聚丙烯粉料、粒料熔融指数差异原因分析

熔融指数是划分聚丙烯牌号的关键指标。在锦西石化聚丙烯装置开车期间,聚丙烯粉料熔融指数分析数据重复性不好,且与聚丙烯粒料的熔融指数存在较大差异。车间无法正常组织生产,聚丙烯产品无法在装袋前确定正确牌号。针对这一问题,通过实验,逐步查找聚丙烯粉料、粒料的熔融指数差异的根本原因。确定主要原因在于聚丙烯粉料未去活,测试粉料熔融指数前未进行合适的样品预处理。通过实验确定最优的样品预处理方法。使用这一方法便于生产过程控制,保证产品的质量稳定,提高了公司的经济效益。

STUDY ON THE CAUSE OF THE DIFFERENCE BETWEEN POLYPROPYLENE POWDER AND PELLET

Melt index is a key index to divide polypropylene grade.During the startup of Jinxi polypropylene plant,the repeatability of the melt index data for polypropylene powder was not good.And there was a big difference in melt index between polypropylene powder and pellet.The workshop couldn’t organize regular operation and the grade of polypropylene products couldn’t be confirmed correctly before bagging.Aiming at solving this problem,the root cause for the difference between polypropylene powder and pellet were found out through some experiments.It was determined that the difference was caused by lack of deactivation of polypropylene powder and lack of proper sample pretreatment before testing powder melt index.The optimal sample pretreatment method has been set through experiment.This method is convenient for production process control.And it may ensure the stable quality of the products and improve the economic benefits of the company.