GB2147564A

GB2147564A - Reusable packaging enclosure

Info

Publication number: GB2147564A
Application number: GB8326787A
Authority: GB
Inventors: Eric Lucas
Original assignee: Imperial Chemical Industries Ltd
Current assignee: Imperial Chemical Industries Ltd
Priority date: 1983-10-06
Filing date: 1983-10-06
Publication date: 1985-05-15
Also published as: ZA847352B; GB8326787D0

Abstract

A packaging assembly comprises an open-mouthed enclosure and a flap for sealing engagement with a contact portion of the enclosure to cover at least partically the mouth, the contact portion and flap together constituting a sealing zone, wherein the sealing zone comprises a plurality of independently activatable sealing areas (20,21) for successive sealing of the enclosure. The sealing areas (20,21) may comprise zones of adhesive material or designated sealing zones if the material of the assembly is heat sealable. The assembly is suitably employed as a reusable mail bag, which provides evidence of interference with the contents during transit. Alternatively, the assembly may be in the form of a box.

Description

SPECIFICATION Reusable packaging enclosure This invention relates to the packaging of articles and, in particular, to a reusable packaging enclosure.

Packaging enclosures of various kinds, such as cartons, sacks and envelopes, are extensively employed for the protection and/or transport of articles of commerce. In certain circumstances, for example - if an article delivered in a sealed enclosure is found, after inspection, to be defective, it may be necessary for the recipient to return the article to the supplier. Desirably, therefore, the sealed enclosure should be readily openable without destruction of the enclosure and be resealable for further use.

A problem with a readily resealable enclosure is that the contents thereof can easily be pilfered or interfered with particularly when the contents comprise a number of articles, without the recipient being aware that the enclosure has been opened and reclosed. Desirably therefore the sealing technique should be such as will provide evidence of any unauthorised tampering with the contents during storage or transit of the enclosure.

We have now devised a reusable enclosure which fulfils the aforementioned objectives.

Accordingly, the present invention provides a packaging assembly comprising an openmouthed enclosure and a flap for sealing engagement with a contact portion of the enclosure to close the mouth, the contact portion and flap together constituting a sealing zone, wherein the sealing zone comprises a plurality of independently activatable adhesive elements for successive sealing of the enclosure.

The packaging enclosure may be of any configuration which provides a cavity into which may be inserted a variety of contents including articles, such as packets, postal packages, books, leaflets, letters, cash, securities etc, which cavity may be closed to retain the contents therein by means of a flap which can be arranged to cover at least a portion of the mouth of the cavity and to overlap a contact portion of the enclosure for sealing engagement therewith. Suitable enclosures include cartons, boxes, envelopes (e.g. postal envelopes) and sacks.

For ease of description the invention is hereinafter described in relation to a simple, polymeric sack of generally rectangular configuration which is of particular utility as a mail-bag, although it will be appreciated that assemblies of other configurations and kinds are within the scope of the invention.

Although a closure flap may be provided independently of the enclosure, in a preferred embodiment of the invention the closure flap is integral with the material of the enclosure.

For example, in the case of a mail-bag, the closure flap conveniently constitutes an extension of a wall portion of the bag projecting beyond, and foldable over, the mouth of the bag.

To permit successive sealings, and intermediate openings, of the enclosure, the respective independently activatable adhesive elements should be axially spaced-apart in the sealing zone, i.e. substantially along an axis extending from the base and through the oppositely-located mouth of the enclosure.

The degree by which the adhesive elements are spaced apart is not critical, although the spacing between adjacent adhesive elements in the closed and sealed configuration of the assembly should be sufficient to permit severance of the flap between adjacent elements, for example - by means of a blade or scissors etc, to open the enclosure and permit access to the contents thereof.

The adhesive elements may be located exclusively on one or other of the respective cooperable surfaces of the flap and contact portion of the enclosure or, if desired, may be distributed between the two surfaces with at least one adhesive element on each of the respective cooperable flap and contact surfaces.

Providing the pattern of adhesive elements permits successive sealing, opening and resealing of an enclosure, the nature or shape of an individual adhesive element is not important. For example, an individual element may be in the form of a deposit - for example, circular, square or rectangular, but preferably extends across substantially the entire width of the flap or contact portion in a direction substantially normal to the axis of the enclosure, suitably as a linear pattern of individual deposits or, preferably, as a continuous adhesive strip.

The plurality of adhesive elements comprises at least two independently activable elements, to permit sealing, opening and resealing of an original enclosure, although, if desired, three or more adhesive elements may be provided on an assembly to extend the sealing, opening and resealing sequence.

An adhesive element may comprise any conventional adhesive material which will develop a bond in the sealing zone of sufficient strength to deform the material of the enclosure when the bond is ruptured, thereby providing visual evidence of interference with the enclosure during storage or transit. Thus, the adhesive material may be activatable by moisture, by heat, by contact or by pressure. In the case of an enclosure fabricated from a suitable material, such as a heat-sealable olefin polymer, the adhesive elements may simply comprise designated regions of the flap and/or contact portion, without the need for an independent adhesive material.

Depending on the nature of the adhesive material, and particularly in the case of a pressure-sensitive adhesive material, a removable, protective layer, such as a patch or strip, may be applied to the operative surface of one or more of the adhesive elements, to prevent inadvertent activation of the element(s), the protective patch or strip being removed only when activation of a particular element is desired. A peelable tape generally provides adequate protection.

A packaging enclosure according to the invention may be made from conventional packaging materials including paper and cardboard. Polymeric films are of particular utility in the production of mail bags. Suitable filmforming materials include polyesters, such as polyethylene terephthalate, vinyl polymers, such as polyvinylchloride, homo- and co-polymers of mono-alpha-olefins, such as ethylene, propylene and butene-1, and blends of such polymers. Low density polyethylene (LDPE), widely used in the production of plastics sacks, is also of utility, particularly when blended with linear low density polyethylene (LLDPE) to provide a film having desirably high tear resistance and tensile strength. Such films are conveniently produced by a conventional, tubular, blown-film technique.

The invention is illustrated by reference to the accompanying drawings in which: Figure 1 is a schematic perspective view of a polymeric side-weld mail bag with two adhesive elements, Figure 2 is a schematic side elevation (not to scale) of the bag of Fig. 1, Figures 3 to 5 depict various stages in the life cycle of the bag of Fig. 2, and Figure 6 is a schematic side elevation (not to scale) of a bag having different arrangement of adhesive elements.

In Fig. 1 of the drawings, a polymeric sideweld bag generally designated 10, has an upper wall 11, a lower wall 12, and side walls 13, 14 which together constitute an enclosure having a base 15 and mouth 1 6.

An extension of the lower wall beyond the mouth provides a closure flap 1 7 the upper surface 18 of which can be folded over into cooperating engagement with a contact portion 1 9 of upper wall 11 to close mouth 16.

Two adhesive elements in the form of continuous adhesive strips 20, 21 extend across the width of upper flap surface 18.

As shown in Fig. 2 of the drawings, each adhesive element is respectively provided with a protective tape 22, 23 to prevent inadvertent activation of the adhesive.

In Fig. 3 of the drawings, packets 24, 25 have been introduced into the enclosure, protective tape 23 has been removed, flap 1 7 folded over upon contact surface 1 9 and pressed into engagement therewith to activate the pressure-sensitive element 21, thereby to close mouth 1 6 and to seal the enclosure.

To open the enclosure, flap 18 is cut along zone 26, between adhesive elements 20, 21, and the contents can then be removed, as shown in Fig. 4 of the drawings, the remnants of flap 1 7 and adhesive element 21 remaining adhered to contact portion 1 9 of upper wall 11.

Fig. 5 illustrates a possible re-use of the enclosure, packet 25 having been reintroduced into the enclosure, protective tape 22 removed, the residual free portion 27 of the flap folded over upon contact surface 1 9 and pressed into engagement therewith to activate pressure-sensitive adhesive element 20 to reseal the enclosure. To open the enclosure to remove the contents, the residual flap may be cut along zone 28.

It will be appreciated that three or more adhesive elements may be employed to extend the opening/sealing sequence, as required.

In Fig. 6 of the drawings, adhesive elements 20, 21 are disposed respectively on surface 1 8 of flap 17, and on contact surface 19.

Claims

1. A packaging assembly comprising an open-mouthed enclosure and a flap for sealing engagement with a contact portion of the enclosure to close the mouth, the contact portion and flap together constituting a sealing zone, characterised in that the sealing zone comprises a plurality of independly activatable adhesive elements for successive sealing of the enclosure.

2. An assembly according to claim 1 characterised in that the plurality of adhesive elements is located exclusively on one or other of the flap and contact portion.

3. An assembly according to either of claims 1 and 2 characterised in that at least one of the adhesive elements comprises a protective layer.

4. An assembly according to any one of the preceding claims characterised in that an adhesive element extends substantially across the width of the flap or contact portion.

5. An assembly according to any one of the preceding claims characterised in that the adhesive elements comprise a pressure-sensitive adhesive.

6. An assembly according to any one of the preceding claims characterised in that the flap is integral with the enclosure.

7. An assembly according to any one of the preceding claims characterised in that it is fabricated from a polymeric film.

8. An assembly according to claim 7 characterised in that the film is heat-sealable and each adhesive element comprises a designated zone of the flap or contact portion.

9. A mailbag comprising an assembly according to any one of the preceding claims.