PVDF、PVC

Photovoltaic Film—Special Non-Stop Screen Changer for PVDF Backsheet (Fluoropolymer Film)
Ethylene-based plastics (such as PVC, PVDC, PVDF) place extremely demanding requirements on screen changers, including corrosion resistance, temperature stability, rapid operation, and easy cleaning. These materials are characterized by high density, poor flowability, and high melt pressure. Their corrosive nature can cause damage to the main extruder, dies, and the entire screen changer system. Therefore, this specialized screen changer must be capable of withstanding high pressure and corrosion.

Maintaining a constant temperature in the screen changer is essential when processing ethylene-based plastics. To meet this requirement, this dedicated screen changer is equipped with a temperature control device for the filter screen, ensuring that the temperature of the new screen matches that of the screen being replaced.

For screen changers designed specifically for ethylene-based plastics, a key technical challenge is how to clean the filter screen (also referred to as the breaker plate or distributor plate) quickly and conveniently. Cleaning the breaker plate for ethylene-based plastics is difficult, costly, and must also address environmental and occupational health considerations. Our solution is to design the breaker plate as a modular component (a patented design), fundamentally transforming the filtration system of conventional screen changers. Its advantages are threefold: First, the filter element and the screen carrier are separated. Since the specialized screen changer has different requirements for the filter element (emphasizing corrosion resistance) and the screen carrier (requiring wear resistance), designing them separately allows for the selection of appropriate materials for each, resulting in lower investment costs. Second, the several parts of the screen assembly work together to achieve filtration. Once replaced, the assembly can be immediately disassembled, and the residual melt in each part can be easily cleaned out. This ensures product quality and makes screen installation very convenient. Third, the modular design of the screen assembly allows for easy and low-cost replacement of wear-prone parts or other damages caused by operators.