Rohm Gmbh Chemische Fabrik

Roehm Gmbh & Co Kg

Helmut Haring

Hans Lorenz

Michael Mueller

Heinz Gross

Michael Meier-Kaiser

Volker Benz

Volker Mende

Berthold Schoenig

Roland Schuchmann

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plastic A with the proviso that A and B are incompatible and the strips (2) made of plastic B are subsequently withdrawn.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

For producing a multi-extrudate of thermoplastically processable plastic, a coextrusion adapter block has a multi-part slide having a plurality of side-by-side slide sections mutually spaced in a direction transverse to the flow direction and slidably fitted in the adapter block for movement to adjustably protrude into a secondary runner for adjusting the thickness of a molten extrudate therein. A multi-layer extrudate emerging from the adapter block is further extruded in an extrusion die, and the thickness of at least one layer thereof is measured at a plurality of positions along the width thereof. The width measurements are used to control the positions of corresponding slide sections so that the layer thicknesses can be accurately controlled during an extruding operation.

Process and system for producing multi-layer extrudate

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Reinheim, Germany

Helmut Haring