Hoechst Celanese Corporation

Celanese Gmbh

Celgard Inc.

James J Lowery

Jack Robinson

Neil D Plotkin

Tai-Shung Chung

Edward R Kafchinski

Charles J Runkle

C William Fulk, Jr

Harold M Fisher

Hubert Bader

Daniel E Leone

A contactor for degassing liquids includes a perforated core, a plurality of microporous hollow fibers, and a shell. The fibers surround the core and have two ends. A tube sheet affixes the ends of the fibers. A baffle is located between the tube sheets. The hollow fibers are closed at the baffle. The shell encloses the fibers, tube sheets, and the baffle. The system for degassing liquids includes a source of liquid containing a gas, a source of vacuum, and the contactor.

Contactor for degassing liquids

A process for producing a polyhalogenated microporous film having a very narrow pore size distribution and good temperature and chemical resistance. The process involves blending a polyhalogenated copolymer with a polyethyloxazoline utilizing a solvent which is a nonsolvent for the polyhalogenated copolymer but a solvent for polyethyloxazoline, forming a film from the blend, drying the film, heating the film to a temperature at or above the melting point of the polyhalogenated copolymer and under conditions such that the microparticulate particles at their points of mutual contact will neck together to form a relatively continuous matrix and extracting the polyethyloxazoline from the film utilizing a solvent for the binder particle to form a microporous film.

Process for formation of halogenated polymeric microporous membranes

Disclosed are a process for forming an open-celled microporous membrane (e.g., in film or fiber form) and a novel microporous membrane formed thereby. The process generally includes sequential cold and hot stretching operations, whereby the cold stretching operation is preferably accomplished in a plurality of discrete cold stretching steps. In this regard, the total cold stretch extension is of greater than about 30 percent, and advantageously greater than about 40 percent based upon the initial unstretched length of the nonporous precursor, with this total cold stretch ratio being distributed among a plurality of discrete cold stretching steps. The novel membranes of this invention are characterized by decreased pore size and increased pore densities. For example, the membranes of this invention will have an average pore radius as determined by mercury porosimetry of less than about 0.040 micron. The membranes of this invention, moreover, exhibit a distinctive 'bluish' color hue (i.e., a Macbeth Coloreye.TM. b* value of less than about -10 as determined by placing a single ply sample of the membrane against a black background).

Microporous membranes having increased pore densities and process for

The present invention provides microporous hollow fiber with improved structural and performance characteristics and a process and apparatus for preparing the improved fiber. The microporous hollow fiber possesses substantially uniform wall thickness, cross-sectional dimensions and porosity. Such characteristics are obtained by melt spinning hollow fiber precursor under defined conditions in a substantially vertically upward direction and subjecting the precursor to a symmetrical quenching step which may be achieved using a hollow annular structure surrounding the precursor. The structure, which is connected to a source of gas, has one or more openings on its inner surface that distribute the gas against the precursor in a substantially uniform manner.

Method for preparing a uniform polyolefinic microporous hollow fiber

Microporous hollow fiber and process and apparatus for preparing such

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Charlotte, NC, United States of America

James J Lowery