Press Felt for Papermaking

Abstract

A press felt comprises a base body, a wet paper web side batt layer, and a press side batt layer. The wet paper web side batt layer includes a web contact side batt layer and a base body side batt layer, the latter being composed of core-in-sheath fibers with a core of high molecular weight nylon with an absolute viscosity of 80 mPa·s or more and a sheath of nylon with a lower melting point than the core. The wet paper web contact side batt layer is made of nylon fibers which are not core-in-sheath fibers.

1 . A press felt for papermaking comprising a base body and a batt layer having a wet paper web side layer and a press side layer,
 characterized in that said wet paper web side layer is composed of a wet paper web contract side batt layer and a base body side batt layer,   said base body side batt layer having a core-in-sheath fiber comprising a core member made of high-molecular-weight nylon with an absolute viscosity of 80 mPa·s or more and a sheath member made of nylon with a lower melting point than the core member; and   said wet paper web contact side batt layer being made of nylon without said core-in-sheath fiber.   
   
   
       2 . A press felt as claimed in  claim 1 , in which a content rate of said core-in-sheath fiber in said base body side batt layer ranges from 10% to 60%. 
   
   
       3 - 4 . (canceled) 
   
   
       5 . A press felt as claimed in  claim 1 , in which said base body side batt layer has a plurality of layers in which the content rate of said core-in-sheath fiber increases incrementally from the side press side toward the paper side thereof. 
   
   
       6 . A press felt as claimed in  claim 1 , in which said base body is a fabric woven with a warp yarn and a weft yarn which are monofilament single yarns. 
   
   
       7 . A press felt as claimed in  claim 2 , in which said base body side batt layer has a plurality of layers in which the content rate of said core-in-sheath fiber increases incrementally from the press side toward the paper side thereof. 
   
   
       8 . A press felt as claimed in  claim 5 , in which said base body is a fabric woven with a warp yarn and a weft yarn which are monofilament single yarns. 
   
   
       9 . A press felt as claimed in  claim 7 , in which said base body is a fabric woven with a warp yarn and a weft yarn which are monofilament single yarns.