Abstract: Novel laminated, polyfluorocarbon microporous membranes are made up of three or more sheets of aggregated microporous fluorocarbon polymer. A fine porosity pore-containing microporous fluorocarbon polymer sheet has an average pore diameter of from about 0.01.mu.m to about 1.0.mu.m. This fine porosity sheet is laminated between a first sheet or sheets of larger porosity microporous fluorocarbon polymer and a second sheet or sheets of larger porosity microporous fluorocarbon polymer. At least one and preferably both of the first and second sheets has an average pore diameter of from about 1.0.mu.m to about 10.0.mu.m. A novel microporous polyfluorocarbon filter cartridge utilizing the membrane is also disclosed. A cartridge body formed of polyfluorocarbon has an inlet and outlet with a membrane assembly disposed in the cartridge so that fluid moving from the inlet to the outlet must pass therethrough.

Abstract: Novel microporous, asymmetric, integral, composite piolyfluorocarbon, e.g., polytetrafluoroethylene, membranes are disclosed. These membranes are made up of two or more sheets of microporous fluorocarbon polymer having different average pore sizes, arranged to provide an increasing gradations in average pore size from one surface of the membrane to the other, and are useful as microfilters for removing fine particle contaminants, including bacteria, from fluids such as those encountered in the electronics and pharmaceutical industries.

Abstract: A cylindrical pressure vessel housing a filter media wherein the vessel is formed from a tubular thermoplastic pipe portion having opposite conical shaped end portions integrally formed with molded internal base portions with one base portion having integrally molded thereto the filter media in sealed position within the vessel housing.

Abstract: End capping a filter cartridge. The filter cartridge contains a hollow central core for passage of fluid, a membrane around the central core through which the fluid also passes, at least one support for the membrane in intimate contact with the membrane, a cage for holding the membrane and the support in contact with the central core, and an end cap for sealing the cartridge.