installation for the extrusion of sheets blow for the production of a sheet of synthetic material and method for the management of the installation for the extrusion of sheets blow

摘要

An extruder/blown film machine for the production of plastic film has a blowing head with ring nozzle and/or an outer closed circulating elastic ring nozzle lip to discharge a preliminary tube. It has also a device to blow the preliminary tubing and an external air cooling arrangement with rotating air distributor; during operations at least one of the nozzle lips is held in position by segmental memnbers acting radially over the circumference of the lip; the cooling air system is divided into individual segments with controls for the volume of air flow; the controls for the lip(s) and for the air flow volume are parts of a regulating device. In this device the adjustment/thickness deviation characteristics of the regulating circuitry acting on the lip, and the similar characteristics of the regulating circuitry acting on the cooling air distributor overlap; also, the device acts on the adjusting deviation characteristic which is proportional to the setting over the whole range of adjustments. ADVANTAGE - The layout appreciably tightens the tolerances across the film produced.