WO2004043811A1

WO2004043811A1 - Zipper bag

Info

Publication number: WO2004043811A1
Application number: PCT/GB2003/004851
Authority: WO
Inventors: James Laing Murray
Original assignee: Supreme Plastics Holdings Limited
Priority date: 2002-11-13
Filing date: 2003-11-10
Publication date: 2004-05-27
Also published as: AU2003282223A1; GB0226388D0

Abstract

The bag is formed from a single folded sheet (10) of plastics material. The sheet (10) is folded to form an internal gusset (12), the walls of which are releasably secured to each other by interengaging zipper profile strips (16a, 16b). A weld (20) closes the top of the bag. The gusset (12) has a circular zone (14 in figure 2) formed by perforations in the gusset. The contents of the bag are introduced through the open, bottom end of the bag opposite the gusset (12). The bottom of the bag is then sealed. The contents are accessed by cutting off the upper sealed edge to gain access to the zipper seal. After opening the zipper seal, the material of the circular zone is removed to provide access to the contents of the bag and thereby constitutes a tamper-evident feature. Perforations may be provided below the weld (20) to facilitate removal of the upper sealed edge of the bag.

Description

ZIPPER BAG

This invention relates generally to recloseable plastics bags and like containers, and more particularly to such bags and containers which incorporate a tamper-evident feature. The invention is also concerned with methods of making such bags and like containers. The invention is more particularly concerned with plastics bags and like containers which are intended to hold moist contents, where it is important that the contents do not dry out and where the user is likely to remove the contents one by one over an extended period of time, such as in the case of moist wipes. Plastics bags for such goods are often provided with a slider by means of which the user can open and close the bag to remove the contents. However, the use of sliders gives rise to problems in manufacture and increases the cost of manufacture.

It is an object of the present invention to provide an improved plastics bag or like container, especially for moist contents, which can be manufactured at lower cost and which avoids the need for the use of a slider.

It is a further object of the invention to provide a plastics bag or like container which although recloseable also incorporates a tamper-evident feature, and also includes means to restrict loss of moisture from moist contents within the bag.

Broadly in accordance with the present invention there is provided a plastics bag or like container which comprises a gusset which serves as a baffle between the contents and a recloseable fastener which is provided across the bag, wherein the gusset is provided with a removable portion which, when removed, allows restricted access to the contents within the bag.

Preferably, the baffle is formed as a pouch on the inside of the recloseable fastener with a zone which is arranged to be removed for access to the contents. The zone can be formed by perforations or serrations through the material of the gusset. The zone preferably has a closed-loop shape, more preferably a circular shape, but may have a shape other than that of a closed loop. Also in accordance with the invention there is provided a method of manufacturing a tamper-evident recloseable plastics bag or like container which comprises folding a plastics sheet or film to create an internal gusset, providing a recloseable fastener across the width of the bag on the outside of the gusset, and providing in the material of the gusset a zone which can be removed for access to the contents.

Preferably, a further weld is applied across the width of the bag on the outside of the recloseable fastener.

Advantageously, the bag has a row of perforations through the sheet material to form a tear line between the weld and the reclosable fastener.

In a preferred embodiment of the method, cutting means are used to create perforations or serrations through the material of the gusset to form the zone which is removable by the user for access to the contents of the bag.

In order that the invention may be more fully understood, one presently preferred embodiment of recloseable plastics bag in accordance with the invention will now be described by way of example and with reference to the accompanying drawings. In the drawings:

Fig. 1 is a schematic side view of the bag during the course of manufacture;

Fig. 2 is a schematic plan view of the bag as shown in Fig. 1, to illustrate the removable zone within the baffle; Fig. 3 is a schematic side view of the bag at a further advanced stage in the manufacturing process; and

Fig. 4 is a schematic side view of the completed bag.

Referring to the drawings, there is shown a partially completed bag for holding moist contents, such as wipes, where it is important that the contents are not allowed to dry out and where the contents are likely to be removed by the user one at a time from the pack. As shown most clearly in Fig. 1, the bag is formed from a single folded sheet 10 of plastics material. The sheet 10 is fed from a wound drum or roll (not 5 shown) of sheet material. The sheet is wound over an "A" frame in a manner well known to one skilled in the art, so as to form an internal gusset, as indicated generally at 12, which serves as a baffle. During the folding operation a sharp jaw or other cutting means (not shown but well known to

10 one skilled in the art) is used to create two half-moon or semi-circular serrations which together form a serrated circle 14 as shown in Fig. 2. By the provision of perforations or serrations in this way, this zone encompassed by the perforations or serrations can be removed by the user when the

15 bag is first opened. It thus constitutes a tamper-evident feature .

After the gusset 12 has been formed, a sliderless recloseable fastener in the form of male and female closure elements 16a and lβb is inserted into the gusset and the

20 fastener elements 16a, 16b are welded to the sheet material. Fig. 2 indicates the usable baffle area 18, delimited by imaginary transverse lines 18a, 18b, between the fastener elements 16a and 16b.

After the recloseable fastener 16a, 16b has been welded

25 in place, a further hot or cold weld 20 is applied above the recloseable fastener to close off the top of the bag. This is most clearly illustrated in Fig. 3.

In order to gain access to the contents 24 (for example, a stack of moist wipes) of the bag the user will cut off the

30 outer sealed edge, and can then use the residual flaps to pull the recloseable fastener 16a, 16b apart, thereby to expose the baffle 12 and the removable zone 14. After removal of the zone 14 the contents 24 can then be removed one at a time and the bag can be re-closed using the recloseable fastener 16a,

35 16b. The end of the bag opposite to the end which is provided with the baffle is shown in the drawings as open, with a lip 22 on one side. This is to enable the partially completed bag to be filled with the contents 24 from this open end. After addition of the contents 24, the bag is sealed by a further transverse hot or cold weld 26 whch seals the lip 22 to the opposite bag wall formed by the sheet 10. The finished bag shown in Fig. 4 of the drawings is thus formed.

It should be understood that although the removable zone 14 is shown as circular in the drawings, any other alternative shape could be used, so long as it provides restricted access to the interior of the bag, to reduce loss of moisture from the contents .

Additionally, the top end of the bag can be provided with a respective row of perforations 28a, 28b through the sheet material of the bag wall and the gusset 12 on each side, just below the top seal 20, so that the top seal portion can initially be torn off from the completed bag instead of having to be cut off by the user.

Claims

CLAIMS :

1. A plastics bag or like container which comprises a gusset which serves as a baffle between the contents and a recloseable fastener which is provided across the bag, wherein the gusset is provided with a removable portion which, when removed, allows restricted access to the contents within the bag .

2. A plastics bag or like container according to claim 1, wherein the baffle is formed as a pouch on the inside of the reclosable fastener.

3. A plastics bag or like container according to claim 1 or 2, wherein the removable portion is formed by perforations or serrations through the material of the baffle.

4. A plastics bag or like container according to any preceding claim, wherein the removable portion has a closed- loop shape.

5. A plastics bag or like container according to claim 4, wherein the removable portion is circular.

6. A plastics bag or like container according to any preceding claim, wherein the walls of the bag and/or the gusset are sealed together outwardly of the reclosable fastener, to form a portion of the bag which must be removed to gain access to the reclosable fastener.

7. A plastics bag or like container according to claim 6, wherein the walls of the bag and/or the gusset have respective lines of perforations facilitating removal of the removable portion.

8. A method of manufacturing a tamper-evident recloseable plastics bag or like container which comprises folding a plastics sheet or film to create an internal gusset, providing a recloseable fastener across the width of the bag on the^' outside of the gusset, and providing in the material of the gusset a zone which can be removed for access to the contents .

9. A method according to claim 8, wherein a further weld is applied across the width of the bag on the outside of the reclosable fastener.

10. A method according to claim 9, wherein respective lines of perforations are formed in the walls of the bag and/or the gusset between the further weld and the reclosable fastener to define a portion of the bag which must be removed to gain access to the reclosable fastener.

11. A method according to any of claims 8 to 10, wherein perforations or serrations are formed in the material of the gusset to form the zone which is removable by the user for access to the contents of the bag.

12. A plastics bag or like container substantially as hereinbefore described with reference to the drawings.

13. A method of manufacturing a plastics bag or like container, the method being substantially as hereinbefore described with reference to the drawings.