Heat exchange in the stretch roll-yarn system in stretching complex synthetic yarns

Conclusions

At assigned values of the technological process of yarn stretching (speed, temperature, stretch ratio, and number of turns), both the temperature of the lower stretch roll and also the time of departure into a steady temperature regime are unambiguously determined.

High yarn breakage at the start of operating time for output on twisting and stretching machines may be explained by an insufficient surface temperature of the lower stretch roll.

The temperature of the lower stretch roll surface reaches a steady value after approximately 600 sec (depending on the temperature and rate of fibre movement). The yarn produced during this time has reduced physico-mechanical properties.

To improve the passage of yarns which are drawn on twisting and stretching machines, it is advisable to make the lower stretch rolls heatable at the initial moment of operation, and also to reduce their weight.