The Effect of Rate and Temperature of Drawing on the Properties of Nylon 6,6 Fibers

Abstract

Higher rates and lower temperatures of cold-drawing nylon 6,6 result in both increased fiber strength and an increased amount of the non-recrystallizable Form II endotherm, as measured by differential scanning calorimetry. This may be explained in terms of mobility of the molecular chains in the neck region; long times and high temperature in the neck favor formation of the recrystallizable Form I material, whereas short times and low temperatures, which result in lower mo lecular mobility, favor the non-recrystallizable and stronger Form II. Because of the temperature effect on the drawing a draw pin temperature rise due to friction and work of drawing can have a variable, detrimental effect on yarn strength at a given draw ratio.