添加剂对双峰型HDPE熔体质量流动速率测试的影响

Effect of additives on measurement of melt mass flow rate of bimodal HDPE

熔体质量流动速率(MFR)是树脂生产过程中重要的控制指标,本文主要分析四川石化产双峰型100 N高密度聚乙烯粒料MFR测试值重复性与准确性差的原因。粒料中含有氟弹性体,硬脂酸锌,硬脂酸钙润滑剂,有效的改善了树脂的流动性。氟弹性体吸附、聚集在口模内表面,测试100 N粒料MFR时,测试值突然开始逐渐增大,给生产装置正常生产带来非常大的困难。测试前清除口模内表面残留的氟弹性体、硬脂酸盐与树脂形成的润滑膜,能够显著提高分析结果的精密度与准确度。

Melt mass flow rate(MFR)is an important control index in the resin production process.This paper mainly analyzes the reasons for the poor repeatability and accuracy of MFR test values of bimodal 100 N high density polyethylene granules produced by Sichuan Petrochemical Company.The particles contain fluorine elastomer,zinc stearate and calcium stearate lubricant,which can effectively improve the fluidity of the resin.The fluoroelastomer adsorbs and accumulates on the inner surface of the die.When the MFR of 100 N granular material is tested,the test value suddenly begins to increase gradually,which brings great difficulties to the normal production of the production device.The precision and accuracy of the analysis results can be significantly improved by removing the residual fluoroelastomer,stearate and the lubricating film formed by resin on the inner surface of the die before the test.