Because PVC raw materials are solid powder and cannot be directly formed, the next step is to enter the high-temperature plasticization and extrusion stage. In a high-temperature environment of 210-240°C, the raw materials need to undergo full plasticization for 25-35 minutes to transform from a solid state to a molten state, as if their activity has been awakened. Precisely because of this high-temperature tempering, the molten raw materials can be smoothly extruded through a screw extruder, paving the way for subsequent calendering and forming. When the molten raw materials enter the calender, the inverted L-shaped five-roll calendering process comes into play. Because it is necessary to ensure the film has a uniform thickness and a smooth surface, the temperature and pressure of the rolls must be accurately controlled. The extrusion and stretching of each set of rolls shape the "flowing raw materials" into a "regular base film." At the moment when the film is slowly drawn out by the stripping roll, the initial form of the film is officially born.
Because people's demands for the textures of decorative films have become increasingly diverse, the printing and lamination stage has become the key to endowing the film with "aesthetics." High-precision digital printing technology outlines the delicacy of wood grain and the luxury of marble on the base film, giving the monotonous film a natural texture. For multi-layer composite films that require stronger functionality, because it is necessary to balance decorativeness and practicality, PVC base films, printed middle layers, matte surface films, etc., need to be accurately laminated in sequence to form a multi-layer composite structure. After printing or lamination, the film also needs to go through an embossing process. Because to make the textures clearer and more firmly attached, the embossing unit uses a combination of an upper embossing roll and a lower rubber roll for rolling. At the same time, 40-60°C circulating water is passed into the embossing roll to balance the temperature difference. Some products will also complete matte treatment simultaneously, controlling the glossiness between 20-60°, which is a comfortable range. Every precise operation in these steps is aimed at making the decorative effect of the film closer to nature.
The embossed film has a high temperature and an unstable structure. Because it is necessary to avoid film deformation and surface roughness, the cooling and setting stage is indispensable. The multi-roll gradient cooling process is the "main force" here. The temperature of the five cooling rolls gradually drops from 210°C to 170°C, allowing the film to cool and shrink slowly. Because only gradual cooling can make the film structure denser and the surface smoother, ultimately completing the setting. For scratch-resistant PVC decorative films, because it is necessary to improve the surface protection performance, the surface strengthening treatment is an indispensable link. A special surface treatment agent is evenly coated on the film surface, with the thickness accurately controlled between 0.02-0.10mm. After curing and drying, some products will also enter a curing oven at 30-60°C for further curing. Because this can form a hard protective layer, enabling the film to resist daily scratches.
Finally, because it is necessary to ensure that the decorative film can closely adhere to the substrate in subsequent applications, the back coating stage involves applying a special back coating material to the back of the film to enhance adhesion. The subsequent trimming and packaging is the final check for the finished products-removing edge waste, precise cutting, and rolling into standard rolls. Because it is necessary to ensure that every roll of product can be delivered to customers in perfect condition. From raw material mixing to finished product warehousing, every link exists because of "demand" and achieves high quality because of "precision." The production process of PVC decorative film is not only a process of physical changes but also a integration of craftsmanship and technology. Precisely because of this strict control over every detail, the small decorative film can add a unique luster to the door panels and furniture of thousands of households.
