as follows:

1. Key points of screen printing machine printing process

When the screen printing machine prints, if the scraping pressure is high, the amount of ink will be large, but the screen plate is easy to deform, so the scraping pressure should not be high. The scraping speed is usually 60~200mm/s. The scraping speed is fast, the amount of ink output is small, but it is not easy to block the screen. Therefore, the ink that is easy to block the net should be scraped faster.

When the screen printing machine is printing, the scraping route should be straight line, oblique line and curved line. It should be selected according to the flatness of the substrate and the distribution of graphics and text on the substrate. When the scraping route is long and the ink consumption is large, the amount of scraping ink should be more or even scrape a layer of ink first, and then scrape.

2. Ink preparation before screen printing machine printing

Judgment method for the degree of thickening and thinning: after the ink passes through the screen, the degree of thickening should not appear on the printing surface. The degree of thinning is best to put it on the screen, and the ink can pass through the mesh by its own weight but not drip. When the printed line is thin, it should be thinned, otherwise, it should be thickened.

3. Selection of printing squeegee for screen printing machine

The scraper is mostly made of polyurethane. Polyurethane rubber scrapers have better wear resistance, solvent resistance and resilience. The hardness is 60~80 Shore. For substrates with large screen tension and good surface flatness, scrapers with high hardness should be used. On the contrary, low hardness should be used.

When printing on curved surface, low-degree spherical surface or substrate with poor flatness (partial protrusion), the width of the scraper should be narrow rather than wide.

4. Screen selection of screen printing machine before printing

The quality of silk cloth is stable in quality with uniform diameter and accurate and consistent mesh number.

The generally selected mesh is 450~500 mesh. For substrates with thin lines, high ink fineness, and poor absorbency, a screen with a high mesh number should be used; otherwise, a screen with a low mesh number should be used.

The position of the graphic on the screen and the size of the screen during plate making should be determined according to the structure and size of the substrate and the position of the graphic on the substrate. If the design is not good, it will affect the quality of silk screen printing, or even fail to screen printing. In addition, it is best to use one screen printing for the graphics and text on the same printed matter. If it is divided into two or more screen printing, more processes will reduce the pass rate of screen printing.