The Effect of Fine Structure on the Mechanical Properties of Synthetic Fiber

합성섬유의 미세구조가 역학적 성질에 미치는 영향

This study has been designed to investigate the influence of drawing and heating conditions affecting on the change of fine structures by x-ray and birefringence measurements (in particular, on the degree of orientation in crystalline and amorphous phases) and on the mechanical properties of PET fibers. In a crystalline region, relationship between birefringence contribution, ncx, and breaking stress is expressed by a linear function, and clear structural discontinuities are observed between ncx and yield stress. In an amorphous area, relationship between birefringence contribution, na(1-x), and yield stress shows a linearity and that between na(1-x) and breaking stress is indicated by a quadratic curve. The existence of structural transformational region could easily be presumed by the fact that an inflection and tensile characteristics exists at the range of draw ratio 2.0~2.5. Particularly, it is found that an inflection phenomenon of yield stress is under the contol of a crystalline region and that of breaking stress is swayed by an amorphous area.