METHOD FOR THE PRODUCTION OF A BIODEGRADABLE PLASTIC FILM, AND FILM
A method for producing a biodegradable plastic film or a composite film, and the film obtained by such method. The film has barrier properties and is made at least of a biodegradable basic plastic material and a second plastic material having barrier properties. The film is useful in particular for packaging sensitive goods.
1 . A method of producing a biodegradable plastic film or a film assembly having barrier properties, comprising producing the film or film assembly at least from a biodegradable base plastic material and a second plastic material having barrier properties.
2 . The method according to claim 1 , which comprises extrusion, and wherein the plastic materials are mixed before extrusion and then extruded together.
3 . The method according to claim 2 , wherein the plastic materials are mixed together before extrusion to form a masterbatch and are then extruded together with further base material.
4 . The method according to claim 2 , wherein the plastic materials are each extruded as film plies and conjoined.
5 . The method according to claim 4 , wherein the plastic materials are jointly coextruded.
6 . The method according to claim 4 , wherein the extruded film plies are finished with an adhesion promoter and conjoined with further film plies to form a multi-layered assembly.
7 . The method according to claim 6 , wherein the plastic film or the multilayered assembly is oriented.
8 . The method according to claim 3 , wherein a stabilizer is added to the masterbatch or mixture.
9 . The method according to claim 3 , wherein an adhesion promoter is added to the masterbatch or mixture.
10 . The method according to claim 4 , wherein an adhesion promoter is introduced between two film plies in each case.
11 . The method according to claim 10 , wherein the adhesion promoter is coextruded together with at least one of the two film plies.
12 . The method according to claim 10 , wherein the adhesion promoter is applied onto one of the film plies.
13 . The method according to claim 1 , wherein the base plastic material is admixed with a further plastic material to enhance the compatibility with the barrier material.
14 . The method according to claim 13 , wherein the base plastic material is mixed with a portion of the barrier material.
15 . The method according to claim 1 , wherein the barrier material is admixed with a further plastic material to enhance the compatibility with the base material.
16 . The method according to claim 15 , wherein the barrier material is mixed with a portion of the base plastic material.
17 . The method according to claim 1 , wherein the film is heat molded.
18 . The method according to claim 1 , wherein a biodegradable barrier material is used.
19 . A biodegradable plastic film obtained by a method according to claim 1 , which comprises a PLA (polylactide) as base plastic material.
20 . The biodegradable plastic film according to claim 19 , which comprises a polyvinyl alcohol (PVOH) as additional plastic material.
21 . The biodegradable plastic film according to claim 20 , which comprises a modified PVOH.
22 . The biodegradable plastic film according to claim 19 , which comprises an ethylene-containing vinyl alcohol (EVOH) additional plastic material.
23 . The biodegradable plastic film according to claim 22 , which comprises a modified EVOH.
24 . The biodegradable plastic film according to claim 19 , which comprises a further additive material having barrier properties.
25 . The biodegradable plastic film according to claim 19 , which is produced from a blend of PVOH, modified PVOH, EVOH, modified EVOH and/or further additive materials.
26 . The biodegradable plastic film according to claim 19 , wherein the base plastic material is admixed with up to 50% of the additional plastic material.
27 . The biodegradable plastic film according to claim 19 , wherein the additional plastic material is admixed with up to 50% of base plastic material.
28 . The biodegradable plastic film according to claim 19 , which comprises an adhesion promoting polymer.
29 . The biodegradable plastic film according to claim 28 , wherein the adhesion promoting polymer is a polyethylene or polypropylene, modified by grafting.
30 . The biodegradable plastic film according to claim 28 , wherein the adhesion promoting polymer is an acrylate-based adhesion promoter.
31 . The biodegradable plastic film according to claim 30 , wherein the adhesion promoting polymer is an ethylene acrylate adhesion promoter.
32 . The biodegradable plastic film according to claim 19 , wherein the adhesion promoters are modified with maleic anhydride or the like.
33 . The biodegradable plastic film according to claim 28 , wherein the adhesion promoter is blended with a further plastic material.
34 . The biodegradable plastic film according to claim 33 , wherein the adhesion promoter is blended with the base material and/or the barrier material.
35 . The biodegradable plastic film according to claim 19 , wherein the film is constructed of at least one film layer which has barrier properties with regard to gases.
36 . The biodegradable plastic film according to claim 35 , wherein the film layer is constructed of the base material mixed with the additional plastic material.
37 . The biodegradable plastic film according to claim 35 , wherein the film is constructed of at least two film layers.
38 . The biodegradable plastic film according to claim 37 , comprising one layer fabricated from the base material and another from the additional plastic material.
39 . The biodegradable plastic film according claim 32 , wherein an adhesion promoter is provided between two successive film layers.
40 . The biodegradable plastic film according claim 32 , wherein individual film layers are modified.
41 . The biodegradable plastic film according to claim 40 , wherein the individual film layers are blended with a material which is identical to a material of a next film layer.
42 . The biodegradable plastic film according to claim 19 , wherein the film is oriented.
43 . The biodegradable plastic film according to claim 19 , wherein the film is transparent.
44 . The biodegradable plastic film according to claim 19 , wherein the film is opaque.
45 . The biodegradable plastic film according to claim 19 , wherein the barrier material is biodegradable.
46 . A method of packaging sensitive goods, comprising packaging the goods in a plastic film according to claim 19 , wherein the film has barrier properties with regard to oxygen or the like, and contains nonmodified PLA.