| 摘要 |
<p>Cooling apparatus for tubular plastics film made by a film blowhead has provision for air cooling and for replacement of the internal cooling air through a central aperture in the blowhead. The cooling apparatus comprises superposed cooling air supply rings having outlet apertures facing the inside of the film and apertures extending axially through the air supply rings for the passage of the cooling air from the lower into the higher air supply rings and radial apertures for withdrawing the cooling air that is blown out of the outlet apertures between the air supply rings. The air supply rings consist of superposed cylindrical rings interconnected by tubular webs that pass through the rings and form radial apertures, the rings being supported on one another at least by their inner ring portions and bounding an annular passage between each other.</p> |
