Abstract: A process for the preparation of polybenzazole filaments which comprises (a) extruding a solution of polybenzazole polymer in a mineral acid through a spinneret having at least 100 holes, which are arranged to form a annular pattern around the center of the spinneret, the center and at least two radial sections of the spinneret having no holes and an average width which is at least about 3 times the minimum pitch of the holes, thereby forming filaments of the polymer solution; (b) drawing the filaments of the polymer solution through a quench chamber while providing a substantially radial gas flow therein across the spinneret from at least two different directions; and (c) washing and drying the filaments of the polymer solution under conditions sufficient to form polybenzazole filaments.

Abstract: A RIM apparatus has a separate hydraulically actuated monomer dispensing system associated with one of at least two different fluid chemical monomers to be mixed and molded. Each system is connected with a separate hydraulic fluid delivery cylinder (one for each monomer) for receiving hydraulic fluid therefrom and is operable for dispensing the associated monomer to a RIM mixing head and mold at a rate proportional to the rate that said hydraulic fluid is delivered thereto from the connected delivery cylinder. Each delivery cylinder is supported at a preselected position with its axis spaced radially from a reference axis and at least one thereof is bodily adjustable radially with respect to said reference axis and to the axis of another delivery cylinder. Each delivery cylinder discharges hydraulic fluid at a rate proportional to the rate of movement of an associated piston therein.