Corrugating rolls are exposed to constant friction and pressure during operation, so surface treatment plays a key role in extending their life and ensuring stable performance. At Yonghui, we offer several surface finishing options, including electroplated hard chrome and tungsten carbide coating, which are widely used in high-speed corrugators. To enhance durability and resistance to wear, all rolls undergo a combined surface hardening process, developed in-house. This multi-step treatment includes surface coating, nitriding, tempering, and cryogenic treatment, which collectively improves the roll’s microstructure and increases surface hardness. After processing, our rolls consistently reach HRC ≥ 60, ensuring excellent performance even in demanding production environments.

Surface finish has a direct impact on board quality, glue application, and machine performance. We use a dedicated polishing process that results in a smooth, clean surface while maintaining flute accuracy. Our rolls typically reach a surface roughness of Ra 0.2–0.4, and we apply a silicone oil coating to reduce friction, prevent sticking, and improve overall wear resistance. This finish supports smoother paper feeding and cleaner glue transfer in high-speed environments.

Tungsten carbide rolls are ideal for high-output corrugators that require durability and long service intervals. Compared to standard steel rolls, they offer several key advantages:

• Stronger bond between coating and base material prevents delamination during extended use
• Higher surface hardness improves wear resistance and extends roll life significantly
• Uniform and controlled coating thickness ensures better flute definition and dimensional accuracy
• After treatment and specialized polishing, the surface roughness reaches Ra 0.4–0.6, which meets the requirements of high-speed corrugators
• When paired with custom flute profiles such as UV or UVV, they help increase board stiffness, reduce glue consumption, and minimize waste of core paper