Patent ID: 8444898

Claim:
A process for the continuous preparation of solutions comprising up to 50 wt. % of an UHMW PO having an intrinsic viscosity from 5 to 45 dl/g measured in decalin at 135° C comprising the steps of: a) forming a slurry of UHMW PO particles in a solvent for the UHMW PO at a first temperature which is below the temperature at which said UHMW PO particles will dissolve in said solvent; b) processing said slurry through an extruder operating such that a mixture of said solvent and said UHMW PO is formed at aseond temperature above the melting temperature of said UHMW PO, and the throughput rate of UHMW PO is at least the quality 2.5 D 2 (2.5×D×D) grams per minute, where D represents the screw diameter of said extruder in centimeters, the mixture containing domains of molten polymer and solvent having sizes of microscopic dimensions; c) discharging said mixture from the extruder; and d) passing said mixture through a heated vessel at a temperature above the melting temperature of said UHMW PO in said solvent, said heated vessel having a volume such that the average residence time of the mixture in said vessel is from 2 to 120 minutes, whereby a homogeneous solution of said UHMW PO is formed having the UHMW PO dissolved in the solvent.