The importance and operation of the stretch net in screen printing

The so-called screen printing, is the use of screen printing plate, the plate on the graphic by the through hole, printing ink through the screen through the hole in the surface of the substrate to form a print, and then complete the graphic reproduction of the printing method.

Stretch the net. The process of straining the mesh into the frame. In mass production, we use lightweight aluminum frames that are not easily deformed, stable, durable, easy to use, and resistant to resistance. The frame size should be larger than that of the plate, at least 10-20 cm on each side. The beginning and end of the squeegee movement should be at least 10-15 cm longer than the printed version.

In order to adapt to the needs of export products, we often use 270-300T yellow polyester mesh imported from Japan or Germany in the production. For particularly delicate prints, we often use 350T imported yellow mesh in order to better achieve the tone of the pattern. Reproduction. Screen printing uses ultraviolet light for exposure in the printing plate. Blue-violet is the mixed reflection of the two hue of cyan and magenta in the color, that is, the lack of yellow hue in black. At the time of exposure, the blue-violet plus mesh yellow is superimposed on black. Therefore, the surface of the yellow screen (ie, the bottom of the emulsion layer) is not light-sensitive or less exposed, so that the “back-lighting” phenomenon does not occur, and the resulting image has high definition and no vignetting occurs. In order to save raw materials, we often use positive stretch nets when stretching nets. That is, the latitude and longitude of the wire mesh is perpendicular or parallel to the edge of the frame. When tension is required, the tension is appropriate, the wire is uniform, and the tension between the periphery and the center is even and stable.

The specific steps are as follows: first clamp the screen around the equidistant distance, and then send in compressed air. When the pressure reaches 6kg, close the air valve and transfer the tension of the screen evenly. After that, tighten and relax. Then repeat and relax. Two or three times, after the screen is fully stretched, the tense and center tensions are measured with a tensiometer. At this time, the mesh and the frame can be fixed by the adhesive (usually acetic acid emulsion or epoxy adhesive). The contact part. After being dried, the extra screen mesh is fixed on the other side of the screen frame to prevent the screen from loosening or falling off, thereby increasing the service life of the screen plate.

Reprinted from: China Washing & Dyeing Industry Information Center