Multi‑roll cold rolling mill gains continuous technical development thanks to small work roll diameter and high mill rigidity. Among different models, the 20‑roll Sendzimir mill achieves fast upgrading and wide‑ranging industrial adoption. For a long time, domestic steel plants apply multi‑roll cold rolling mills to process hard‑to‑deform metal strips such as stainless steel, silicon steel and alloy steel. With rapid economic growth in recent years, multi‑roll cold rolling mills gradually expand into carbon structural steel production to manufacture high‑precision, ultra‑thin steel strips.
Core Advantages of Multi‑roll Cold Rolling Mill
First of all, support back‑up rolls bear loads for work rolls. This setup greatly lowers bending force on work rolls along strip width, so manufacturers can adopt much smaller‑diameter work rolls.
Secondly, the mill delivers boosted rigidity. It improves finished product dimensional accuracy by around four times compared with conventional rolling equipment.
Thirdly, it supports diverse alloy steel grades. Moreover, the mill reaches extremely thin final strip thickness that ordinary rolling units cannot easily achieve.
In addition, the contact area inside deformation zone shrinks accordingly. Total rolling force drops, which brings obvious energy‑saving effects.
Besides, operators cut down required rolling passes. This change lifts overall production efficiency and lowers unit production cost.
What is more, higher rolling tension optimizes strip flatness and final profile quality.
Finally, compact overall footprint reduces one‑time capital investment. Its direct screw‑down design accepts thicker incoming raw materials and improves operational safety.
Main Drawbacks of 20‑roll Sendzimir Multi‑roll Cold Rolling Mill
Even though 20‑roll Sendzimir multi‑roll cold rolling mill features tiny work roll diameter, high stand rigidity, tiny thickness deviation and excellent strip profile, it still has notable practical limitations.
To start with, the mill owns limited roll opening range. Adjustment procedures remain complicated. Once strip breakage and roll wrapping accidents take place, on‑site troubleshooting consumes plenty of working hours.
Furthermore, stacked roll assemblies block heat dissipation. Poor process lubrication and cooling restrict maximum rolling speed. After repeated optimization of spray layout and cooling circulation system, modern 20‑roll mills can finally hit top speed up to 1000 m/min.
Additionally, multiple contact roll sets generate extra power loss. Losses come from back‑up roll bearing friction, roll rotation resistance and idle running consumption. Especially for ultra‑thin strip rolling, these useless power wastes stack up. Consequently, its total power consumption stays close to that of four‑roll cold rolling mill.
Last but not least, the whole mechanical structure is highly complicated. Equipment manufacturing, field installation and commissioning all demand high‑level technical requirements.
Practical Application Suggestion
Production teams shall match mill selection with target material, final thickness requirement and expected line speed. Multi‑roll cold rolling mill fits priority for hard alloy and ultra‑thin strip tasks. For mass‑produced medium‑thickness carbon steel strips, four‑roll cold rolling mill still keeps comprehensive cost performance strengths.