THIN FILM FOR WASTE PACKING

Abstract

The present invention refers to a polymeric film comprising odor barrier material for and being able to packing malodorous waste. The film comprises at least 95% biodegradable materials.

Claims

1. A multilayer film for malodorous item packaging, where the film comprises: a layer comprising a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) and a barrier layer comprising an oxygen barrier material, wherein the film comprises at least 95% biodegradable material, and wherein the film has a thickness from 10 to 50 microns.

2. The multilayer film of claim 1, wherein the layer comprising a blend of PBAT and PLA is designed as inner layer or outer layer of the film.

3. The multilayer film of claim 1, wherein the film comprises an inner layer and an outer layer, and wherein each of the inner layer and the outer layer comprises the blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA).

4. The multilayer film of claim 1, comprising the following layer structure: OUTER LAYER/INTERMEDIATE LAYER/BARRIER LAYER/INTERMEDIATE LAYER/INNER LAYER

5. The multilayer film of claim 1, comprising the following layer structure: OUTERLAYER/ABUSE LAYER/INTERMEDIATE LAYER/BARRIER LAYER/INTERMEDIATE LAYER/ABUSE LAYER/INNER LAYER

6. The multilayer film of claim 1, wherein the film has a weight of between 15 g/m.sup.2 and 45 g/m.sup.2.

7. The multilayer film of claim 1, wherein the PLA content in a layer comprising a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) is less than 50% per weight.

8. The multilayer film of claim 1, wherein the barrier layer comprises amorphous PVA polymer.

9. A method for packaging malodourous items comprising the use of the multilayer film of claim 1.

10. A method for producing a multilayer film of claim 1, wherein the method is a hot blown film method or wherein the film is produced by extrusion through a flat cast die.

11. The multilayer film of claim 2, comprising the following layer structure: OUTER LAYER/INTERMEDIATE LAYER/BARRIER LAYER/INTERMEDIATE LAYER/INNER LAYER

12. The multilayer film of claim 2, comprising the following layer structure: OUTERLAYER/ABUSE LAYER/INTERMEDIATE LAYER/BARRIER LAYER/INTERMEDIATE LAYER/ABUSE LAYER/INNER LAYER

13. The multilayer film of claim 2, wherein the film has a weight of between 15 g/m.sup.2 and 45 g/m.sup.2.

14. The multilayer film of claim 2, wherein the PLA content in a layer comprising a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) is less than 50% per weight.

15. The multilayer film of claim 2, wherein the barrier layer comprises amorphous PVA polymer.

16. The multilayer film of claim 3, comprising the following layer structure: OUTER LAYER/INTERMEDIATE LAYER/BARRIER LAYER/INTERMEDIATE LAYER/INNER LAYER

17. The multilayer film of claim 3, comprising the following layer structure: OUTERLAYER/ABUSE LAYER/INTERMEDIATE LAYER/BARRIER LAYER/INTERMEDIATE LAYER/ABUSE LAYER/INNER LAYER

18. The multilayer film of claim 3, wherein the film has a weight of between 15 g/m.sup.2 and 45 g/m.sup.2.

19. The multilayer film of claim 3, wherein the PLA content in a layer comprising a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) is less than 50% per weight.

20. The multilayer film of claim 3, wherein the barrier layer comprises amorphous PVA polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0053] According to a first aspect the present invention is directed to a multilayer film for malodorous item packaging, wherein the film comprises [0054] a layer comprising a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) and [0055] a barrier layer comprising an oxygen barrier material, [0056] wherein the film comprises at least 95% biodegradable material and wherein the film has a thickness from 10 to 50 microns.

[0057] According to a preferred embodiment the film has a weight of between 15 g/m.sup.2 and 45 g/m.sup.2.

[0058] In a further preferred embodiment the PLA content in a layer comprising a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) is less than 50% per weight.

[0059] In a further preferred embodiment, the film comprises the construction:

OUTERLAYER/ABUSELAYER/INTERMEDIATELAYER/BARRIER LAYER/INTERMEDIATE LAYER/ABUSE LAYER/INNER LAYER

[0060] In another preferred embodiment, the film comprises the construction

OUTERLAYER/INTERMEDIATELAYER/BARRIERLAYER/INTERMEDIATE LAYER/INNER LAYER

DETAILED DESCRIPTION OF THE LAYERS

Barrier Layer

[0061] In a preferred version of the invention, the oxygen barrier material is substantially amorphous PVA polymer.

[0062] The substantially amorphous PVA polymer is described e.g. in U.S. Pat. No. 8,026,302 by Nippon Gohsei. This material can be used by itself or in a blend with a minor content of other materials in order to assist in maintaining the oxygen barrier properties at high humidity levels. Amorphous polyamide is preferred in a percentage not exceeding 10%, preferable not exceeding 5% per weight.

[0063] The oxygen barrier material preferably has a weight of less than 10 g/m.sup.2, more preferably less than 5 g/m.sup.2 and even more preferably less than 3 g/m.sup.2.

Outer Layer.

[0064] In a preferred version, the outer layer comprises a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA).

[0065] In a further preferred version, the weight of the outer layer is less than 15 g/m.sup.2, more preferably less than 10 g/m.sup.2.

[0066] In a further preferred version, the layer may also comprise other polymers such as polybutylene succinate (PBS), polybutylene succinate adipate (PB SA) and/or polycaprolactone (PCL).

[0067] In a further preferred embodiment the PLA content in the layer is less than 70%, preferable less than 50%, more preferably less than 40%.

[0068] In a further preferred version the layer comprises additives like slip agents, antiblock agents, antioxidants and/or moisture absorbers and/or adsorbers.

Inner Layer

[0069] In a preferred version, the inner layer comprises a blend of polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA).

[0070] In a further preferred version, the thickness of the outer layer is less than 25 microns, more preferably less than 15 microns.

[0071] In a further preferred version, the layer may also comprise other polymers such as polybutylene succinate (PBS), polybutylene succinate adipate (PB SA) and/or polycaprolactone (PCL).

[0072] In a further preferred embodiment the PLA content in the inner layer is less than 70%, preferable less than 50%, more preferably less than 40%.

[0073] Ina further preferred version the layer comprises additives like slip agents, antiblock agents, antioxidants and/or moisture absorbers and/or adsorbers.

Intermediate Layers

[0074] In the intermediate layers, typical adhesive resins like maleic anhydrite modified polymers may be used. Typical examples are polymers as described in US 2014/0308534.

Additives

[0075] Additives well known in the art may be used in one or more layers of the present invention. Slip additives, antiblock additives, antifog, polymer processing aids may be used if pertinent. In order to increase the mechanical properties the film may be crosslinked with one of the following methods.

Crosslinking

[0076] Preferably the film is crosslinked. The film can be crosslinked by any known method suitable to crosslink polymer films according to the present invention. Preferably the crosslinking is obtained by e-beam radiation, gamma radiation, moisture crosslinking using silane grafting compounds, or peroxide crosslinking.

Production of the Film

[0077] The preferred production method for the film is the hot blown film method, which is well known in the art. Other methods like extrusion through flat cast die are also possible.

[0078] The film may be in tubular form or sealed at the edges or single sheet configuration. Centrefold configuration is also possible.

Potential Uses of the Film as Per the Invention

[0079] Except the use of the film in storing waste with the help of a cassette as described above, the film can be used in pouch, bag, tubular or other configuration for uses such as [0080] retail bags [0081] garbage bags [0082] hygiene bags
and other similar applications.

EXAMPLES

Example 1

[0083] A 5 layer film is produced in a commercial hot blown film line with the following recipe (all percentages are percentages by weight)

TABLE-US-00001 Inner layer 80% ECOVIO F2331 + 10% PBAT based antiblock + 10% PBAT based slip, 13 microns Adjacent layer 100% ADH 1, 4 microns Barrier layer 100% G POLYMER OKS 8074, 4 microns Adjacent layer 100% ADH1, 4 microns Outer layer 90% ECOVIO F2331 + 5% PBAT based antiblock + 5% PBAT based slip, 7 microns

[0084] ADH1 is a maleic anhydride modified aliphatic polyester copolymer.

[0085] G POLYMER OKS 8074 is an amorphous PVA polymer.

[0086] Ecovio F2331 is a ready-made compound comprising PBAT and PLA. The PLA content in the layer is less than 30% by weight.

Example 2

[0087] A 5 layer film is produced in a commercial hot blown film line with the following recipe (all percentages are percentages by weight)

TABLE-US-00002 Inner layer 80% ECOVIO F2331 + 10% PBAT based antiblock + 10% PBAT based slip, 13 microns Adjacent layer 100% ADH 1, 4 microns Barrier layer 100% G POLYMER OKS 8074, 3 microns Adjacent layer 100% ADH1, 4 microns Outer layer 90% ECOVIO F2223 + 5% PBAT based antiblock + 5% PBAT based slip, 7 microns

[0088] Ecovio F2331 is a ready-made compound comprising PBAT and PLA. The PLA in both the inner and the outer layer is less than 30%.

COMPARATIVE EXAMPLE

[0089] A 5 layer film is produced in a hot blown film commercial line with the following recipe (all percentages are percentages by weight)

TABLE-US-00003 Inner layer 80% EAO1 + 15% SNR1 + 5% ADDITIVES, 7 microns Adjacent layer 100% ADH 1, 2.5 microns Barrier layer 100% EVOH 1, 2 microns Adjacent layer 100% ADH1, 2.5 microns Outer layer 100% PP, 2, 5 microns
EAO1 is ethylene octene copolymer, Dowlex 5056G, density 0.919.
SNR1 is an inorganic additive compound
EVOH 1 is an ethylene vinyl alcohol as defined herein,TESTS [0090] 1. Odor testing. [0091] 2. Cassette compression test is explained below.

Cassette Compression Test

[0092] The test is performed as described in the following:

[0093] A commercial litter cassette is emptied and then filled with 20 meters of film of each example, all slitted at the same width. Then the “spring back effect” of each film is monitored in order to judge if the film could work in a cassette filling operation. Then a lid is put and the operator tries to remove the film from the cassette simulating the real procedure done by the people using this system.

[0094] According to the test, the films of the examples 1 and 2 had a good “spring back” effect. During the second part of the test they were removed by the cassette without breakages or other problems.

[0095] The film according to comparative example 1 has very good “spring back” effect. In general, its performance in this test was equal to the examples as per the invention.

Odor Testing

[0096] 30 soiled nappies were packed in a tube made of each ones of films according to examples 1 and 2 and comparative example—10 nappies per each film. Then they were put each one in a hermetically closed glass jar.

[0097] After 24 h, a panel of 7 people evaluated each sample, and rated the film with best odor barrier properties with a score of 3, the second-best with a score of 2, and the third-best with a score of 1.

[0098] The films received the following total score:

TABLE-US-00004 Example 1 16 Example 2 13 Comparative Example 13