Process and apparatus for cooling the parison of thermoplastic melt extruded from a film blowing head

摘要

In a method for cooling the tubular web of a thermoplastic synthetic melt 3 extruded from a film blowing head 12, cooling primary air is blown in the direction towards the tubular web 3 out of at least one annular gap 8 surrounding the annular nozzle gap 2 of the blowing head. The primary cocling air flow is preferably at a temperature of less than 0 DEG C and this cooling air flow is surrounded by a secondary air flow of dry air at a temperature of at least 0 DEG C. A second annular gap 14 is provided for the secondary air. <IMAGE>