Yarn comprising gel-forming filaments or fibres
View Patent ↗A yarn comprising gel forming filaments or fibers particularly one used to make a woven or knitted wound dressing or other gelling fabric structure. The invention provides a yarn comprising a blend of from 30% to 100% by weight of gel-forming fibers and 0% to 70% by weight of textile fibers. Process for making the yarns are also described including those using rotor spinning.
1. A yarn comprising a blend of from 30% to 100% by weight gel-forming fibres and 0% to 70% by weight textile fibres, wherein the fibres are rotor spun to produce the yarn, and the yarn has a dry tensile breaking strength of at least about 400 cN, the yarn capable of being converted into a fabric by knitting.
2. A yarn as claimed in claim 1 wherein the staple fibre length is from 30 to 60 mm.
3. A yarn as claimed in claim 1 having a dry tensile strength of at least 10cN/tex.
4. A yarn as claimed in claim 1 wherein the yarn comprises a blend of from 50% to 100% by weight of gel forming fibres with from 0% to 50% of textile fibres.
5. A process for making a yarn comprising gel-forming fibres comprising the steps of:
blending staple gel-forming fibres optionally with textile fibres;
carding to form a continuous web;
drawing the web to produce a sliver and rotor spinning to produce a yarn; wherein the yarn has a dry tensile breaking strength of at least about 400 cN.
6. A process for making a yarn comprising gel forming fibres or filaments, comprising the steps of
(i) obtaining a yarn of cellulosic filaments or fibres;
(ii) chemically modifying the yarn to give the yarn gel forming properties,
wherein the chemically modified yarn has a dry tensile strength of at least about 400 cN, the yarn capable of being converted into a fabric by knitting.
7. A process as claimed in claim 6 wherein the chemical modification is carboxymethylation using a reaction fluid comprising a solution of an alkali and monochloroacetate in an organic solvent.
8. A process for making a yarn as claimed in claim 5 wherein the tensile strength of the yarn is at least 10cN/tex.
9. A yarn as claimed in claim 1 wherein the gel forming fibres are polysaccharide fibres, chemically modified cellulosic fibres, pectin fibres, alginate fibres, chitosan fibres, hyaluronic acid fibres or fibres derived from gums.
10. A yarn as claimed in claim 1 wherein the gel forming fibres are modified cellulose fibres.
11. A process for making a yarn as claimed in claim 5 wherein the gel forming fibres are polysaccharide fibres, chemically modified cellulosic fibres, pectin fibres, alginate fibres, chitosan fibres, hyaluronic acid fibres or fibres derived from gums.
12. A process for making a yarn as claimed in claim 5 wherein the gel forming fibres are modified gel forming fibres.
13. A process for making a yarn as claimed in claim 6 wherein the tensile strength of the yarn is at least 10 cN/tex.
14. A process for making a yarn as claimed in claim 6 , wherein the gel forming fibres are polysaccharide fibres, chemically modified cellulosic fibres, pectin fibres, alginate fibres, chitosan fibres, hyaluronic acid fibres or fibres derived from gums.
15. A process for making a yarn as claimed in claim 6 wherein the gel forming fibres are modified gel forming fibres.
16. A process for making a yarn as claimed in claim 5 , wherein the gel forming fibres are modified cellulose fibres.
17. A process for making a yarn as claimed in claim 6 , wherein the gel forming fibres are modified cellulose fibres.