Review of a Mathematical Treatment of the Heat Transfer in Multi-layer Film Blowing

In this paper the heat exchange between the film sleeve and cooling medium in the three layer film blowing is described. Model equations are presented to describe the relationship between the changes in temperature in each layer and the thermal energy transferred by conduction, convection and radiation including the heat generated by viscous dissipation and crystallisation process. Furthermore a mathematical method of approximate estimation of the required length of the cooling path, basing on model equations of heat transfer, is presented.