The belt-type fully automatic screen changer is a highly efficient, fully automated device designed specifically for filtering polymer melts. It is one of the mainstream types of screen changers, and its core advantage is the ability to achieve zero-downtime continuous operation without any manual intervention throughout the entire process.

I. Core Structure and Working Principle

It primarily consists of three components: the filter housing, the heating and cooling system, and the electrical control system. The filter uses a 10–20-meter-long mesh belt (customizable upon request) and features a water-cooled sealing structure.

The equipment uses a pressure sensor at the feed inlet to monitor melt pressure in real time. When impurities accumulate on the filter mesh, causing the pressure to reach a preset threshold, or when a preset time-based filter change interval is reached, the system automatically initiates the filter change process: First, localized heating reduces the melt viscosity, driving the filter belt to uniformly withdraw the old filter screen while the new one is simultaneously fed into the working position. The cooling system then activates, rapidly solidifying the residual melt to form a seal, thereby preventing material leakage. Throughout the process, there is virtually no fluctuation in material flow or pressure.

II. Key Advantages

Fully Automated Operation: Once pressure or time parameters are set, the equipment automatically completes the entire screen-changing process without the need for manual supervision.

High Production Continuity: The screen-changing process occurs without stopping production. Screen lengths are customizable and can support up to 2–6 months of uninterrupted production, significantly reducing downtime losses.

Stable Product Quality: There are no significant fluctuations in material pressure or flow during screen changing, preventing issues such as product deformation or uneven thickness. No scrap material is generated, and raw material consumption is minimized.

Reliable and Durable Operation: Featuring a water-cooled, self-sealing design, the system prevents material leakage and eliminates component wear, ensuring a long service life and easy maintenance.

III. Applications

It is compatible with the vast majority of thermoplastic polymers, including PP, PE, ABS, PS, PET, and PVB. It is widely used in the production of high-precision products that require high material pressure stability, such as cast film, optical film, sheets, plates, chemical fiber spinning, wire drawing, optical fiber, and pelletizing. It is particularly suitable for extrusion production lines requiring long periods of continuous operation.