POF Shrink Film is the main component of PE and PP, and it is different from the PVC, POF is a flexible environmental shrink film, in the combustion process will not release toxic gases, but also can contact food directly. POF shrink film is made of multi-layer PE or PP film co-extruded, which makes POF has various different characteristics, such as texture is soft, tough, high transparency and high shrinkage. POF has low temperature sensitivity, it will not become brittle yellow at low temperature and will not shrink at 40-50 degrees. POF shrink film need a vent hole to leak air from the shrink film, and it is important to expose to the appropriate temperature at the right time, the correct circulating wind speed is also important. When the PVC heat treatment will begin to shrink immediately, so the packaging machine air circulation on the PVC shrink film is not important. But POF Shrink Film is very dependent on the circulating air to achieve a complete contraction. Some of the simpler packaging machine can not adjust the speed of circulating air, when the shrinkage of POF material will be quite difficult.