采用物理方式模拟聚对苯二甲酸乙二醇酯(PET)薄膜的“针孔现象”,然后对其进行透湿性能测试,研究3种温湿度条件下针孔个数、温度、针孔有无毛边对PET薄膜渗透性能的影响规律,基于最小二乘法探讨了针孔率与水蒸汽透过率之间的经验关系。结果表明:在不同温湿度条件下,PET薄膜水蒸汽透过率均随着针孔个数的增加呈线性趋势上升,在38℃、相对湿度90%的高温高湿状态下,针孔个数对薄膜水蒸汽透过率的影响最大;针孔无毛边时的薄膜水蒸汽透过率明显大于有毛边时的水蒸汽透过率,且随着针孔数量的增加,针孔无毛边相对有毛边时的水蒸汽透过率增长率逐渐增大;在38℃、相对湿度90%的高温高湿度条件下针孔率与薄膜水蒸汽透过率之间为二次函数关系,另外两种温湿度条件下为一次线性比例关系。

The pinhole phenomenon of polyethylene terephthalate (PET) film was simulated by physical method,and then its moisture permeability was tested.The effects of number,temperature and pinhole had hairy edges of pinhole on the permeability of PET films under three different temperature and humidity conditions were studied.Furthermore,the empirical relationship between the pinhole rate and the water vapor permeability was discussed based on the least square method.The results indicated that the water vapor permeability of PET film increased linearly with the increase of pinhole number under different temperature and humidity conditions.The pinhole number had the greatest influence on the water vapor permeability of PET film at 38℃ and 90 RH%.The water vapor permeability of film without hairy edges was obviously higher than that of film with hairy edges.With the increase of the number of pinholes,the growth rate of water vapor permeability of film without hairy edges was gradually increased compared with that of film with hairy edges.The relationship between the pinhole rate and the water vapor permeability of the film was quadratic function at 38℃ and 90RH%,and their relationship was linear proportional relationship at the other two temperature and humidity conditions.