Film production in multiroller calender - using cascade system of rollers with wedge in one gap to blend, fuse, dispensed, melt, degas and form material in one single pass

摘要

In the production of films on multi-roller calenders (with 3 or more and primarily 4 to 5 rollers) several individual stages are combined together; the first gap is designed geometrically, thermally and kinematically to homogenise and melt the material, and its processing into film is made in the next gap by using wedge-shaped tools. Premixed material or powder/granules are fed into a roller and repeatedly passed round it; the roller can be heated. A specific portion of the homogenised material is next taken off and passed over roller into the gap between rollers e.g. for repeated similar treatment and, in the case of a 5-roller calender, again in the next gap. This produces a very uniform material. ADVANTAGE - The method utilises a conventional calender but combines together a number of stages