Microfiber-containing fiber reinforced facer mats and method of making

Abstract

Fiber-reinforced composite mats are described that include a non-woven web of fibers. The web of fibers may include a first group of fibers having an average fiber diameter from about 8 μm to about 25 μm, and a second group of fibers having an average fiber diameter from about 0.5 μm to about 6.5 μm. A binder bonds together the non-woven web of fibers into the fiber reinforced composite having an air permeability of 250 cfm/ft 2 or less. Also described are gypsum boards that include one or more facers affixed to at least one surface of the gypsum board. The facers may be made from the above, described fiber-reinforced composite mats.

What is claimed is: 
     
         1 . A fiber-reinforced composite mat comprising:
 a non-woven web of fibers, wherein the fibers comprise:
 a first group of fibers having an average fiber diameter from about 8 μm to about 25 μm; and 
 a second group of fibers having an average fiber diameter from about 0.5 μm to about 6.5 μm; and 
   a binder to bond together the non-woven web of fibers into the fiber reinforced composite, wherein the composite has an air permeability of 250 cfm/ft 2  or less.   
     
     
         2 . The fiber-reinforced composite of  claim 1 , wherein the air permeability of the composite is 250 cfm/ft 2  to about 150 cfm/ft 2 . 
     
     
         3 . The fiber-reinforced composite of  claim 1 , wherein the air permeability of the composite is 250 cfm/ft 2  to about 200 cfm/ft 2 . 
     
     
         4 . The fiber-reinforced composite of  claim 1 , wherein the air permeability of the composite is about 230 cfm/ft 2  to about 235 cfm/ft 2 . 
     
     
         5 . The fiber-reinforced composite of  claim 1 , wherein the first group of fibers have an average fiber diameter of about 13 μm. 
     
     
         6 . The fiber-reinforced composite of  claim 1 , wherein the second group of fibers have an average fiber diameter of about 2.5 μm. 
     
     
         7 . The fiber-reinforced composite of  claim 1  wherein:
 the first group of fibers comprise about 70 wt. % to about 90 wt. % of a total weight of fibers; and 
 the second group of fibers comprise about 10 wt. % to about 30 wt. % of the total weight of fibers. 
 
     
     
         8 . The fiber-reinforced composite of  claim 7 , wherein the second group of fibers comprises about 20 wt. % of the total weight of the fibers. 
     
     
         9 . The fiber-reinforced composite of  claim 1 , wherein the thickness of the fiber-reinforced composite comprises about 10 mils to about 30 mils. 
     
     
         10 . The fiber-reinforced composite of  claim 1 , wherein the binder comprises a styrene-acrylic copolymer. 
     
     
         11 . The fiber-reinforced composite of  claim 1 , wherein the binder comprises a water repellant additive. 
     
     
         12 . The fiber-reinforced composite of  claim 1 , wherein the composite is a facer for a building material. 
     
     
         13 . The fiber-reinforced composite of  claim 1 , wherein the building material comprises gypsum board. 
     
     
         14 . The fiber reinforced composite of  claim 1 , wherein the fibers are selected from the group consisting of glass, mineral, wool, ceramic, carbon, metal, refractory materials, and mixtures thereof. 
     
     
         15 . The fiber reinforced composite of  claim 1 , wherein fibers are glass fibers selected from the group consisting of E glass, C glass, T glass, sodium borosilicate glass, and mixtures thereof. 
     
     
         16 . A gypsum board comprising:
 a fiber-reinforced composite facer affixed to at least one surface of the gypsum board, wherein the facer comprises:
 a non-woven web of fibers, wherein the fibers comprise:
 a first group of fibers having an average fiber diameter from about 8 μm to about 25 μm; and 
 a second group of fibers having an average fiber diameter from about 0.5 μm to about 6.5 μm; and 
 
 a binder to bond together the non-woven web of fibers into the fiber reinforced composite, 
   
       wherein the fiber-reinforced composite facer has an air permeability of 250 cfm/ft 2  or less. 
     
     
         17 . The gypsum board of  claim 16 , wherein the gypsum board comprises two or more of the fiber-reinforced composite facers. 
     
     
         18 . A process for manufacturing a fiber-reinforced composite, the process comprising:
 blending a first group of fibers having an average fiber diameter from about 8 μm to about 25 μm with a second group of fibers having an average fiber diameter from about 0.5 μm to about 6.5 μm to form a non-woven web of fibers;   contacting the non-woven web of fibers with a binder solution to form a wet mat; and   curing the wet mat to form a fiber-reinforced composite mat, wherein the fiber-reinforced composite mat has an air permeability of 250 cfm/ft 2  or less.   
     
     
         19 . The process of  claim 18 , wherein the process further comprises applying an aqueous slurry to a surface of the fiber-reinforced composite mat, wherein the slurry comprises at least one material selected from the group consisting of calcium sulfate, calcium sulfate hemi-hydrate, and hydraulic setting cement. 
     
     
         20 . The process of  claim 18 , wherein the process further comprises:
 providing a first facer comprising the fiber-reinforced composite mat;   distributing an aqueous slurry to form a layer on the first facer, wherein the aqueous slurry comprises at least one material selected from the group consisting of calcium sulfate, calcium sulfate hemi-hydrate, and hydraulic setting cement;   applying a second facer onto the top of the layer formed from the aqueous slurry to form a laminate;   separating the laminate into individual pieces; and   drying the pieces, wherein the first facer provides a first face of the dried piece with a smoothness sufficient to permit the dried article to be directly painted.   
     
     
         21 . The method of  claim 20 , where the dried piece comprises a piece of gypsum board.