Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Heat Transfer Processes in Film Casting of Compressible Polymers

Get access (open in a dialog) DOI: 10.1615/IHTC15.fcv.009814
pages 3285-3299

Abstrakt

A two–dimensional model of the film casting process of semi–crystalline polymers that accounts for the compressibility, molecular orientation and the crystallization of the polymer macromolecules and the heat exchanges with the surrounding gases is presented. The model’s rheology is assumed to consist of Newtonian and polymeric contributions; the former depends on the temperature, molecular orientation and crystallization, whereas the latter depends on the temperature and molecular orientation. The model also accounts for the thermal boundary layer of the gases on the film’s free surface. It is shown that the activation energy of the polymer’s dynamic viscosity has a large effect on the film’s thickness, temperature, crystallization and solidification, and that solidification occurs closer to the maximum swell location at moderate activation energies than at high ones. The planar film characteristics are found to be almost of the film’s Reynolds numbers for values of this parameter equal to or less than 10?3, whereas the rates of molecular orientation, crystallization and cooling decrease as the velocity of the gases away from the film’s free surface is increased.