The production process of PVC film is not complicated. Ordinary production lines generally consist of a roller press, a printing machine, a back coating machine, and a cutting machine. They mainly produce thin films with a thickness of only 0.3 mm to 0.7 mm through the direct stirring of the roller press, the rotation of the roller shaft, and high-temperature rolling. At the same time, the printing machine prints patterns on the front side of the film, and a back coating machine attaches a layer of back coating on the back side of the film. Don't underestimate this back coating, it is an important guarantee for the high-quality performance of PVC film. The back coating is composed of special materials and is a high-energy affinity agent. It is precisely because of this layer of back coating that PVC films can tightly blend with medium density boards or other boards, without opening the adhesive for ten or even fifteen years. The biggest problem with ordinary facial mask is that it can not solve the problem of film falling off. Due to the fact that the entire production process is carried out at high temperatures (the temperature inside the rolling machine reaches 220 degrees), this makes the PVC film highly resistant to light and fire, ensuring the high quality of the PVC film. Of course, the requirements for production machines are very high. Typically, the cost of a production line's production equipment is about 39 million marks, equivalent to approximately 160 million yuan in Chinese currency. On the other hand, the production process of PVC film is quite simple, and the machine output is also large. Therefore, when viewed comprehensively, PVC is actually a low input, high output product.