Method of producing latex bonded nonwoven fabric

Abstract

An aqueous based polymer binder that is useful for consolidating nonwoven fabrics made from cellulosic fibers. The polymer binder comprises one or more polymer compositions and is stabilized by one or more high molecular weight protective colloids. While the binder may be utilized with unconsolidated nonwoven fabric webs made by a variety of methods, the binder is particularly useful for application to webs made via the latex bonded airlaid or multibonded airlaid methods. The consolidated fabric upon converting is acceptable for use in cigarette filters as an alternative to cellulose acetate fibers.

1 . A method of producing a nonwoven fabric for use in cigarette filters comprising the steps of forming a web of fibers, and optionally other filling components, via the latex bonded airlaid or multibonded airlaid method and coating the web with an aqueous based polymer binder comprising one or more polymer compositions and one or more stabilizing agents, wherein the nonwoven fabric comprises in the range of about 30 to about 2 parts by dry weight of the binder and in the range of about 70 to about 98 parts by dry weight of the fibers and other filling components, and wherein the binder, fibers and filling components are acceptable for use in cigarette filter applications.  
     
     
         2 . The method of  claim 1 , wherein the fibers comprise fluff pulp fibers.  
     
     
         3 . The method of  claim 1 , wherein the binder comprises one or more polymer compositions selected from the group consisting of vinyl acetate homopolymers, ethylene vinyl acetate copolymers, copolymers of vinyl acetate with vinyl esters of long-chain saturated aliphatic carboxylic acids with lengths up to C 18 , vinyl acetate/veova copolymers and mixtures thereof.  
     
     
         4 . The method of  claim 3 , wherein the one or more polymers are polymerized from monomers selected from the group consisting of ethylene, vinyl acetate, vinyl esters of aliphatic carboxylic acids having chain lengths up to C 18  and mixtures thereof.  
     
     
         5 . The method of  claim 1 , wherein the one or more stabilizing agents are high molecular weight protective colloids.  
     
     
         6 . The method of  claim 5 , wherein the high molecular weight protective colloids are selected from the group consisting of polyvinyl alcohol, ethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxymethycellulose, carboxymethylcellulose, sodium, potassium, and magnesium salts of carboxymethylcellulose, dextrins, gum arabic and mixtures thereof.  
     
     
         7 . A nonwoven fabric for use in cigarette filters made according to the method of  claim 1 .  
     
     
         8 . A polymer binder composition for use in the consolidation of nonwoven fabric webs for application in cigarette filters comprising one or more polymer compositions and one or more high molecular weight protective colloids, wherein the polymers are polymerized from monomers selected from the group consisting of ethylene, vinyl acetate and vinyl esters of aliphatic carboxylic acids with chain lengths of up to C 18 .  
     
     
         9 . The polymer binder composition of  claim 8 , wherein the one or more high molecular weight protective colloids are selected from the group consisting of polyvinyl alcohol, ethylcellulose, hydroxyethylcellulose, methylcellulose, hydroxymethycellulose, carboxymethylcellulose, sodium, potassium, and magnesium salts of carboxymethylcellulose, dextrins, gum arabic and mixtures thereof.  
     
     
         10 . The polymer binder composition of  claim 8 , wherein the polymer composition is selected from the group consisting of vinyl acetate homopolymers, ethylene vinyl acetate copolymers, copolymers of vinyl acetate with vinyl esters of long-chain saturated aliphatic carboxylic acids with lengths up to C 18 , vinyl acetate/veova copolymers and mixtures thereof.  
     
     
         11 . A nonwoven fabric for use in cigarette filters comprising the polymer binder composition of  claim 8.