X-ray diffraction determination of the effective temperature applied to fibers during processing

X-ray diffraction studies of the relationship between structure and fiber t hermal processing during texturing of yarns or in fabric production has bee n helpful in understanding the causes of differential dyeing, as present in barre, or changes in the physical properties of fabrics. Crystalline order indices (COI), derived from parameters measured on the XRD diagrams of sam ples carefully treated at increasing temperatures and based on the fiber's continuous structural transition from less order toward a more highly order ed state, help to obtain simple correlations capable of determining the "ef fective temperature'' of production samples as received during processing. Defects induced during processing by faulty temperature controls can, by th is correlation, be recognized and corrective steps taken. This paper descri bes the behavior of nylon 6 (polycaprolactam), poly(ethylene terephthalate) (PET), and Qiana (R).