阻隔性薄膜透湿性能的电解法和红外法测试分析

Analysis of Water Vapor Permeability of Barrier Plastic Films by Electrolytic and Infrared Detection Sensor Methods

采用电解法和红外法研究了不同温度、湿度下阻隔性塑料薄膜的水蒸气透过率,分析了温度、薄膜类型对透湿性能的影响。结果表明,12μm聚对苯二甲酸乙二酯(PET)薄膜的透湿性能最大,其次是25μm的PET薄膜,25μm聚偏二氯乙烯(PVDC)薄膜和12μm PET/铝箔(PET/Al)复合薄膜的水蒸气透过率相近且最小;这4种薄膜的水蒸气透过率均随温度的升高而增大,温度对12μm PET/Al、25μm PVDC薄膜的水蒸气透过率影响较小,水蒸气透过率的对数形式与热力学温度的倒数呈线性关系;红外法的测试结果基本都大于电解法,对于25μm PVDC薄膜和12μm PET/Al薄膜,2种测试结果的差异较大,而对于12μm PET薄膜和25μm PET薄膜,2种测试结果的差异较小。

Water vapor transmission rates of barrier plastic films were investigated at different temperatures and relative humidity by electrolytic and infrared detection sensor methods.Effects of temperature and film type on the water vapor permeability were analyzed,and the experimental results obtained from the electrolytic and infrared detection sensor methods were compared.The results indicated that PET film with a thickness of 12μm presented greater water vapor permeability than that with a thickness of 25μm.PET/A1 film with a thickness of 12μm and PVDC film with a thickness of 25μm exhibited smaller water vapor permeability than that of the two PET films.The water vapor transmission rates increased with an increase in temperature for these four barrier plastic films.However,the temperature had less effect on the water vapor transmission rates of PET/A1 film with a thickness of 12 and PVDC film with a thickness of 25μm,and there was a linear relationship between the logarithm of water vapor transmission rate and the reciprocal of thermodynamic temperature.Test results obtained from the infrared detection sensor method were greater that those from the electrolytic detection sensor one.The difference between these two test results for PET/A1 film with a thickness 12μm and the PVDC with a thickness 25μm was larger than those for PET films with thicknesses of 12 and 25μm