How does the screen printing machine work?

Working principle of screen printing machine : Take the commonly used flat screen printing machine with hand-shaped screen as an example: the power is transmitted through the transmission mechanism, so that the squeegee kneads the ink and the screen printing screen in motion, so that the screen printing screen and the substrate form a nip line , because the screen has tensions N1 and N2, a force F2 is generated on the squeegee, and the resilience makes the screen printing screen not touch the substrate except the impression line, and the ink is under the effect of the kneading force F1 of the squeegee. Through the mesh, it leaks from the moving nip to the substrate.

After unidirectional printing, the squeegee leaves the substrate together with the screen printing screen, and returns to the ink at the same time, which completes a printing cycle. The distance between the upper surface of the substrate and the screen printing screen after the ink is returned is called the same plate distance or screen distance, which should generally be 2 to 5mm. When printing by hand, the method and proficiency of the operator directly affect the formation of the embossed line. In practice, screen printing operators have accumulated a lot of valuable experience, which can be summarized in six points in detail, that is, to ensure the linearity, uniformity, equiangularity, pressure equalization, centering and verticality of the squeegee in motion. That is to say, the squeegee should travel in a straight line during printing, and should not shake left and right; it should not be slow in front and fast in back, fast in front and slow in back, or suddenly slow and fast; the inclination angle to the ink plate should remain unchanged, and special attention should be paid to overcoming the inclination angle. A common problem that gradually increases; the printing pressure should be kept uniform and consistent; the distance between the squeegee and the inner sides of the screen frame should be kept equal; the ink board should be kept perpendicular to the frame.

The operation cycle program of the flat screen screen printing machine: taking the flat screen platform type monochrome semi-automatic hand screen printing machine as an example, one of its operation cycles is: feeding→positioning→dropping→lowering to the ink plate, rising back to the ink plate → ink scraping stroke → rise to the ink plate → lower back to the ink plate → lift the plate → ink return stroke → release the positioning → receive.

In the continuous cycle operation, as long as the function can be realized, the time taken by each operation should be as short as possible, so as to shorten the synchronization of each operation cycle and improve the operation efficiency.