Process for the production of vermiculite foil

1. A method of producing a sealing foil for gaskets comprising the steps of:

(a) the application of a wet sealing foil material to a forming sheet to form a layer;

(b) partially drying the said wet sealing foil layer on the forming sheet;

(c) removing the said layer from the forming sheet to form a core free gasket sealing foil; and

(d) forming, preferably cutting the layer into at least one suitable shape for use in the formation of a gasket; the sealing foil comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the said CEV component being at least partially derived from dry CEV.

2. A sealing foil for a gasket comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the said CEV component being at least partially derived from dry CEV, the sealing foil not including a core carrier material wherein the sealing foil is suitable for forming, preferably cutting, into a suitable shape for use in combination with a gasket support layer.

3. A method according to claim 1 , wherein the sealing foil layer is combined with a gasket support layer prior to or after the cutting step.

4. Use of a sealing foil for a gasket, the said sealing foil comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the said CEV component being at least partially derived from dry CEV, the sealing foil not including a core carrier material, in the manufacture of a gasket.

5. A method of manufacture of gasket comprising the steps of:

(a) applying a sealing foil comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the said CEV component being at least partially derived from dry CEV, the sealing foil not including a core carrier material to a support layer to form a gasket material and, optionally,

(b) forming, preferably cutting, the gasket material to thereby form the required gasket shape.

6. A method according to claim 5 , wherein the step (a) is preceded by the step (c) of removal of the sealing foil from a forming sheet.

7. A method according to claim 5 , wherein step (b) is carried out prior to step (c).

8. A method according to claim 1 , wherein the sealing foil is at least partially dry prior to use as a sealing foil.

9. A method according to claim 1 , wherein the sealing strip has a small moisture content during use in manufacture.

10. A method according to claim 1 , wherein the sealing strip has a small moisture content during removal from a forming sheet on which the sealing foils are formed.

11. A gasket comprising a sealing foil comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the said CEV component being at least partially derived from dry CEV, wherein the sealing foil has a moisture level of between 3-20% w/w of the sealing foil resilient material during manufacture of the said gasket.

12. A method according to claim 1 , wherein the solids content of the wet sealing foil material is in the range 20-70% w/w of the wet sealing foil material prior to partially drying the said wet sealing foil layer on the forming sheet.

13. A method according to claim 1 wherein the wet sealing foil layer material dough is dried at temperatures between 50-135° C.

14. A method or gasket or sealing foil according to claim 1 , wherein the resilient layer comprises particles of gas-exfoliated vermiculite.

15. A method or gasket or sealing foil according to claim 14 , wherein the material used may be milled or otherwise reduced in particle size.

16. A method of producing a sealing foil according to claim 1 , wherein the sealing foil width is at least 10 cm.

17. A sealing foil for a gasket according to claim 2 , wherein the sealing foil width is at least 10 cm.

18. Use of a sealing foil for a gasket according to claim 4 , wherein the sealing foil width is at least 10 cm.

19. A gasket comprising:

a sealing foil comprising:

a resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the CEV component being at least partially derived from dry CEV;

a wet configuration in which:

the resilient material is adapted to be applied to a forming sheet; and

the sealing foil comprises a solids content in the range 20-70% w/w of the

sealing foil; and

a partially-dried configuration in which:

the sealing foil comprises a moisture level of between 2-20% w/w of the resilient material; and

the resilient material is adapted to be removed from the forming sheet.

20. A method of producing a sealing foil for gaskets, the sealing foil comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the said CEV component being at least partially derived from dry CEV, comprising the steps of:

(a) the application of a wet sealing foil material comprising a mixture of dried CEV and CEV available in a slurry form to a forming sheet to form a layer;

(b) partially drying the said wet sealing foil layer on the forming sheet;

(c) removing the said layer from the forming sheet to form a core free gasket sealing foil; and

(d) forming, preferably cutting the layer into at least one suitable shape for use in the formation of a gasket.

21. A sealing foil for a gasket comprising a resilient material, the resilient material comprising a CEV component in a proportion of at least 25% w/w of the sealing foil, the said CEV component being at least partially derived, during production of the gasket, from dry CEV, the sealing foil not including a core carrier material wherein the sealing foil is suitable for forming, preferably cutting, into a suitable shape for use in combination with a gasket support layer.