Patent ID: 6068804
Filing Date: 2000-05-30
Classification: B29C,D21H,Y10S

Abstract:
A process of producing an asphalt-impregnated fiberboard comprising:(a) forming an aqueous slurry of (i) a fibrous material and (ii) asphalt, the solids content of the slurry being less than about 8 weight percent, the asphalt being included in the slurry in an amount of about 30 to 50% by weight solids, and optionally up to about 15% by weight solids being asphalt incorporated in the aqueous slurry in the form of an emulsion,(b) mixing the slurry to uniformly distribute components (i) and (ii) contained therein,(c) dewatering the slurry to form a wet mat of the components, the dewatering being accomplished by continuously dewatering the aqueous slurry on a moving porous carrier capable of passing drainable water therethrough and retaining solids thereon,(d) pressing the wet mat to consolidate it, and(e) drying the consolidated wet mat, with the proviso that the process includes no hot pressing of the dried consolidated mat formed by step (e).