抄録
The structure of poly (ethylene terephthalate) fibers with longitudinal fluctuation in cross-sectional area of so-called Thick and Thin (T&T) fiber was investigated. The molecular orientation in the thick part was significantly lower than the thin part. However, there lies little relation between the Lorentz density and the molecular orientation. The increase in crystallinity after heat treatment in the boiling water was also irrespective of the molecular orientation. A permanganic etchant was made, and the change in surface morphology was investigated using the SEM. On the surface of thin parts, lots of channels parallel to the fiber axis were observed.
