| 摘要 |
1422624 Extruding tubular film WINDMOLLER & HOLSCHER 29 Jan 1974 [12 Feb 1973] 04044/74 Heading B5A In an extrusion die for blown film, molten material is supplied to a housing 4 through a conduit 2 leading to radiating distributing passages 8 which connect with respective helical grooves 9 formed on the surface of an insert, the insert forming with the housing a gap of increasing size which permits molten material to overflow increasingly across the grooves 9, and the air for cooling the blown film is supplied and removed through concentric passages 16, 18 extending axially of the housing and connected to respective inlet and outlet tubes 14, 19 which pass between the distributing passage 8 to the exterior of the housing. Air from a pump 12 is directed to an external cooling ring 11 and via the inlet tube 14 and passage 16 to an internal cooling ring 17. The air is extracted from close to where the cooled film is flattened through a pipe 18 and two or more outlet tubes 19 which are externally connected by a conduit (not shown) to a pump 20. There may be an equal number of inlet tubes also interconnected externally by a conduit. |
