Die geometry induced heterogeneous morphology of polypropylene inside the die during die-drawing process
Die geometry induced heterogeneous morphology of polypropylene inside the die during die-drawing process
复制标题
在模头拉伸过程中，模头几何形状导致模头内聚丙烯的异质形态
DOI：
10.1016/j.polymertesting.2018.12.019
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发表时间：
2019-04-01
期刊：
影响因子：
5.1
通讯作者：
Men, Yongfeng
中科院分区：
文献类型：
--
作者：
Lyu, Dong;Sun, Yingying;Men, Yongfeng
采用广角X射线衍射技术研究了热拉伸过程中等规聚丙烯（iPP）在通过模具成型时的形态分布。记录了模拉iPP外层（靠近模壁的层）和内层（模具中心的层）微观结构的演变。结果表明，外层和内层之间形态分布的差异随从模具入口到出口的距离而变化。一般来说，在模具内部的中间变形区域可以发现外层和内层之间有较大差异，而在模具的入口和出口区域这种差异消失。这些行为可解释为模具内部存在力场不均匀分布的结果，这是由模具几何形状和拉伸力的倾斜引起的。这项工作表明，通过分析模拉样品的形态可以揭示模具内部的不均匀力场。
The morphology distribution of isotactic-polypropylene (iPP) shaped through a die during hot stretching process was investigated via wide-angle X-ray diffraction technique. The evolution of micro-structures in the outer layer (layer closer to the die wall) and the inner layer (layer in the center of die) of die-drawn iPP were both recorded. It turned out that the difference of morphology distribution between outer and inner layers changes with the distance from the die entrance to exit. In general, a larger difference between outer and inner layers could be found at the intermediate deformation region inside the die while such difference disappeared at both of the entrance and exit regions of die. These behaviors could be interpreted as a result of the existence of a heterogeneous distribution of force field inside the die, which was caused by the die geometry and inclination of the drawing force. This work showed that the heterogeneous force field inside the die could be revealed through analyzing the morphology of a die-drawn sample.