Blowing head for film tubing prodn. - has outer air cooling ring divided at regular intervals round circumference into sectors heated individually as required

摘要

The blowing head for the production of thermoplastic film tubing has connections for the feed and venting of cooling air for the interior, at least one feed passage for the polymer melt to an annular nozzle, an outer cooling ring for the extruded tubing, and devices to supply variably heated air to segments round the circumference of the tubing. The outer cooling ring is divided into sectors in which the air blown on to the tubing are individually heated and/or cooled as required. ADVANTAGE - The design of the head is compact (in contrast with earlier designs)