Pure aluminum foil is brittle, flexible strength is not enough, usually to be printed on varnish or aluminum foil ink, which can improve the flexibility of aluminum foil, improve the cutting effect. Under normal circumstances, printing ink can not print light oil, can also meet the requirements of cutting, that is, separate printing light oil or ink can meet the requirements of cutting. The printing surface is too hard or too soft is not conducive to cutting, the printing surface is too slippery or too blunt is not conducive to cutting.
Generally, the content of nitrocellulose in aluminum foil ink can be adjusted to meet the requirements. The number of seconds of nitrocellulose is proportional to the hardness. If single nitrocellulose fails to meet the requirements, two kinds of nitrocellulose can be combined to meet the requirements. The slippery degree of the surface can choose wax powder to adjust to meet the requirements.
Some smoothing AIDS are usually added to improve the printing effect, to prevent the production of orange peel, and to smooth the ink layer for cutting. There is a point to pay attention to is not to add too much leveling agent, because some leveling agent has the reaction of extinction, which will affect the brightness and adhesion of aluminum foil ink printing.
Greasy dirty refers to the excessive amount of oil on the surface of the aluminum tip after rolling. Besides, there is extra oil on the surface except for the rolling oil film, which is visible to the naked eye in the process of cutting production and inspection of the finished product.
These oils are mainly caused by the roller neck or the upper and lower part of the mill outlet, splashing, dropping on the surface of the box, abnormal appearance of the mill roller cleaner, and the drop of the mill thickness measuring head.
These greasy dirty will bring greater harm to the surface of aluminum foil: first, because most of the finished aluminum boxes as decorative or packaging materials, must have a clean surface;The second is its thin thickness, in the subsequent annealing easy to form bubbles, and because of the amount of oil in the formation of too much residue and influence
Greasy dirty defect is a very important index to evaluate the quality of the aluminum foil.