NZ525610A

NZ525610A - Laminated plastic and metal film suitable for providing airtight packaging for articles soup cubes and the like

Info

Publication number: NZ525610A
Application number: NZ52561003A
Authority: NZ
Inventors: Andraes Michalsky; Rinaldo Battegazzore; Jochen Hertlein; Rolf Bachmann
Original assignee: Huhtamaki Ronsberg
Priority date: 2003-05-01
Filing date: 2003-05-01
Publication date: 2004-10-29

Abstract

Disclosed is a plastic film suitable for packaging three dimensional objects, such as soup cubes . Such films comprise a base film that is metallised on one side, and which comprises an oriented polypropylene or PET film . On the metallised side of the film there is a pattern coating of a sealing lacquer that seals at a raised temperature on some areas, and the areas of the film where the sealing liqueur is not applied are provided with an overlacquer that is also pattern coated. Preferably the polypropylene or PET film is oriented biaxially and may have a primer or tie layer between the metallization and the printing . The base film may be a compact film, and may have cavities in the form of vacuoles or produced by foaming .

Description

525 6 10 NEW ZEALAND PATENTS ACT, 1953 No: Date: COMPLETE SPECIFICATION PLASTIC FILM We, HUHTAMAKI RONSBERG ZWEIGNIEDERLASSUNG DER HUHTAMAKI, a German company of Deutschland GmbH & Co KG, Heinrich Nicolaus-Str. 6, D-87671 Ronsberg, Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: (followed by page la) INTELLECTUAL PROPERTY OFPICI ©F NX " 1 MAV 2003 RECEIVED la Description The invention relates to a plastic film, especially for packaging three-dimensional objects such as soup cubes in particular, with a base film made from a polyolefin or polyethylene terephthalate that is preferably metallised on one side.

DE-A-199 48 286 discloses a plastic film, particularly for packaging preferably cube-shaped products such as soup cubes, where the plastic film consists of a polyolefin film, preferably PE or PP.

Known plastic films suitable for packaging three-dimensional objects, preferably cube-shaped products such as soup cubes, have the problem that the packaging process is difficult to handle and/or the packaging does not guarantee an airtight closure.

On the basis of this, the aim of the invention is to design a plastic film of the kind outlined above in such a way that simple packaging of the objects and largely airtight closure of them is guaranteed.

In the solution to this problem proposed by the invention, an oriented polypropylene film, preferably a biaxially oriented polypropylene film or a PET film, is provided as the base film, on one side of which, preferably the side with the metallisation, printing is provided, to which in turn a pattern coating of a sealing lacquer that seals at a raised temperature is applied.

In a particular aspect, the present invention provides a plastic film for packaging three-dimensional objects, said film comprising a base film, which is metallised on one side and which comprises an oriented polypropylene or PET film, wherein on the metallised side of the film a pattern coating of a sealing lacquer that seals at a raised temperature is applied and wherein the areas of the film to which the sealing lacquer is not applied are provided with an overlacquer that is also pattern coated. property" OFFICE OF N.Z 13 AUG 2004 RECEIVED Polypropylene film oriented in one direction or biaxially and PET film have very good tightness properties, which are improved even more by the addition of metallisation on one side.

The pattern coated sealing lacquer permits tight closure of a pack made from this plastic film that is folded around the object, with the pattern application making sure that only as much sealing lacquer is used as is necessary for closing purposes.

In accordance with an advantageous further development of the invention, the areas of the printing and / or metallisation to which the sealing lacquer is not applied are provided with an overlacquer that is also pattern coated.

This means that these areas of the print motif and / or the metallisation in addition to those coated with the sealing lacquer are protected and the thickness of the film remains consistent across its entire width, so that even winding of the film is possible.

In another advantageous further development of the invention, a primer and / or tie layer is provided between the metallisation and the printing.

It has proved to be very advantageous if in accordance with another advantageous further development of the invention a compact film is provided as the base film. As used herein, the term "compact film" is to be understood as meaning a film that has no holes or the like incorporated within the film.

A film with cavities in it can, however, be provided as the base film in accordance with the invention too.

INTELLECTUAL PROPERTY OFFICE OF N.2 13 AUG » RECEIVED 3 Both types of film have proved to be very effective in this context, with the film with cavities in it appearing to be largely opaque, because light refraction occurs at the edges of the cavities.

The cavities can take the form of vacuoles that are produced when the film is oriented.

It is, however, also possible to produce the cavities by foaming.

If a compact base film is used, a thickness of about 10 to 100 p., preferably 20 to 50 \i and in particular 28 to 32 p. is provided for this film in accordance with the invention.

If a base film with cavities is used on the other hand, a thickness of about 10 to 100 (a., preferably 20 to 50 |j. and in particular 35 to 40 (i has proved to be advantageous.

It is provided in another advantageous further development of the invention that the side of the base film facing away from the printing that is located preferably on the inside is provided with at least one further layer.

One embodiment of the invention is illustrated in the drawings: Fig. 1 is a diagrammatic cross section of a film structure with a clear film and Fig. 2 is a diagrammatic cross section of another film structure with an opaque film. 1 in Fig. 1 is a plastic film that has a base film 2 which consists of oriented polyproplyene (OPP). The orientation can be carried out either in one direction or biaxially. This base film 2 is provided with metallisation 3 on one side. To improve bonding, the metallisation 3 is provided on its side facing away from the base film 2 T:\DATEN\WORD\4P\RO\Ro7280\7280deb_e.sxw with a primer layer 4, to which in turn printing 5 is applied. A pattern coating of a sealing lacquer 6 that seals at a raised temperature is applied to this printing 5, with the sections to which this sealing lacquer 6 is not applied being provided with an overlacquer 7.

A thickness of 30 (j. has proved to be effective for the base film 2 made from oriented polypropylene (OPP). The areas to which the sealing lacquer 6 are applied are arranged in such a way that tight closures can be produced when a section of the plastic film 1 is folded up around a three-dimensional object that is not illustrated.

The main difference in the embodiment of a plastic film 21 as shown in Fig. 2 is that an opaque and oriented polypropylene film (OPP) with a thickness of 38 n is used as the base film 22.

The opacity of the base film is produced during orientation, when vacuoles are formed in the film and cause refraction of light.

The cavities can, however, also be produced by foaming the film.

The base film 22 has metallisation 3 in this case as well, to which printing 5 has been applied via a primer layer 4. A pattern coating of sealing lacquer 6 is applied to this printing 5 too, so that this lacquer is only present at the places needed to form and close a pack. The remaining sections are again provided with an overlacquer 7.

An application thickness of 1 to 5 g/m2 is specified for the overlacquer 7; this thickness can vary between 0.1 and 15 g/m2 according to requirements and is adapted to the thickness of the sealing lacquer 6 that is applied.

T:\DATEN\WORD\4P\RO\Ro7280\7280deb_e.sxw The side of the base film 22 facing away from the metallisation can - as the illustration shows - be provided with another coating 8, in order to achieve further barrier properties.

A PET film can be used as the base film instead of a polypropylene film.

T:\DATEN\WORD\4P\RO\Ro7280\7280deb_e.sxw

Claims

WHAT WE CLAIM IS:

1. A plastic film for packaging three-dimensional objects, said film comprising a base film, which is metallised on one side and which comprises an oriented polypropylene or PET film, wherein on the metallised side of the film a pattern coating of a sealing lacquer that seals at a raised temperature is applied and wherein the areas of the film to which the sealing lacquer is not applied are provided with an overlacquer that is also pattern coated.

2. A plastic film according to claim 1, wherein the three-dimensional objects are soup cubes.

3. A plastic film according to claim 1 or 2, wherein the polypropylene or PET film is biaxially oriented.

4. A plastic film according to claim 1, 2 or 3, wherein a primer and/or tie layer is provided between the metallization and the printing.

5. A plastic film according to any one of claims 1 to 4, wherein a compact film is provided as the base film.

6. A plastic film according to any one of claims 1 to 4, wherein a film with cavities in it is provided as the base film.

7. A plastic film according to claim 6, wherein the cavities take the form of vacuoles that are produced when the film is oriented. f INTELLECTUAL PROPERTY OFFICE OF N.Z 13 AUG 2004 RECEIVED ■4> «

8. A plastic film according to claim 6, wherein the cavities are produced by foaming.

9. A plastic film according to claim 5, wherein the compact base film has a thickness of from about 10 to 100 |im.

10. A plastic film according to claim 9, wherein the thickness is from 20 to 50 pm.

11. A plastic film according to claim 9, wherein the thickness is from 28 to 32 pm.

12. A plastic film according to claim 6, 7 or 8, wherein the base film with cavities in it has a thickness of from about 10 to 100|im.

13. A plastic film according to claim 12, wherein the thickness is from 20 to 50 pm.

14. A plastic film according to claim 12, wherein the thickness is from 35 to 40 pm.

15. A plastic film according to any one of claims 1 to 14, wherein the side of the base film facing away from the printing is provided with at least one further layer.

16. A plastic film according to claim 15, wherein the side of the base film that is provided with the at least one further layer is located on the inside.

17. A plastic film according to any one of claims 1 to 16, substantially as herein described.