Orthographic Paper Original Stencil Tips

Once, the factory undertook a batch of dispatches and finished products were plain text brochures for A4 paper. The customer has used Word to arrange the brochure and bring the electronic document to our factory to produce sulfuric acid paper. Since Word has no output anti-word function, plus the computer with the Founder system in our factory is just a problem, it can not be reversed sulfuric acid paper. According to the requirements of 8 A4 paper just to fight a large off from the pirated version. Since it is a positive character, the density is increased first (text strokes are slightly thicker and some good prints are made), and the exposure time is also 1/3 less than usual, which is 80 seconds (300W iodine lamp, ordinary anti-word sulfuric acid paper exposure time is 120 seconds) . However, after the development, there are still problems with the text. Is the exposure time long? Or high developer concentration? However, the positive sulfuric acid paper that had been dried on the previous day still had 8 pages, and there was no problem with the same time, concentration, and temperature. After careful observation, it was found that the middle text of the layout was better and the surrounding text was imaginary. This understands that the original layout is too big. Most of the light of the printing plate light source is irradiated onto the sulfuric acid paper at right angles. Although the scattering property of the paper is very strong, only a small amount of light crosses the boundary of the text line under the premise of appropriately reducing the exposure, and the light should not be exposed. Membrane, so the middle of the text made a little virtual; and away from the center of the layout, the light is inclined to sulfuric acid paper, coupled with the strong scattering of sulfuric acid paper, there will be more light across the boundaries of text lines, The photosensitive film that should not have been exposed is sensitized, thus causing the text around the printing plate, especially the four corners, to be imaginary.

After the cause of the fault was found, the original large split sulfuric acid paper was divided into four exposures and the fault disappeared. The specific operation is as follows:

1. Put the already-spun sulfuric acid paper on the PS plate as required and stick it with transparent tape.
2. Completely cover the three octa-unsulfated papers with black paper, move the PS plate, and expose the unopened octahedron to the exposure light source (the plate-making machine is large enough) for the first exposure.
3. Use the same method to expose the other three octaves, then use a developing solution that is 20%～30% higher than the usual concentration and a high temperature of 3～5°C to develop, and then repair the dirt and protect the plate.
Although the above method can solve the problem, but the effect is poor, and it takes too much time, it is not used as a common method, and is only used when it is a last resort.

Source: Zhejiang Online Technology Market