Deformation resonance in orientational drawing of high-modulus viscose fibre twist

Increasing the orientational draw ratio of a freshly spun high-modulus fibre above some limit causes the appearance of periodic thinning in the drawn twist. It was hypothesized that thinning is formed according to the mechanism of deformation resonance described previously for spinneret drawing of spinning solutions and melts. An explanation of the mechanism of deformation resonance was proposed, where this phenomenon takes place during drawing of an inhomogeneous material due to partial fracture of the weaker part of it. The proposed hypothesis is in satisfactory agreement with the experimental data. In production of high-modulus viscose fibres, the orientational draw ratio should not exceed 2.1-2.2 (110-120%), and the first drawing should be within the limits of 1.6-1.7 (60-70%).