Surface Treatment and Service Life of Injection Molding Machine Screws

Release Date:

2026-01-04

Injection molding machine screws operate under conditions of high temperature, high pressure, high mechanical torque, and significant friction; therefore, surface treatment technologies are critical for enhancing wear resistance and extending service life.
Surface treatment technologies primarily include quenching, nitriding, boronizing, thermal spraying, and dual-alloy thermal spraying. These processes enhance the surface hardness of screws and improve their wear resistance. For instance, nitriding forms a hard nitride layer that reduces wear; for filled plastics or reinforced materials (such as glass fiber), advanced treatments like dual-alloy thermal spraying can further enhance wear resistance.
Factors influencing service life include process parameters, material properties, and maintenance management. The service life of a screw is affected by the type of plastic, processing temperature, screw speed, moisture content, and impurities; under ideal conditions, it can typically reach about 8 years, but in practice, actual service life varies considerably depending on operating conditions.
Optimizing service life requires a comprehensive approach that integrates process control and maintenance: Process parameter optimization—maintain barrel temperature within the plastic’s optimal plasticization range to prevent dry friction; adjust screw speed, particularly when processing filled plastics, by reducing it to minimize wear.
Material pre-treatment: Ensure that the plastic is thoroughly dried to remove moisture, thereby preventing the formation of high-pressure steam particles that can exacerbate wear; rigorously screen raw materials to avoid contamination by metal chips and other foreign matter.
Regular maintenance: Monitor screw and barrel wear, record changes in production parameters to predict the optimal time for replacement, and avoid “running until failure.”