Smooth reinforced cementitious boards

Abstract

A composite fabric for use in reinforcement of cementitious boards and similar prefabricated building wall panels. The fabric includes an open mesh first component of continuously coated, high modulus of elasticity strands and a nonwoven second component fabricated from alkali resistant thermoplastic material. The high modulus strands of the first component are preferably bundled glass fibers encapsulated by alkali and water resistant thermoplastic material. The composite fabric also has suitable physical characteristics for embedment within the cement matrix of the panels or boards closely adjacent the opposed faces thereof. The reinforcement provides long-lasting, high strength tensile reinforcement and impact resistance for the panels or boards. The reinforcement also enables the boards to have smooth outer faces suitable for painting, papering, tiling or other finishing treatment. Included as part of the invention are methods for making the reinforcement, cementitious boards and panels including the reinforcement, and methods for manufacturing such boards and panels.

What is claimed is:  
     
         1 . Composite fabric reinforcement for cementitious boards comprising: 
 an open mesh first component of high modulus of elasticity fiber strands continuously covered by alkali-resistant polymeric material; and    a nonwoven web second component.    
     
     
         2 . The reinforcement of  claim 1  wherein said polymeric material is thermoplastic material.  
     
     
         3 . The reinforcement of  claim 1  wherein said second component is fabricated from thermoplastic material.  
     
     
         4 . The reinforcement of claims  2  or  3  wherein said thermoplastic material is selected from the group consisting of olefins, polyolefins, olefin copolymers, polypropylene, polyethylene, ethylene propylene rubber, thermoplastic polyolefin rubber, polyvinylidene chloride, polyvinyl chloride compounds, ethylene-propylene diene monomer, copolymers of polybutylene and propylene, and copolymers of styrene and butadiene.  
     
     
         5 . The reinforcement of  claim 1  wherein said mesh has a strand count of about 2 to about 15 strands per inch in each direction.  
     
     
         6 . The reinforcement of  claim 1  wherein said strands comprise bundled glass fibers having a linear density of about 33 to about 300 tex.  
     
     
         7 . A substantially planar cementitious board having first and second opposed faces, said cementitious board comprising: 
 cementitious matrix material; and    composite fabric reinforcement embedded within said cementitious matrix material, said reinforcement comprising an open mesh first component of high modulus fiber strands continuously coated with alkali-resistant polymeric material and a nonwoven web second component.    
     
     
         8 . The board of  claim 7  wherein said polymeric material is thermoplastic material.  
     
     
         9 . The method of  claim 7  wherein said second component is fabricated from thermoplastic material.  
     
     
         10 . The method of claims  8  or  9  wherein said thermoplastic material is selected from the group consisting of olefins, polyolefins, olefin copolymers, polypropylene, polyethylene, ethylene propylene rubber, thermoplastic polyolefin rubber, polyvinylidene chloride, polyvinyl chloride compounds, ethylene-propylene diene monomer, copolymers of polybutylene and propylene, and copolymers of styrene and butadiene.  
     
     
         11 . A method of making reinforcement for cementitious boards comprising the steps of: 
 (a) providing an open mesh first component of high modulus of elasticity fiber strands covered with alkali-resistant polymeric material;    (b) providing a nonwoven web second component; and    (c) uniting said first and second components.    
     
     
         12 . The method of  claim 11  wherein said polymeric material is thermoplastic material.  
     
     
         13 . The method of  claim 11  wherein said second component is fabricated from thermoplastic material.  
     
     
         14 . The method of claims  12  or  13  wherein said thermoplastic material is selected from the group consisting of olefins, polyolefins, olefin copolymers, polypropylene, polyethylene, ethylene propylene rubber, thermoplastic polyolefin rubber, polyvinylidene chloride, polyvinyl chloride compounds, ethylene-propylene diene monomer, copolymers of polybutylene and propylene, and copolymers of styrene and butadiene.  
     
     
         15 . The method of  claim 11  further comprising the step of treating at least one of said first and second components to enhance at least one of wetting and adhesion characteristics thereof.  
     
     
         16 . The method of  claim 15  wherein said treating step is performed before said uniting step.  
     
     
         17 . The method of  claim 15  wherein said treating step is performed after said uniting step.  
     
     
         18 . The method of  claim 11  wherein said mesh has a strand count of about 2 to about 15 strands per inch in each direction.  
     
     
         19 . The method of  claim 11  wherein said strands comprise bundled glass fibers having a linear density of about 33 to about 300 tex.  
     
     
         20 . A method of making a reinforced cementitious board having first and second faces, said method comprising the steps of: 
 selecting composite fabric reinforcement comprising an open mesh first component of high modulus of elasticity fiber strands continuously covered with alkali resistant polymeric material and a nonwoven web second component; and    embedding said reinforcement in cementitious matrix material.    
     
     
         21 . The method of  claim 20  wherein said polymeric material is thermoplastic material.  
     
     
         22 . The method of  claim 20  wherein said second component is fabricated from thermoplastic material.  
     
     
         23 . The method of claims  21  or  22  wherein said thermoplastic material is selected from the group consisting of olefins, polyolefins, olefin copolymers, polypropylene, polyethylene, ethylene propylene rubber, thermoplastic polyolefin rubber, polyvinylidene chloride, polyvinyl chloride compounds, ethylene-propylene diene monomer, copolymers of polybutylene and propylene, and copolymers of styrene and butadiene.  
     
     
         24 . The method of  claim 20  wherein said mesh has a strand count of about 2 to about 15 strands per inch in each direction.  
     
     
         25 . The method of  claim 20  wherein said strands comprise bundled glass fibers having a linear density of about 33 to about 300 tex.  
     
     
         26 . The method of  claim 20  further comprising, prior to said step of embedding, the step of treating at least one of said first and second components to enhance at least one of wetting and adhesion characteristics thereof.