注射速度对制品成型结晶形态的影响

以某平板塑件为例，以聚丙烯（PP）为实验材料，通过成型取样、X射线衍射实验及数据处理技术相结合的方法研究了注射速度对制品结晶形态的影响规律及影响效应。结果表明，在正常情况下，PP塑件的结晶类型主要为α、β两种晶型；制品的结晶度随注射速度的增大存在极点，呈现倒V字形的变化趋势；制品整体取向度与晶格畸变量具有类似的变化趋势，均随注射速度的增大而增大，而晶粒尺寸的变化则与注射速度呈现负相关性；注射速度对制品晶粒的影响最为显著，结晶度影响其次，影响显著性顺序依次为晶粒尺寸>结晶度>晶格畸变>取向度>晶型，对于本试样，最佳注射速度应控制在180 mm/s。

Effect of Injection Velocity on Crystall Morphology of Injection Molded Parts

The effect of injection speed on the crystallization properties of polypropylene (PP) was studied. Plotting crystallinity vs. injection velocity a “Λ” shaped curve was obtained. The orientation and lattice distortion increased, while the crystallite dimension decreased with increasing injection speed. The order of the parameters sensitive to injection speed was crystallite dimension, crystallinity, lattice distortion, orientation, crystal form.