Glass Mat with Synthetic Wood Pulp

Abstract

A non-woven mat may be generated using synthetic wood pulp and short glass fibers. The non-woven mat may be made in very thin, light weight configurations for various uses. The synthetic wood pulp may serve as a dispersant to disperse the glass fibers in a mixture prior to using paper making techniques to form the mat. A heat flux may bind the glass fibers by melting the synthetic wood pulp to form a mat. The mat may be calendered. In some embodiments, the mat may have a secondary application of a polymer, such as PVDF or PMMA which may further strengthen the mat.

1 . A method for manufacturing a glass fiber non-woven mat for use as a separator for an electrochemical cell, said method comprising:
 creating a mixture comprising glass fibers, synthetic wood pulp, and a liquid carrier;   mixing said mixture to disperse and suspend said glass fibers and said synthetic wood pulp in said liquid carrier;   passing said mixture through a screen to deposit said glass fibers and said synthetic wood pulp onto said screen;   heating said glass fibers and said synthetic wood pulp to at least partially melt said synthetic wood pulp and at least partially bind said glass fibers to create said glass fiber non-woven mat.   
     
     
         2 . The method of  claim 1 , said mixture comprising a ratio of said synthetic wood pulp to said glass fibers between 40% and 80%. 
     
     
         3 . The method of  claim 2 , said mixture comprising at least 1% polyethylene oxide. 
     
     
         4 . The method of  claim 2 , said synthetic wood pulp being polyethylene having a moisture content of at least 25%. 
     
     
         5 . The method of  claim 4 , said glass fibers having a nominal length of no more than 0.5 inches. 
     
     
         6 . The method of  claim 5 , said glass fibers having a nominal length of no more than 0.25 inches. 
     
     
         7 . The method of  claim 6 , said heating comprising a first heating step and a second heating step, said first heating step being performed at least partially while said glass fibers and said synthetic wood pulp are on said screen and said second heating step being performed after said glass fibers and said synthetic wood pulp are removed from said screen. 
     
     
         8 . The method of  claim 7 , said second heating step being a higher temperature than said first heating step. 
     
     
         9 . The method of  claim 8 , said method further comprising:
 calendering said glass fiber non-woven mat.   
     
     
         10 . The method of  claim 9 , said calendering comprising said second heating step. 
     
     
         11 . The method of  claim 1  further comprising:
 applying a second polymer to said glass fiber non-woven mat. 
 
     
     
         12 . The method of  claim 11 , said second polymer being a different polymer from said synthetic wood pulp. 
     
     
         13 . The method of  claim 12 , said second polymer being PVDF. 
     
     
         14 . The method of  claim 12 , said second polymer being PMMA. 
     
     
         15 . The method of  claim 1 , said mixture being created by a mixing method comprising:
 performing a first mixing operation said synthetic wood pulp in a first mixture comprising polyethylene oxide and water; and   diluting said first mixture with water to form said mixture.   
     
     
         16 . The method of  claim 15 , said first mixing operation comprising ultrasonic mixing. 
     
     
         17 . The method of  claim 16 , said first mixture comprising no more than 4% polyethylene oxide. 
     
     
         18 . The method of  claim 17 , said first mixture comprising no more than 2% polyethylene oxide. 
     
     
         19 . The method of  claim 1 , said glass fiber non-woven web having an areal weight between 5 and 20 grams per meter squared. 
     
     
         20 . The method of  claim 1 , said glass fiber non-woven web having an areal weight of less than 10 grams per meter squared.