Gkss-forschungszentrum Geesthacht Gmbh

Membrana Gmbh

D.o.r.n.e.y Technologie Gmbh

Bernd Seibig

Dieter Paul

Quan Huang

Klaus-Viktor Peinemann

Frank Wiese

Hartmut Stenzel

Alfred Reymann

Rebecca Klotzer

Helmut Dittmer

Method for producing foamed microporous polymer molded bodies by melting a thermoplastic polymer in a first zone of an extrusion device, mixing in a highly volatile blowing agent, conveying the polymer melt containing the blowing agent into a second zone in which dissolution of the blowing agent occurs to saturation of the polymer melt at the foaming temperature, and molding and foaming of the loaded polymer melt to a foamed structure, whereby, in the second zone, a pressure above 90 bar, a blowing agent concentration above the critical minimum concentration for complete foaming, and the foaming temperature, lying above the solidification temperature of the polymer melt saturated with blowing agent, are set such that the polymer molded body obtained has a porosity in the range between 40 and 90 vol. % and an open-cell pore structure with uniform cross-sectional distribution. Foamed microporous polymer molded bodies in the form of particles comprising a thermoplastic polymer with uniform open-cell pore structure, a porosity of 40 to 90 vol. %, an accessible proportion of pore volume of at least 0.75 and an average cell size between 1 and 100 &#x3bc;m.

Method for producing foamed polymer molded bodies and said foamed polymer molder bodies

A method using a two part process line is proposed for manufacturing foams from polymers or polymer mixtures useful for making molded bodies. The process line is divided into at least one first part and one second part. The polymer or polymer mixture is melted in the first part and a gas at a pressure increased relative to the melt pressure is added with the influence of a shearing and/or kneading device on the melted polymer or polymer mixture enriched with gas. In the second part of the process line, foam is formed from the gas-enriched polymer or polymer mixture at a higher pressure than the pressure in the first part of the process line. Membranes can be made from the molded bodies made by the method described above.

Method for producing foams made of polymers or polymer mixtures and moulded articles made from said foams

In a method of producing hollow fiber membranes, wherein a molten polymer charged with a gas under pressure is provided in an extrusion apparatus, the polymer melt including the gas under pressure is extruded from the extrusion apparatus through a hollow fiber-forming extrusion nozzle with a predetermined pressure drop which provides for a concurrent expansion of the gas contained in the polymer melt thereby forming a porous hollow fiber membrane.

Method of producing hollow fiber polymer membranes

A method of making a shaped part having members that are positively interconnected via thermal treatment. The shaped part includes a metallic member having a first flange that is delimited by an outer contour of the metallic member and projects essentially at right angles therefrom. The first flange defines a recess-like opening having a base in which is provided a circumferential groove that extends essentially parallel to the first flange. A second flange is formed between a base of the groove and a contiguous surface of the metallic member. Prior to creation of the positive interconnection between the metallic member and the ceramic member, at least the metallic member is heated up, and then the ceramic member is introduced into the recess-like opening of the metallic member.

Method of making a shaped part comprising a metallic member and a

A shaped part having members that are positively interconnected via thermal treatment. The shaped part includes a metallic member having a first flange that is delimited by an outer contour of the metallic member and projects essentially at right angles therefrom. The first flange defines a recess-like opening having a base in which is provided a circumferential groove that extends essentially parallel to the first flange. A second flange is formed between a base of the groove and a contiguous surface of the metallic member. The shaped part also includes a ceramic member that is received in the recess-like opening. Prior to creation of the positive interconnection between the metallic member and the ceramic member, at least the metallic member is heated up.

Shaped part comprising a metallic member and a ceramic member

An adapter element that allows machine elements to be accommodated in a centered manner with zero play, with these machine elements having different thermal expansions over broad temperature ranges. The adapter element has a sleeve-like portion that has tongue-like regions defined therefrom. Flattened or planar regions are provided on the inner and/or outer surface of the sleeve-like portion, with these planar regions at least partially overlapping the tongue-like regions.

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Geesthacht, Germany

Bernd Seibig