The relationships between the structural changes and the thermal deformations of fibers and plastics by shock heating are important industrially, relating to the problems of the dimensional stability. The author made a shock heating apparatus by which the fiber length changes by shock heating can be detected on the recorder automatically.
In this paper, the peculiar deformation phenomena observed for shock heated high crystalline oriented nylon 6 and polypropylene monofilaments were discussed thermodynamically on the basis of the modified Flory's theory on melting of polymers. Thus it was pointed out that the comparison of the shrinkage behavior occurred in heating procedure at constant rate with that by shock heating is valid to clarify the fiber structures.