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When printing plant in Dalian told do you screen print analysis on common problems
Author£ºTime£º2013-8-7 10:49:19 Hits£º´Î

As we all know, screen printing production process consists of many parts and processes. If these links and are not careful there would have been a series of questions, brings a series of trouble. In order to avoid our mistakes during the producing process, small series and here are some examples we see:
A, on the screen of color
Screen color varied, mainly white, yellow, amber, red, in the course of the yellow wire is preferred. We produce commonly used in Japan and NBC Switzerland 270~280T the yellow screen, printed on exceptionally fine, US imports of commonly used 350T yellow screen.
Why yellow screen it? We know that nature's colorful and dazzling colors are light, no light, no color, light color is by resolution of the frequency of the light wave. Red, Orange, yellow, green, cyan, blue, and purple is all the optic nerve can feel light, known as visible light. Object the appearance of selective absorption and reflection of light are not the same color, in short, we're able to see any color that is the color of light. When a beam of light hits the yellow appearance, and if the yellow light is reflected, affect our optic nerve coloring, other colors are absorbed, and so we see the object color is yellow.
Because the screen printing plate exposure time, the choice is ultraviolet light, light cyan and magenta in color purple mixture of both color reflects light, that is deficient in the Black-Yellow hue. At the time of exposure, and purple plus the yellow overlay screen black, the yellow screen appearance (bottom of the emulsion layer) are not sensitive or less exposure, and thus does not render "back Sun" imagery, get picture definition, no vignetting occurs.
Second, the photosensitive emulsion coating
Manufactured of photosensitive liquid into the stainless steel tank, photosensitive solution accounted for about half of the slots. Coating trough with skew screen bottom touch while slot skewed out of photosensitive liquid, slowly and evenly along the wire mesh surface trough to top coating. Coating speed is not too fast, too fast will cause photographic emulsions bubble, pinhole happens in film; too slow can cause photosensitive emulsion coating and unevenness. In order to achieve the best coating effects, and best start with the printing substrate touch side coating, coating area should be slightly smaller than the screen box and screen upside down and coated again, the network version and ultimately boring after coating so that the photographic emulsion, loaded mesh. 30~35¡æ hot-air dry is the best, this can shorten the boring moments. If higher temperatures exceed 40 ° c, stencil thermal fog occurs symptoms.
Three, plate, trimming
Prior to printing, you should review the film photographic unit and plate glass is dirty or dust on the surface, best with a cotton swab dipped in alcohol to clean after the first operation. Silver halide film looks for positive, Kit, glossy side of a disagreement. When printing, film emulsion should be dense and network version of the emulsion surface fitting, leave seam line for exposure. Exposure time should be based on the PC got the variety, coating thickness of photographic film, a Yang image of black solid and printing needs may be. The coating layer thickness of photographic film, needs the exposure time is longer, so that the version of the film completely cured. Graphic black solid level not on the ruoyang image, namely the gray instead of black, you should shorten the exposure time, time developing the extended accordingly, so that is not some completely transparent photographic images.
In order to strengthen the unit, progressive resistance and solvent resistance, avoiding contact Edition box screen printed transfer ink, can reinforce the frame with wide tape enveloping the marginal, with gelatin or emulsions of congestion on their bonding, stencil pinholes and unwanted openings. Small blemishes and kept a small amount about drawing some sensitive glue wide tape push-stick could be used, but also quietly using cyclohexanone or alcohol swab, with a tiny needle slipped a little bit, stencil adhere to transparent. But soft, too huge that could compromise network version.