Second, the ink is not firmly fixed on the substrate
When printing on substrates, it is very important to perform strict degreasing and pre-processing inspections on substrates before printing. When the surface of the substrate adheres to substances such as oils, adhesives, and dust, poor adhesion between the ink and the substrate can result. Inadequate surface treatment of plastic products before printing can also result in poor ink fixation.
As a printing material for polyethylene film, in order to improve the adhesion performance with the ink in the printing, must be surface flame treatment, if the metal material must be degreasing, dust removal processing before printing, printing should be in accordance with the required temperature of the ink drying Treatment, if the improper drying treatment will also produce ink film peeling failure. In addition, in the textile printing, in order to make the textile waterproof, silicon processing is generally performed, so that the phenomenon of ink sticking is not likely to occur during printing.
Items such as glass and ceramics are sintered at high temperatures after printing, so as long as the temperature is properly treated, adhesion is good. A simple method to test the good or bad fixing fastness of the ink film: When the material to be printed is paper, the printing surface can be repeatedly bent to see whether the ink at the fold is peeled off. If the ink is peeled off, its bonding strength is weak. In addition, the printed matter is exposed to rain to see if the ink is easily peeled off. This is also a way to check the firmness of the ink film.
Insufficient adhesion of the ink itself causes the ink film to become weak, and it is better to replace other types of ink for printing. Improper use of diluting solvent may also result in the phenomenon that the ink film is not firmly fixed. When selecting the diluting solvent, the properties of the ink must be taken into consideration so as to avoid the phenomenon that the ink and the substrate are not firmly bonded.