GB2386234A

GB2386234A - A machine-readable-code bearing laminate label, having dye distributed in an adhesive layer

Info

Publication number: GB2386234A
Application number: GB0123818A
Authority: GB
Inventors: Christopher Michael Bates
Original assignee: Willett International Ltd
Current assignee: Willett International Ltd
Priority date: 2001-10-03
Filing date: 2001-10-03
Publication date: 2003-09-10
Anticipated expiration: 2021-10-03
Also published as: GB0123818D0; GB2386234B

Abstract

A laminated substrate has a base layer and an adhesive layer (24), a dye is distributed in the adhesive layer (24) and the dye is selectively coded with, machine-readable information. Preferably the dye (eg cyanine) is one whose structure can be locally altered physically, for example by exposure to a laser beam, to provide bar codes or other information which can be read by a non-contact reader. The lable may be used on the inner surface of film packing (14) used on some cigarette packets.

Description

Coding of substrates This invention relates to a process of applying a machinereadable coding to a substrate, and to a substrate carrying such a coding.

There are many applications where it is desired to apply a coding, eg a manufacturing batch number or a manufacturing date, to products in a way such that the coding can be read by machine but (generally) is not visible to the eye.

Use of a non-visible coating can also be useful in particular in preventing counterfeiting of products, or at least giving the ability to differentiate genuine products (which have a particular code applied to them, from counterfeit products which do not have the code. The system may also be used to determine the original source of the product pack to enable product routing history to be checked in cases of suspected parallel or'grey goods' trading.

According to the invention, there is provided a laminated substrate which has a base layer and an adhesive layer, wherein a dye is distributed in the adhesive layer and the dye is selectively coded with machine-readable information.

The base layer is preferably reflective.

The substrate may in particular be a tear tape for an outer film cover for a product such as a packet of cigarettes or a foodstuffs or pharmaceutical carton, and the adhesive layer can be that used to attach the tear tape to the outer film cover of such a product.

The coding carried by the dye is preferably invisible to

the eye.

The dye can be a dye which can be locally melted by a laser beam which doesn't burn holes in the dye but rather melts it slightly. The areas where the melting has taken place can then be read by a suitable reader and converted into the required information. Typically organic dyes such as cyanine can be used.

This type of writing/reading arrangement is known in the manufacture of compact discs (CDs).

The dye can typically be applied by an ink jet device or by other application process such as flexographic printing and coating, other rotary printing, flat screen printing or coating or pad/tamp printing or coating.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a conventional cigarette packet with a polypropylene film outer cover, and Figure 2 shows a simplified section through part of the film cover of Figure 1, on the line II-II.

The cigarette packet 10 shown in Figure 1 is of conventional form, with a flip-top lid 12. The pack is wrapped in an outer film cover 14, normally of transparent polypropylene film. The cover is provided with a tear strip 16 which has an exposed tab 18 which can be grasped to pull the strip which then tears the film cover so that the cover can be removed and the packet opened. The

presence of the cover 14 helps to ensure freshness of the packet contents and also to prevent tampering with the contents.

The tear strip 16 is applied on the inside surface of the film 14. Figure 2 shows, considerably simplified, the construction of the tear tape. The strip comprises a film layer 20, an ink layer 22 and an adhesive layer 24. The ink layer provides colour to the strip, so that its' presence is visible. The ink is usually a reflective ink, typically gold coloured.

The adhesive layer 24 contains an adhesive substance mixed with a dye which can be modified after application to the film cover 14, to contain coded information. For example, the dye can be exposed, in the direction of the arrow 26, to laser light which locally melts the dye, resulting in a dye state which can later be read by a suitable reader scanning the strip 16, in the direction of the arrow 26.

The laser light will be reflected from the reflective ink layer 22 and thus will not damage any underlying layers of material.

The code imparted to the dye/adhesive layer can be in any appropriate pattern, which will be determined by the movement path of the laser which does the'writing'.

Codes will be digital in form and will typically be in the form of a bar code or an array of dots or lines which can be read by laser.

The adhesive layer 24 is invisible to the naked eye, and the eye will just see the light reflected, through the adhesive layer, from the reflective ink layer 22.

After wrapping of the pack, the adhesive/dye layer will be

protected by the outer film cover 14.

The dye may be mixed homogeneously throughout the adhesive layer or may be applied only in local areas. The adhesive /dye mixture may be applied by an inkjet printing process.

The coding can be carried out after the strip has been attached to the film 14, or after the film has been wrapped around the pack 10. In some circumstances the code may be applied to the adhesive layer prior to attachment of the film 14.

The invention can be applied to any pack which has a tear strip as described. This includes not only cigarette packets, but also CD and audio tape cassettes, pharmaceutical packs and certain foodstuffs. The dye may also be incorporated in the inks used for printing secondary cartons constructed of kraft card material providing the necessary process steps are taken to enable readability. The invention is not however limited to any particular product pack.

The dye used can be any dye which can be modified by a non-contact treatment to produce a change which results in a local, physical change in the dye structure which can be read by an external, non-contact reading device.

Particularly suitable dyes are those used in the manufacture of compact discs.

The digital codes written into the dyes may also be encrypted to give further covert protection where the system is used for anti-counterfeiting purposes.

Claims

CLAIMS: 1. A laminated substrate which has a base layer and an adhesive layer, wherein a dye is distributed in the adhesive layer and the dye is selectively coded with machine-readable information.
2. A substrate as claimed in claim 1, wherein the base layer is reflective.
3. A substrate as claimed in claim 2, wherein the base layer comprises a film layer having a reflective layer applied thereto.
4. A substrate as claimed in any one of the preceding claims, wherein the base layer is a tape.
5. A substrate as claimed in any one of the preceding claims, wherein the dye is one which can be locally modified to provide a local, physical change in the adhesive/dye.
6. A substrate as claimed in claim 5, wherein the dye can be melted to provide an alteration which can be read by a suitable reader.
7. A substrate as claimed in claim 5, wherein the dye is canine.

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8. A substrate as claimed in any one of the preceding claims, wherein the machine readable information is in a digital form.
9. A substrate as claimed in claim 8, wherein the information in a bar code.
10. A substrate as claimed in any one of the preceding claims, wherein a protective layer is provided to the adhesive/dye layer.
11. A substrate as claimed in claim 1 substantially as hereinbefore shown in and as described with respect to the accompanying drawings.
12. An article having attached thereto a substrate as claimed in any one of claims 1 to 11 so that the information carried by the substrate can be scanned through the adhesive layer.
13. An article as claimed in claim 12, wherein the dye in the adhesive layer is locally modified by a laser beam to form physical changes in the dye.
14. An article as claimed in claim 13, wherein the modification of the dye is carried out after the substrate has been applied to the article.
15. An article as claimed in any one of claims 12 to 14,

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wherein the substrate is applied to the inner surface of a translucent wrapping for the article and the information in the adhesive layer is to be read through the translucent wrapping layer.
16. An article as claimed in any one of claims 12 to 14, substantially as hereinbefore shown in and as described with respect to the accompanying drawings.