Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure, using a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin is extruded to form a shaped object. The solvent used is one for which the demixing temperature of a solution of 25% by weight of the polyolefin in this solvent is 10 to 70° C. above the solidification temperature. After leaving the die, the shaped object is cooled using a liquid cooling medium that does not dissolve the polymer up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: The invention relates to a carrier in the form of particles, which can be loaded with aqueous media. Said particles are formed from a porous hydrophobic polymer substrate, have an average particle size ranging between 50 ?m and 5000 ?m, and are provided with an at least partly open-pore structure having an average pore diameter ranging between 1 ?m and 200 ?m. The inventive carrier can be loaded with 10 to 95 percent by weight of water relative to the total weight of the loaded carrier, said loadability being determined by contacting the carrier with water. Also disclosed is a storage device which is based on said carrier and is loaded with an aqueous medium. The invention further relates to a method for producing such a carrier in the form of particles that are based on a hydrophobic polymer, said carrier being loadable with 10 to 95 percent by weight of water.

Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure, using a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin is extruded to form a shaped object. The solvent used is one for which the demixing temperature of a solution of 25% by weight of the polyolefin in this solvent is 10 to 70° C. above the solidification temperature. After leaving the die, the shaped object is cooled using a liquid cooling medium that does not dissolve the polymer up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: Process for producing integrally asymmetrical hydrophobic polyolefinic membranes with a separation layer, in particular for gas exchange, via thermally induced liquid-liquid phase separation. A solution of at least one polyolefin in a solvent system containing a compound A and a compound B is extruded to form a shaped object. Compound A is a strong solvent and compound B a weak non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium, which does not dissolve the polymer and does not react chemically with it, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: Process for producing hydrophobic polyolefinic membranes for gas exchange via thermally induced liquid-liquid phase separation is disclosed. A solution of at least one polyolefin in a solvent system, of a compound A and a compound B having a viscosity less than 60 mPa s, is extruded to form a shaped object. The compound A is a solvent and compound B preferably a non-solvent of the polymer, and the boiling point of compound A is at least 50° C. higher than that of compound B. After the shaped object leaves the die, at least one surface thereof is subjected to an atmosphere promoting evaporation of compound B, and the shaped object is subsequently cooled until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: Process for producing an integrally asymmetrical hydrophobic polyolefinic membrane with a sponge-like, open-pored, microporous support structure and a separation layer with a denser structure compared to the support structure, via a thermally induced liquid-liquid phase separation process. A solution of at least one polyolefin in a solvent system consisting of a compound A and a compound B is extruded to form a shaped object. Compound A is a weak solvent and compound B a non-solvent for the polymer. After leaving the die, the shaped object is cooled using a solid or liquid cooling medium that does not dissolve or react chemically with the polymer at temperatures up to the die temperature, until the phase separation and solidification of the high-polymer-content phase take place.

Abstract: The invention concerns porous fibers and membranes, methods for their preparation and for their use. The fibers are characterized by a smooth porous surface and an apparent density of between about 10 to 90% of the true density of the polymeric starting material employed. The process involves the formation of a homogeneous mixture of at least two components, one of which is a meltable polymer and another liquid inert with respect to the polymer. The mixture formed must be of a binary type, in which there is a temperature range of complete miscibility and a range in which there is a miscibility gap. The mixture is extruded at a temperature above the separation temperature into a bath containing at least some of the inert liquid which is at a temperature below the separation temperature. Upon introduction of the mixture into the bath, the fiber structure of the product is fixed.

Abstract: A method for production of porous hollow polymer fiber membranes. A homogeneous mixture is prepared from at least two components where one component is a fusible polymer (10 to 30 percent) and a solvent component (70-90%) is inert relative to the polymer and where said components form a binary system having in the liquid state a region of complete miscibility as well as a miscibility gap. The mixture is extruded at a temperature above the phase segregation temperature of the mixture through a hollow fiber nozzle into a spinning tube containing a solvent inert to the polymer and having a temperature below the segregation temperature. Fiber and liquid are moved in the spinning tube in the same direction at about the same speed. After solidification the hollow fiber membrane is washed with a solvent.

Abstract: The invention concerns porous fibers and membranes, methods for their preparation and for their use. The fibers are characterized by a smooth porous surface and an apparent density of between about 10 and 90% of the true density of the polymeric starting material employed. The process involves the formation of a homogeneous mixture of at least two components, one of which is a meltable polymer and another liquid inert with respect to the polymer. The mixture formed must be of a binary type, in which there is a temperature range of complete miscibility and a range in which there is a miscibility gap. The mixture is extruded at a temperature above the separation temperature into a bath containing at least some of the inert liquid which is at a temperature below the separation temperature. Upon introduction of the mixture into the bath, the fiber structure of the product is fixed.

Abstract: An apparatus and method for mixing two or more distinct fluids is disclosed, and which includes a housing, a sleeve fixedly mounted in the housing and defining a mixing chamber, and a rotatable mixing head having a grooved outer surface disposed in the mixing chamber. At least one of the fluids is fed radially through the sleeve and into the mixing chamber, so as to be sheared and highly dispersed in the mixing chamber by contact with the rotating mixing head. In one embodiment, the sleeve includes a plurality of distinct openings for permitting the passage of the fluid, and in another embodiment the sleeve is composed of a porous metallic material, with the pores of the material defining the openings for the passage of the fluid.

Abstract: Method and apparatus for the production of porous tubing. One extrudes a homogeneous mixture of at least two components, one component a meltable polymer and the other component a liquid inert in relation to the polymer, both components forming a binary system which in liquid aggregate state displays a range of complete miscibility and a range with a miscibility gap, at a temperature above the separation temperature, substantially vertically upwardly using a circular slot nozzle and blowing of gas or dosing-in of liquid into the interior of the nozzle, into a bath, which displays a temperature below the separation temperature, allows the tubing to solidify, and extracts or lixiviates the tubing. Preferred embodiments include the use of water at a temperature from 15.degree. to 90.degree. C.

Abstract: A multi-component filament consisting of at least two polymer components and having a cross-section in which a matrix component separates several peripherally arranged segments of one or more segment components from each other, and a process for the production of such matrix/segment filaments, wherein the segment component is injected into the matrix component and fed to the spinneret opening in a combined stream with a plurality of segment components separated by the matrix. The multicomponent filament can be drawn to obtain individual microfilaments of less than 1 dtex after splitting, e.g. by false twist texturing.

Abstract: A multi-component filament consisting of at least two polymer components and having a cross-section in which a matrix component separates several peripherally arranged segments of one or more segment components from each other, and a process for the production of such matrix/segment filaments, wherein the segment component is injected into the matrix component and fed to the spinneret opening in a combined stream with a plurality of segment components separated by the matrix. The multicomponent filament can be drawn to obtain individual microfilaments of less than 1 dtex after splitting, e.g. by false twist texturing.

Abstract: A filament of a thermoplastic synthetic polymer having a plurality of adjacent, separate discontinuous cavities is made by a process wherein a silicone oil and an inert gas or gas-forming substance are dispersed in a polymer melt, and the melt is extruded into a filament. The melt contains up to and including 1% by weight of the silicone oil, based on the weight of the melt, at the time it is extruded and up to and including 10% by weight of an inert gas.

Abstract: A filament of a thermoplastic synthetic polymer having a plurality of adjacent, separate discontinuous cavities is made by a process wherein a silicone oil and an inert gas or gas-forming substance are dispersed in a polymer melt, and the melt is extruded into a filament. The melt contains up to and including 1% by weight of the silicone oil, based on the weight of the melt, at the time it is extruded and up to and including 10% by weight of an inert gas.

Abstract: A cooling tower with a non-self-supporting envelope which is supported by a net of cables and by pulling elements extending from a portion of a supporting post which portion protrudes upwardly beyond the outlet opening of the cooling tower mantle, in which annular means surround the outlet opening of the mantle and are connected to the supporting post by elements extending in a spoke-like manner from the supporting post and at least partially subjected to pull only.