EXPERIMENTAL STUDY ON THE DYNAMIC MODULI OF TWISTED SLIVER IN THE RANGE OF LOW FREQUENCY

Abstract

The effects of tension and twist to the dynamic moduli mainly, modulus of elasticity, coefficient of viscosity and energy loss, of crimped viscose spun rayon sliver (length 20cm, linear density 0.038g/cm) were investigated by means of the damped oscillating method of pendulum type under the low frequency of 0.5cps.During the investigation, it was found that the amplitude of each sliver (maximum relatived deformation: 0.75%) damped exponentially as the oscillation decreases. Then dynamic properties of twisted sliver were evaluated by application of the theory of the visco-elastic models, and following results were obtained.(1) In the case of fixed twist number of sliver, in the range of twist 0 to 6 turns per initial length of 20cm, modulus of elasticity, coefficient of viscosity and energy loss of each sliver increased respectively with increasing applied loads of sliver from 0 to 50g. (See Fig. 6, 7 & 8).(2) In the case of fixed applied load, in the range of 0 to 60g, modulus of elasticity, coefficient of viscosity and energy loss of each sliver increased reqpectively with increasing twist numbers from 0 to 6 per initial length 20cm. (See Fig. 6, 7 & 8)(3) Comparing the dynamic properties of loaded sliver twist previously with those of twisted sliver loaded previously it was found that, at the same number of twist per initial length, the values of period and logarithmic decrement of the latter were equal to those values of the former, when the tension of the latter were lower than that of former. (See Fig. 3. 4 & 10)