Patent ID: 6736971
Filing Date: 2004-05-18
Classification: B01D,B05B,B05C,B29C,B32B,Y10T

Abstract:
A process for forming a continuous, unsupported, multilayer phase inversion microporous membrane having at least two layers, comprising of the acts of:operatively positioning at least one pre-metering dope applying apparatus capable of applying at least two independently pre-metered polymer dopes relative to a continuously moving nonporous support coating surface; cooperatively applying the pre-metered polymer dopes onto the continuously moving nonporous support coating surface so as to create a multilayer polymer dope coating on the nonporous support coating surface; and subjecting the multilayer dope coating to contact with a phase inversion producing environment so as to form a wet multilayer phase inversion microporous membrane precursor; and separating the wet multilayer phase inversion microporous membrane precursor from the nonporous support coating surface at some point prior to complete drying of the membrane.