AU2003203874B2

AU2003203874B2 - Plastic film

Info

Publication number: AU2003203874B2
Application number: AU2003203874A
Authority: AU
Inventors: Rolf Bachmann; Rinaldo Battegazzore; Jochen Hertlein; Andreas Michalsky
Original assignee: Huhtamaki Ronsberg Zweigniederlassung der Huhtamaki Deutschland GmbH and Co KG
Current assignee: Huhtamaki Ronsberg Zweigniederlassung der Huhtamaki Deutschland GmbH and Co KG
Priority date: 2002-05-11
Filing date: 2003-04-28
Publication date: 2009-03-05
Anticipated expiration: 2023-04-28
Also published as: ATE461126T1; PT1361171E; ES2341230T3; DE10221141A1; EP1361171A2; ZA200303107B; EP1361171B1; CN100556686C; BR0301371A; PL207013B1; EP1361171A3; AU2003203874A1; CN1461702A; MXPA03004082A; IL155498A0; CA2426984A1; PL360049A1; DE10221141B4; BR0301371B1; DE50312511D1

Abstract

Plastic film (1, 21), especially for packaging rectangular objects such as stock cubes, comprising a base film (preferably metallised on one side) consisting of biaxially oriented polypropylene film or polyethylene terephthalate film with printing (5) (preferably on the metallised layer (3)) and an outer layer of heat-sealing varnish (6) in the appropriate places.

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant Invention HUHTAMAKI RONSBERG ZWEIGNIEDERLASSUNG DER HUHTAMAKI DEUTSCHLAND GMBH CO KG Title: PLASTIC FILM The following statement is a full description of this invention, including the best method of performing it known to me/us:

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N, Description Plastic film 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 cubeshaped products such as soup cubes, where the plastic film consists of a polyolefin film, preferably PE or PP.

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.

According to the present invention, there is provided a plastic film containing a polyolefin or polyethylene terephthalate base film in which the base film comprises an oriented polypropylene film having printing provided on one surface or side thereof, a sealing lacquer applied to the printing provided on the base layer, said sealing lacquer N A 4lboumrC \PI P nlc 9(XX)49P9T 14 ALSpccAP49314 Ro28l1dox 21)AIA Sbeing sealed at a raised temperature, and an overlacquer applied to the printing wherein the sealing lacquer and the overlacquer are both applied to the printing in a S pattern coating in which the pattern coating comprises the overlacquer being applied to c-I areas of the printing to which the sealing lacquer is not applied so as to form the plastic film with a subsantially uniform thickness.

1- 00 In the solution to this problem proposed by the invention, an oriented polypropylene mc film, preferably a biaxially oriented polypropylene film or a PET film, is provided as 0 the base film, on one side of which, preferably the side with the metallisation, printing (Ni NMWclbou Cas\PcnW9(O-49999P49314 ALASpccP493 14,Ro7280 dmc is provided, to which in turn a pattern coating of a sealing lacquer that seals at a raised temperature is applied.

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.

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

H:\Vlma\Kep\Specifications\P493 4.Ro728O.doc 28/04/03 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 P 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 t, preferably 20 to 50 ,p and in particular 35 to 40 p 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 H:\Valma\Keep\Spcifctions\P49314.Ro728O.doc 28104/03 bonding, the metallisation 3 is provided on its side facing away from the base film 2 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 t 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 p 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/m 2 is specified for the overlacquer 7; this thickness can vary between 0.1 and 15 g/m 2 according to requirements and is adapted to the thickness of the sealing lacquer 6 that is applied.

H:\Valma\Kcep\Speciflcations\P493 14.Ro728O.doc 28/04/03 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.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the word "comprises" has a corresponding meaning.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

H:\Valma\Kep\Specirciion'P493 14.Ro728O.doc 28/04/03

Claims

1. A plastic film containing a polyolefin or polyethylene terephthalate base film in which the base film comprises an oriented polypropylene film having printing provided on one surface or side thereof, a sealing lacquer applied to the printing provided on the base layer, said sealing lacquer being sealable at a raised temperature, and an 0 o overlacquer applied to the printing wherein the sealing lacquer and the overlacquer are S both applied to the printing in a pattern coating in which the pattern coating comprises the overlacquer being applied to areas of the printing to which the sealing lacquer is c not applied.

2. A plastic film according to claim 1 for packing three-dimensional objects.

3. A plastic film according to claim 2 in which the three-dimensional object is a soup cube.

4. A plastic film according to any preceding claim in which the base film is metallised on one side or surface.

A plastic film according to claim 4 in which the printing is applied to the side being metallised.

6. A plastic film according to any preceding claim in which the oriented polypropylene film is a biaxially oriented polypropylene film or a polyethylene terephthalate film.

7. A plastic film according to any one of claims 4 to 6 wherein a primer and/or tie layer is provided between the metallisation and the printing. N:\Mlburn\CI.T.I mlUW 9(M)049 314 AL Spcmi04934 I4Ro728 doc 2)A) A9 I S

8. A plastic film according to any preceding claim wherein the base film is a compact film.

9. A plastic film according to any preceding claim wherein the base film is a film provided with cavities therein. 00oo Mc

10. A plastic film according to claim 9, wherein the cavities take the form of vacuoles that are produced when the film is oriented.

11. A plastic film according to claim 9, wherein the cavities are produced by foaming.

12. A plastic film according to any one of claims 8 to 11, wherein the compact base film has a thickness of 10 to 100 t.

13. A plastic film according to claim 12 wherein the compact base film has a thickness of 20 to 50 p.

14. A plastic film according to claim 12 wherein the compact base film has a thickness of 28 to 32 t.

A plastic film according to claim 9 to 14 wherein the base film provided with cavities has a thickness of 10 to 100 t.

16. A plastic film according to claim 15 wherein the base film provided with cavities has a thickness of 20 to 50 pi.

17. A plastic film according to claim 15 wherein the base film provided with cavities has a thickness of 35 to 40 N Welbour(\CarPl\PnIc90(XU--49999PP314 A SpvcciP493 14 RoM2tdc 201011)9 S

18. A plastic film according to any preceding claim in which the plastic film formed by the application of the pattern coating has a substantially uniform thickness. O

19. A plastic film according to any one of the preceding claims, wherein the side of the base film facing away from the printing, preferably the inner side of the film, is 00 C provided with at least one further layer. A plastic film substantially as hereinbefore described with reference to the accompanying drawings. N \MclbomrrrCCDY\PIIcnlUYIIX)-9"99\P 14. A L Spc-P491 14 ROM28l dx IOA I)Y