[Guide: Roll printing is the most common defect of thin plate products, and the amount of information is slightly larger. So today I only refine dry goods, don't talk nonsense. 】

　　What is roll printing?

　　Roll mark is the mark caused by the damage of the roller surface or the foreign matter that is periodically copied to the steel plate as the roller rotates.

　　The rollers are made of soft polyurethane and chrome-plated hardened rollers; they are functionally distinguished from idler rollers, pinch rollers, steering rollers, rollers, etc.; and the cause of roller marks may be roller damage or adhesion of foreign objects, including foreign objects. There are hard foreign bodies and soft foreign bodies.

　　The permutations and combinations of so many factors have led to one result: the shape and cycle of the roller print are all odd and ever-changing.

　　Characteristics and identification of roller printing:

　　The core feature of 　　 roller printing is "periodical duplication", which determines its three elements: similar appearance, same position, and equal period. (The distance to the edge of the strip is the same, and the periodic interval between the roll marks is the same)

　　Of course, occasionally there will be more complicated situations. But no matter how the roll print changes, continuously measure 3 to 4 points. If all of the above three elements are met, then we can confirm that it is: the upper (or lower) surface, the roller print with a period of ***mm from the edge of the strip with a distance of ***mm.

　　The classification of roll printing and its influence on use

　　Classification

　　Roller prints can be roughly divided into three categories according to their appearance or reasons: convex hull, plate surface damage, and rolling. The typical morphology is as follows:

　　Convex type: like a mosquito bag, the roll mark is gentle, the boundary is not obvious, and the thickness of the steel plate does not change.

　　Board surface damage: There are obvious damaged points in the roll marks, deep into the surface, and there are sharp bumps on the reverse side.

　　Rolling type: It is produced under high pressure working conditions on both sides of rolls, etc., the boundary of the roll mark is clear, and there is no obvious protrusion on the reverse side (there may be bright spots).

　　Impact on use

　　Convex hull type: After the blanking line fine-straightening machine, it will be improved, and it will continue to be lightened when stamping;

　　Board surface damage: because there are damaged points on one side and sharp protrusions on the other side, it is difficult to improve in the subsequent processing;

　　Rolling type: Since there is no obvious trace on the reverse side, most of them can be turned over and used.