1. Core functions: Filter impurities and ensure melt purity

Hot melt adhesive raw materials (such as PUR hot melt adhesive) may become contaminated with impurities, unmelted particles, or aged materials during production or transportation. The screen changer intercepts these impurities using a filter screen, preventing them from entering the extrusion mold. This helps avoid surface defects (such as bubbles or cracks) or internal defects (such as pores) in the product, ensuring the uniformity and stability of the hot melt adhesive.

2. Enhancing Production Efficiency: Non-stop Screen Changing, Reducing Downtime

Screen changers (such as single-plate dual-station, dual-column dual-station, and belt-type automatic screen changers) support non-stop screen changing, with filter screen switching time reduced to within 30 seconds, avoiding the drawbacks of traditional manual screen changing that requires downtime. Calculated annually, this can improve efficiency by 10%-15% and reduce scrap caused by frequent equipment startups and shutdowns. Equipped with pressure sensors and automated systems, the screen-changing process is automatically triggered when screen blockage reaches a pre-set threshold, eliminating the need for manual inspection and reducing operational complexity and labor intensity.

3. Optimized process performance: improved plasticization and rheological behavior

During the extrusion process, the screen changer increases backpressure to help remove moisture and low-molecular-weight volatiles from the raw material, reducing the risk of bubbles or layering in the finished product. This is particularly suitable for moisture-sensitive hot-melt adhesive formulations.

4. Extending Equipment Lifespan: Reducing Mold Wear and Blockages

Impurities are one of the primary causes of mold wear and flow channel blockages. The screen changer reduces the impact of impurities on molds through pre-filtering, extending mold lifespan and lowering downtime and maintenance costs caused by mold damage.

Selection and maintenance recommendations

Select the type based on process requirements

Single-plate screen changer: Suitable for small and medium-sized production lines, with lower costs and moderate screen-changing efficiency.

Dual-column hydraulic screen changer: Supports high-pressure and high-temperature conditions, with a large filtration area, suitable for large-scale production lines.

Belt-type automatic screen changer: Enables fully automatic continuous screen changing, suitable for high-capacity, unmanned workshops.

Key Parameter Matching

Operating Temperature: Must cover the melting range of the hot melt adhesive (e.g., PUR hot melt adhesive typically ≤220°C).

Operating Pressure: Selected based on the extruder backpressure (e.g., ≤40 MPa).

Heating Method: Electric heating or thermal fluid heating, ensuring temperature uniformity.

The screen changer is a core auxiliary device in hot melt adhesive extrusion production lines, significantly improving product quality and production efficiency by filtering impurities, enhancing efficiency, optimizing processes, and extending equipment lifespan. Its value is particularly prominent in applications such as PUR hot melt adhesives, recycled material processing, and high-precision film production. Proper selection and maintenance can further amplify its advantages, helping enterprises achieve efficient and stable production.