可生物降解聚乳酸长丝的熔融纺丝工艺

 为了纺制高品质的聚乳酸长丝,采用熔融纺丝方法,优化切片干燥工艺,并研究了纺丝工艺参数（纺丝温度、纺丝速度、拉伸倍数、拉伸温度）对聚乳酸长丝性能（粘均分子量、取向、机械性能等）的影响关系,最终确定了最佳的纺丝工艺。结果表明：最优的切片干燥工艺为：分两阶段进行干燥，第一阶段由室温逐步升温至60-65℃,停留3-4h预结晶,第二阶段逐步升温至100℃干燥15h,最终切片含水率低于0.005%。最佳纺丝工艺为：纺丝温度195℃、纺丝速度1000m/min、拉伸倍数为3、拉伸温度T1/T2/T3=72℃/80℃/82℃。

Melt spinning process of biodegradable PLA filaments

In order to spin the high quality PLA filament, the melt spinning method was applied and the chip drying process was optimized. The effect of spinning parameters, including spinning temperature, spinning speed, stretching ratio and stretching temperature, on the qualities of PLA filament (viscosity average molecular weight,orientation and mechanical property) were also researched. The results indicate that: the PLA chip should be dried in two stages. First stage, the temperature should climb up to 60-65℃, for 3-4h, in order to pre-crystallize, second stage, increased drying temperature up to100℃ for 15h. At last, the chip moisture content was lower than 0.005%. The optimum spinning parameters were as follows: 195℃ spinning temperature, 1000m/min spinning speed, 3 stretching ratio and T1/T2/T3=72℃/80℃/82℃stretching temperature.