초록
연신비와 연신온도를 달리한 PET filament 사의 열응력을 상온에서 27$0^{\circ}C$까지 온도를 변화시키면서 측정하였다. 실험결과를 토대로 연신비와 연신온도 변화에 따른 실의 역학적 및 점탄성적 변화를 비교 검토하였다. 최대 열응력은 연신비가 커질수록 증가하였고 또 연신온도가 높을수록 감소하였다. 그러나 연신비가 3.5, 4.0인 것은 연신온도가 증가할수록 열응력도 증가하였다. 최대 열응력 온도는 연신비가 커질수록 증가하였다. 그러나 연신비가 3.5 이상인 것은 거의 변화하지 않았고 또 연신온도가 증가할수록 최대 열응력 온도는 감소하는 경향을 보였다.
The thermal stress of polyethlene terphthalate filament yarns which were manufactured at different draw ratios and drawing temperatures was measured in the temperature range of 2$0^{\circ}C$ to 25$0^{\circ}C$ by using the Kanebo Engineering Thermal Stress Tester. On the basis of the experimental results, the effect of the draw ratio and drawing temperature on the thermal stress and viscoelastic properties of yarn was investigated. The behaviors of the thermal stress and loss tangent with respect to temperature are similar, but those of the maximum thermal stress and maximum loss tangent with respect to draw ratios are opposite. Maximum thermal stress decreases with drawing temperature while maximum loss tangent increases. But in the case of high draw ratios such as 3.5 and 4.0 maximum thermal stress increases with drawing temperature while maximum loss tangent decreases. Maximum thermal stress temperature and maximum loss tangent temperature increase with draw ratio, but they almost do not change at the draw ratios 3.5 and 4.0. They tend to decrease with drawing temperature.
