Roehm Gmbh & Co Kg

Evonik Roehm Gmbh

Volker Mende

Wolfgang Scharnke

Michael Mueller

Michael Meier-Kaiser

Hans Lorenz

Volker Benz

Berthold Schoenig

Helmut Haring

A process for the production of a translucent, IR-reflective plastic element, consisting entirely or at least in part of an impact-resistant, thermoplastic plastic, containing IR-reflective particles made of a lamellar-shaped carrier pigments coated with a metal oxide and the plastic element made therefrom.

IR reflective elements made of impact-resistance plastic, and a process for their production

An extrusion die has a distributing tool; a profiling nozzle; and at least three melt-flow ducts; a first melt-flow duct is routed around a second melt-flow duct or the distributing tool using a branch and is merged again downstream from the branch; and a third melt-flow duct opens into the second melt-flow duct. The extrusion die is suitable for extrusion of a hollow-chamber profiled panel of a thermoplastic plastic with a layered structure which comprises a top and bottom layer of a first plastic melt; and an intermediate layer of a second plastic melt disposed in an interior of a hollow chamber profile. The first plastic melt is allocated to the first melt-flow duct and to the second melt-flow duct and the second plastic melt is allocated to the third melt-flow duct. During the extrusion the second plastic melt is deposited onto the first plastic melt upstream from or in the region of the branch, and a distribution of the deposited second plastic melt is regulated using the distributing tool. The second melt-flow duct conveying the first plastic melt and the deposited second plastic melt is then merged with the first melt-flow duct in the profiling nozzle, whereupon the first plastic melt from the first melt-flow duct is deposited on the second plastic melt from the second melt flow duct, to sandwich the second plastic melt between two layers of the first plastic melt; and the united plastic melts are shaped to the hollow-chamber profiled panel during ejection from the profiling nozzle.

Extrusion die for making hollow-chamber profiled panels of thermoplastic plastic with interior coextruded layer

The invention relates to optical diffuser plates (1) made of transparent plastics such as polycarbonate or polymethacrylate. Several thin strips (2) made of plastic B inserted into plates made of transparent plastic A with the proviso that A and B are incompatible and the strips (2) made of plastic B are subsequently withdrawn. The hollows that are formed in the plate (1) made of plastic A are used to deflect light.

Optical diffuser plates

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Darmstadt, Germany

Volker Mende