AU2004200382A1

AU2004200382A1 - Tamper evident coin bags

Info

Publication number: AU2004200382A1
Application number: AU2004200382A
Authority: AU
Inventors: Phillip Rolls
Original assignee: ROLLSPACK Pty Ltd
Current assignee: ROLLSPACK Pty Ltd
Priority date: 2003-02-03
Filing date: 2004-02-03
Publication date: 2004-08-19

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

TO BE COMPLETED BY APPLICANT Name of Applicant: ROLLSPACK PTY LTD Actual Inventor(s): PHILLIP ROLLS Address for Service: CALLINAN LAWRIE, 711 High Street, Kew, Victoria 3101, Australia Invention Title: TAMPER EVIDENT COIN BAGS The following statement is a full description of this invention, including the best method of performing it known to us:- 03/02/04,atl3147.speci front page, This invention relates to tamper evident bags that are suited to storing and/or transporting coins or other heavy valuable objects.

BACKGROUND OF THE INVENTION Various tamper evident bags or satchels have been proposed for storing and/or transporting valuable articles such as bank notes and documents. These are generally in the form of a plastic envelope that has a sealable closure flap. The closure flap or adhesive that secures the flap is usually of a material which exhibits a visual change if attempts are made to tamper with the seal that is formed when the envelope is sealed. The visual change may be a change in colour, the appearance, or a change in the appearance of printed words or signs. Such bags or satchels are generally adequate when light weight materials are required to be stored or transported. However, when heavier objects such as coins are required to be stored or transported the known bags or satchels are not adequate. Bags suitable for coins may be required to hold up to 10kg of coins. Bags containing this mass of coins are prone to damage, especially when bags are tossed during transport. To simply construct known bags or satchels out of heavier film weight plastic materials is not a satisfactory solution to this problem.

It would be desirable to have bags or satchels that are suitable for storing and/or transporting heavy items, especially coins.

SUMMARY OF THE INVENTION This invention provides in one form a tamper evident plastic coin bag, the front and rear of the bag being formed from first and second plastic sheet material respectively, the bag having: an upper handle portion joined to a lower storage portion, the lower storage portion having an opening to enable access to the interior of the lower storage portion of the bag; a closure portion for closing the opening, the closure portion being formed from a third plastic sheet material which also forms part of the upper handle portion; an adhesive strip for securing the closure portion to the front of the bag to seal the opening, the adhesive strip being formed on one of the closure portion and the bag, and the adhesive strip and the closure portion and the front of the bag having mutually opposing surfaces which are adhered together to seal the opening when the closure portion is positioned for closing the opening; a removable backing strip for the adhesive strip; the closure portion and the adhesive strip being adapted such that a visual change is evident when the opening seal is broken or attempted to be broken, and wherein the 03/02/04,at 13147.rollspack speci2 -3opening is in the form of a slit spaced from where the upper handle portion joins the lower storage portion.

Preferably the three plastic sheets that form the upper handle portion are heat welded.

Preferably the third plastic material comprises cross-laminated high density polyethylene and the closure portion is the form of a flap.

Preferably the first and second plastic sheet materials are formed by folding one sheet end-to-end.

Preferably the first and second plastic sheet materials of the lower storage portion and the upper handle portion of the coin bag comprises a blend of linear low density polyethylene and polypropylene.

Preferably the slit is spaced 3 20mm and more preferably 5 10mm from where the upper handle portion joins the lower storage portion of the coin bag.

Preferably the removable backing strip is silver-release tape to allow video detection during filling/processing of the coin bag.

Preferably the lower storage portion of the coin bag has one or more heat welded seams along portion of the perimeter of the bag.

Preferably the sides of the lower storage portion of the coin bag include scalloped edges that reveal, in use, tampering into the storage portion of the bag from the side.

DESCRIPTION OF THE INVENTION The invention will be described by reference to a preferred embodiment provided as a non-limiting Example shown in Figure 1. Figure 1 is a perspective view of a coin bag according to the invention.

Referring to Figure 1, a coin bag 1 is formed by centre folding end-to-end a sheet of 125tm thick film of blended linear low density polyethylene and polypropylene, the sheet being of approximate size 200mm x 800mm. This folded sheet forms the first sheet 2 and second sheet 3 which form the front and rear of the bag respectively. A plastic sheet 4 of cross-laminated high density polyethylene (Valeron) 75Rm thick and approximate size 200mm x 150mm is laid on top of the folded sheet with the top edge of the Valeron sheet aligned to where the ends of the folded sheet meet. The Valeron polyethylene homopolymer that is preferably used is formed from two webs of resin adhesively joined together. This film is available from Valeron Strength Films, U.S.A. A heat welded dividing seam 5 (shown ghosted) is formed by heat welding the Valeron sheet 4 along a line parallel and approximately 110mm from the top edge 6. This weld separates the coin 03/02/04,at 3147.rollspack speci,3 bag into an upper handle portion 7 and a lower storage portion 8. A further parallel heat weld 17 is formed below the dividing seam 5 and forms part of the dividing seam. The two longer sides 9 of the plastic sheets are then heat welded together to form lengthwise seams 10. However, the sides of the Valeron sheet material below the horizontal heat weld are not heat welded to the sheet below. This allows this portion of the Valeron sheet to form a foldable flap 11. A heat weld is formed across the top edge 12 and down part of the way down the sides towards the dividing seam 5. An oval hand hold opening 14 is formed in the handle portion 7 using a heat sealing cuter. It will be appreciated that while the above description refers to the heat welding being conducted sequentially, the heat welds are usually formed simultaneously, and this may also include cutting the hand hold. It will also be appreciated that if the folded sheet described above is replaced with separate first and second sheets an additional heat weld will be required along the bottom edge of the bag.

The flap portion 11 has an adhesive applied to it to form an adhesive strip 14. A silver backing strip 15 (shown with a corner lifted) is then applied to the adhesive strip 14.

It will be appreciated that in practice, several bags are usually made using rolls of plastic and the bags are separated, by cutting operations, from each other after heat welding. The side edges can be cut to provide a fine scallop edging (not shown) with peaks 5mm apart.

A horizontal opening slit 16 is made in the storage portion 8 of the bag some 8mm below the welded seam 17 that divides the upper handle portion 7 from the lower storage portion 8. Spacing the slit this distance from the welded seam strip 17 means the storage portion 8 is strong. In use coins encounter the welded seam 17 rather than the sealed slit 16. This represents an improvement over bags where the opening is formed at an edge of a bag. The opening in the form of a slit may be located a further distance from the joining weld. However, if it is located much greater than 20mm from the weld, the flap is required to be larger and accordingly is wasteful of materials.

The tamper evident aspects of the bag may be provided by selecting adhesive that is sufficiently strong to cause physical distortion, de-lamination or tearing of the flap if the flap is peeled back or attempted to be peeled back from the adhesive strip. These changes provide visual evidence of tampering. This aspect may also be provided by selecting adhesives that exhibit colour changes when tampered with. It may also be provided by printing patterns 18 with fugitive ink on at least that portion of the bag where the seal is formed. The removal of the flap leads to at least partial removal of the printing.

Reapplying the flap leads to a distortion or lack of alignment in the patterns. Suitable 03/02/04,at13147.rollspack speci4 adhesives are Henkel 746-21 and Henkel Q8746. The coin bag may also be printed (not shown) with information such as bar codes and may also provide spaces for information to be added by pen.

One of the advantages of using a tri-laminate handle portion where the upper layer is made from Valeron is that a strong handle portion can be provided together with a tough flap portion. Use of the preferred blended polymer of linear low density polyethylene and polypropylene for the first and second sheet materials provides low slip properties which allow stacking. An additional layer of anti-skid varnish may be applied during printing process to enhance the stacking properties further. The preferred blended polymer also provides high film strength at relatively low film thickness. We have found film thickness of 100 150p.m to be particularly advantageous.

It will be appreciated that without departing form the present invention several changes can be made. For example, the pattern or ornamentation could be applied to the flap material. Additional weld seams may also be provided to strengthen the perimeter of the bag. It will also be appreciated that the bags of the present invention may also be used to store and/or transport light weight objects.

03/02/04.at 13147.rollspack

Claims

1. A tamper evident plastic coin bag, the front and rear of the bag being formed from first and second plastic sheet material respectively, the bag having: an upper handle portion joined to a lower storage portion, the lower storage portion having an opening to enable access to the interior of the lower storage portion of the bag; a closure portion for closing the opening, the closure portion being formed from a third plastic sheet material which also forms part of the upper handle portion; an adhesive strip for securing the closure portion to the front of the bag to seal the opening, the adhesive strip being formed on one of the closure portion and the bag, and the adhesive strip and the closure portion and the front of the bag having mutually opposing surfaces which are adhered together to seal the opening when the closure portion is positioned for closing the opening; a removable backing strip for the adhesive strip; the closure portion and the adhesive strip being adapted such that a visual change is evident when the opening seal is broken or attempted to be broken, and wherein the opening is in the form of a slit spaced from where the upper handle portion joins the lower storage portion.

2. A tamper evident plastic coin bag as defined in claim 1 wherein the three plastic sheets that form the upper handle portion are heat welded.

3. A tamper evident plastic coin bag as defined in claim 1 or claim 2 wherein the third plastic material comprises cross-laminated high density polyethylene and the closure portion is in the form of a flap.

4. A tamper evident plastic coin bag as defined in any one of claims 1 to 3 wherein the first and second plastic sheet materials are formed by folding one sheet end-to- end.

A tamper evident plastic coin bag as defined in any one of claims 1 to 4 wherein the first and second plastic sheet materials of the lower storage portion and the upper handle portion of the coin bag comprises a blend of linear low density polyethylene and polypropylene.

6. A tamper evident plastic coin bag as defined in any one of claims 1 to wherein the slit is spaced 3 20mm and more preferably 5 10mm from where the upper handle portion joins the lower storage portion of the coin bag. 03/02/04,at 13147.rollspack spcci.6 -7-

7. A tamper evident plastic coin bag as defined in any one of claims 1 to 6 wherein the removable backing strip is silver-release tape to allow video detection during filling/processing of the coin bag.

8. A tamper evident plastic coin bag as defined in any one of claims 1 to 7 wherein the lower storage portion of the coin bag has one or more heat welded seams along portion of the perimeter of the bag.

9. A tamper evident plastic coin bag as defined in any one of claims 1 to 8 wherein the sides of the lower storage portion of the coin bag include scalloped edges that reveal, in use, tampering into the storage portion of the bag from the side.

10. A tamper evident plastic coin bag as defined in claim 1 and substantially as hereinbefore described with reference to the Figure and the Example. DATED this 3 r d day of February, 2004 ROLLSPACK PTY LTD By their Patent Attorneys: CALLINAN LAWRIE 6^ d 03/02/04,atl 3147.rollspack speci.7