provided. In Figure 1 a reclosure tape 10 of elongated form is provided and the reclosure tape has a base section 1 1 and co¬ operating engagement members 12 and 13. The member 12, for example, may be in the form of an elongated groove having a narrow mouth and the member 13 may be in the form of a bulbous member which is a snap fit into the groove in the member 12. The elements 12 and 13 are therefore spaced apart on the base 11 and substantially parallel. This is a known construction. The reclosure tape, often known as a "zipper", is affixed to the packaging material 4 so that the longitudinal axis of the reclose tape and the longitudinal axis of the bag forming material are substantially parallel. The elements 12 and 13 are desirably closed before the tape is applied to the packaging 4 so that the correct register of the tape is achieved during connection. Although the closed "zipper" is preferable the invention could be performed with an open "zipper" or even two strips 17 as shown in figure 6. In Figure 7 the strips 18 are extended upwardly and sealed in the area 19. The connection as can be seen from figure 4 is desirably such that the tape has an adhered section 15 adjacent each side edge of the tape and the nonadhered section at 16 between the adhered sections 15. The adherence between the tape and the packaging material may be in any known form, for example, by the use of suitable glues or adhesives or by heat welding or otherwise as required. The tape can pass adjacent a pressure device such as, for example, rollers which in the case of figure 1 may be in the area 20 of the tube so that the tube itself is used as an anvil against which the pressure is applied. In the construction of figure 2 pressure may be applied in the area 21, for example, and this can be achieved by providing suitable pressure members and an anvil each side of the packaging material 4. In the embodiment of figure 5 the tape 10 has no reclose element.

The tapes 10 can be applied at any position on the packaging material 4 but if a line from the centre of the tube to the join 7 is considered as 0° then desirably the tapes are positioned at 90°, 180° or 270° from the join, for example, the lapped join 7. The positions of 90° and 270° have some advantage in that it is possible to use the construction with a pre-existing vertical form fill machine without moving the position of the sealing and cutting bars 8 which is desirable. If any other position is chosen such as 180° ie. directly opposite the seam at 7, then it would usually be necessary to rotate the position of the sealing bars 8 so as to provide the tape at a suitable edge of the bag that is to say in particular the edge of the bag which will become the opening in use. If the tape has a non heat sealable extemal surface then rotation of jaws would not be necessary even if the tapes are applied at 180° to the position of the join.

Once applied the construction will substantially have the configuration shown in figure 3 with the tape 10 adhered to the bag material 4 with a bridge 23 of the bag material below the elongated closure members 12 and 13. The area at the bridge 23 can be provided with perforations or a weakened line 24 if desired. In further alternatives a tear strip or other construction could be provided if desired.

In each embodiment of Figures 3 to 7 the constructions provide a tamper evident feature as attempts to open the bag will be evident either on the tape 10 or strips 17 or 18, or the bag material 4. The use of the invention is as follows.

In use the bags are made on a vertical form fill apparatus substantially in the known manner. The tape is positioned as above described and becomes positioned at the position of the bag which it is intended to open. When a consumer, for example, wishes to open the package 1 formed they can tear through the tape, for example, by using a knife or scissors or a tear strip or otherwise as provided and then open the reclose elements. The bridge 23 is then torn through, for example, by means of a line of perforations or tear strip or other weakened line and the contents of the bag are then accessible. The bag can be substantially reclosed by reclosing the reclose elements 12 and 13.

Thus it can be seen that a method of forming a bag and/or a bag are provided which have some advantages. At least in the preferred form the tape is simple to apply and it is a particular advantage of the construction that the apparatus can be provided as a retro fit to existing vertical foπn fill machinery. Methodology also allows a high percentage of satisfactory seals to be achieved.

Claims

CLAIMS:

1. A method of forming a recloseable bag comprising the steps of;

providing a tape or tapes or strip or strips comprising an elongated base member;

providing packaging material in the form of a sheet of flexible material;

2. A method as claimed in claim 1 wherein the method further includes filling the bag at least before the bag and tape or tapes or strip or strips are separated from the following packaging material and following tape or tapes or strip or strips.

3. A method as claimed in either claim 1 or claim 2 wherein said bags are formed on form fill apparatus.

4. A method as claimed in claim 3 wherein the tube of the form fill apparatus is used as an anvil against which the tape or tapes or strip or strips is applied to the material.

5. A method as claimed in claim 3 wherein the tape or tapes or strip or strips is applied to the material before the material reaches the form fill tube.

6. A method as claimed in any one of claims 3 to 5 wherein the material is lapped about the tube and the tape or tapes or strip or strips is applied at one of 90°, 180° or 270° from the lapped position.

7. A method as claimed in any one of the preceding claims wherein the tapes or tapes or strip or strips include reclosure elements.

8. A method as claimed in claim 7 wherein the co-operating closure members are inter-engaged before the tape or tapes or strip or strips is engaged with the packaging material so that in cross section the tape or tapes or strip or strips has an adhered section at each side edge of the tape or tapes or strip or strips and an unadhered section between the adhered sections.

9. A method as claimed in any one of the preceding claims wherein the packaging material is provided with a line of perforations or line of weakened material and the tape or tapes or strip or strips is positioned so that when the tape or tapes or strip or strips has been adhered to the bag the line of perforations or line of weakened material is positioned adjacent the unadhered part of the tape or tapes or strip or strips.

10. A method of forming a recloseable bag substantially as herein described with reference to the accompanying drawings.

1 1. A package when formed by a method according to any one of the preceding claims.