PVDC高阻隔热收缩膜收缩率彩响因素的研究

The factors influencing the shrinkage of high-barrier heat-shrinkable PVDC Him

采用多层共挤(三泡法)工艺制备了PVDC高阻隔热收缩膜,研究了拉伸比、吹胀比、收缩温度、原料及加工温度对PVDC高阻隔热收缩膜收缩率的影响。结果表明:薄膜的纵向收缩率几乎与拉伸比成线性关系,横向收缩率与拉伸比无关;薄膜的横向收缩率几乎与吹胀比成线性关系,纵向收缩率与吹胀比无关;薄膜的横向及纵向收缩率与收缩温度的线性相关程度较高;吹塑的原料PE.EVA及PVDC、膜坯的冷却温度、预热温度均影响制品的收缩率。

High-barrier heat-shrinkable PVDC film was prepared by multi-layer coextrusion(three-bubbling method)process.The effects were studied of tensile ratio,blowing ratio,shrinkage tem・perature,raw materials and processing temperature on the shrinkage of the film.The results showed that the longitudinal shrinkage of the film was almost linearly dependent on the tensile ratio,while the transverse shrinkage was independent of the tensile ratio.The transverse shrinkage of the film was almost linearly dependent on the blow up ratio,while the longitudinal shrinkage was independent of blow up ratio.The transverse and longitudinal shrinkage of the film had a high linear correlation with the shrinkage temperature.The blow molding raw materials PE,EVA and PVDC,the cooling temperature and preheating temperature of the film blank all affected the shrinkage of the product.