冷却方式对滚塑制品结晶性能和力学性能的影响

采用不同冷却方式(水冷、风冷、自然冷和保温冷),对滚塑级线型低密度聚乙烯的结晶性能和力学性能进行了研究。结果表明,滚塑加工的冷却过程符合牛顿冷却定律,冷却系数和结晶度有着良好的线性关系,并从非等温结晶动力学理论中推导出符合牛顿冷却定律的结晶动力学方程;同时发现,结晶度和材料的拉伸强度、弯曲及冲击性能有着良好的线性关系,这为滚塑加工过程中,通过控制冷却系数,精确控制制品的力学性能提供了理论基础和实验案例。

Influence to Crystalline Property and Mechanical Property of Rotomolding Product by Cooling Method

Using different cooling methods,including water cooling,air cooling,natural cooling and insulation cooling,a re-search was made on crystalline properties and mechanical properties of rotomolding grade linear low density polyethylene. The result show that the cooling process of rotomolding producing conforms to Newton cooling law,the cooling coefficient has well linear rela-tion with crystallinity,and from non-isothermal crystallization kinetics theory a crystallization kinetics equation is deduced,which conforms to Newton cooling law. Moreover,it is found that,crystallinity has well linear relation with material's tensile strength, bending and impact properties. This study provides a theoretical basis and experiment case for rotomolding process that through con-trolling the cooling coefficient,the product's mechanical properties can be precisely controlled.