The competition in the printing industry is becoming more and more fierce, and the offset printing process technology is becoming more and more mature. In order to improve product quality, it is often necessary to start with the details of the printing, careful and thoughtful consideration of its production accessories and process technology. Digital quick printing, offset printing has a small printing pressure, small printing deformation value, good original rendering effect, soft color tone, clear dot, rich printing layer, fast printing and low loss, so it is widely used in the printing of various products, especially Suitable for printing color transition dot version, lines, small text, etc. Now combined with my many years of work experience, for the control of offset printing technology, and colleagues in the industry to discuss.
First, design plate technology technology control
1. The printed solid layout should avoid the use of small characters, lines and transitional dots in the same color version, so as to avoid the phenomenon that the pressure, the amount of ink can not be balanced, the paste is enlarged, the dot is enlarged or the ink layer is not thick enough, which affects the product quality.
2. There are overprinting parts between the printing plates of Shanghai. The overprinting edge of one of the plates must be properly expanded to overcome the phenomenon of “whitening” of the edges due to inaccurate overprinting.
3. When printing in four colors, pay attention to the angle of the cable when making the film. Normally, the cable angles are Y90°, M45°, C75°, and K15°. Generally, the angle of the main tone screen is 45°.
Second, the process technology control on printing
1. Temperature and humidity control of the printing environment.
Controlling the temperature and humidity of the production workshop is an important part of improving the accuracy of product overprinting. The temperature and humidity of the offset printing workshop should be relatively balanced and the temperature should be kept between 20~25°C, and the humidity should be kept between 50%~60%.
2. Reasonable selection of offset PS version. PS plate plays an important role in offset printing. It is mainly composed of two layers of photosensitive layer and plate base. The thickness is generally 0.15~0.3mm. It is required that the photosensitive layer after exposure should have good lipophilicity and the base should be good. Hydrophilicity. PS plate should meet the basic performances such as flat layout, uniform thickness, stable size, not easy to deform, clean surface, good dot reduction, high printing durability, good ink balance during printing, and not easy to get dirty.
3. Reasonable selection of blankets. As the medium of imprint transfer, the blanket has a great influence on the quality of offset printing products. The correct selection of blankets plays an important role in improving product quality. The blanket is composed of synthetic rubber and woven fabric, and the woven fabric layer is usually formed by laminating 3 to 4 layers of fabric to synthetic rubber. The selection of the blanket should be based on the principle of good appearance quality, high flatness, good elasticity, good ink transfer, small compressive deformation, high tensile strength, low elongation and good surface rubber properties.