Construction Board

Abstract

The present application provides wood fiberboard comprising wood fibers bound together with a binder polymer resin that imparts additional strength and moisture resistance. As well, the fiberboard incorporates a thermal fire suppressing inorganic expandable flake graphite and sodium silicate component to render the fiberboard to be non-combustible and fire resistant. As well, a manufacturing process for adding the inorganic graphite and polymer resin binder into the fiberboard and applying the silicate onto the fiberboard is provided.

What is claimed is: 
     
         1 . A fiberboard composition comprising:
 a plurality of ligno-cellulosic fibers; and   an inorganic expandable flake graphite in an amount between 10 and 50 percent by weight for providing fire resistance.   
     
     
         2 . The fiberboard composition of  claim 1 , further comprising a waterborne polymer binder resin in a suitable amount for providing water resistance. 
     
     
         3 . The fiberboard composition of  claim 1  further comprising a silicate for enhancing fire resistance. 
     
     
         4 . The fiberboard composition of  claim 1 , wherein said inorganic expandable graphite does not expand at temperatures less than about 240° C. 
     
     
         5 . The fiberboard composition of  claim 2 , wherein said waterborne polymer binder resin is selected from the group consisting of: latex, natural rubber, gutta-percha, styrene-butadiene rubber, styrene-isoprene rubber, polyisoprene, polybutadiene, polychloroprenes, organic polysulphides, butyl rubber, halogenated butyl rubber, chlorinated polyethelene, chlorosulfanated polyethylene, ethylene-propoylene rubber, butadiene acrylonitrile copolymers, polyvinyl acetate, vinyl-acrylic, styrene-acrylic, and all acrylic polymers. 
     
     
         6 . The fiberboard composition of  claim 3 , wherein said silicate is selected from the group consisting of: sodium silicate and potassium silicate. 
     
     
         7 . The fiberboard composition of  claim 3 , wherein said silicate contains around 10% water. 
     
     
         8 . A method of making a fiberboard comprising:
 forming a pulp slurry comprising a plurality of ligno-cellulosic fibers and water;   adding of an inorganic expandable graphite to said pulp slurry for providing fire resistance to the fiberboard;   pressing said pulp slurry and said inorganic expandable graphite to form at least one layer of pre-fiberboard composition;   interfelting said layer of pre-fiberboard composition to form a pre-fiberboard; and   drying said pre-fiberboard.   
     
     
         9 . The method of making a fiberboard of  claim 8 , further comprising adding of a waterborne polymer binder resin to said pulp slurry for providing water resistance and strength to the fiberboard. 
     
     
         10 . The method of making a fiberboard of  claim 8 , further comprising coating said pre-fiberboard with a silicate for enhancing fire resistance of said fiberboard. 
     
     
         11 . The method of making a fiberboard of  claim 8 , further comprising press rolling said pre-fiberboard to limit roughness of the fiberboard. 
     
     
         12 . The method of  claim 8 , wherein said inorganic expandable graphite does not expand at temperatures less than about 240° C. 
     
     
         13 . The method of  claim 8 , wherein said inorganic expandable graphite is added at a rate of about 10 lbs per minute. 
     
     
         14 . The method of  claim 9 , wherein the waterborne polymer binder resin is selected from a group consisting of: latex, natural rubber, gutta-percha, styrene-butadiene rubber, styrene-isoprene rubber, polyisoprene, polybutadiene, polychloroprenes, organic polysulphides, butyl rubber, halogenated butyl rubber, chlorinated polyethelene, chlorosulfanated polyethylene, ethylene-propoylene rubber, butadiene acrylonitrile copolymers, polyvinyl acetate, vinyl-acrylic, styrene-acrylic, and all acrylic polymers. 
     
     
         15 . The method of  claim 9 , wherein the waterborne polymer binder resin is added at a rate of between about 2 to about 3 gallons per minute into said pulp slurry. 
     
     
         16 . The method of  claim 10 , wherein said silicate coating is selected from the group consisting of: sodium silicate and potassium silicate. 
     
     
         17 . The method of  claim 10 , wherein said silicate coating contains around 10% water. 
     
     
         18 . The method of  claim 11 , wherein said press-rolling is performed under a temperature of between about 450 to about 500° F. 
     
     
         19 . The fiberboard composition of  claim 1 , wherein the composition comprises approximately 30% of the inorganic expandable graphite by weight. 
     
     
         20 . The fiberboard composition of  claim 1 , wherein the composition comprises approximately 15% of the inorganic expandable graphite by weight. 
     
     
         21 . The fiberboard composition of  claim 1 , wherein the composition comprises approximately 1 to 3% of the waterborne polymer binder resin.