Stress relaxation during the orientation stretch of synthetics fibres

Conclusions

Results of investigating structural changes during the process of orientation stretching above the glass point (“hot” stretching) for a number of thermoplastic fibres have been examined: polyethylene, polypropylene, polyvinyl chloride, chlorine, kapron, nitron, lavsan, vinol, and acetate yarns, plus results of heat-treatments under tension and in the free state. The possibility of describing the relaxation of internal stresses in these fibres in terms of the concept of “operating” volume has been shown.

A correlative determination of the dependence of fibre stress dispersion during the process of orientation stretch and setting the structure of polyester yarn on the dispersion in yarn heat treatments has been established, as well as a dependence of the dispersion of physicomechanical properties on dispersion in fibre tension by steps in the technological process.