Seamed felt for forming fiber cement articles and related methods

Abstract

A fiber cement felt is includes a set of fine top machine direction yarns and a set of fine top cross machine direction yarns interwoven with the top machine direction yarns to form a top fabric layer. A set of coarse bottom machine direction yarns and a set of coarse bottom cross machine direction yarns are interwoven to form a bottom fabric layer. Seam loops merge with the bottom machine direction yarns and define longitudinal ends of the press felt. A batt layer overlies the top fabric layer. The fiber cement felt is positioned on a series of support rolls of a fiber cement forming machine, and then the longitudinal ends of the fiber cement felt is joined at the seam loops to form an endless belt. A fiber cement slurry is deposited on the fiber cement felt, and moisture is removed from the slurry.

1 . A method of forming a fiber cement article, comprising the steps of: 
 (a) providing a fiber cement felt, the fiber cement felt comprising: 
 a set of fine top machine direction yarns;  
 a set of fine top cross machine direction yarns interwoven with the top machine direction yarns to form a top fabric layer;  
 a set of coarse bottom machine direction yarns;  
 a set of coarse bottom cross machine direction yarns interwoven with the bottom machine direction yarns to form a bottom fabric layer;  
 seam loops merging with the bottom machine direction yarns and defining longitudinal ends of the press felt; and  
 a batt layer overlying the top fabric layer  
   (b) positioning the fiber cement felt on a series of support rolls of a fiber cement forming machine; then    (c) joining the longitudinal ends of the fiber cement felt at the seam loops to form an endless belt;    (d) depositing a fiber cement slurry on the fiber cement felt; and    (e) removing moisture from the slurry to form a fiber cement web.    
   
   
       2 . The method of  claim 1 , wherein the bottom cross machine direction yarns are between about 50 tex and about 3000 tex.  
   
   
       3 . The method of  claim 1 , wherein the bottom cross machine direction yarns are between about 80 and about 1500 tex.  
   
   
       4 . The method of  claim 1 , wherein the bottom machine direction yarns are between about 500 and about 4000 tex.  
   
   
       5 . The method of  claim 1 , wherein the bottom machine direction yarns are between about 1000 and about 4000 tex.  
   
   
       6 . The method of  claim 1 , wherein the bottom machine direction yarns include upper and lower portions, each of which interweave with the bottom cross machine direction yarns, and wherein the upper portions and lower portions of the bottom machine yarns merge with the seam loops.  
   
   
       7 . The method of  claim 1 , wherein the bottom machine direction yarns and the bottom cross machine direction yarns interweave in a plain weave pattern.  
   
   
       8 . The method of  claim 1 , further comprising a batt layer attached to and underlying the bottom machine direction yarns.  
   
   
       9 . The method of  claim 1 , wherein the top cross machine direction yarns and top machine direction yarns are selected from the group consisting of: single monofilaments and monofilament twists.  
   
   
       10 . The method of  claim 1 , wherein the top cross machine direction yarns and top machine direction yarns have a diameter of about 0.2 mm to about 1.0 mm.  
   
   
       11 . The method of  claim 1 , wherein the top cross machine direction yarns interweave with the top machine direction yarns in a series of repeat units in which each top machine direction yarn passes over two adjacent machine direction yarns and under the next two adjacent machine direction yarns.  
   
   
       12 . The method of  claim 1 , wherein the joining step comprises inserting a pintle wire in the seam loops to join the longitudinal ends of the fiber cement felt.  
   
   
       13 . A method of forming a fiber cement article, comprising the steps of: 
 (a) providing a fiber cement felt, the fiber cement felt comprising: 
 a set of fine top machine direction yarns;  
 a set of fine top cross machine direction yarns interwoven with the top machine direction yarns to form a top fabric layer;  
 a set of coarse bottom machine direction yarns, the bottom machine direction yarns comprising polyamide and aramid, the yarns having a fineness of at least 2000 tex;  
 a set of coarse bottom cross machine direction yarns interwoven with the bottom machine direction yarns to form a bottom fabric layer;  
 seam loops merging with the bottom machine direction yarns and defining longitudinal ends of the press felt; and  
 a batt layer overlying the top fabric layer  
   (b) positioning the fiber cement felt on a series of support rolls of a fiber cement forming machine; then    (c) joining the longitudinal ends of the fiber cement felt at the seam loops to form an endless belt;    (d) depositing a fiber cement slurry on the fiber cement felt; and    (e) removing moisture from the slurry to form a fiber cement web.    
   
   
       14 . The method of  claim 13 , wherein the bottom cross machine direction yarns are between about 50 tex and about 3000 tex.  
   
   
       15 . The method of  claim 13 , wherein the bottom machine direction yarns and the bottom cross machine direction yarns interweave in a plain weave pattern.  
   
   
       16 . The method of  claim 13 , further comprising a batt layer attached to and underlying the bottom machine direction yarns.  
   
   
       17 . The method of  claim 13 , wherein the joining step comprises inserting a pintle wire in the seam loops to join the longitudinal ends of the fiber cement f