AIR COOLING RING FOR PLASTIC BLOWN FILM

摘要

Apparatus for cooling blown film by directing air flow against the exterior of the emerging film bubble, the air flow being generated by an annular plenum about which air swirls in a torus-like mass and a plurality of radially-directed fin elements spaced uniformly about the circumference and communicating with the plenum, whereby the fin elements intercept peripheral elements of the swirling air and turn these air flow elements radially inward. Flow passages combine and deliver these air flow elements to an annular outlet surrounding the bubble exterior.