Patent ID: 6776940
Filing Date: 2004-08-17
Classification: B01D,B29B,B29K,B32B,D06N

Abstract:
A method for manufacturing a three-zone microporous membrane, the method comprising the steps of:providing at least one vessel for containing a ternary phase inversion polymer mother dope; formulating a ternary phase inversion polymer mother dope in the at least one vessel to effect dissolution and equilibrium mixing of the polymer, solvent and nonsolvent; maintaining the mother dope in the vessel at a temperature sufficient to stabilize and maintain the dope formulated after cooling from the formulation temperature; providing a dope processing site having at least one dope application means; operatively connecting the at least one vessel to the dope processing site such that the mother dope is transported from the at least one vessel to the dope processing site; operatively positioning at least one thermal manipulation means between the at least one vessel and the dope processing site; thermally manipulating the mother dope transported from the at least one vessel in the at least one thermal manipulation means into any one of a plurality of different possible pore size producing dopes; and applying a predetermined one of the plurality of different possible pore size producing dopes received from the at least one thermal manipulation means to a scrim at the dope processing site to produce reinforced, three-zone microporous membrane.