PVA热收缩包装薄膜的研究与应用

PVA热收缩薄膜具有优异的水溶性和生物降解性能,目前其生产方法主要有流涎法(湿法)和挤出吹塑法(干法),其热收缩工艺可分为一步法和两步法。PVA薄膜通过增塑改性可以降低结晶度,从而增加热收缩性能。其中,增塑改性工艺中的主要影响因素为增塑剂,拉伸工艺中的主要影响因素是拉伸温度和拉伸倍数,骤冷工艺中的主要影响因素是冷却温度及受冷均匀,收缩工艺中的主要影响因素是热收缩温度。PVA热收缩薄膜的市场应用空间较大,其研究方向主要为新型绿色可降解热收缩包装薄膜。

Research and Application of PVA Shrinkable Packaging Film

The PVA thermal shrinkage film has excellent water soluble and biological degradation performance. Currently the production methods of PVA film mainly contain salivation (wet) and extrusion blow molding (dry) method while the thermal shrinkage process can be divided into one-step and two-step approach. The degree of crystallinity in PVA film can be reduced through plasticizing modification, thus to increase thermal shrinkage performance. Plasticizer is the main influencing factor in the plasticizing modification in the process. The main factor in drawing process is the tensile temperature and draw ratio. Cooling temperature and uniformity in cooling are main influencing factors in quenching technology. Thermal shrinkage temperature is the main influencing factor in shrinkage process. The market of PVA thermal shrinkage film application is promising, and the future research is mainly direceted at new types of green degradable heat shrinkable packaging film.