Understand the maintenance effect of polymer protective film

The polymer protective film uses the principle of the stretching direction of polymer molecular chains and is formed by quenching and setting. The physical principle is that when in a highly elastic state, grasp the stretching direction of the high polymer, and then suddenly cool the high polymer below the glass transition temperature, the molecular orientation freezes, and then rises to a certain temperature, the molecular movement will cause stress relief. The molecule returns to its original state, causing contraction. The polymer protective film is a thermoplastic film that stretches during the production process and shrinks to heat during use. Therefore, no matter which printing method is used, before designing the surface pattern, the horizontal and vertical shrinkage of the material and the allowable deformation errors in all directions of the decorative painting must be considered. It can ensure the accurate restoration of the shrinking pattern, text and barcode in the container. The lateral shrinkage rate of the protective film material used for printing is 50% to 52% and 60% to 62%. In special cases, 90% is required, and the longitudinal shrinkage is 6%. Next: PE heat shrinkable film has a higher shrinkage rate Previous: The effect achieved by PE heat shrinkable film