Refined fiber

Abstract

A refined fiber having an average length of 2 to 4 millimeter, a filler retention value of at least 18%, and a green strength value of at least 1.8 mJ/mm 2 is described. The fiber is obtainable by a process wherein never dried yarn or sliver having a length of at least 1 meter is refined, by at least the step of feeding the yarn or sliver and a liquid into a refiner, which includes refiner fillings having a body surrounding a central hole, and at least one inlet for the yarn or sliver. Thus obtained fibrillated fiber may be used for making friction materials, gaskets, brake pads, or brake linings.

1 . A refined fiber having a length weighted length LL 0.25  of 2 to 4 millimeter, a filler retention value of at least 18%, and a green strength value of at least 1.8 mJ/mm 2 . 
     
     
         2 . The fiber of  claim 1  obtained by a process wherein never dried yarn or sliver having a length of at least 1 meter is refined, by at least feeding the yarn or sliver and a liquid into a refiner, which comprises refiner fillings having a body surrounding a central hole, and at least one inlet for the yarn or sliver. 
     
     
         3 . The fiber of  claim 1  wherein the fiber is never dried. 
     
     
         4 . The fiber of  claim 1  wherein the green strength value is 1.8 to 3.5 mJ/mm 2 . 
     
     
         5 . The fiber of  claim 1  wherein the fiber is PPTA fiber. 
     
     
         6 . Friction materials, gaskets, brake pads, or brake linings comprised of the refined fiber of  claim 1 . 
     
     
         7 . (canceled) 
     
     
         8 . The fiber of  claim 1  wherein the refined fiber is comprised of cellulose, hempen, cotton, wool, aramid, polyamide, polyester or polyacrylonitrile.