COEXTRUSION APPARATUS, SINGLE-LAYER EXTRUSION APPARATUS, AND RETROFIT KIT, AS WELL AS METHOD FOR MEASURING A LAYER THICKNESS FOR PRODUCING A PLASTIC FILM, AND FOR RETROFITTING AN EXTRUSION APPARATUS

摘要

The invention relates to a coextrusion apparatus, to a single-layerextrusion apparatus, to a retrofit kit, as well as to amethod for measuring a layer thickness, for producing aplastic film, and for retrofitting an extrusion apparatus.From the state of the art, it is known to add a detectionagent in the form of a fluorescent granulate into the startingmaterial at the extruder, in order to be able to measure thelayer thickness of the layer in the film composite producedfrom this starting material.However, it is proposed to feed a detection agent in onlybeyond the extruder. This leads to a clearly shorter runningtime of the detection agent through the system and thereby toclearly faster measurability of changes in the productionparameters.