NUMERICAL-ANALYSIS OF COOLING AIR SYSTEMS IN FILM BLOWING

Air rings, used today in film blowing systems, have been developed dow n the years through trial and error experiment. They represent the lim iting factor concerning the efficiency of film blowing lines with resp ect to throughput and take-off speed. Numerical simulation of the cool ing and optimization of future cooling systems. Individual process and geometric parameters can be changed interactively with the effects on flow and heat transfer processes being analysed and applied to simila r situations. The knowledge acquired regarding the physical interactio ns in the cooling of blown film makes a targeted optimization possible . The purpose of this paper is to present the foundamentals for calcul ating turbulent air flows in blown film extrusion and, additionally, a model for complete FE-simulation of the flow and heat transfer proces ses. Furthermore, the achieved simulation results will be discussed.