浅析注塑工艺对二醋酸纤维素力学性能的影响

Influence of injection molding process on mechanical properties of cellulose diacetate

使用不同的工艺条件对二醋酸纤维素塑料(DACP)进行注射成型,将注塑温度、注射速度、压力等条件逐个改变,研究不同条件下DACP注塑制品力学性能的变化。结果表明,随着注塑条件的改变,材料的性能会出现一些规律性的变化,其中注塑温度对DACP韧性和断裂伸长率的影响较大,随着温度的提高韧性增强,断裂伸长率大幅增加,但在230℃以上材料出现黄变。过高或过低的注塑速度都会造成DACP的冲击性能下降,中速(55%)的注射速度冲击强度最高。压力的变化对性能的影响不大,但过高的压力可能导致飞边的等缺陷的产生。工艺选择注塑温度为225℃,注射速度为55%、压力为9 MPa时整体性能较好。因此选择合适的注塑工艺,对DACP制品的性能有所改善。

Cellulose diacetate plastic(DACP)was injection molded under different process conditions with a change in the injection temperature,injection speed,pressure,and other conditions one by one.The mechanical properties of the injection⁃molded products were investigated.The results indicated that with a change in the injection conditions,the molded products presented a regular change in their performance.The injection temperature exhibited a greater influence on the toughness and elongation at break of the molded products.Their toughness was further enhanced with an increase in the injection temperature,followed by a significant improvement in the elongation at break.However,the molded products started yellowing at a temperature of above 230℃.An over high or over low injection speed might lead to deterioration in the impact resistance of the molded products.The products molded at a medium speed of 55%exhibited the highest impact strength.The change of injection pressure generated little effect on the performance of the molded products;however,an excessive pressure led to some defects such as flashing.The molded products exhibited the optimal overall performance at an injection temperature of 225℃,an injection speed of 55%,and an injection pressure of 9 MPa In this sense,selecting an appropriate injection molding process condition can improve the performance of the injection⁃molded DACP products.