1. Printing
Inspiratory insufficiency during printing causes the printing plate outlets to be misplaced and false, which will directly cause floral patterns. The original film and the printing plate glass should be cleaned to prevent dust from entering; when the suction must be waited until the original film and the PS plate are in close contact with each other before exposure; the exposure time is moderate, and it should be selected according to the different plates and film content. The time is short. If the time is too long, the outlets will be dried out and the small outlets will be bald.
2. Paper
Poor quality paper, surface unevenness or hair loss, powder off phenomenon will appear when the flower version. At this time, the paper should be replaced or the rubber roller should be scrubbed, or it can be printed first after diluting agent (colorless) or polishing agent. Offset printing is more likely to occur when offset paper is printed. In general, the problem can be solved by increasing the pressure and adjusting the ink and de-adhesive to change the fluidity and viscosity of the ink.
3. Liner
Improper selection and installation of gaskets are also a major factor in the production of floral patterns. It is necessary to ensure that the three-roller liner is smooth and has good elasticity; in daily work, it is necessary not to take multiple sheets and arrogance to prevent paper and debris from rolling off the rollers and liners; during daily maintenance, attention should be paid to the fact that scattered parts cannot be placed arbitrarily. Prevent it from falling into the roller gap and rolling the roller.
Blanket should use imported air cushion rubber, liner should also use imported air cushion or printing special felt, pad paper also applies coated paper. Plate cylinder liners can be coated with coated paper or film to keep the surface of the cylinder clean and often scrubbed. When the blanket and liner are installed, they should be kept clean and flat to prevent wrinkles. After long-term use, if the rubber blanket and liner are not flexible or rolled, they should be promptly replaced.
4. Water, ink road
Incorrect adjustment of water, ink roller or water, ink roller aging and deformation tend to appear after the flower version. The improper adjustment of water and ink roller will affect the even transfer of ink. The water roller light is easy to paste the plate, while the heavy one is easy to vibrate. The plate is worn and the plate is dropped. The ink roller is light and the plate can't evenly ink, while the weight is easy to appear ink bar. When the water and ink rollers are used for a long time, deformation and aging occur, and the ink is unevenly distributed and unstable, it should be replaced in time. To prevent ink emulsification. Sometimes, the ink is too thin, the oil is too heavy, or the layout water is too large to make the water pour into the ink roller, causing the ink to emulsify, and the phenomenon of stencil printing occurs. At this point should be promptly replaced ink, cleaning ink roller, the best choice for some of the quality of the brand ink, of which fine particles, fast drying, good printability of imported ink is better.
5. Stress
In general, when the pressure is small, it is prone to appear on the plate. However, if the pressure is adjusted too large, it will easily abrade the plate. This will cause the printing plate to lose its print, the plate off, and the deformation of the paper, which will seriously affect the overlay accuracy. How to achieve the desired pressure is the focus of pressure adjustment. It must be installed in strict accordance with technical requirements. The proper selection of the thickness of blankets and liners, and appropriate pressure, can both reproduce smooth and full dots, while maintaining sufficient resistance to printing forces.
Author/Luo Haijun
Reprinted from: Printing Technology
