Study On The Spinning Process And Structure Performance About PLA Fiber And The Blends Fiber

In this paper, melt-spinning method was used to manufacturing import polylactic acid (PLA) to be fiber and the basic performance of chips as well as spinning and post-processing technology conditions has been explored. The forming conditions and structure performance of PLA/PBS blends has been searched as well the PLA/PP blends. By using the scanning electron microscopy (SEM), differential scanning calorimetry (DSC), small-angle X-ray diffraction (SAXS) and dynamic mechanical analysis (DMA)and other means of analysis to this study, it found that 230℃can be the best spinning temperature to form PLA fiber. The system of spinning speed for 1000m/min and post-drawing 3.5 times can made the breaking strength up to 4.1cN/dtex, elongation at break 21% and the crystallinity 45%. The optimal spinning temperature of PLA/PBS blends is 220℃and the prime one of the PLA/PP blends is 235℃, when it has good spin ability. With the additives (PBS or PP) increase in the content, the system compatibility gradually deteriorate, resulting in fiber blends to reduce the breaking strength, and improve the uptake, reduce the glass transition temperature, thermal stability decreased, but the fiber crystallinity of PLA/PBS blends increased, and the fiber crystallinity of PLA/PP blends reduced.In addition, the article also focused on pure PLA fiber spinning, PLA / PBS blend fibers and PLA / PP blend fibers in different media degradation situation. The results show that three types of fiber could not tolerance with acid and alkali, particularly in the alkaline environment, they would be seriously degraded, and the more increase the environmental temperature, the more prone to degradation. After PBS added into PLA, PLA/PBS fibers are more susceptible to depredate than pure PLA fibers, but when they mixed with PP, under the same conditions, the degree of the degradation in PLA / PP fiber are more gently than pure PLA fiber.