Memtec LLC

Other

Robert J Streeton

Clinton V Kopp

Paul S Khoo

Douglas L Ford

Richard D Grant

Kerrie Wyatt

Matthew B Lee

Thomas W Beck

Marcus J Fabig

A hollow fiber membrane is produced having an outer surface, and inner surface enclosing a lumen, and a continuous network of interconnecting pores extending from the outer surface to the inner surface, wherein substantially all of the pores have an elongated dimension and a shortened dimension, the elongated dimension being oriented substantially parallel to the axis of the hollow fiber, wherein the ratio of the elongated dimension to the shortened dimension is substantially constant from the outer surface to the inner surface, and wherein the pores change shape to increase the shortened dimension in response to a high pressure differential imposed across the membrane by increasing fluid pressure within the lumen.

Hollow fiber membranes

Method of making polyvinylidene fluoride membrane

Extrusion of hollow membranes is improved by coextruding a coating fluid layer about the extrudate of heated polymer solution with its interior lumen forming extrudate. The coating fluid is disposed between the forming hollow fiber and a cooling fluid, and controls the rate of heat transfer to afford superior control over the structure and form of the hollow fiber produced in the invention. The coating fluid is typically the same material as the cooling fluid, and often is the same material as the solvent for the polymer in the heated polymer solution.

Hollow fibre membrane extrusion

Extrusion head for forming polymeric hollow fiber

A method of making a porous polymeric material by heating a mixture of a thermoplastic polymer and a cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of 4.0 to 6.0 to a temperature and for a time sufficient for the polymer and surfactant to mutually dissolve. The mixture is then cooled to a temperature so that non-equilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the polymer and surfactant so that the polymer and surfactant form two intermingled separate phases of large interfacial surface area. The surfactant is then removed from the polymer. The porous polymeric material produced by the above method has a lacey or filamentous structure consisting of a plurality of polymer strands connected together at spaced apart locations along each strand.

Process of making a porous hollow fiber membrane

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Windsor, Australia

Robert J Streeton