不同黏度聚丙烯流动性能及其皮芯型纺黏纤维

Flow Properties of Polypropylene with Different Viscosity and Its Sheath-Core Spunbonded Fibers

研究了不同黏度聚丙烯熔体的表观黏度与切变速率、温度之间的关系,并比较了不同黏度聚丙烯熔体制得的皮芯型纺黏纤维的力学性能和结构。结果表明:随着温度的升高,黏度越大的聚丙烯熔体的表观黏度减小速率越快;随着切变速率的加快,熔体的表观黏度不断减小。在相同的纺黏工艺条件下,低黏度的聚丙烯熔体制得的皮芯型纤维更细,断裂强度更小;与机械牵伸工艺相比,聚丙烯复合纤维的解取向程度改变不明显,黏度越小的聚丙烯复合纤维取向度和结晶度越大。采用不同黏度聚丙烯熔体制备的皮芯型纺黏纤维,仅部分纤维截面会呈现皮芯型结构。

The relationship between apparent viscosity and shear rate,temperature of polypropylene(PP)melt with different viscosity was studied,and the mechanical properties and structure of sheath-core spunbonded fibers prepared by PP melt with different viscosity were compared.The results show that the apparent viscosity of polypropylene melt with higher viscosity decreases faster with the increase of temperature.As the increase of shear rate,the apparent viscosity of melt decreases.Under the same spunbonded condition,the sheath-core fiber prepared by low viscosity PP melt has smaller fineness and fracture strength.Compared with the mechanical drafting process,the orientation of PP composite fiber does not change obviously,and the orientation and crystallinity of low-viscosity polypropylene composite fiber increase.The some of the cross-section of sheath-core fibers prepared by PP melt with different viscosity present a sheath-core structure.