微发泡注塑制品表面质量的优化研究  

Study on surface quality optimization of microfoaming injection-molded products

作　　者：翟玉娇 信春玲[1] 何亚东[1] 闫宝瑞[1] 乔林军 ZHAI Yujiao;XIN Chunling;HE Yadong;YAN Baorui;QIAO Linjun(College of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]北京化工大学机电工程学院,北京100029

出　　处：《中国塑料》2022年第2期19-26,共8页China Plastics

摘　　要：以聚丙烯(PP)和高纯氮气为原料,采用高压短时和低压长时两种注气方式进行了微发泡注塑实验,并在以低压长时为注气方式的实验中,在不同熔体温度、注气压差和储料长度下,研究了冷却时间与制品表面出现大气泡概率之间的关系。结果表明,通过高压短时注气方式得到的制品表面出现大气泡的概率较高,严重影响制品质量;采用低压长时注气方式,制品表面出现大气泡的概率显著降低;延长冷却时间可以完全消除制品表面的大气泡,且在一定范围内,熔体温度越高、注气压差越大、储料长度越大,消除大气泡所需要的最佳冷却时间越长。Micro-foaming injection molding experiments were carried out using two gas injection methods,i.e.,a high pressure short time method and a low pressure long time method,with polypropylene and high-purity nitrogen as raw materials.In the experiment with the low pressure and long time as the gas injection method,the relationship between the cooling time and the probability of large bubbles on the product surface was investigated under the conditions of different melt temperatures,injection pressure differences and storage lengths.The results indicated that the probability of large bubbles appearing on the surface of the products obtained from the high-pressure short-time gas injection was high.This seriously affects the quality of products.The probability of large bubbles on the product surface was reduced significantly by using the low-pressure and long-term gas injection.The large bubbles on the product surface could be eliminated completely by prolonging the cooling time.In a certain range,the higher the melt temperature,the greater the injection pressure difference and the longer the storage length,the longer cooling time is needed to eliminate the large bubbles.

关 键 词：微发泡注塑 大气泡 注气方式 冷却时间 工艺参数 

分 类 号：TQ328.06[化学工程—合成树脂塑料工业]