VERFAHREN ZUR EXTRUSION VON KUNSTSTOFFTAFELN UND DARAUS HERGESTELLTE FRESNEL-LINSEN

摘要

The invention relates to a process for extrusion of plastic plates with very fine-textured surface by means of an extrusion installation equipped with an extruder and a three-roller smoothing unit including one roller with a structure-imparting surface, the installation being designed for coextrusion and the plastic plates being made via two extruders as coextrudate CX consisting of a highly viscous base moulding material and an extruded-on low-viscosity moulding material NF, and being structured superficially via the three-roller smoothing unit, and also Fresnel lenses produced by means of the process and solar collectors manufactured therefrom.