Compostable multilayer membranes and cartridges using such membranes

1. A compostable multilayer membrane, for cartridges containing soluble products or products adapted to be brewed by pressurized water or other fluid, the compostable multilayer membrane comprising:

a first barrier layer containing a compostable barrier film;

a first metallization layer;

an intermediate layer containing at least one adhesive;

a second barrier layer containing a compostable barrier film;

a layer adjacent to the first barrier layer, on a side opposite to the first metallization layer, the adjacent layer comprising heat-resistant lacquer;

a second metallization layer between the intermediate layer and the second harrier layer; and

a filter made of nonwoven fabric;

wherein the compostable barrier film of the first barrier layer is not made of cellulosic material,

wherein the compostable barrier film of the second barrier layer is not made of cellulosic material,

wherein the compostable multilayer membrane has an Oxygen Transfer Rate (OTR) value lower than 0.5 cc/m 2 /day/atm, and

wherein the filter is adjacent to the second barrier layer on a side opposite to the intermediate layer.

2. The compostable multilayer membrane of claim 1 , wherein a thickness of the compostable multilayer membrane is greater than or equal to 40 microns (μm) and less than or equal to 200 μm.

3. The compostable multilayer membrane of claim 1 , wherein the compostable multilayer membrane has an elastic modulus greater than or equal to 3 Newtons (N) and less than or equal to 30 N, as measured according to ASTM F 1306.

4. The compostable multilayer membrane of claim 1 , wherein the compostable barrier film of the first barrier layer is oriented or non-oriented, and

wherein the compostable barrier film of the second barrier layer is oriented or non-oriented.

5. The compostable multilayer membrane of claim 1 , wherein the at least one adhesive comprises: polyurethane adhesives;

one-, two-, or multi-component adhesives; adhesives comprising blocked isocyanates; or pressure-sensitive adhesives (PSA).

6. The compostable multilayer membrane of claim 1 , further comprising:

a third barrier layer containing lacquer having oxygen-barrier properties;

wherein the compostable multilayer membrane has an OTR value lower than 0.1 cc/m 2 /day/atm.

7. The compostable multilayer membrane of claim 6 , wherein the lacquer having oxygen-barrier properties comprises lacquers based on polyvinylidene chloride (PVDC); polyvinyl alcohol resin as such or modified with silanes; cellulose; acrylic resin; or epoxy resin.

8. The compostable multilayer membrane of claim 1 , wherein the first metallization layer is composed of aluminum and/or the second metallization layer is composed of aluminum.

9. The compostable multilayer membrane of claim 8 , wherein a thickness of the first metallization layer is greater than or equal to 200 Angstroms (Å) and less than or equal to 500 Å.

10. The compostable multilayer membrane of claim 1 , wherein the first metallization layer and/or the second metallization layer are formed by deposition of SiOx and AlOx oxides.

11. The compostable multilayer membrane of claim 1 , further comprising:

a third barrier layer between the intermediate layer and the first metallization layer;

wherein the third barrier layer comprises lacquer having oxygen: barrier properties.

12. The compostable multilayer membrane of claim 11 , wherein the lacquer having oxygen-barrier properties comprises lacquers based on polyvinylidene chloride (PVDC); polyvinyl alcohol resin as such or modified with silanes;

cellulose; acrylic resin; or epoxy resin.

13. The compostable multilayer membrane of claim 11 , wherein the lacquer having oxygen-barrier properties is coupled to the first metallization layer using primer.

14. The compostable multilayer membrane of claim 1 , wherein the compostable barrier film of the first barrier layer is oriented, and

wherein the compostable barrier film of the second barrier layer is oriented.

15. The compostable multilayer membrane of claim 1 , wherein the compostable barrier film of the first barrier layer is oriented, and

wherein the compostable barrier film of the second barrier layer is non-oriented.

16. The compostable multilayer membrane of claim 1 , wherein the compostable barrier film of the first barrier layer is non-oriented, and

wherein the compostable barrier film of the second barrier layer is oriented.

17. The compostable multilayer membrane of claim 1 , wherein the compostable barrier film of the first barrier layer is non-oriented, and

wherein the compostable barrier film of the second barrier layer is non-oriented.

18. The compostable multilayer membrane of claim 2 , wherein the compostable multilayer membrane has an elastic modulus greater than or equal to 3 Newtons (N) and less than or equal to 30 N, as measured according to ASTM F 1306.

19. The compostable multilayer membrane of claim 8 , wherein a thickness of the second metallization layer is greater than or equal to 200 Angstroms (Å) and less than or equal to 500 Å.

20. The compostable multilayer membrane of claim 12 , wherein the lacquer having oxygen-barrier properties is coupled to the first metallization layer using primer.