Introduction: Roller printing is the most common defect in thin-plate products, and the amount of information is slightly larger. So today only refine dry goods, not nonsense.
What is roll printing?
The roll print is an impression caused by damage to the surface of the roll or foreign matter being periodically copied to the steel sheet as the roll rotates.
The thin plate product is in contact with nearly a thousand rolls in the cold rolling process, the diameter of the roller is from a minimum of 3 cm to a maximum of more than 1.5 m. （The difference in roller diameter is the same as the difference in the planet below）
The roller is made of soft polyurethane and chrome-plated hardened roller; it is functionally divided into a roller, a pinch roller, a steering roller, a roller, etc.; and the cause of the roller mark may be roller damage or foreign matter adhesion, wherein foreign matter is There are hard foreign objects and soft foreign bodies.
The combination of so many factors leads to a result: the shape and cycle of the roll print are strange and infinite.
Rolling features and identification:
The core feature of the roll print is “cycle copy”， which determines his three elements: similar appearance, same position, and equal periods. （The distance from the edge of the strip is the same, the periodic spacing between the roll marks is equal）
Sometimes more complicated situations are encountered, such as the appearance of two roll prints on the same roller. At this time, pay attention to the measurement period, which is similar to the measurement below.
Of course, there will be more complicated situations occasionally. But regardless of how the roll print changes, 3 to 4 points are continuously measured. If all of the above three elements are met, then we can confirm that it is: the upper （or lower） surface, the ***mm of the strip edge, the cycle of ***mm.
Classification of roll printing and its impact on use
According to the shape or cause, the roller printing can be roughly divided into three categories: convex hull, slab damage, and rolling. The typical topography is as follows:
Is it a bit abstract? We further analyze their cross-sectional morphology:
Convex bag type: Like a mosquito bag, the roll marks are gentle, the boundary is not obvious, and the thickness of the steel plate is not changed.
Board damage category: There are obvious damage points in the roller marks, which are deep into the surface, and there are bumps with sharp protrusions on the reverse side.
Rolling type: Roller and other double-sided large pressure conditions, the roll mark boundary is clear, the back side is not obviously raised （may have bright spots）.
Impact on use
Convex bag type: After the blanking line finishing machine, it will be improved, and it will continue to be reduced when punching;
Board damage category: Because there is a damaged point on one side and a sharp protrusion on the other side, it is difficult to improve in subsequent processing;
Rolling class: Since there is no obvious trace on the reverse side, most of them can be used for turning over.