Patent ID: 6056529
Filing Date: 2000-05-02
Classification: B01D

Abstract:
A system for controlling the thermal manipulation of a ternary phase inversion polymer master dope to a temperature no higher than a predetermined temperature prior to delivery of the dope to a dope processing site, the system comprising:a vessel for containing a ternary phase inversion polymer master dope, the dope having been exposed to a mixing temperature, to establish a first dope temperature memory, which is no higher than the temperature necessary to effect dissolution and equilibrium mixing of the polymer, solvent and nonsolvent, the vessel and the dope contained therein being maintained at a temperature nominally lower than the mixing temperature, such temperature being sufficient to stabilize and maintain the mixture after cooling from the mixing temperature;a pump, operatively connected to the vessel, for incrementally transporting portions of the dope from the vessel to a dope processing site; andheating means, operatively connected to the pump and the dope processing site, for elevating the temperature of at least a portion of the dope being incrementally transported from the vessel and through the heating means to any one of a possible plurality of different predetermined temperatures, each dope portion being incrementally transported through the heating means being elevated to a temperature within about .+-.0.2.degree. C. of a selected one of the possible plurality of different predetermined temperatures to establish any one of a possible plurality of different second dope temperature memories, each predetermined temperature being selected from a calibrated characterization curve which describes the relationship between the dope being processed and the resulting pore size in the formed membrane.