POF is the meaning of thermal shrinkage film. POF is called multi-layer co-extrusion polyolefin thermal shrinkage film. It is made of linear low density polyethylene (LLDPE) as the intermediate layer, and copolypropylene (PP) as the inner and outer PP layer. It is extruded by three extruders, then processed by die forming, bubble blowing and other special processes. (1) Thinning of materials - saving energy and resources, reducing environmental pollution? 2) Safety of use - attaching importance to human health, product safety and non-toxicity? 3) Diversification of varieties - high performance, multi-function, to meet different packaging needs? 4) Specialization of services - attaching importance to the ability to provide overall solutions? 5) High-end products. OPS (heat shrinkable film) is a new type of body-fitted packaging material which meets the requirements of environmental protection. OPS heat shrinkable film has high strength, high rigidity, stable shape, and good gloss and transparency. OPS is lighter. The proportion of OPS is only 1.05. For OPS, PVC and PET with the same thickness and area, OPS can reduce the weight by 25%.