A common problem of the silk screen printing
As is known to all,Silk screen printingThe production process includes multiple links and steps.If a don't pay attention to these links and step will produce a series of problems, a series of trouble.In order to avoid you make a mistake in the production process, here small make up lists several examples for your reference:
A, about the color of the screen
Screen color is varied, basically have white, yellow, amber, red and so on, with yellow silk screen is preferred.Japan is commonly used in our productionNBCAnd the Swiss plug270~280TYellow silk screen, the special fine print, we often use 350TThe import of yellow silk screen.
Why use yellow silk screen?We know that the nature of gorgeous color is a function of the light, no light, no color, the color of light is decided by the frequency of light waves.Red, orange, yellow, green, green, blue, purple is the light of the people can feel the optic nerve, called visible light.Surface selective absorption and reflection of light and get a different color, in short, we can see any color is light color.When a beam of light to yellow surface, only the yellow light is reflected, stimulate the visual nerve of us and color, and other light is absorbed, so we see the object's color is yellow.
Due to theScreen printingExposure in print, using ultraviolet light, light is by the color of blue and purple hue magenta two hybrid reflected light, which means a lack of yellow hue in the black.At the time of exposure, purple stacked plus yellow silk screen is black, so the yellow screen surface (that is, the bottom of the emulsion layer) is not sensitive or less exposure, so as not to appear“Back to bask”Phenomenon, get high image resolution, won't produce halation.
Second,Sensitive glueThe coating of
Will make a good coating solution put into stainless steel vats, coating solution accounted for about half of the tank.Coated screen bottom contact with inclined trough, while tilting groove outflow liquid photosensitive, slowly and evenly to slot upwards along the screen surface coating.Coating speed cannot too fast, too fast will cause emulsion foaming, the membrane surface can produce pinhole;The slow cause emulsion coating uneven.In order to obtain the best effect of coating, it is better to start with the printing contact with substrates that side of the coating, coating area than silkNet frameSmaller, then coated screen upside down again, and finally to screen negative after coating is dry, so that the emulsion with mesh.with 30~35℃ hot air drying is the best that we can shorten the drying time.If the temperature is higher, more than40℃, the screen will produce hot phenomenon of fog.
Three, plate burning, dressing
Print before, should first check film photosensitive surface and the glass surface of the printing machine for dirty or dust, it's best to dip in with cotton yarn after alcohol is wiped clean again.With silver halide adhesion of the surface of the film as positive, side of base unique luster for reverse.Plate burning, the film should be release.it plane and network version of the emulsion surface dense joint, leave a bite line for exposure.Exposure time should be according to the types of photosensitive thorn, photosensitive film coating thickness and Yang picture black solid degree and printing requirements.The photographic film coating layer thickness, requires the exposure time is longer, corresponding to version of the film completely cured.If Yang pictures on the black solid enough, namely grey and not black, should shorten the exposure time, accordingly, to extend the time of development, so that not photosensitive graphic part completely transparent.
Version in order to strengthen, improve the water resistance and solvent resistance, prevent leakage screen during in combination with the space/printing ink, can strengthen the graphic edge, with wide tape paper bag sealing with adhesive or emulsion plugging its censorship of, pinhole on the screen, and should not have open hole section.For the design of small stain and left a littleSensitive glue, can use wide adhesive tape paper press the glue, can also use the cyclohexanone or alcohol wipe gently, also can with tiny needles, gently to keep screen appear.But action straight soft, action is too big, can damage the screen.
Source: my consumables of the net