GB2032882A

GB2032882A - Bags

Info

Publication number: GB2032882A
Application number: GB7927855A
Authority: GB
Original assignee: FRANKO PLASTICS Ltd
Current assignee: FRANKO PLASTICS Ltd
Priority date: 1978-09-29
Filing date: 1979-08-10
Publication date: 1980-05-14

Abstract

A security bag is formed from a single sheet of polyethylene folded over so that one section is longer than the other. The adjoining edges (12, 14) are seam-welded and the overhanging section forms a flap (18). An adhesive which forms a very strong bond with the plastics material is applied by peelable strips close to the edge (16) of the front panel (14) and close to the flap edge (18). The adhesive is chosen so as to have a bond between itself and the material greater than the breaking strength or at least stretching strength of the material. Alternatively, a weakened region in the form of a line of perforations (30) is formed either in the material forming the front panel (24) or the material in the region of the fold (20). <IMAGE>

Description

SPECIFICATION Improvements in and Relating to Bags Field of Invention This invention concerns bags and particularly plastic security bags. The invention is of particular application in the field of banking and commerce where it is desired to seal into a bag money or documents in such a way that tampering with the contents once the bag has been sealed cannot be achieved without revealing that fact.

Background to the Invention Many transactions involve the giving and receiving of money or documents and where these have to be left for a period of time or transmitted by third parties an element of trust has to enter into the situation unless steps can be taken to preserve the money or documents in such a way as to indicate that the package has or has not been tampered with in transit. The element of trust is then strengthened since if a package which has been secured at one end arrives at the other end in the same condition as it left the sender the recipient can be assured that the contents are exactly as the sender intended and the sender can rely on the fact that if the bag is delivered intact to the recipient the recipient will receive that which the sender wishes to remit to him.

Object of the Invention It is an object of the present invention to provide a cheap and simple form of bag-like device for containing documents or money which can be readily sealed but which cannot be broken into once it has been sealed without indicating the fact that the bag has been tampered with.

The Invention According to the present invention a bag for storing articles is formed from plastics sheeting and includes an opening having an integral flap which can be folded over the opening so as to secure the interior of the bag, at least the flap having applied thereto an adhesive which will form a bond with the surface of the bag onto which the flap is stuck which bond is stronger than the breaking strength of the plastics material from which the bag is formed so that the bag cannot be opened once the flap has been folded over and sealed in position without ripping the material forming the bag.

A bag having the above features, once sealed, cannot easily be opened without tearing or at least stretching the plastics film of the bag, and consequently it is obvious to the recipient whether an attempt has been made to tamper with the contents. Unfortunately, with bags made from heavier gauges of plastics film, the opening of a sealed bag may be possible without that fact being revealed from the appearance of the bag, since the strength of the bond (particularly after it has only just been made) may not be sufficiently strong relative to the plastics material, to ensure that the plastics material is stretched or ripped by the opening procedure.

According to a preferred feature of the present invention there is provided a bag for storing articles formed from plastics sheeting which defines an opening and an integral flap which can be folded over the opening so as to close the bag, at least the flap having applied thereto an adhesive which will form a bond with the material of the bag over which the flap is folded, the material of the bag or the flap having a weakened zone in the region of the opening so that once the flap has been folded over the opening and bonded to the material adjacent the opening, the adhesive bond cannot be broken without tearing the bag at least along the weakened zone.

The weakened zone conveniently is in the form of a line of perforations which may be formed next to the region along which the flap is connected to the main area of the bag, either in the bag material or the flap material. Alternatively a line of perforations may be formed adjacent the adhesive on the flap, in the portion of the flap remote from the fold joining the flap to the bag.

Other possibilities include reducing the thickness of the plastics sheet material along a similar line, or even connecting the integral flap to the main area of the bag by means of a weakened line which then may additionally serve to define the line about which the flap is folded.

Preferably an adhesive of appropriate form is applied both to the inside surface of the flap and to the external surface of the bag adjoining the opening therein so that both mating surfaces which are brought into contact when the flap is folded over have an adhesive layer thereon.

Typically the bag is formed from a single sheet of plastics material, typically polythene which is folded approximately in half so that one half is slightly longer than the other so as to form a flap and the two adjoining edges are seam-welded or otherwise bonded to form the bag.

Preferably the adhesive is of the type sold under the trade name Macbond S1 140 or Macbond S1 147 or an equivalent.

Where an adhesive of this type is used, it is most conveniently applied to the bag and to the flap by sticking onto the bag in the region of the opening, and on the underside of the flap, adhesive-backed tape in which the adhesive is the preferred adhesive, the adhesive thereby forming a strong bond with the plastics material so that when the tape is peeled away from the polythene a layer of adhesive is left bonded to the plastics sheeting both on the flap and on the bag.

To provide increased carrying capacity the bag may be gusseted.

To allow for printing or writing on the bag or flap, or both, the plastics material is preferably surface etched to provide a matt surface finish over at least a part of its area.

It is to be understood that the invention is not limited to the use of polyethylene sheet or polythene sheet nor to the specific adhesives referred to above.

The invention will now be described by way of example with reference to the accompanying drawings.

In the Drawings Fig. 1 is a front view of a plastics security bag constructed in accordance with the invention, Fig. 2 is an edge view of the bag shown in Fig.

1, Fig. 3 is a front view of another security bag embodying the invention, and Fig. 4 is a front view of another security bag embodying the invention.

Detailed Description of the Drawings As shown in the drawings, a bag is formed from a single length of plastics sheet such as polyethyiene sheet which is folded at 10 and seam-welded along the two abutting edges 12 and 14 so as to form an evelope or bag. When folding the sheet the position of the fold 10 is selected off-centre so that when the two parts are folded together and welded the edge 16 of the one fold is spaced from the edge 18 of the other fold at the open end of the bag.

The result is that a flap generally designated 20 is formed and in accordance with the invention a first length of adhesive backed tape 22 is applied to the side of the flap which will abut the external surface of the front flap 24 and a second length of similar adhesive-backed tape 26 is applied to the surface of the front flap 24 close to and parallel with the edge 1 6 of the front flap.

The adhesive on the adhesive-backed tape forms a poor bond with the tape material but is selected so that it forms a very strong bond with plastics material of the flap 20 and front flap 24.

In this way once the tape has been applied to the plastics sheet material forming the flap 20 and front flap 24, it is quite possible to peel the tape material from the plastics sheet material as shown in dotted outline at 28 in Fig. 1 so as to leave exposed the film of adhesive which has become bonded to the plastics sheet material.

After removing both lengths of tape, the flap 20 can be folded over and stuck to the front flap 24.

By selecting an adhesive in accordance with the invention so that the bond between the adhesive and the plastics material is stronger than the breaking strength of the plastics material, the result is that the flap 20 cannot be undone without ripping or severing or otherwise damaging the material forming the bag.

In the embodiment shown in Fig. 3 a weakened region is introduced into the structure adjacent the bond, to make it more difficult to open the bag without revealing that it has been opened.

To this end, running parallel to the edge 16 of the front panel 24 (and between the tape 26 and the major part of the front panel of the bag) is a line of relatively small perforations 30, extending substantially right across the front panel. The adhesive on the tape 22 and 26 is selected so that the flap 20 is bonded securely to the front part 24, but even if the bond is for any reason not of sufficiently high strength, it will still prove impossible to undo the flap 20 from the front part 24 once sealed thereto, without tearing the bag along the line of perforations 30.

In the embodiment shown in Fig. 4 a line of perforations 32 is formed in the material of the flap, between the layer of adhesive-backed tape 22 and the opening formed by the edge 1 6. As with the embodiment shown in Fig. 3, any attempt to lift the flap to break the bond when the flap has been stuck to the front panel 24, will result in a tear along the line of perforations 32.

Although not shown the lower end of the bags shown in Figs.1,3 and 4 may be formed with a gusset.

A preferred material for the adhesive-backed tape is Macbond S 140 or S 147.

A preferred plastics material from which the bag is formed is polyethylene sheet.

Claims

1. A bag for storing articles formed from plastics sheeting which includes an opening having an integral flap which can be folded over the opening so as to secure the interior of the bag, in which at least the flap has applied thereto an adhesive which will form a bond with the surface of the bag onto which the flap is stuck, which bond is stronger than the breaking strength of the plastics material from which the bag is formed, so that the bag cannot be opened once the flap has been folded over and sealed in position without ripping the material forming the bag.

2. A bag for storing articles formed from plastics sheeting and which includes an opening having an integral flap which can be folded over the opening so as to close the bag, in which at least the flap has applied thereto an adhesive which will form a bond with the material of the bag over which the flap is folded and in which the material of the bag or the flap has a weakened zone in the region of the opening so that once the flap has been folded over the opening and has been bonded to the material adjacent the opening, the adhesive bond cannot be broken without tearing the bag at least along the weakened zone.

3. A bag as claimed in claim 2 in which the weakened zone is in the form of a line of perforations.

4. A bag as claimed in claim 3 in which the line of perforations is formed next to the region along which the flap is connected to the main area of the bag.

5. A bag as claimed in claim 3 or claim 4 in which the weakened zone is formed in the bag material.

6. A bag as claimed in claim 3 or claim 4 in which the weakened zone is formed in the flap material.

7. A bag as claimed in claim 3 or 4 in which the weakened zone is formed adjacent the adhesive on the flap, in the portion of the flap remote from the fold joining the flap to the bag.

8. A bag as claimed in claim 2 in which the weakened zone comprises a region of reduced thickness of the plastics sheet material.

9. A bag as claimed in claim 2 in which a weakened line is formed in the material of the flap along with the flap is folded to close the bag.

10. A bag as claimed in claim 9 in which the weakened line is in the form of a line of perforations.

11. A bag as claimed in any of the preceding claims in which an adhesive is applied both to the inside surface of the flap and to the external surface of the bag adjoining the opening so that both mating surfaces which are brought into contact when the flap is folded over, have an adhesive layer thereon.

12. A bag as claimed in any one of the preceding claims which is formed from a single sheet of plastics material which is folded approximately in half so that one half is slightly longer than the other half so as to form a flap and the two adjoining edges are bonded to form the bag.

13. A bag as claimed in claim 12 in which the two adjoining edges are seam-welded.

14. A bag as claimed in any one of the preceding claims in which a strip of material bearing the adhesive is applied with the adhesive in contact with the plastics material to the region or to those regions of the bag and/or flap to which the adhesive is to be applied and prior to folding over the flap to close the bag, the strip of material is peeled away leaving a layer of the adhesive bonded to the plastics material ready to form a bond when the flap is folded over.

1 5. A bag as claimed in any one of the preceding claims in which at least the lower end of the bag is gusseted.

16. A bag as claimed in any one of the preceding claims in which the material from which the bag or the flap or both are formed is surface etched to provide a matt surface finish over at least a portion of its area to allow for writing or printing at least on that area of the bag which has been so treated.

1 7. A bag for storing articles constructed and arranged substantially as herein described with reference to and as illustrated in Figs. 1 and 2 of the accompanying drawings.

1 8. A bag for storing articles constructed and arranged substantially as herein described with reference to and as illustrated in Fig. 3 of the accompanying drawings.

1 9. A bag for storing articles constructed and arranged substantially as herein described with reference to and as illustrated in Fig. 4 of the accompanying drawings.