Sometimes knife marks and take-up scratches occur during the processing of the slitting machine. Today, Bangzhou is here to introduce to you the reasons for knife marks in slitting machine processing.

Knife mark: the knife mark on the surface of the steel belt caused by the inner edge of the disc knife. It usually occurs at the thickness of the edge knife. Continuous or intermittent knife marks can occur. 

1. Knife marks caused by aprons and bead: the apron at the wide part of the matching knife is too high, the apron at the narrow part is too low, or the pressure of the bead is too large, and the height of the knife and the through plate is inconsistent with the knife mark.

2. Knife marks produced by meaty knives and rubber rings: For meaty disc knives, when the rubber ring is used, the surface of the finished product will produce intermittent pressure due to the swinging of the disc knives when using the rubber ring. Produce wrinkles.

3. Wrinkles caused by the longitudinal swing of the knife and apron: In addition to the above-mentioned partial meat, the knife and the apron will also produce knife marks when they swing, that is, the intermittent knife marks produced by the knife on the surface of the product.

4. Knife mark produced by the secondary knife: In order to prevent the knife from twisting due to side pressure during thick plate processing, a secondary knife is usually equipped next to the main knife. The outer diameters of the two blades are slightly different. Once a sharp secondary knife is used, a knife mark will be produced. You can use a once-used knife with a rounded edge as the secondary knife or use the secondary knife with the same outer diameter to prevent such knife marks. 

Coiling scratches: When the steel coil is rolled in a relaxed state, the internal layers of the steel coil will slide, and various scratches will occur on the surface of the steel plate and the scratches caused by repeated friction of the scratched points. In addition, even a normally coiled steel coil will be scratched when coiled under a tension exceeding the normal tension.

1. Coiling scratches on the decoiler: When the back tension applied by the decoiler exceeds the base material coiling tension, or the brake applied by the decoiler is insufficient, or the pressure of the pressure stop roller of the decoiler is insufficient, it will cause the steel coil to relax. Then produce scratches.

In addition, the loose steel coils will be re-tensioned when uncoiling on the machine, resulting in scratches. Once the anti-tension of the uncoiler is too large, the steel plate is suddenly wound tight when it is pulled and loosened, which will also cause scratches. Therefore, measures should be taken to reduce the braking force when the work is completed.

2. Coiling scratches on the winder: After the production line is stopped, it is easier to loose the coil when it is restarted. The slack of the shear outer ring, the lateral dislocation of the steel coil during unwinding, etc. will cause scratches. In addition, straight-pull shearing, when the loose steel coil is inserted into the mandrel and re-tightened, coiling scratches will occur.

3. Coiling scratches in the hand-cranked expander: The slack roll that is wound under the state of insufficient tension, when the hand-cranked expander is tensioned, will be misaligned and wound, resulting in scratches. In addition, the lateral swing and overlap of the steel belt in the looper will also cause scratches.

Wuxi Bangzhou Machinery Manufacturing Co., Ltd. is a company specialized in steel coil straightening machine, slitting line, cut to length line and flat bar straightening and chamfering machine. Our company is a professional slitting machine manufacturer. If you are interested in slitting machines, don’t hesitate to contact with us.