基于ISO标准比较不同热收缩膜的收缩性能

目的研究不同材质热收缩膜的热缩力和冷缩力与温度的关系,确定各收缩膜收缩时测试的方向,验证试验设置温度与最大热缩力出现时间等参数的关系。方法依照ISO 14616空气加热原理试验方法,测试不同材质热收缩膜在最佳设置温度下(最大热缩力出现在15~30 s内时的温度)的收缩性能,并设置一系列试验温度对国内外3种性能差异较大的热收缩膜进行大量测试。结果不同热缩膜的最大冷缩力、最大热缩力的趋势并不相同,热收缩方向因收缩膜的材质及加工工艺而异,而同种热收缩膜在不同的FST-02薄膜热缩性能测试仪上表现出基本一致的收缩性能。结论ISO 14616规定的试验方法和仪器基本适用于各种材质的热收缩膜,仅试样测试方向、温度设置范围需根据收缩膜的材质及加工工艺进行调整。

Comparison of the Thermal Shrinkage Properties of Heat-shrinkable Films Based on ISO Standard

To study the thermal shrinkage properties of heat-shrinkable films, including shrinking force, contracting force and shrinking direction, and to determine the influences of the test temperature and the test duration to reach the maximum shrinking force on the shrinkage properties. According to the air heating principle test method in ISO 14616, the heat-shrinkable films were treated in the heated air to determine the shrinkage properties of various heat-shrinkable films at the optimal temperature (the temperature at which the maximum recorded shrinking force occurred between 15 s and 30 s). Multiple tests were conducted with three types of heat-shrinkable films with distinct thermal shrinkage properties at a series of temperature. The trends of maximum shrinking force and maximum contracting force of various heat-shrinkable films were different. And the shrinking direction was different for films with different materials and processing technologies. The same heat-shrinkable film demonstrated basically identical thermal shrinkage properties on different FST-02 film film thermal shrinkage testers. The test method and instrument specified in ISO 14616 were suitable for all kinds of heat shrinkable films, except that the sample direction and scope of preset temperature should be adjusted according to the material and the processing technique of the heat-shrinkable films.