Patent ID: 8444816

Claim:
A process for making a fibrillated thermoplastic and polyarenazole pulp for use as reinforcement material, comprising: (a) combining pulp ingredients including: (1) thermoplastic fiber that is capable of being fibrillated and having an average length of no more than 10 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 thermoplastic 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 thermoplastic and polyarenazole pulp with the fibrillated thermoplastic 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 thermoplastic fibrils and/or stalks are substantially entangled with the polyarenazole fibrils and/or stalks.