具有规则微结构表面聚丙烯塑件的超声模压粉末成型

利用自制的组合式模具,通过超声模压粉末成型工艺,制得形状尺寸可控的聚丙烯微塑件,成功复制了模芯表面的微沟槽阵列结构。设计单因素实验,研究了超声能量、焊接压力、保压时间对聚丙烯微结构塑件成型的影响。结果表明,适当增加超声能量与焊接压力,可有效提高熔体的填充能力。当超声能量为1000 J、焊接压力为115 kPa、保压时间为8 s时,所制得的微结构塑件具有较好的表面形貌复制率。差示扫描量热和X射线衍射分析表明,超声能量的增加不会改变聚丙烯的晶体结构;随着超声能量的增加,微结构塑件的结晶度降低、晶粒细化。

Ultrasonic Powder Molding of Polypropylene Parts with Regular Micro-Structured Surfaces

The PP micro-structured parts with controllable shape and size were fabricated by the modular mold and micro ultrasonic powder molding(micro-UPM).The micro-structure on the surface of the mold core was successfully replicated.Single-factor experiments were designed to investigate the effects of ultrasonic energy,welding pressure,and holding time on the molding of PP micro-structured parts.The results show that the increase of ultrasonic energy or welding pressure is beneficial to improving the filling capacity of the melt.Micro-structured parts with good surface morphology replication rates are fabricated at an ultrasonic energy of 1000 J,a welding pressure of 115 kPa and,a holding time of 8 s.DSC and XRD analysis show that the increase in ultrasound energy does not change the PP crystal structure,the crystallinity of the micro-structured parts decreases,the grains are refined.