| Abstract: | Melt spinning of poly(ethylene terephthalate) was studied by measuring the filament tension at the take-up roll and by measuring filament diameter D(X) at various distances X below the spinnerette. A new method is developed to calculate temperature distribution both along and perpendicular to the fiber axis. Results of these calculations are compared with experimental values. The attenuation of filament diameter depends primarily on the take-up speed and the output rate. Spinning temperature and molecular weight have relatively small effects. Mass flow rate and take-up speed are the major factors controlling the cooling rate, while other spinning parameters such as polymer molecular weight and spinnerette orifice size have a small effect. The Trouton viscosity β is both temperature and molecular weight dependent. Values of β derived from these experiments can be expressed mathematically as follows:  |
