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Biaxially oriented film production line---Casting system
2024-07-09
The biaxially oriented film production line is a key equipment for producing high-quality films. The casting system is a key component used to control the thickness and quality of the film in the biaxially oriented film production line. The casting system directly affects the stretching effect and performance of the film. The following focuses on the casting system in the biaxially oriented film production line.
1. Composition of the casting system
The casting system mainly includes die, chill roll and electrostatic adsorption device, etc.
①Die: The die plays an important role in controlling the thickness of the film in the biaxially stretched film production line. By adjusting the structural design and process parameters of the die, the thickness of the film can be accurately controlled to ensure that the thickness of the film is stable and consistent during the production process.
②The chill roll (commonly known as the casting roll) is a key equipment for rapidly cooling the viscous melt flowing out of the die to a glassy state with uniform thickness. The function of the chill roll is to gradually make the thick film amorphous and minimize crystallization to avoid adverse effects on the next stretching process. This can ensure that the quality and performance of the film are improved.
③ The electrostatic adsorption device uses electrostatic action to enable the thick film to be in close contact with the chill roll to prevent air from being drawn in during the rotation of the chill roll, thereby ensuring the smooth progress of heat transfer and cooling effects. The function of the electrostatic adsorption device is to ensure that the chill roll can effectively cool the thick film, thereby affecting the quality and efficiency of the entire film production process.
2.Casting method
There are two main methods of casting, namely direct polymer casting and polymer slice extrusion and remelting casting. Direct casting is a common polymer processing method. In this method, the polymer raw material is directly injected into the mold and deformed into a sheet after heating and pressure treatment. This method is easy to operate and has high production efficiency. It is suitable for products with high requirements on the shape of the finished product. For example, some parts that require a specific shape can be manufactured by direct casting to ensure the accuracy and consistency of the product.
Compared with the direct casting method, the extrusion remelting casting method also has certain advantages in polymer processing. This method first extrudes the polymer raw material into a shape through an extruder, and then remelts it to finally form a cast product. This method can effectively reduce material waste and improve resource utilization. At the same time, the extrusion remelting casting method can further improve the performance of polymer materials and increase the durability and stability of the product.
The stable operation and excellent performance of the casting system are essential for the production of high-quality films. In BOPA packaging film production line, BOPETG heat shrink film production line and PET film production line, the casting system is indispensable and lays a solid foundation for film manufacturing. By continuously optimizing the design and operation of the casting system, the performance and quality of the film can be improved to meet the market demand for high-quality film products.
