| JP5796322 | Lid material |
| JP4839680 | Biaxially stretched polyester film with excellent adhesiveness |
| JP2005288986 | LAMINATE |
GAREGNANI ANTONIO (IT)
| EP1332868A1 | 2003-08-06 | |||
| US4532189A | 1985-07-30 | |||
| FR2795995A1 | 2001-01-12 | |||
| US20010055692A1 | 2001-12-27 | |||
| US6706343B1 | 2004-03-16 | |||
| EP1258348A1 | 2002-11-20 | |||
| US5261536A | 1993-11-16 |
CLAIMS
1) An extendable multilayer film made of plastic material, in particular for packaging, characterized in that it comprises at least three layers: a first layer
(1) made of adhesivizing material, a second layer (2) made of linear material, and a third layer (3) made of copolymer or monomer.
2) The film according to the preceding claim, characterized in that said second layer (2) of linear material is set between said first, adhesivizing, layer (1) and said third layer (3) made of copolymer or monomer; thus obtaining that said extendable multilayer film has a particularly transparent appearance and presents an adhesivizing surface to be positioned in contact with the product to be packaged and a copolymer or monomer surface, opposed to said adhesivizing surface, facing outwards.
3) The film according to Claim 1, characterized in that said third, copolymer or monomer, layer (3) is set between said first, adhesivizing, layer (1) and said second layer (2) of linear material; thus obtaining that said extendable multilayer film presents an adhesivizing surface to be positioned in contact with the product to be packaged and a surface of linear ' material, opposed to said adhesivizing surface, facing outwards.
4) The film according to any one of the preceding claims, characterized in that said third layer (3) is a polypropylene layer.
5) The film according to Claim 2 or Claim 3, characterized in that, considering only the overall weight of the second layer (2) and of the third layer (3), the linear material of the second layer (2) has a weight percentage of from 20 wt% to 90 wt%, whereas the copolymer or monomer of the third layer (3) is present in a weight percentage of from 80 wt% to 10 wt%.
6) The film according to the preceding claim, characterized in that the second layer (2) has 60 wt% of linear material and in that the third layer (3) has 40 wt% of copolymer or monomer. 7) The film according to any one of the preceding claims, characterized in that said linear material is a metallocenic-catalysis material for enhancing the resistance to perforation.
8) The film according to Claim 1, characterized in that it comprises one or more further layers added to or set between the preceding three layers (1, 2, 3) .
9) The film according to any one of the preceding claims, characterized in that said third layer (3) is a layer of copolymer of a random type. 10) A high-strength and high-transparency extendable film, in particular for packaging, substantially as described and illustrated in the present description and in the attached drawings. |
HIGH-STRENGTH AND HIGH-TRANSPARENCY EXTENDABLE
MULTILAYER FILM
*****
The present invention relates to the ' packaging
^ sector, and regards, in particular, to an innovative extendable film made of plastic material characterized by a higher strength and degree of transparency as compared to traditional extendable films.
More specifically, said extendable film is a multilayer film and comprises at least three layers: an adhesivizing layer, a copolymer or monomer layer, and a layer of linear material. Currently known on the market are extendable films, which, albeit having a certain degree of transparency, do not enable the label of the product that is packaged by means of the film itself to be read easily. This entails the drawback that, if a person wishes to read the ^ label of the product packaged properly, he has to tear the package at least partially.
Consequently, the main task of the present invention is to overcome this drawback by providing an extendable film for packaging characterized t by high strength and transparency.
The above has been obtained, according to the invention; by providing an extendable multilayer film, which comprises at least three layers: an adhesivizing layer, a copolymer or monomer layer, such as, for example, polypropylene, and a layer of linear material.
It is preferable for the layer of linear material to be set between the adhesivizing layer designed to
come into contact with the product to be packaged and the copolymer or monomer layer.
A better understanding of the invention will be obtained from the ensuing detailed description and with reference to the attached drawings, which illustrate, purely by way of example, two preferred embodiments. In the drawings :
Figure 1 shows a first embodiment of a film made up of three layers: an adhesivizing layer, a polypropylene layer, and a layer of linear material set between the first two layers, in which the layer of linear material is set between the other two layers;
Figure 2 shows a second embodiment of a film, similar to that of Figure 1, in which the polypropylene layer is set between the layer of linear material and the adhesivizing layer.
With reference to Figure 1, in the first embodiment described, a high-strength extendable film having a particularly high degree of transparency is provided, which comprises three layers: a first, adhesivizing, layer 1, a second layer 2 made of linear material, and a third layer 3 made of copolymer or monomer, where said second layer 2 of linear material is set between the adhesivizing layer 1 and the copolymer or monomer layer 3.
According to a peculiar characteristic of the invention, the film with three payers has an adhesivizing surface to be positioned in contact with the product to be packaged, and a copolymer or monomer surface, opposed to said adhesivizing surface, facing outwards. In other words, as. may be seen in Figure 1,
on a gathering reel, the first, adhesivizing, layer 1, in direct contact with said reel, is coupled to the second layer 2 of linear material and, the latter is coupled to the third, copolymer or monomer, layer 3. According to the invention, considering only the overall weight of the second layer 2 and of the third layer 3, it is preferable for the linear material of the second layer 2 to have a weight percentage of from 20 wt% to 90 wt% and for the copolymer or monomer of the third layer 3 to have a weight percentage of from 80 wt% to 10 wt%.
For example, it is envisaged that the second layer 2 will have 60 wt% of linear material and that the third layer 3 will have 40 wt% of copolymer or monomer. It is moreover preferable for said linear material to be a metallocenic-catalysis material in order to enhance the resistance to perforation.
In the example described, said third layer 3 is a polypropylene layer. In the second embodiment shown in Figure 2, an extendable multilayer film is provided similar to the one described so far, in which, however, the copolymer or monomer layer 3 is set between the adhesivizing layer 1 and the layer 2 of linear material. Advantageously, as already mentioned, the films described are provided with a greater stiffness as compared to traditional films and a modest elastic return. This enables particularly rigid packagings to be obtained without the palletized freight being deformed by the normal elastic return.
Finally, according to the invention, it is
preferable for the copolymer or monomer of the third layer 3 ' to be a copolymer of a random type.
The present invention has been described and illustrated according to two preferred embodiments, but it is understood that modifications and/or equivalent replacements may be made by any person skilled in the branch, without thereby departing from the sphere of protection of the present industrial patent right. For example^, it is possible to provide an extendable film having one or more further layers added or set between the ones described so far.