Analysis of Main Factors Affecting Print Quality from Printing Process (I)

Quality is the life. The quality of the product is directly related to the market competitiveness of the company. In the printing production process to ensure the quality of printed matter, eliminate the quality problems caused by technical errors, it is necessary to pay attention to the work. This article analyzes the printing process and discusses the main factors affecting the quality of the printed product.

First, the impact of plate-making film on printing quality

The process of developing and fixing the film after exposure directly relates to the sharpness and contrast of the image on the film. Therefore, for the plate-making film, the key is to look at the density of the graphic part and the contrast between the graphic part and the non-graphic part. The higher the density, the greater the contrast and the better the quality of the plate-making film, and the quality of the printing plate produced with it can be guaranteed. In addition, the thickness of plate-making film base also has an impact on plate-making quality. Generally, thin-film film is better than thick-film film.

Second, the impact of printing on print quality

During the printing process, the intensity of the light source, the distance of the light source from the plate material, and the length of the exposure time all affect the quality of the printing plate. Strong light source, short distance, relatively short exposure time; weak light source, long distance, relatively long exposure time. Under a certain light source and distance, as the exposure time increases, the decomposition of the film in the visible part of the plate is intensified until the photo-defective film surface is completely decomposed. If the exposure time continues to increase, no light is seen on the edge of the pellicle film surface due to exposure to strong light, and the photographic film gradually begins to decompose, so that the resulting printed image line will become thin, even missing and blurred. If the exposure time is not enough, the non-graphic part will not be completely resolved on the surface of the photochemical film, and the non-graphic part of the printing plate will still have a film, and it will become dirty on the printing. In addition, the exposure time required for different brands of plates is not the same and must be noticed.

In addition, when the printing plate is evacuated, the degree of close contact between the film and the printing plate also affects the quality of the printing plate. If the printing is not carried out, the printed plate may suffer from ghosting and blurring.

Third, the development of the print quality

1. Developer concentration

The concentration of developer is too large and the development is too fast, which can easily cause excessive development of the printing plate. The lines of the images and lines are thin, the fine dots are missing or the images are thin and unclear, affecting the printing quality; the concentration of the developer is too small, and the concentration of the developer is too small. Difficult to clean, easy to dirty when printing on the machine.

2. Development time

If the development time is too long, the film surface where the printing plate is not exposed to light will be easily dissolved, and the printing plate image will become light and thin, resulting in false printing and unclear printing; the development time is too short, and the photolysis film is too short. It is not easy to completely remove the surface and it is easy to get dirty when printing. The proper development time is when the plate is washed after development, and the photolytic film surface just flushes out. If the concentration of the liquid is relatively large, the development time should be shortened accordingly; otherwise, the development time should be extended accordingly.