A PROCESS AND APPARATUS(PLANT)FOR PREPARING FILM OR BAND TYPE MATERIALS HAVING ENHANCED UPER SURFACE ROUGHNESS AND ANTIBLOCKING PROPERTIES

摘要

The invention relates to a process and a system for increasing the surface roughness and for the antiblocking of polyester film tapes, in which an additive preventing blocking and promoting the surface roughness is added to the film tape made of a polymer during its production. To this end the additive is mixed with a part of the polymer, metered and melted in a worm extruder in a first treatment zone, and subsequently dispersed in a second treatment zone with the other part of the polymer after the metering thereof. Subsequently the dispersed mixture is subjected to underpressure in a third treatment zone as well as forced out of the worm extruder and finally pelletised in a manner known per se, dried and mixed with other polymers for special intended uses. Overall, an especially fine distribution of the additive or the additives in the polymer and in the film tapes produced therefrom is achieved.