METHOD AND DEVICE FOR COOLING SYLINDRICAL WEB OF MELT THERMOPLASTIC SYNTHETIC MATERIAL EXTRUDED FROM FILM BLOW HEAD

摘要

PURPOSE: To increase the heat output of an inflation device by exposing a tubular web of a thermoplastic synthetic melt to primary cooling air with below specific temp. and surrounding this primary cooling air by a secondary air stream comprising dry air with a specific temp. or more. CONSTITUTION: In a method for cooling a tubular web 3 of a thermoplastic synthetic melt extruded from a film blowing head 1, cooling air is blown to the tubular web 3 in the direction going toward the tubular web 3 or in the direction parallel thereto from the annular nozzle gap 2 of the film blowing head 1 or a cooling ring 6 equipped with the annular outlet cap 8 surrounding the tubular web 3. The tubular web 3 is exposed to primary cooling air with a temp. of below 0 deg.C supplied to the annular outlet cap 8 from a vertical connection pipe 10 through an annular chamber 9. The primary cooling air is surrounded by the secondary air stream of dry air with a temp. higher than 0 deg.C supplied to an outlet gap 14 from a horizontal intake pipe 17 through an annular chamber 16.