The Critical Function of Pinch Rolls in Second-Hand Hot Rolling Mills​

Pinch rolls are essential material-handling components in second-hand hot rolling mills, responsible for guiding and stabilizing steel strips between rolling stands and during coil winding. Their performance directly impacts production continuity, strip quality, and equipment safety.​

Strip Tracking Accuracy​

In second-hand hot rolling mills, pinch rolls with rubberized surfaces (Shore A 85-90 hardness) ensure precise strip tracking, reducing lateral deviation to ≤5mm across the strip width (1000-2200mm). This is critical for multi-stand rolling, where even a 10mm deviation can cause the strip to hit the stand side guides, leading to edge damage or production stoppages. The rolls’ adjustable lateral positioning (±10mm) allows operators to correct minor tracking errors in real time, maintaining production continuity and reducing scrap rates by 15-20%.​

Tension Maintenance Between Stands​

Pinch rolls between rolling stands in second-hand hot rolling mills maintain a stable tension (5-20 kN, depending on strip thickness) to prevent strip slack or stretching. For example, when rolling 5mm-thick carbon steel strips, insufficient tension can cause the strip to "loop" between stands, forcing the mill to stop and resulting in 10-15 minutes of downtime per incident. Properly adjusted pinch rolls eliminate this issue, ensuring the mill operates at its rated speed (150-200m/min for thin strips).​

Coil Winding Quality​

During coil winding in second-hand hot rolling mills, pinch rolls apply uniform pressure (0.3-0.8 MPa) to the outer layer of the forming coil, ensuring tight, consistent coil density (7.4-7.8 g/cm³). This prevents "loose coils" that are difficult to handle and store, reducing coil damage during transportation by 60-70%. The rolls’ speed synchronization with the coiler mandrel (±0.5% speed accuracy) also prevents strip slippage, which can cause surface scratches or coil telescoping.​

Maintenance Guidelines​

To ensure reliable performance of pinch rolls in second-hand hot rolling mills:​

• Inspect roll surface wear weekly; replace rolls if rubber coating thickness reduces by more than 20% or if cracks/peeling occur.​

• Check roll pressure daily using load cells; adjust if pressure deviates by more than 0.1 MPa from the setpoint.​

• Lubricate roll bearings monthly with high-temperature grease (resistant to 200°C) to withstand the hot strip environment.​

• Align rolls quarterly using a laser alignment tool; adjust if parallelism deviation exceeds 0.05mm.​

For second-hand hot rolling mills processing high-temperature strips (≥900°C), upgrading to pinch rolls with heat-resistant rubber coatings (resistant to 250°C) can extend roll life by 2-3 times and reduce the frequency of roll changes, further improving production efficiency.​

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