GB2190065A - Collated stacks of web articles - Google Patents

Abstract

A stack of articles, e.g. plastics cash bags 10, is kept together by releasable adhesion between adjacent pairs of articles. Preferably this uses pairs of dots 33 (1.0-1.5mm diameter) of pressure sensitive adhesive on the cuff portions EFIJ of the bags. In use, bags 10 can be peeled off, and are not substantially contaminated with adhesive. <IMAGE>

Description

SPECIFICATION Collated stacks of web articles The present invention relatesto collated stacks of web articles, by which is meant articles composed largely of web materials such as paper or plastics films; and particularly to pocket-like articles. It is particularly concerned with stacks of bags, and especially cash bags of plastics materials.

Plastics bags, particularly those manufactured from LDPE (low density polyethylene) are notoriously difficultto deal with, for producer and user alike. Such bags tend to be floppy and slippery, so that a bundle if not controlled soon becomes an untidy heap which is difficultto reorganise. To avoid this, bags may be provided as an elongate web wound on a reel with lines of perforations across the web adjacent the end seal of each bag. This is only practicable for simple bags. In any case the result is bulkyand requires a special support. Alternatively stacks may be formed of bags each of which has an apertured extension flap (generally a continuation of the backwall). The stack is suspended by means of the apertures. Individual bags are torn free, along tear lines in the flap. The flap material is wasted; and once again a special support is needed.

One particular form of plastics bag is a cash bag.

Examples are described in UK patents Nos.

1,269,517, 1,334,831 and 1,359,099. Cash bags are at present produced in accordance with these patents in a production process which terminates with the bags falling into compartments whence they are manually picked up in bundles of about 100 bags and secured with rubber bands. The bundles are placed in cardboard boxes for delivery to customers. If the bands break, untidy jumbles result. The manual collection means that the process cannot readily be speeded up.

Such cash bags are of relatively complex shape and it would not be easy to manufacture them as continuous webs or with headers (which would in any case have disadvantages as previously described).

According to the invention there is provided a collated stack of discrete individual pocket-like web articles wherein adjacent articles are separably adhered together, preferably with pressure sensitive adhesive.

The articles may be bags, particuarly plastics bags.

The invention is particularly applicable to cash bags.

The articles are preferably adhered by means of adhesive engaging a minor proportion of a major surface of each article. Thus articles may have one or more areas of adhesive applied, e.g. in the form of strips or spots. Small spots are preferred, especially a pairofspotswhich may be of diameter 1 to 1 1/2mm when applied (spreading out when articles are urged together). These can suffice to keep the bags together during normal handling, while permitting easy separation. Furthermore a separated bag bears only a tiny, almost unnoticeable quantity of adhesive. This is desirable not only from an aesthetic viewpoint, but also because it is very important that there should be negligible risk oftransfer of adhesive to coins placed in a cash bag.

Some embodiments of the invention wiil now be described in greater detail with reference to the accompanying drawing which shows a plan view of a cash bag.

The illustrated bag 10 is formed from a single strip of thermoplastic material, such as LDPE. The strip is folded back on itself so that the bag has areas of one, two and three plies. Heat sealing atthe longitudinal edges (AH and BG) seals overlying plies together.

The main pocket portion 12 of the bag is formed by a layerthat is folded back atthe bottom (HG) of the bag to a line EF spaced some way from the top AB. Atthis intermediate line EF the folded overlap isfolded back on itself so that it overlies the pocket portion, and terminates at IJ. This folded over flap EFIJ forms a cuff portion 14, sealed along its edges EJ and Fl and open at the bottom, atthe edge lJ. Above the pocket portion 12, a tuck-in flap ABFE is provided by the rear wall of the bag 10which extends upwardly to fold line AB where it is folded forwardly on top of itself. It terminates at line CD, which is spaced from the mouth EF of the pocket portion 12. For use, articles such as coins are placed into the pocket portion 12 through the mouth at EF.The bag can then be closed by turning the cuff portion 14 inside out and tucking the upper region ABFE ofthe bag inside it. This much is conventional and is described in greater detail in the patentspecificationsalready referred to.

To facilitate formation of a collated stack of bags which can maintain its integrity, the upper surface of the bag 10 (namely the surface shown in the drawing) has one or more minor areas of adhesive applied. The preferred adhesives are pressure-sensitive adhesives, which may be hot-melt adhesives. A particularly preferred adhesive is a pressure-sensitive adhesive with a solvent(MEKorethyl acetate) base. Various configurations of adhesive have been tried.These include: (1) a transverse stripe 20 close to the top of the top flap ABCD, extending for most of the width of the bag; (2) the transverse stripe 20 together with a similar stripe 22 adjacent the bottom of the pocket portion 12; (3) at one side of the bag, a longitudinal stripe 24 extending for most of that part ofthe pocket portion 12 not covered by the cuff portion 14; together with a longitudinal portion 26 on the top flap ABCD; (4) the longitudinal stripe 24 together with a corresponding stripe 28 at the other side ofthe pocket portion 12; and (5) a short transverse stripe 30 in a central region of the bag, preferably on the cuff portions 14. These configurations all succeed in connecting bags securely.However they are not at present preferred because they involve relatively large quantities of adhesive which tends to be visible on a separated bag (and may cause it to stickto things unintentionally, or transfer adhesive to other objects). Furthermore, with configurations (3) and (4) it was found difficultto control the application of adhesive to bags on a production line working art a high rate (e.g. 100 or even 150 bags per minute). If adhesive gets onto the machinery, it must be shut down for cleaning; and such interruptions seriously increase costs.

The preferred area for application of glue is the surface of the cuff portion 14 (i.e. the area EFIJ). The particularly preferred configuration is a pair of small spots 33 of adhesive, at respective sides of the bag, approximately midway between the edges EF and IJ of the cuff portion 14. With high rates of working it is not possible to position the adhesive spots precisely.

With a bag travelling in the transverse direction (arrow 32), we can define target areas 34for receiving the adhesive; these are about 10 or 15mm long. The spots of adhesive are less than 4mm in diameter, and preferably about the size of pinheads, i.e. about 1 to 1 1/2mm in diameter. Bags to which adhesive has been applied in this fashion pass into collecting receptacles, and are pressed down. The adhesive dots thereby spread out somewhat (possiblyto a diameter as great as 1 Omm or even more), and adjacent bags are adhered together.

Despite the small quantity of adhesive involved, we have found that the stacks thus produced maintain their integritywell. The standard cash bags are either 76x 147mmor104x 138mm,andmadeofLDPEof thickness 40-60ym thick. A stack of 100 such bags has been found to hold together when thrown 3 metres onto a table. When required, a single bag can be peeled away easily, and any adhesive remaining on it is virtually unnoticeable. Of course, use of more adhesive may be desirable for some purposes, e.g. if bags are required to be stuck again, or with different bag materials. Fora somewhatstrongerconnection we may use an upper transverse stripe 20. It is also possible, when using adhesive on the cuff portion 14,to arrange that, when the bag is sealed by inversion of the cuff portion 14, the adhesive should then seal the bag shut.

Of course, the invention is not restricted to cash bags. An example of anotherfield is the collation of stacks of bags as used by retailers for articles sold to customers. Although the preceding discussion has referred to plastics bags, the invention is also applicable to paper articles, in which case more adhesive is likely to be required.

Claims (11)

1. Acollated stack of discrete individual pocket-like web articles wherein adjacent articles are separably adhered together.

2. Astackaccordingto claim 1 wherein the articles are adhered together by means of pressure sensitive adhesive.

3. A stack according to claim 1 or 2 wherein the articles are offlexible plastics material.

4. A stack according to any preceding claim wherein adjacent articles are adhered by means of adhesive engaging a minor proportion of a major surface of each article.

5. A stack according to claim 4wherein adjacent articles are adhered by means of one or more spots of adhesive, the spots initially having diameters less than 4mm.

6. A stack according to claim 5 wherein the spots initially have diameters in the range 1.0 to 1 .5mm.

7. A stack according to any preceding claim wherein the articles are cash bags.

8. A stack of cash bags according to claim 7 wherein each bag has a front face with a cuff portion intermediate its top and bottom, and bags are adhered at their cuff portions.

9. A stackof articles substantially as any herein described with reference to the accompanying drawing.

10. A method of producing a stack according to any preceding claim comprising applying adhesive to articles, collating them into a stack, and compressing the stack to enhance adhesion.

11. Amethodofproducing astackofarticles substantially as any herein described with reference to the accompanying drawing.