The production of PVC film mainly includes raw material preparation, batching and mixing, melt extrusion, calendering and cooling, traction and winding, surface treatment, quality inspection and packaging and other steps.
In the raw material preparation stage, the main raw material is PVC resin, which is a mixture of polymers and additives. In addition, additives such as plasticizers, stabilizers, and fillers are also required, and the types and proportions of these additives are adjusted according to the performance requirements of the final product.
The next step is the batching and mixing process, where PVC resin and various additives are mixed evenly in a certain proportion to form PVC composites. In this step, temperature and time control are crucial to ensure the uniformity and stability of the mixture.
Melt extrusion is one of the key steps in PVC film production. The mixed PVC composite material is fed into an extruder, heated to a molten state at high temperature and pressure, and extruded into a continuous film through the extruder's mold. The temperature and pressure of the extruder need to be adjusted according to the different PVC formulations to ensure that the material can be fully melted and extruded evenly.
The molten extruded PVC material is then processed by a calender machine to become a thin film. During the calendering process, parameters such as temperature, speed, and tension need to be strictly controlled to ensure uniform film thickness and flat surface. In order to prevent the film from deforming or sticking at high temperatures, it is also necessary to undergo cooling treatment to quickly set the film.
The PVC membrane that has been calendered and cooled needs to be towed and rewinded. During the traction process, the speed and tension should be controlled to ensure the flatness and uniformity of the membrane material. When winding, attention should be paid to adjusting the position and tension of the core to avoid wrinkles or deformation of the film material.
In order to improve the surface hardness and anti-slip properties of PVC films, surface treatment is also required. Commonly used surface treatment methods include coating, coating, and lamination, which can significantly improve the practicality and aesthetics of film materials.
Finally, the PVC film material is tested and packaged. Quality testing covers thickness, hardness, transparency, tensile strength, and other aspects to ensure that the quality of the film meets the requirements. When packaging, choose appropriate packaging materials and methods to protect the film from damage during transportation and use.
The entire PVC film production process requires strict control of process parameters and technical requirements at all levels to ensure the quality and performance of the final product. At the same time, with the advancement of science and technology, the production process of PVC film is also constantly being optimized and improved to meet the needs of a wider range of applications.