METHOD FOR PRODUCING THERMALLY CROSS-LINKABLE POLYMER MELTS BY CONCENTRATION OF POLYMER SOLUTIONS AND SIMULTANEOUS MIXING THEREOF WITH MODIFYING LIQUIDS IN A PLANETARY ROLLER EXTRUDER

A method for producing thermally cross-linkable polymer melts by concentration of polymer solutions and simultaneous mixing thereof with modifying liquids in a planetary roller extruder, the planetary roller extruder consisting of an atmospherically operated filling zone formed of at least one roller cylinder, and of a downstream degassing and cooling zone, which is operated under vacuum and which consists of at least four coupled roller cylinders, which each have a vacuum opening in the cylinder surface. Each of the at least four roller cylinders forms a vacuum zone to be operated independently, wherein, following evaporation of at least parts of the solvent in the atmospherically operated filling zone, the mass flow of polymer solution fed into the first vacuum zone of the first roller cylinder is less than 75 % of the mass flow fed originally to the planetary roller extruder, wherein the rest of the content of solvent in the polymer solution after the third vacuum zone is less than 1 % by weight and the polymer solution coming from the last roller cylinder is fed to a coating apparatus.