Reasons and solutions for folding and printing defects of packaging steel strips

1) Defect features: horizontal fold lines or edges on the surface. Thin packaging steel strips appear as folded edges and have a bumpy feel.
　　（2）Causes
　　①The anti-radial bending deformation of the coiled annealed coil when it is flattened and uncoiled.
　　②The wrap angle of the air pressure roller of the leveling uncoiler is too large for the packaging steel strip, which causes the packaging steel strip to bend in the opposite radial direction.
　　③The smoothing roll plastic control and pressing operation are poor, so that the smoothing extension is not enough to eliminate the folding.
　　④ There is a tendency to bond between layers of steel coils.
　　 (3) Prevention and elimination methods
　　①Adjust the horizontal position of the air pressure roller to reduce the wrap angle of the air pressure roller and the bending deformation of the strip.
　　②Under the condition of ensuring the shape of the plate, increase the flat extension.
　　③Reduce the bonding of steel coils.
　　（4）Check and judge
　　① Check with the naked eye.
　　②The normal board has slight folds. Considering the specific situation, 2 sets of high-quality boards are allowed to have two slight folds larger than half of the board width. Three groups of boards are allowed to have three slight folds larger than one-half of the board width. Severely intensive printing is judged as waste.