Change of Fine Texture of Nylon 12 by Drawing

Abstract

In order to examine the relation between the fine texture of Nylon 12 sheets and the drawring conditions, fiber identity period (FIP), crystallite size, degree of crystal orientation and crystallinity were carried out for dumbbell type test specimens before and after drawing under various conditions, changing temperarures from 50 C to 160 C and draw ratios from 2.4 to 4.0.Original specimens and most of the drawn-specimens showed their X-ray diffraction patterns specfic to g -from (Fig.2(a), (b)). However, for specimens drawn at temperatures from 140 C to 160 C and draw ratios from 2.4 to 3.0, a splitting of the equatorial reflection(d=4.1A)was observed in the X-ray photograph(Fig.2(c)). DSC curve did not show any sign of new crystalline from to present.Calculated values of FIP from each order of reflections did not coincide each other, but increased as the order became higher. Further, with rasise of drawing temperature, values of FIP, crystallite size and crystallinity increased, while the degree of the orientation was almost unchanged (Figs.3, 4, 7, Tables 1, 2). On the other hand, with the increase of draw ratio, the degree of the erientation became greater, while FIP, crystallinity and crystallite size were almost uninfluenced (Fig.8).On the basis of these findings, factors affecting the anomalous FIP observed in the X-ray diffractometry and the deformation mechanism of crystallites due to drawing were discussed.