INVESTIGATION OF THE COOLING JETS USED IN THE BLOWN FILM MANUFACTURING PROCESS

摘要

The flow field of a dual-lip air ring used in the blown film manufacturing process was studied experimentally. The static pressure distributions on a model bubble was measured using manometers while the fluctuating pressure was measured using microphones. The flow field caused by the air ring was measured using single and cross-wire probes. It was found that the pressure distribution below the forming cone was determined by the lower jet velocity. The flow and the pressure distribution on the bubble above the forming cone was determined by the ratio of the upper and the lower jet velocities where two jets interact and by the upper jet after the upper jet attached to the bubble.