Abstract
This investigation deals with the mechanism of thermal shrinkage of drawn polyethylene filament. The samples used were prepared from drawn polyethylene filaments by heat treating at various temperature. The degree of orientation, dynamic modulus, coefficient of thermal shrinkage and thermal stress were measured. As heat treating temperature rises, the shrinkage increases rapidly, but the degree of orientation does not vary and maintains its high value. This fact implies that the thermal shrinkage of drawn polyethylene arises from sliding and relaxation of helical unit rather than from the disorientation usually by melting. The temperature dependence of dynamic modulus and the thermal shrinkage coefficient vary widely with the heat treating temperature, reflecting the differences in the internal structure.
