1. Working principle of screen printing machine Taking the commonly used hand-shaped flat screen printing machine as an example, the working principle of the screen printing machine can be described as follows: the power is transmitted through the transmission mechanism, so that the squeegee squeezes the ink and the screen printing plate in motion, so that the screen The printing plate and the substrate form an impression line. Because the screen has tension N1 and N2, it generates a force F2 on the squeegee. The resilience makes the screen printing plate not contact the substrate except the impression line. The ink is in contact with the substrate. Under the action of the squeezing force F1 of the squeegee, the printing is leaked from the moving embossing line to the substrate through the mesh. During the printing process, the screen printing plate and the squeegee move relative to each other, and the squeezing force F1 and the resilience F2 also move synchronously. Under the action of the resilience, the screen returns in time to disengage from the substrate in order to avoid The blot is dirty. That is, the screen is constantly deformed and rebounded during the printing process. The squeegee is separated from the substrate together with the screen printing plate after the one-way printing is completed, and at the same time, it returns to the ink to complete a printing cycle. The distance between the upper surface of the substrate and the reverse side of the screen printing plate after the ink is returned is called the same-page distance or screen distance, which should generally be 2 to 5 mm. In manual printing, the technique and proficiency of the operator directly affects the formation of the impression line. In practice, screen printing workers have accumulated a lot of valuable experience, which can be summarized into six points, namely, to ensure the straightness, uniformity, isometric, equalizing, centering and vertical edge in the movement of the squeegee. In other words, the squeegee board should move straight forward during printing, and cannot move left and right; it cannot be slow in front and fast in the back, slow in the front and slow in the back or suddenly slow and fast; the inclination angle to the ink board should remain the same, and special attention should be paid to overcome the inclination angle The common problem of increasing gradually; the printing pressure should be kept even and consistent; the distance between the squeegee and the inner sides of the screen frame should be equal; the ink plate should be perpendicular to the frame.
Post time: Oct-28-2023
