Spin draw process of making partially orientated yarns from polytrimethylene terephthalate

一种由聚对苯二甲酸亚丙基酯制备部分取向纱的纺拉成形法，包括下述步骤：(a)挤出和纺聚对苯二甲酸亚丙基酯，并由其形成单丝或复丝，(b)通过使纱线与一定温度下的转动第一对导丝辊接触而加热纱线，所述导丝辊的温度使得纱线温度高于聚对苯二甲酸亚丙基酯纱线的玻璃化转变温度并低于其冷结晶温度，(c)在第一对导丝辊和第二对导丝辊之间移动纱线，和(d)在低于第二对导丝辊1-15％的速度和低于聚对苯二甲酸亚丙基酯纱线的玻璃化转变温度的温度下，卷绕纱线。 This invention is a spin draw process for making partially oriented yarn from polytrimethylene terephthalate (PTT) which comprises the steps of: (a) extruding and spinning PTT in forming a monofilament or multifilament yarn therefrom, (b) heating the yarn by contacting it with a first pair of godets moving at a speed in and at a temperature set to give a yarn temperature above the glass transition temperature and less than the cold crystallization temperature of PTT, (c) drawing the yarn between the first godet pair and a second pair of godets moving at a speed and a temperature of from 45 to 120° C. and having a draw ratio of 0.7 to 3.0, and (d) winding the yarns at the speed of 1 to 15% less than that of the second godet pair at a yarn temperature less than the glass transition temperature of PTT yarn.