Natural fiber treatment process

Abstract

The invention refers to a natural fiber treatment process in order to enable the fibers to be conditioned for optimal yarn production, and subsequently of base fabrics. The process comprises the stages of an alkaline treatment, bleaching and the addition of a softening agent.

1 ) A process for treating natural fibers comprising the following stages:
 (a) subjecting the natural fibers to alkaline treatment;   (b) subjecting the fibers obtained in stage (a) to a bleaching phase; and   (c) adding a softening agent to the fibers obtained in stage (b).   
     
     
         2 ) process according to  claim 1 , wherein the natural fibers are from the Aspargaceae family. 
     
     
         3 ) process according to  claim 2 , wherein natural fibers are selected from sisal, Pique, henequen and abaca. 
     
     
         4 ) process according to  claim 1 , wherein the alkaline treatment of stage (a) is carried out by incorporating the natural fibers in a solution of NaOH or KOH 15% (w/v) at a temperature between 25° C. and 100° C. and a time period between 0.1 and 24 hours. 
     
     
         5 ) process according to  claim 1 , wherein the bleaching phase of stage (b) is carried out by chemical treatment or enzymatic treatment. 
     
     
         6 ) process according with  claim 1 , wherein the bleaching phase of stage (b) is carried out by adding an anti-foaming agent, a strong base, a catalyst and a bleaching agent, maintaining a temperature between 20° C. and 100° C., for a period of time between 0.1 and 24 hours. 
     
     
         7 ) process according to  claim 6 , wherein the anti-foaming agent is a stearic derivative of alcohols or siloxanes, the strong base is NaOH or KOH. 
     
     
         8 ) process according to  claim 6 , wherein the catalyst is selected from inorganic salts, hydrocarbons, alcohols, organic acids and derivatives thereof. 
     
     
         9 ) process according to  claim 6 , wherein the bleaching agent is selected from hydrogen peroxide, sodium chlorite, sodium hypochlorite and mixtures thereof. 
     
     
         10 ) process according to  claim 1 , wherein the bleaching process of stage (b) is carried out by means of an enzymatic treatment consisting of adding at least one ligninolytic enzyme selected from peroxidases, oxidases, laccases and mixtures thereof, at a temperature between 20° C. and 80° C. for 0.1 to 168 hours. 
     
     
         11 ) process according to  claim 1 , where the softening agent of stage (c) is selected from silicones, silicone emulsions, silicone nanoemulsions, ligninolytic enzymes and mixtures thereof. 
     
     
         12 ) process according to  claim 1 , which additionally includes a drying stage, carried out at a temperature between 15° C. and 80° C. 
     
     
         13 ) Natural fibers obtained through the process of  claims 1  to  12 , characterized by the following properties: 
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                   Property 
                   Range 
                 
                     
                     
                 
                     
                 
                 
                 
                 
                 
               
                     
                   Length 
                   20-35 
                   mm 
                 
                     
                   Fineness/Diameter 
                   54-125 
                   mm 
                 
                     
                   Tensile strength 
                   48-257 
                   MPa 
                 
                 
                 
                 
               
                     
                   Lignin content 
                   4.2-7.6% 
                 
                     
                   Cellulose content 
                    60-80% 
                 
                     
                   Hemicellulose content 
                    0-13.5%