Some questions about printed materials (8)

What should I do if the paper loses powder?
Paper is a film-like product made from the basic raw materials for papermaking—plant fibers, fillers, compounds, and pigments—after proper processing. The surface strength (ie, bonding force) of the paper is the bonding strength between the plant fibers, the filler, and the compound. In the printing process, each time the stamp is imprinted, the ink transferred from the printing plate to the blanket or paper is about half, that is, the ink film is split, half is transferred away, and the other half is left on the printing plate or the blanket. The viscosity of the ink will prevent the ink layer from splitting. When the viscosity of the ink is strong, the split sometimes does not occur in the ink film but occurs at the weakest point where the paper fibers, fillers, and glue are bonded. If the bonding force between the surface structures of the paper is not sufficient to resist the tension when the ink film is separated, the phenomenon of paper stripping and fluffing occurs during printing. The so-called de-powdering is that part of the filler material in the paper leaves the surface of the paper, and the lint-free part of the surface of the paper is covered with plant fibers. These sticky fillers and plant fibers will stick to the plate or blanket, causing a dirty plate, and defects will appear on the next few prints. These dusts and papers will also move against the direction of ink movement. Mixed with the ink, fill in the gap between the printing plate's Internet point and paste the plate to reduce the printing plate's resistance to printing.

The surface strength of paper is mainly determined by the raw materials and processes of papermaking. Paper bleaching, hair loss, etc., are generally caused by the poor quality of paper products. In addition to negotiating with the printing customer, try to replace the paper as much as possible. In addition, the operator should also take the following measures according to the specific conditions of the printed paper:
1 Adjust the viscosity of the ink used properly. Adding an appropriate amount of a detackifier or diluent to the ink improves the adhesion of the ink to the paper.
2 Adjust the printing pressure appropriately so that the printing pressure is reduced, or the printing speed is appropriately reduced, so that after the imprinting, the peeling force between the printing plate and the paper or between the blanket and the paper will be reduced.
3 In the printing process, take measures (such as mechanical dust removal or wind flooding, etc.) to eliminate paper dust, paper dust, and dust on the surface of the paper.
4 If lithography causes hair loss and de-foaming due to the stickiness of the blanket, a layer of sulphur powder may be applied to the surface of the blanket. If it still does not solve the problem, replace the blanket.