Hello, everyone, I am the editor, today I will introduce to you some specific technical points of Stenter printing.
The adjustment and control of the screen pitch of the screen printing machine during printing is one of the important factors that affect its quality. The screen printing operation union of the screen printing machine makes corresponding adjustments to the screen printing screen pitch in order to ensure the printing quality.
If the squeegee pressure is high when the screen printer is printing, the amount of ink will be large, but the screen is easy to deform, so the squeegee pressure should not be high. The scraping speed is usually 60~200mm/s. The printing speed is fast and the ink output is small, but it is not easy to block the network. Therefore, the ink that is easy to block the network, the scraping speed should be faster.
When the screen printing machine is printing, the squeegee route should be straight line, diagonal line and curved line. It should be selected according to the flatness of the substrate and the distribution of pictures and texts on the substrate. When the squeegee line is long and the ink consumption is large, the amount of squeegee should be more or even a layer of ink should be squeezed first, and then squeegee.
The raw material of the scraper is mostly polyurethane. The polyurethane rubber scraper has good abrasion resistance, solvent resistance and resilience. Its hardness is 60~80 Shore. For the substrate with high screen tension and good surface flatness, a squeegee with high hardness should be used. On the contrary, low hardness should be used.
When printing on a curved surface, a low-degree spherical surface, or a substrate with poor flatness (partially convex), the width of the squeegee should be narrow rather than wide.
The method of judging the degree of density adjustment: The degree of density is based on the fact that after the ink passes through the screen, there is no silk screen or wire drawing on the printing surface. The degree of diluteness is best placed on the screen, and the ink can reach through the mesh by its own weight but not drip. When the printed lines are thin, the dots should be thinner, otherwise, the dots should be thicker.