Patent ID: 7753666
Filing Date: 2010-07-13
Classification: B29C

Abstract:
1. An apparatus for cooling a molten plastic film tube exiting a die outlet of an extrusion die, the molten plastic film tube moving vertically upward in a vertically extending tube path having a longitudinal axis, comprising: an inlet passage adapted to direct cooling air through the extrusion die to an interior of the plastic film tube, at least one air dispensing device coupled to the inlet passage, the at least one air dispensing device configured to receive the cooling air and to direct a flow of the cooling air out of the at least one air dispensing device in an approximately circumferential and a generally upward direction about the longitudinal axis generating a rotating flow of the cooling air along the longitudinal axis, wherein the rotating flow of the cooling air in the interior of the plastic film tube cools the plastic film tube and reduces impact on an inner surface of the plastic film tube, and wherein the at least one air dispensing device comprises: a top section having a first set of teeth; a bottom section having a second set of teeth; at least one intermediate section installed between the top section and the bottom section to direct the rotating flow of cooling air out of the at least one air dispensing device in an approximately circumferential and a generally upward direction about the longitudinal axis.