Radially dependent stress and modeling of solidification in filament melt spinning

When polymer fibers are manufactured by melt spinning, axial velocity is ne arly uniform across any cross section but temperature and stress vary signi ficantly across the fiber radius. Thus, the fiber solidifies from the outsi de in, with the fiber being solid on the outside but molten on the inside f or some distance before complete solidification, and stress near solidifica tion, the controller of mechanical properties of the spun fiber, has radial variation. We present a computationally, ID melt spinning model which reco gnizes the radially inhomogeneous solidification region, and computes axial and radial dependence of stress in the spinline. With this radial resoluti on. stress near solidification is now the stress evaluated on a surface nea r the solidification boundary. In simulations of melt spinning processes, w e investigate features of the solidification boundary, and stress near soli dification, and examine how these change as material properties and process conditions change. As part of this study, we propose and investigate a sol idification criterion that is a function of both stress and temperature.