METHOD AND APPARATUS FOR MANUFACTURING TUBULAR FILMS, PIPES OR FILMS IN PLASTIC MATERIAL

For manufacturing antistatic plastics material, it is extruded through an annular die (20) as a film bubble (B), while bubble inflation air and finely dispersed liquid are introduced inside it, to be precise by controlled metering at a predetermined distance (h) above a blowing diehead (10). Either the liquid contains antistatic agents or, in particular hydrophilic, antistatic agents such as fatty acid ester are added to the material to be moulded. In the region where inflation air is fed to the film bubble (B), internal air exchange takes place with continuous partial air removal from the inside, preferably in countercurrent to the supply of the bubble inflation air and the liquid to be atomised. An inner nozzle (40) as spray head is seated on the upper end of a supporting tube (30), in particular passing through the blowing diehead (10), at a predetermined distance (h) above the annular die (20) and is fed by separate lines (34, 36) inside an air suction-removal channel (30, 32), which is surrounded by the bubble inflation air feed tube (22). In the region of the annular die (20), which is enclosed by a cooling ring (24), the supporting tube (30) may secure or form a flow stabiliser (28), by means of which an air suction-removal ring or connecting piece (32) is arranged. The atomiser feed lines (34, 36) may be preceded by cleaning filters and/or pressure governors.