Press felt and base fabric

Abstract

A press felt and a base fabric. The base fabric ( 10 ) includes seam loops ( 4 ) for joining the transverse joining edges of the press felt to each other. In addition to the longitudinal yarns ( 2, 3 ) that form seam loops, the base fabric includes longitudinal surface yarns ( 6 ) extending over a seam ( 1 ) on the web-side surface (D). At the seam, there are additional transverse yarns ( 7 ), which are attached at least to the longitudinal surface yarns so as to form a seam flap ( 8 ). The longitudinal surface yarns ( 6 ) are cut after batt fibre has been attached.

1 . A press felt comprising: 
 at least one base fabric, which includes a bottom side and a side facing the web to be dried and several longitudinal yarns and transverse yarns and where at least some of the longitudinal yarns are arranged to form several seam loops at a first transverse joining edge of the press felt and at a second transverse joining edge, the joining edges of the base fabric being arrangeable edge on edge to form a seam, where the seam loops of the first joining edge and the second joining edge intermesh and form a seam loop channel, into which a seam yarn connecting the joining edges can be inserted;    a seam flap, which is arranged to cover the seam on the press felt surface facing the web, and    at least one batt fibre layer arranged at least on the base fabric surface facing the web, and wherein    the base fabric has at least a three-layer structure which comprises, in addition to the longitudinal yarns forming seam loops, at least one layer of longitudinal surface yarns on the web-side surface of the base fabric, the yarns being arranged to attach to at least some of the transverse yarns,    the longitudinal surface yarns are arranged to continuously extend over the seam when the base fabric is manufactured,    several additional transverse yarns are provided at the seam, the yarns being attached at least to the longitudinal surface yarns, and    the longitudinal surface yarns have been cut after the attachment of batt fibre to form a seam flap.    
   
   
       2 . A press felt according to  claim 1 , wherein 
 the base fabric is a woven structure formed in one phase in one weaving machine.    
   
   
       3 . A press felt according to  claim 1  wherein 
 the structure of the seam flap is reinforced by providing it with at least one additional reinforcing material layer.    
   
   
       4 . A press felt according to  claim 1  wherein 
 the structure of the seam flap is reinforced by attaching the longitudinal surface yarns to the transverse additional yarns by an adhesive and/or by melting their materials.    
   
   
       5 . A press felt according to  claim 1 , wherein 
 at least some of the longitudinal surface yarns are made of plied yarn and that the longitudinal yarns forming seam loops are monofilaments.    
   
   
       6 . A base fabric for a press felt, the base fabric comprising 
 a bottom side and a web side;    several longitudinal yarns, which are arranged to form seam loops on a first and a second transverse edge of the base fabric;    several transverse yarns, which are arranged to attach to the longitudinal yarns,    at least one layer of longitudinal surface yarns on the web side of the base fabric, in addition to the longitudinal yarns that form seam loops    and wherein    the longitudinal surface yarns are attached to at least some of the transverse yarns,    the longitudinal surface yarns extend continuously over the seam formed by the seam loops on the first and the second edge, and    the area where the seam is to be formed is provided with several additional transverse yarns, which are attached at least to the longitudinal surface yarns.    
   
   
       7 . A base fabric according to  claim 6 , wherein 
 each longitudinal yarn is arranged to run in the base fabric so that it does not cross the other longitudinal yarns.