Absorbent material

1. A non-woven absorbent product comprising an admixture of

(i) 75-85% by weight of carboxymethyl chitosan fibres, and

(ii) 15-25% by weight of chitosan fibres incorporating at least one antimicrobial agent;

wherein the at least one antimicrobial agent is an insoluble compound and is only present in the chitosan fibres of (ii), said at least one antimicrobial agent being present at a level of 5-20% by weight based on the weight of chitosan fibres of (ii).

2. A product as claimed in claim 1 wherein the carboxymethyl chitosan has a degree of carboxymethylation in the range 0.3-1.4.

3. A product as claimed in claim 1 wherein the insoluble compound is a silver compound.

4. A product as claimed in claim 3 wherein the silver compound has a silver content of greater than 50% by weight as calculated on the basis of the chemical formula of the salt but excluding any water of crystallisation.

5. A product as claimed in claim 1 wherein the insoluble compound is a copper salt.

6. A product as claimed in claim 5 wherein the copper salt has a copper content of at least 33% by weight as calculated on the basis of the chemical formula of the salt but excluding any water of crystallisation.

7. A product as claimed in claim 1 wherein the insoluble compound is a salt of iodine.

8. A product as claimed in claim 1 wherein the chitosan contains EDTA or a salt thereof.

9. A product as claimed in claim 1 which comprises:

(i) about 80% by weight of the carboxymethyl chitosan fibres, and

(ii) about 20% by weight of the chitosan fibres containing the said at least one antimicrobial agent.

10. A product as claimed in claim 1 which is a needled felt.

11. A method of producing a non-woven absorbent product comprising an admixture of

(i) 75-85% by weight of carboxymethyl chitosan fibres, and

(ii) 15-25% by weight of chitosan fibres incorporating at least one antimicrobial agent;

wherein the at least one antimicrobial agent is an insoluble compound and is only present in the chitosan fibres of (ii), said at least one antimicrobial agent being present at a level of 5-20% by weight based on the weight of chitosan fibres of (ii), said method comprising the steps of:

(i) providing said carboxymethyl chitosan fibres;

(ii) providing said chitosan fibres incorporating said at least one antimicrobial agent; and

(iii) blending said carboxymethyl chitosan fibres and said chitosan fibres incorporating at least one antimicrobial agent to produce the absorbent product.

12. A method as claimed in claim 11 wherein said chitosan fibres incorporating said at least one antimicrobial agent are prepared by spinning a dope containing dissolved chitosan and an antimicrobial agent into a precipitation bath to produce fibres.

13. A method as claimed in claim 11 wherein said insoluble compound is a silver compound.

14. A method as claimed in claim 13 wherein the silver compound has a silver content of greater than 50% by weight as calculated on the basis of the chemical formula of the salt excluding any water of crystallisation.

15. A method as claimed in claim 12 wherein said insoluble compound is a copper salt.

16. A method as claimed in claim 15 wherein the copper salt has a copper content of at least 33% by weight of copper based on chemical formula of the salt but excluding any water of crystallisation.

17. A method as claimed in claim 11 wherein said chitosan fibres containing said at least one antimicrobial agent are prepared by spinning a dope containing dissolved chitosan into a precipitation bath to form fibres and treating said precipitated fibres with a treatment solution which contains an antimicrobial agent.

18. A method as claimed in claim 17 wherein the antimicrobial agent in said treatment solution is iodine and/or a salt of iodine.

19. A method as claimed in claim 18 wherein said antimicrobial agent in said treatment solution is PHMB.