| 摘要 |
A cooling device in a blowing unit for tubular plastic films (1) is proposed in which cooling air is fed in through an inner and outer annular gap (18, 13), and an extraction tube (6), penetrating the blowhead (2) axially, and an air-guide tube (25), which surrounds the extraction tube (6) coaxially, are provided. In order, in a device of this type, to achieve increased cooling on the inside of the tubular films and thus to achieve a corresponding increase in throughput, at the same time as an improvement in the tubular film stability, it is provided that an equalisation chamber (22) fed with air is provided at the bottom of the air-guide tube (25) and merges with a radial secondary air-outlet gap (26) which is located approximately in the surface of the air-guide tube (25) and has a comparatively large outlet cross-section compared with the inner annular gap (18). For certain conditions, the width of the inner annular gap (18) and/or of the secondary air-outlet gap (26) or of the equalisation chamber (22) can be adjusted. <IMAGE> |
