抄録
The mechanism of winding of a hard-twist yarn was experimentally examined in relation to the behavior of the yarn layer when heat-set was applied to the yarn package.
The results obtained are as follows:
(1) The radial pressure after reaching equilibrium with increasing yarn layer is in proportion to the twisting torque of a yarn.
(2) The axial stress which compresses the flanges and the radial pressure which tightens up the barrel increase with increasing in the torque of the twisted yarn.
(3) When heat-set is applied to the yarn package, the radial pressure which is caused by shrinkage of the yarn layer begins to increase suddenly as the temperature of the cylinder raises up to the glass transition temperature of the component fibers of the yarn, and reaches a constant value as the temperature becomes constant. On the other hand, the axial stress increases with increasing temperature owing to the axial expansion in the yarn layers, which is caused by the growing radial shrinkage, and then decreases since the yarn shrinks inversely to the direction that the flange is pressed.
