Absorbent material

Abstract

This invention relates to absorbent materials useful in the manufacture of absorbent articles, in particular dressings for the advanced wound care market. The absorbent materials of the present invention are sulfonated polysaccharides, particularly water-insoluble cellulose alkyl sulfonates in which the cellulose is substituted by one type of alkyl sulfonate group. The invention also provides a process for the manufacture of such materials. The preferred cellulose alkyl sulfonate described herein is cellulose ethyl sulfonate. Reinforcing fibers and/or antimicrobial agents are optionally applied to the cellulose alkyl sulfonate.

What is claimed and desired to be secured by Letters Patent is as follows: 
     
         1 . A non-woven absorbent fabric comprising:
 a gelling fiber; and   a reinforcing fiber comprising between 4 and 30 weight percent of the fabric, wherein the gelling fiber is blended or bonded with the reinforcing fiber within the non-woven fabric.   
     
     
         2 . The non-woven absorbent fabric of  claim 1 , wherein the absorbency of the fabric is not lower than the absorbency of a fabric comprising the gelling fiber without the reinforcing fiber. 
     
     
         3 . The non-woven absorbent fabric of  claim 1 , wherein the absorbency of the fabric is at least 15 g/g. 
     
     
         4 . The non-woven absorbent fabric of  claim 1 , wherein the wet strength of the fabric is at least 0.6 N/cm. 
     
     
         5 . The non-woven absorbent fabric of  claim 4 , wherein the wet strength of the fabric is at least 1 N/cm. 
     
     
         6 . The non-woven absorbent fabric of  claim 5 , wherein the wet strength of the fabric is at least 2 N/cm. 
     
     
         7 . The non-woven absorbent fabric of  claim 1 , wherein the wet strength of the fabric is greater than the wet strength of a non-woven fabric comprising the gelling fiber without the reinforcing fiber. 
     
     
         8 . The non-woven absorbent fabric of  claim 7 , wherein the reinforcing fiber comprises between 10 and 30 weight percent of the fabric. 
     
     
         9 . The non-woven absorbent fabric of  claim 1 , wherein the reinforcing fiber has a linear density between 0.7 and 30 decitex. 
     
     
         10 . The non-woven absorbent fabric of  claim 9 , wherein the reinforcing fiber has a linear density between 0.7 and 4.0 decitex. 
     
     
         11 . The non-woven absorbent fabric of  claim 1 , wherein said reinforcing fiber comprises a thermoplastic biocomponent fiber that is thermally bonded to said gelling fiber. 
     
     
         12 . The non-woven absorbent fabric of  claim 1 , wherein the gelling fiber is a polysaccharide fiber. 
     
     
         13 . The non-woven absorbent fabric of  claim 12 , wherein said reinforcing fiber comprises a cellulosic fiber. 
     
     
         14 . The non-woven absorbent fabric of  claim 13 , wherein said reinforcing fiber comprises a solvent spun cellulose fiber. 
     
     
         15 . The non-woven absorbent fabric of  claim 14 , wherein said solvent spun cellulose fiber comprises 10 to 30 weight percent of the fabric and has a linear density of 0.7 to 30 decitex. 
     
     
         16 . The non-woven absorbent fabric of  claim 12 , where in the gelling fiber is a polysaccharide alkyl sulfonate. 
     
     
         17 . The non-woven absorbent fabric of  claim 1 , wherein the gelling fiber is derived from the group consisting of alginic acid, carboxymethylcellulose, carboxymethylchitosan, and salts thereof. 
     
     
         18 . The non-woven absorbent fabric of  claim 1 , wherein the gelling fiber has a fiber free absorbency of 0.9% saline solution as a test liquid of at least 8 g/g. 
     
     
         19 . The non-woven absorbent fabric of  claim 1 , wherein the gelling fiber has a fiber free absorbency of 0.9% saline solution as a test liquid of at least 2 g/g. 
     
     
         20 . A non-woven absorbent fabric comprising:
 a gelling fiber; and   a reinforcing fiber, wherein the absorbency of the fabric is not lower than the absorbency of a fabric comprising the gelling fiber without the reinforcing fiber.   
     
     
         21 . The non-woven absorbent fabric of  claim 20 , wherein the absorbency of the fabric is at least 15 g/g. 
     
     
         22 . The non-woven absorbent fabric of  claim 21 , wherein the reinforcing fiber has a linear density between 0.7 and 30 decitex. 
     
     
         23 . The non-woven absorbent fabric of  claim 22 , wherein the reinforcing fiber has a linear density between 0.7 and 4.0 decitex. 
     
     
         24 . The non-woven absorbent fabric of  claim 20 , wherein said reinforcing fiber comprises a thermoplastic biocomponent fiber that is thermally bonded to said gelling fiber. 
     
     
         25 . The non-woven absorbent fabric of  claim 20 , wherein the gelling fiber is a polysaccharide fiber. 
     
     
         26 . The non-woven absorbent fabric of  claim 25 , wherein said reinforcing fiber comprises a cellulosic fiber. 
     
     
         27 . The non-woven absorbent fabric of  claim 26 , wherein said reinforcing fiber comprises a solvent spun cellulose fiber. 
     
     
         28 . The non-woven absorbent fabric of  claim 27 , wherein said solvent spun cellulose fiber comprises 10 to 30 weight percent of the fabric and has a linear density of 0.7 to 30 decitex. 
     
     
         29 . The non-woven absorbent fabric of  claim 25 , where in the gelling fiber is a polysaccharide alkyl sulfonate. 
     
     
         30 . The non-woven absorbent fabric of  claim 20 , wherein the gelling fiber is derived from the group consisting of alginic acid, carboxymethylcellulose, carboxymethylchitosan, and salts thereof. 
     
     
         31 . The non-woven absorbent fabric of  claim 20 , wherein the gelling fiber has a fiber free absorbency of 0.9% saline solution as a test liquid of at least 8 g/g. 
     
     
         32 . The non-woven absorbent fabric of  claim 20 , wherein the gelling fiber has a fiber free absorbency of 0.9% saline solution as a test liquid of at least 2 g/g. 
     
     
         33 . A process for forming a non-woven absorbent fabric comprising:
 blending a gelling fiber with a reinforcing fiber through a card to form a fiber web, wherein the reinforcing fiber comprises no more than 30 weight percent of the fiber web;   forming a non-woven fabric by needlebonding or thermally bonding the fiber web.