PVC润滑剂金属润滑性能的转矩流变仪评价方法

A Method for Evaluating the Metal Lubricating Performance of PVC Lubricants Using a Torque Rheometer

研究了用转矩流变仪测试评价聚氯乙烯(PVC)润滑剂的金属润滑性能(通常称为脱模性能),结果表明:通过观测用转矩流变仪混炼PVC配混料时初形成熔体对混炼室金属表面的黏结性随润滑剂用量的变化,可确定润滑剂的临界脱模用量(完全不黏结混炼室金属表面所需最小用量),而临界脱模用量的倒数可作为评价润滑剂金属润滑性能的定量指标。与传统的双辊机黏辊时间法相比,新方法不但测试结果重现性更高,而且因为能有效消除润滑剂热稳定性能差异的影响,因此能更好反映润滑剂在实际加工中的金属润滑性能。

The test and evaluation of the metal lubricating perfbrmance, as metal release performance,of PVC lubricants using a torque rheometer were studied. It was found that the critical levels for metal release, that was, the minimum levels for completely not sticking to the metal surface of the mixing chamber, of the lubricants could be determined by observing the change of the stiekness of the melt formed initially to the metal surface of the mixing chamber with the levels of lubricants when the PVC eompounds were mixed using a torque rheometer under the common processing condition, and the reciprocal of the critical level for metal release of a lubricant could be used as a quantitative index for evaluation of metal lubricating performance. Compared with the traditional method using the sticking time determined with a mill as the evaluation index, test remits could be given by the new method not only with higher reproducibility, but also reflected better the metal lubricating performances of lubricants used in practical processings,because the influence of differences in heat stabilizating performances of lubricants could be eliminated effectively.