| 摘要 |
A cooling gas ring for use in producing plastics film by inflation molding, comprises a plurality of slits (37-39) for guiding cooling air onto the film (3) being extruded from the die (1). These slits are defined by a plurality of frusto-conical bodies (23-26) which are arranged like a set of nesting boxes and are provided with different exit angles at the outlet slits (37-39). Through appropriate distribution of the air outlets for cooling the film, a uniform inflation molding becomes possible, allowing a greater molding speed at the same time. The wider ends (23a-26a) of the channel-defining bodies are mutually threaded (at 23c- 26c) in such a manner that they may be independently adjusted along an axial direction. With the additional provision of a retractable annular plate (46) at outlet (42) of main cooling air channel (27), and proper adjustment of the channel defining bodies, the air ring may be adapted to molding dies of different diameters. <IMAGE> |
