Abstract: The invention relates to a composite membrane with a porous polymer support layer and a polymer top layer, whereby the porous polymer support layer is of polyacrylonitrile (PAN), polyacrylamide, polyetheretherketone (PEEK), polyetherketone (PEK), polysulfon or polyethersulfon, whereas the polymer top layer is a dense layer comprising polyvinyl chloride with selective water permeability. Preferably the membrane is provided with a porous polyacrilonitril support layer and a polyvinyl chloride top layer. Further the invention comprises the application of such a composite membrane for the dehydration of organic solvents using such a composite membrane.

Abstract: The invention relates to a process for preparing a microporous membrane, starting from a mixture of at least a hydrophobic polymer and a hydrophilic polymer, by dissolving these polymers first in a suitable solvent or mixture of solvents and subsequently by coagulating in a coagulation bath. According to the invention a more or less hydrophilic membrane is prepared by removing the membrane so obtained from the coagulation bath and subsequently by leaching at least a part of the hydrophilic polymer from the matrix, alternatively followed by hydrophobization. Said leaching of the hydrophilic polymer occurs by treatment of the membrane with an oxidizing/hydrolizing agent. The invention furthermore comprises microporous membranes, flat or tubular or in the form of hollow fibers, having a good chemical resistance and good mechanical strength.

Abstract: A prevaporation process characterized by excellent separation efficiency employs a membrane that comprises an elastomeric polymer matrix containing zeolite.

Abstract: This invention relates to a process for the preparation of hydrophilic membranes by coagulation of a solution of at least one hydrophobic polymer and at least one hydrophilic polymer in a suitable solvent medium in a coagulation medium. The process according to the invention is characterized in that hydrophilic microfiltration and/or ultrafiltration membranes are prepared by cross-linking the hydrophilic polymer which is present in or on the obtained membrane matrix after the coagulation in an essentially non-swollen state and fixing same as such in or on the polymer matrix. Advantageously the solvents and the undesirable components of the coagulation medium are removed whereby the hydrophilic polymer is converted into an essentially non-swollen state prior to cross-linking. The removal of the undesirable components from the membrane takes place by means of a non-solvent for the hydrophilic polymer according to the invention.

Abstract: Rotating cutting element (1) having a row of cutters (5) placed in recesses at the circumference of a disc. Each recess has radially extending V-shaped front and rear edges (4,3), each cutter (5) has V-shaped front and rear edges (6,7) with the apexes facing away from each other. Each cutter (5) is held in the recess against an abutment (9) by means of a wedge (10) which is tensioned by means of a screw (15).

Abstract: Tool post with tool (9) for metal cutting work of a hollow space, said tool (9) being clamped between a support (3) and a clamp (12) with the support (3) attached to a carrier (1), the support (3) over its entire length as well as the clamp (12) being curved, said curvature (6,22) having a center line parallel to the longitudinal axis of the tool (9) in a plane through the cutting edge (8) of the tool (9) and inside the cutting circle of the tool, preferably carrier (1) and support (3) being designed such that support (3) and clamp (12) can be placed on either side of the carrier (1).

Abstract: This invention relates to a process for the preparation of hydrophilic membranes by coagulation of a solution of at least one hydrophobic polymer and at least one hydrophilic polymer in a suitable solvent medium in a coagulation medium. The process according to the invention is characterized in that hydrophilic microfiltration and/or ultrafiltration membranes are prepared by cross-linking the hydrophilic polymer which is present in or on the obtained membrane matrix after the coagulation in an essentially non-swollen state and fixing same as such in or on the polymer matrix. Advantageously the solvents and the undesirable components of the coagulation medium are removed whereby the hydrophilic polymer is converted into an essentially non-swollen state prior to cross-linking. The removal of the undesirable components from the membrane takes place by means of a non-solvent for the hydrophilic polymer according to the invention.