In the process of cutting strip equipment, if the steel roll is rolled in a loose state, the layer inside the roll will slip. This may cause different scratches on the surface of the steel plate, as well as scratches caused by repeated friction at the scratch points. In fact, during operation, even ordinary rolled steel coils will produce bruises when the stress is greater than normal. It mainly includes the following three situations:
1. Scratches caused by unreasonable settings.
The main situations are as follows: during the operation, the loose steel coils will be re-tensioned when unwinding on the machine, resulting in scratches. When the back tension applied by the rewinder is greater than the coiling tension of the base material, or the pressure of the stop roller is insufficient, or the brake applied by the rewinder is insufficient, it will cause the steel coil to slack and cause scratches. Once the back tension is too large, the steel plate will suddenly tighten when it is pulled and loosened, and scratches will also occur. Therefore, measures should be taken to reduce the braking force of the rewinder when the work is over.
2. The rewinder is scratched due to improper setting.
After shutdown, it is easy to loose the coil during the restart process. The shearing slack of the outer ring, the lateral misalignment of the coil during the unwinding process, etc., may cause scratches. In addition, coiling scratches will appear when straight-pull shears and loose steel coil ferrules are rewinded.
3. Winding scratches are caused by manual expanders.
When the slack coils gathered under the condition of insufficient tension of the rewinder are tightened with a manual expander, they will be misaligned and scratched.
