PVC films are widely applied in food packaging, agriculture, and industrial packaging. Extrusion and calendering are the two main production processes.
Extrusion: Efficiency Meets Cost Advantage
Extrusion centers around a screw extruder. The compact equipment is space-saving and easy to install and debug. After mixing materials according to the formula, they quickly enter the extruder. As the screw rotates at high speed, materials are rapidly plasticized by shear force and precise heating. Then, they are extruded into the initial film shape through a carefully designed die head, and are finally cooled and shaped by the cooling rollers and the air ring. The process is continuous with high efficiency.
The film’s thickness ranges from 0.01mm to 2mm, suiting various needs. Although less uniform in thickness than calendered films, it works for products with low precision requirements. Using recycled materials cuts costs. With low equipment investment and energy consumption, it offers a large profit margin. Thus, extrusion films are mainly used in agriculture and industrial packaging, like greenhouse films and cargo stretch films.
Calendering: Synonymous with High-end Quality
The equipment of the calendering method is composed of multiple high-precision heating rollers. Common ones are three-roll, four-roll or five-roll calenders, and the rollers need to be carefully adjusted to ensure the operation accuracy. The materials are first initially mixed by a high-speed kneader, then enter the internal mixer for deep plasticization, and after being pressed into sheets by an open mill, they enter the calender. Inside the calender, the sheets are precisely extruded and stretched by multiple heating rollers. By controlling the temperature and spacing of the rollers, the thickness deviation of the film can be stabilized within ±0.005mm, and the surface flatness is high.
Calendered PVC films have uniform thickness, balanced mechanical properties, excellent optical properties, and high transparency. In food packaging, they show off the food and ensure safety. In high-end daily goods and electronic product packaging, their superior quality makes them the top choice.
In the production of PVC films, whether it is the calendering process or the extrusion process, PVC stabilizers play a crucial role. TopJoy Chemical‘s liquid barium-zinc and calcium-zinc stabilizers inhibit PVC degradation at high temperatures, ensure material stability, disperse well in the PVC system, and boost production efficiency. Welcome to contact us at any time and look forward to further cooperation with you!
Post time: Mar-27-2025