COMPOSTABLE LID FOR SEALING A BEVERAGE CAPSULE OR A BEVERAGE PAD AND CAPSULES AND PADS SEALED THEREWITH

1 . Compostable lid for sealing a beverage capsule or a beverage pad wherein the lid comprises a natural-fiber based support obtainable by:

providing a first fibrous base sheet comprising natural fiber material sensitive to a gelatinizing agent;

(ii) treating the first base sheet with a gelatinizing agent to give a treated first fibrous base sheet comprising gelatinized material;

(iii) providing a second fibrous base sheet;

(iv) contacting the treated first fibrous base sheet and the second base sheet with each other;

(v) causing at least partial migration of the gelatinized material from the treated first fibrous base sheet into the second fibrous base sheet to give a multilayer product; and

(vi) neutralizing and/or washing the product thus obtained and then drying it;

wherein the amount of constituents of the lid without determined biodegradability is limited to a maximum of 20% by weight.

2 . Method for the preparation of a compostable lid for sealing a beverage capsule or a beverage pad wherein the lid comprises a natural-fiber based support, the method comprising the following steps:

(i) providing a first fibrous base sheet comprising natural fiber material sensitive to a gelatinizing agent;

(ii) treating the first base sheet with a gelatinizing agent to give a treated first fibrous base sheet comprising gelatinized material;

(iii) providing a second fibrous base sheet;

(iv) contacting the treated first fibrous base sheet and the second base sheet with each other;

(v) causing at least partial migration of the gelatinized material from the treated first fibrous base sheet into the second fibrous base sheet to give a multilayer product; and

(vi) neutralizing and/or washing the product thus obtained and then drying it;

wherein the amount of constituents of the support without determined biodegradability is limited to a maximum of 20% by weight.

3 . Method for the preparation of a compostable packaging material, wherein the packaging material comprises a natural-fiber based support, the method comprising the following steps:

(i) providing a first fibrous base sheet comprising natural fiber material sensitive to a gelatinizing agent;

(ii) treating the first base sheet with a gelatinizing agent to give a treated first fibrous base sheet comprising gelatinized material;

(iii) providing a second fibrous base sheet;

(iv) contacting the treated first fibrous base sheet and the second base sheet with each other;

(v) causing at least partial migration of the gelatinized material from the treated first fibrous base sheet into the second fibrous base sheet to give a multilayer product; and

(vi) neutralizing and/or washing the product thus obtained and then drying it;

wherein the amount of constituents of the support without determined biodegradability is limited to a maximum of 20% by weight.

4 . Packaging material obtainable according to claim 3 .

5 . Compostable lid according to claim 1 , wherein the natural fiber material comprises at least one of cellulose and chitosan.

6 . Compostable lid according to claim 1 , wherein the gelatinizing agent comprises acid.

7 . Compostable lid according to claim 1 , wherein the natural fiber material comprises cellulose fibers that are selected from wood pulp fibers, non-wood vegetable fibers and regenerated cellulose fibers.

8 . Compostable lid according to claim 1 , wherein step (ii) of treating the first base sheet with a gelatinizing agent is performed by passing the first base sheet through the gelatinizing agent.

9 . Compostable lid according to claim 1 , wherein the second fibrous base sheet that is provided in step (iii) comprises natural fiber material.

10 . Compostable lid according to claim 1 , wherein the second fibrous base sheet that is provided in step (iii) is a treated second fibrous base sheet that comprises gelatinized material.

11 . Compostable lid according to claim 1 , wherein the first and the second fibrous base sheets are treated simultaneously in step (ii).

12 . Compostable lid according to claim 9 , wherein step (v) involves at least partial migration of the gelatinized material of the treated second fibrous base sheet into the first fibrous base sheet.

13 . Compostable lid according to claim 1 , wherein the beverage capsule or pad is a coffee capsule or a coffee pad.

14 . Compostable lid according to claim 1 , wherein the lid or packaging material further comprises a coating layer on one or both sides of the natural-fiber based support.

15 . Compostable lid according to claim 1 , having an oxygen transmission rate of less than 10 cm 3 /m 2 /day, when determined at 23° C. and 50% relative humidity.

16 . Compostable lid according to claim 1 , having a water vapor transmission rate of less than 10 g/m 2 /day, when determined at 23° C. and 50% relative humidity.

17 . Coffee capsule or coffee pad comprising the compostable lid according to claim 1 .

18 . Packaging material according to claim 4 , wherein the natural fiber material comprises at least one of cellulose and chitosan;

wherein the gelatinizing agent comprises acid;

wherein the natural fiber material comprises cellulose fibers that are selected from wood pulp fibers, non-wood vegetable fibers and regenerated cellulose fibers;

wherein step (ii) of treating the first base sheet with a gelatinizing agent is performed by passing the first base sheet through the gelatinizing agent;

wherein the second fibrous base sheet that is provided in step (iii) comprises natural fiber material;

wherein the second fibrous base sheet that is provided in step (iii) is a treated second fibrous base sheet that comprises gelatinized material; and

wherein the first and the second fibrous base sheets are treated simultaneously in step (ii).

19 . Packaging material according to claim 18 , wherein step (v) involves at least partial migration of the gelatinized material of the treated second fibrous base sheet into the first fibrous base sheet;

wherein the wherein the packaging material is a food wrapping material;

wherein the packaging material further comprises a coating layer on one or both sides of the natural-fiber based support;

wherein the packaging material has an oxygen transmission rate of less than 10 cm 3 /m 2 /day; and

wherein the packaging material has a water vapor transmission rate of less than 10 g/m 2 /day.

20 . Coffee capsule or coffee pad comprising the packaging material according to claim 4 .