Wet-End Manufacturing Process for Bitumen-Impregnated Fiberboard

Abstract

A process for manufacturing fiberboard by preparing a fiber slurry mixture including containing cellulose fibers and water then atomizing a liquid bituminous material, such as asphalt. The liquid bituminous material is atomized by mixing it with a pressurized gas, such as compressed air, forming a mist comprising droplets of bituminous material having a diameter between 20 microns and 50 microns. A water spray solidifies the bituminous material droplets thereby forming bituminous particles which fall into the fiber slurry within the spray chamber. From there the slurry is sheared, dewatered, and dried, forming a finished fiberboard.

1 . A bitumen-impregnated fiberboard comprising:
 a core comprising
 at least 10% weight bituminous material, alternatively at least 15% weight bituminous material, alternatively, at least 25% weight bituminous material, alternatively, at least 35% weight bituminous material, 
 about 55.5% weight to about 62% weight cellulose fibers, 
 about 3% weight to about 7.5% weight filler materials, 
 about 0.001% weight to about 2% weight dye; and 
   an outer coating disposed on both major sides of the fiberboard.   
     
     
         2 . The bitumen-impregnated fiberboard of  claim 1  wherein the bituminous material is asphalt. 
     
     
         3 . The bitumen-impregnated fiberboard of  claim 2  wherein the filler materials are selected from the group consisting of a wax, a starch, and aluminum sulfate. 
     
     
         4 . The bitumen-impregnated fiberboard of  claim 3  further comprising
 about 1.0% weight to about 2.5% weight wax; 
 about 1.0% weight to about 3.0% weight starch; and 
 about 1.0% weight to about 2.0% weight aluminum sulfate. 
 
     
     
         5 . The bitumen-impregnated fiberboard of  claim 1  wherein the coating is selected from the group consisting of asphalt, flux oil, and fuel oil. 
     
     
         6 . A bitumen-impregnated fiberboard comprising:
 a core comprising   at least 15% weight bituminous material,   cellulose fibers,   one or more filler materials,   about 0.001% weight to about 2% weight dye; and   an outer coating disposed on both major sides of the fiberboard.   
     
     
         7 . The bitumen-impregnated fiberboard of  claim 6  wherein the bituminous material is asphalt. 
     
     
         8 . The bitumen-impregnated fiberboard of  claim 6  wherein the filler materials are selected from the group consisting of a wax, a starch, and aluminum sulfate. 
     
     
         9 . The bitumen-impregnated fiberboard of  claim 6  wherein the coating is selected from the group consisting of asphalt, flux oil, and fuel oil. 
     
     
         10 . A bitumen-impregnated fiberboard or expansion joint comprising:
 from about 10% to about 40% by weight asphalt, wherein the asphalt has a particle size in the range of approximately 20 to 50 microns;   cellulose fibers;   one or more filler materials;   a dye; and   optionally, an outer coating disposed on both major sides of the fiberboard or expansion joint.   
     
     
         11 . The fiberboard or expansion joint of  claim 10 , wherein the fiberboard or expansion joint has a density of at least 20 lb/cu. ft. or greater, alternatively, wherein the fiberboard or expansion joint has a density of at least 21 lb/cu. Ft, alternatively, wherein the fiberboard or expansion joint has a density of at least 23 lb/cu. ft. 
     
     
         12 . The fiberboard or expansion joint of  claim 10 , wherein the fiberboard or expansion joint has a compression, as measured in accordance with ASTM D 1751-04, of at least about 150 psi or greater. 
     
     
         13 . The fiberboard or expansion joint of  claim 10 , wherein the fiberboard or expansion joint has an extrusion, as measured in accordance with ASTM D 1751-04, of less than 0.30 inches, alternatively, wherein the fiberboard or expansion joint has an extrusion, as measured in accordance with ASTM D 1751-04, of less than 0.25 inches, alternatively, wherein the fiberboard or expansion joint has an extrusion, as measured in accordance with ASTM D 1751-04, of less than about 0.15 inches. 
     
     
         14 . The fiberboard or expansion joint of  claim 10 , wherein the fiberboard or expansion joint has a recovery, as measured in accordance with ASTM D 1751-04, of at least 78%, alternatively, wherein the fiberboard or expansion joint has a recovery, as measured in accordance with ASTM D 1751-04, of at least 75%, alternatively, wherein the fiberboard or expansion joint has a recovery, as measured in accordance with ASTM D 1751-04, of at least 65%. 
     
     
         15 . The fiberboard or expansion joint of  claim 10 , wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 24 volume % or less, alternatively, wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 19 volume or less, alternatively, wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 15 volume % or less, alternatively, wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 12 volume % or less. 
     
     
         16 . A bitumen-impregnated fiberboard or expansion joint comprising:
 from about 10% to about 40% by weight bituminous material, wherein the bituminous material has a particle size in the range of approximately 20 to 50 microns;   cellulose fibers;   one or more filler materials;   a dye; and   optionally, an outer coating disposed on both major sides of the fiberboard or expansion joint.   
     
     
         17 . The fiberboard or expansion joint of  claim 16 , wherein the fiberboard or expansion joint has a density of at least 20 lb/cu. ft. or greater, alternatively, wherein the fiberboard or expansion joint has a density of at least 21 lb/cu. Ft, alternatively, wherein the fiberboard or expansion joint has a density of at least 23 lb/cu. ft. 
     
     
         18 . The fiberboard or expansion joint of  claim 16 , wherein the fiberboard or expansion joint has a compression, as measured in accordance with ASTM D 1751-04, of at least about 150 psi or greater. 
     
     
         19 . The fiberboard or expansion joint of  claim 16 , wherein the fiberboard or expansion joint has an extrusion, as measured in accordance with ASTM D 1751-04, of less than 0.30 inches, alternatively, wherein the fiberboard or expansion joint has an extrusion, as measured in accordance with ASTM D 1751-04, of less than 0.25 inches, alternatively, wherein the fiberboard or expansion joint has an extrusion, as measured in accordance with ASTM D 1751-04, of less than about 0.15 inches. 
     
     
         20 . The fiberboard or expansion joint of  claim 16 , wherein the fiberboard or expansion joint has a recovery, as measured in accordance with ASTM D 1751-04, of at least 78%, alternatively, wherein the fiberboard or expansion joint has a recovery, as measured in accordance with ASTM D 1751-04, of at least 75%, alternatively, wherein the fiberboard or expansion joint has a recovery, as measured in accordance with ASTM D 1751-04, of at least 65%. 
     
     
         21 . The fiberboard or expansion joint of  claim 16 , wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 24 volume % or less, alternatively, wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 19 volume % or less, alternatively, wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 15 volume % or less, alternatively, wherein the fiberboard or expansion joint has a water absorption, as measured in accordance with ASTM D 1751-04, of 12 volume % or less. 
     
     
         22 . The fiberboard of  claim 16 , wherein the coating is selected from the group consisting of a dye, an asphalt, a flux oil and a fuel oil. 
     
     
         23 . The fiberboard of  claim 16 , wherein the filler materials are selected from the group consisting of a wax, a starch and aluminum sulfate. 
     
     
         24 . The bitumen-impregnated fiberboard or expansion joint of  claim 16 , wherein the bituminous material is asphalt, alternatively, wherein the bituminous material is a powdered asphalt, alternatively, wherein the bituminous material is a natural asphalt, alternatively, wherein the bituminous material is a synthetic or non-natural asphalt. 
     
     
         25 . A bitumen-impregnated fiberboard or expansion joint made by the process comprising the steps of:
 preparing a fiber slurry mixture by adding a fibrous material to water and agitating the fiber slurry mixture;   transferring the fiber slurry mixture to a spray chamber;   heating a bituminous material to a temperature between 300° Fahrenheit and 400° Fahrenheit, wherein the bituminous material is in a liquid state;   atomizing the liquid bituminous material within the spray chamber by mixing the liquid bituminous material with a pressurized gas, forming a mist comprising droplets of bituminous material having a diameter between approximately 20 microns to 50 microns; solidifying the bituminous material droplets within the spray chamber to form bituminous particles that mix with the fiber slurry in the spray chamber;   adding a dye to the slurry;   dewatering the slurry containing fibers and bituminous particles, leaving a wet mat containing fibers and bituminous particles; and   drying the wet mat thereby forming the fiberboard or expansion joint.   
     
     
         26 . The fiberboard or expansion joint of  claim 25 , wherein the fiberboard or expansion joint comprises from about 10% to about 40% by weight bituminous material. 
     
     
         27 . The fiberboard or expansion joint of  claim 25 , further comprising a coating applied to both major sides of the dried fiberboard or expansion joint. 
     
     
         28 . The bitumen-impregnated fiberboard or expansion joint of  claim 25 , wherein the bituminous material is asphalt, alternatively, wherein the bituminous material is a powdered asphalt, alternatively, wherein the bituminous material is a natural asphalt, alternatively, wherein the bituminous material is a synthetic or non-natural asphalt. 
     
     
         29 . A bitumen-impregnated fiberboard or expansion joint comprising:
 from about 10% to about 40% by weight bituminous material, wherein the bituminous material has a particle size of less than approximately 20 microns;   cellulose fibers;   one or more filler materials;   a dye; and   optionally, an outer coating disposed on both major sides of the fiberboard or expansion joint.   
     
     
         30 . The bitumen-impregnated fiberboard or expansion joint of  claim 29 , wherein the bituminous material is asphalt, alternatively, wherein the bituminous material is a powdered asphalt.