AU2006233201A1 - Film with security printing as well as a method for its production - Google Patents

Description

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AUSTRALIA

Patents Act 1990 THOMAS DEWONOTO KOSASIH COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Film with security printing as well as a method for its production The following statement is a full description of this invention including the best method of performing it known to us:-

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The invention concerns a method to produce a film with security printing as well as a

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0 film produced by this method.

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Printed or metallised films are mostly used for packaging foodstuff, packaging medicines, for the purposes of decoration, gift packaging, to coat car windows, as ,IC insulating material for roofs and air conditioning units as well as for many other Cc purposes.

INO

O 10 Such metallised or printed films for packaging purposes are known, for example, from I US 5 631 066 or DE 19 920 356 Al. Due to the increasing use of such films in the packaging industry it happens more often that, when counterfeiting products counterfeit packaging materials, like the above mentioned films, are also being used. To protect themselves from such counterfeits, many manufacturers attempt to make obvious the authenticity of the product by special markings on the package. Special metallised holograms, for example, are used as markings.

WO 99/13157 discloses a security film, wherein first a printed image is applied, that is subsequently superimposed by a metal coating. Finally, at the overlapping regions the printing ink as well as the metallising is removed and thus a negative image of the printed image is produced.

At the same time, however, the forgers continuously attempt to produce such holograms simply and cheaply and thus strikingly similarly imitate the original hologram.

It is therefore an object of the invention to produce a film as well as a method for its production, that has security features which cannot be simply forged, while at the same time the production of packaging films of this type should be possibly inexpensive.

This objective is achieved by that a film according to the invention is first printed at least on one side with a written or pictorial illustration and subsequently the film is at least partly metallised the on the printed side, so that the metallised section will cover the printed section at least in sections.

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o At every position, where a metallised surface and a printed surface are superimposed, a discoloured area will occur on the printed/metallised surface of the film that may seem white-silverish, but the outer contours and the shape of the printed area can be observed. Viewed from the non-printed side the printed area is unchanged and is behind the metallised surface. By virtue of this clearly visible difference of the two sides of the CI film a security feature, that cannot be simply forged, is produced, achieved by a simple Cc and cost-effective method.

IND

A feature of the invention is that for the film and the method films made from C polyester, PVC, nylon or polypropylene are used.

In the first step of the method these films are printed with mono- or multi-coloured written or pictorial illustrations. In principle all current printing methods, like for example screen printing, pad printing or gravure printing are suitable for this.

According to a further feature of the invention this printed film is afterwards at least partly metallised on the printed side. This metallisation can be carried out by vaporising a metal in the form of selected areas, preferably in the shape of strips. As metal gold, silver, copper, platinum, nickel, titanium or the like may be used. The film is preferably metallised with vaporised aluminium, since in this case a clear mirror effect, often desired, is achieved on the film.

The invention is now described more accurately based on figures, embodiments and claims.

Fig.l shows a schematic cross-section through a metallising machine. Fig.2 shows a view of a foil produced by the method according to the invention, viewed from the nonprinted side. Fig.3 shows a view of the foil of Fig.2, viewed from the printed side. Fig.4 shows a cross-section through the film of Fig.2 along the line IV. Fig.5 shows a crosssection through an alternative embodiment of the film according to the invention. Fig.6 shows an embodiment of the invention in the form of a banknote.

The cross-section shown in Fig.l shows schematically the construction of a metallising machine. For a sectional metallising the previously printed film is placed on the feed

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reel 1. The air in the machine space of the metallising machine is continuously

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O evacuated until a vacuum of approx. 5 xl0 4 mbar is achieved. O

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C The printed film is guided over deflector rollers 5 to the guide roller 2 and the pressure roller 4. Aluminium wire 7, situated on an aluminium coil 6, is fed to the evaporation boat 8 in an evaporation container 10, where it is melted at a temperature of 700-1400 I °C and evaporates due to the high vacuum. The evaporationboat 8 is mounted in the Cc evaporation container 10 via evaporation clamps O 10 The aluminium gas, evaporated in this manner, now evenly adheres to the surface of the I film, that is moved past the evaporation container 10 by means of the guide roller 2.

The speed, with which the film is moved past the evaporation container 10, is 3-5 m/s, and it depends on the required thickness of the metallised coating. Preferred coating thicknesses of metallisation are between 50 to a maximum 300 A.

When not the entire film, only sections of it are to be metallised, an additional film masking strip 13 is used, that is moved by the rollers with indentations 11 past the evaporation container 10 synchronously with the guide roller 12 and the film.

Depending on the desired metallisation pattern there are cut-outs present in the film masking strip 13, through which the metallisation is applied to the film. The rollers with indentations 11 will ensure, that the film masking strip 13 is always in the correct position over the film, so that the desired regions are masked and will not be metallised.

After the metallising process the completed printed and metallised film is cooled and guided via deflector rollers 5 to a take-up reel 3.

Figs.2-4 show views of a film according to the invention, that are printed and metallised using the method according to the invention. Fig.2 shows a view of a film 14 from the non-printed side 16. The printed areas 18 of the letters T and L, shown here as examples, are visible from this side as continuously monochromatic, whereas the metallised strips 17 is behind them and does not interrupt the printed areas 18. If, for example, this film is used as a packaging material, the non-printed side 16 can be, for example, the outward facing side, so that the viewer sees the characters in their appropriate colours.

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Fig.3 shows the same film 14 viewed from the other side, therefore from the printed Sside 15. Because the printing and metallising have been carried out on the same side, O the metallised strips 17 are superimposed on the printed areas 18 of both letters T and C L. The concerned sections of the printed areas 18 are, however, not simply covered, but a discoloured metallised area 19 is produced, that, when aluminium is used as metallising material, has a whitish tint. By metallising in high vacuum at high I temperatures, a portion of the printing ink evaporates and a clearly visible whitish Cc colour occurs, showing the contours of the originally printed area. This discoloured and metallised area 19 cannot be produced for the purpose of forging by using conventional I 10 printing inks. Furthermore, in the case of a conventional printing method it is not possible to produce on large-surfaces such interruptions of the areas in the case of, for example, a lettering so accurately that no perceivable misalignments of the individual letters would occur.

Thus, when viewing a film according to the invention, even lay people can simply differentiate a forgery from a genuine film, since a simply printed film would either look the same viewed from both sides, or perceivable misalignments of the individually printed colours would show up at those places where they would have been discoloured by metallisation. Because two machines are used for the method according to the invention, a printer on the one hand and the above described metallising machine on the other, it is not easy for the forger to produce such a film. Forgeries are usually produced by using only printers, by virtue of which they can create the appearance of an original film only on one side; however, when turning it over, a forgery could be immediately recognisable by anyone due to the missing effects of the discoloured metallised areas.

Fig.4 shows a section through the film of Fig.2, sectioned along the line IV-IV. On the printed side 15 of the film 14 one can recognise the printed area 18, onto which the metallising strips 17 were applied. In the intersecting region a portion of the ink of the printed area 18 was evaporated during the metallising, due to which, when viewing the printed side 15, the above described discoloured metallised area 19 is produced. The coating thicknesses are not shown to scale.

shows a section through an alternative embodiment of a film 14 according to the invention, wherein the entire surface of the printed side 15 was metallised. When viewing the printed/metallised side 15, the effect, that the colour of the print is partly evaporated during metallisation, will occur in this case also. When viewing from the

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non-printed side 16, only the printed area 18 can be recognised. In case of a Smetallisation with, for example, aluminium, regions with varying whitish silvery colour

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will occur depending on the strength of the printing ink applied. When viewed from N, this side, the written or pictorial illustration is discoloured, yet its shape is clearly visible. The whitish silvery discoloured areas produced have a special colour tint, that cannot be achieved using conventional, commercially available, printing inks, due to I which the forger cannot imitate this colour tint. In addition, a transparent sealing Cc coating 20 can be applied to the entire surface.

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S 10 Fig.6 shows an embodiment of the invention in the form of a banknote 21, made from a Ic plastic material. A view from above of the printed/metallised surface is shown. In the region of the metallising strip 17 the overlapping printed areas 18 form the discoloured metallised areas 19. When viewing the rear side, the printed areas 18 can be seen in their original colour.

Claims (10)

1. A method to produce a film with security printing, whereby the film is first printed C at least on one side with a written or pictorial illustration and subsequently the film is metallised on the printed side, characterised in that the film (14) is partly metallised the on the printed side, whereby the metallised section (17) covers non-printed film r sections and partial areas of the printed areas and the partially printed areas, covered by Cc metallisation, change their colours. (NO

2. A method according to claim 1, characterised in that a film made from polyester, N PVC, nylon or polypropylene is used.

3. A method according to claim 1 or 2, characterised in that printing methods, like for example screen printing or pad printing, preferably gravure printing are used for the printing of the film with inks suitable for them.

4. A method according to any one of claims 1 to 3, characterised in that the metallisation is carried out in the form of selected areas, preferably in the shape of strips by depositing a vaporised metal, wherein preferably aluminium is used as metal.

A method according to claim 4, characterised in that the printed area (18) and the metallised area (17) intersect in a region, so that the printed and metallised areas are superimposed in the intersecting region (19).

6. A method according to any one of claims 1 to 3, characterised in that a film with written or pictorial illustration is printed on one side of the film (14) and afterwards the entire surface of the printed side is metallised.

7. A film with security printing is produced using the method according to any one of claims 1 to 6, characterised in that on one side the film (14) has at least one printed coating (18) of written or pictorial illustrations and that this coating is superimposed at least partly by a metallised coating (17).

8. A film according to claim 7, characterised in that the film (14) is made from polyester or polypropylene. NO

9. A film according to claim 7 or 8, characterised in that the metallised coating (17) is O made from gold, silver, copper, platinum, nickel, titanium or similar metals, preferably O from vaporised aluminium. (N

10. A film according to any one of claims 7 to 9, characterised in that the metallised coating (17) has a thickness of 50 to 300 A. (N c DATED this 26th day of October 2006 (N Thomas Dewonoto Kosasih Patent Attorneys for the Applicant: F.B. RICE CO.