高密度聚乙烯对聚丙烯流延膜热封性能的影响

The effect of high density polypropylene on the heat sealing property of polypropylene casting film

以三元聚丙烯热封树脂为原料,通过添加高密度聚乙烯制备了单层流延热封膜,采用热封仪对热封膜进行热封实验,利用热封强度测试和DSC方法研究了热封膜的组成、熔融行为、热封温度对热封强度的影响。实验结果表明,聚丙烯流延热封膜的起始热封温度与热封膜树脂的组成有密切关系,且起始热封温度主要与热封层树脂的熔融行为有关。聚丙烯流延热封膜的起始热封温度随共聚物中聚乙烯含量的增加而降低。参考热封膜树脂非等温结晶之后的熔融行为可以推测热封膜可检测到的热封强度对应的热封温度范围。

A single-layer cast film was prepared by adding high density polyethylene to the polypropylene(PP)heat sealing resin.The influence of the composition,melting behavior and heat sealing temperature of the heat sealing film on the heat sealing strength was studied by the heat sealing strength test and DSC.The experimental results show that the initial heat sealing temperature of PP cast film is closely related to the composition of the resin,and the initial heat sealing temperature is mainly related to the melting behavior of the resin.The initial heat sealing temperature of polypropylene film decreases with the increase of polyethylene content in the copolymer.According to the melting behavior of the resin after non-isothermal crystallization by DSC,the temperature range corresponding to the heat sealing strength detected by heat sealing film can be inferred.