The effect of heat transfer coefficient on crystalline phase development during production of casted film

Abstract

In this study, the stable numerical scheme has been developed for non-isothermal 1.5D film casting model of Silagy et al. (Polym Eng Sci 36:2614-2625, 1996) utilizing viscoelastic modified Leonov model as the constitutive equation and energy equation coupled with crystallization kinetics of semicrystalline polymers considering actual temperature as well as a cooling rate. In the proposed model, forced and natural convection together with a heat radiation emitting from the film surface is considered to model the heat transfer. Model has been successfully validated on the experimental data for linear isotactic polypropylene taken from the open literature. In this work, effect of the forced convection on the neck-in phenomenon (unwanted film width shrinkage during stretching in the post die area) and crystalline phase development during a flat film production was systematically investigated. It is believed that the utilized numerical model together with suggested stable numerical scheme as well as obtained research results can help to more thoroughly understand the processing window for production of flat porous membranes from linear iPP considerably. © 2019 Author(s).