注射成型和注射压缩成型PET瓶坯性能对比分析

Properties Comparison of Injection Molded and Injection Compressiom Molded PET Preforms

采用注射成型和注射压缩成型的方法分别成型聚对苯二甲酸乙二醇酯(PET)瓶坯,并对PET瓶坯性能进行表征。对比研究了2种不同成型方法对透明PET瓶坯的外观形貌、瓶口尺寸、坯壁厚度、同心度、乙醛含量、黏度降和应力线分布状况的影响。结果表明,采用注射压缩成型方法制备的PET瓶坯具有良好的表面质量,其瓶口尺寸、坯壁厚度和同心度均满足标准;与注射成型方法相比,采用注射压缩成型方法制备的PET瓶坯的乙醛含量和黏度降更低,应力分布更为均匀,制品的残余应力更低。该工作为PET瓶坯的加工提供了一种新型、有效的成型方法。

Polyethylene terephthalate （PET） preforms are prepared by injection molding and injection compression molding, respectively. The properties of PET preforms are characterized, and the effects of the two different forming meth ods on the appearance, bottle size, bottle wall thickness, concentricity, AA value, IV drop and stress line distribution of PET preforms are studied. The results show that the PET preforms prepared by injection compression molding has good surface quality with the bottle size, bottle wall thickness and concentricity meeting the standards. Compared with the PET preforms prepared by injection molding method, the PET preforms prepared by injection compression molding has lower AA value and IV drop, more uniform stress distribution and lower residual stress. This work provides a new and effective mold ing method for PET preforms processing.