What is the Wear Mechanism of the Screw and Barrel? Common Repair Methods Explained

The screw and barrel are critical components of plastic extruders, and their condition directly affects product quality and production efficiency. During extrusion, they operate under high temperature and high pressure, which exposes them to continuous friction and mixing with plastic particles. Over time, this leads to different types of wear.

The most common is friction wear. Plastic particles rub against the screw groove and the barrel’s inner wall, gradually removing metal from the surface. Another frequent issue is corrosive wear, which occurs when processing plastics that contain corrosive additives. These chemicals react with the metal surface, accelerating damage.

To address these problems, engineers use a variety of repair and protection methods. Surface coating repair is widely applied: wear-resistant metals or alloys are coated onto the surface, restoring the part and improving hardness and durability. Similarly, surface heat treatments such as nitriding or carbonitriding increase surface hardness and resistance to friction.

For screws and barrels with significant dimensional changes, precision grinding repair can restore original geometry and ensure stable performance in extrusion. In cases of severe or irreversible damage, replacing the entire screw and barrel may be the most reliable solution.

Preventive measures are equally important. Regular inspection, lubrication, and proper operation help reduce wear, extend service life, and minimize unplanned downtime. With systematic maintenance and timely repair, screws and barrels can achieve long-term, stable, and efficient performance in extrusion production.