Patent ID: 8404082

Claim:
A process for making a fibrillated wood pulp and polyarenazole pulp for use as reinforcement material, comprising: (a) combining pulp ingredients including: (1) wood pulp fiber having an average length of no more than 1 cm and being 60 to 97 weight percent of the total solids in the ingredients; (2) rigid rod polyarenazole fiber having an average length of no more than 10 cm and being 3 to 40 weight percent of the total solids in the ingredients; and (3) water being 95 to 99 weight percent of the total ingredients; (b) mixing the ingredients to a substantially uniform slurry; (c) co-refining the slurry by simultaneously: (1) fibrillating, cutting and masticating the fibrillated wood pulp fiber and the polyarenazole fiber to irregularly shaped fibrillated fibrous structures with stalks and fibrils; and (2) dispersing all solids such that the refined slurry is substantially uniform; and (d) removing water from the refined slurry, thereby producing a fibrillated wood pulp and polyarenazole pulp with the fibrillated wood pulp and the polyarenazole fibrous structures having an average maximum dimension of no more than 5 mm, a length-weighted average length of no more than 1.3 mm, and the fibrillated wood pulp fibrils and/or stalks are substantially entangled with the polyarenazole fibrils and/or stalks.