Solid photosensitive resin plate, with its advantages of fast plate making speed, high resistance to printing force, high resolution, no pollution, etc., has become the preferred medium for relief printing in the world today.
We have developed, developed and promoted PVA-500 series solid photosensitive resin plates and YZB series solid photosensitive plate platesetters for more than ten years. We have found that because users do not know enough about the characteristics of plate materials, they have not chosen a platemaking equipment, so that Plate quality is not satisfactory.
Here are some quick ways to master platemaking for your friends to refer to.
The water-soluble solid photosensitive resin plates we used are all photopolymer materials that polymerize under 360 nm UV light. Because it is a water-soluble material, use clean water to wash away unexposed parts. After rinsing, it is dried and then post-exposure to make it stable, improving resistance to moisture and printing.
When using YZB plate making mechanism, first set the flushing temperature, rinse, drying time, drying temperature and post-exposure time, so that it is a constant value in each plate making, so that we only control the exposure with the job Time can be.
1. Exposure first peel off the protective film of the resin plate, coated with some talcum powder, in order to facilitate the absorption of the plate material and prevent the film and the plate material adhesion, and then exposure.
Observe the side of the prepared plate with a magnifying glass (as shown in Fig. 1) and you can see that the photosensitive coating is a trapezoid, and the normal angle a is about 70°. The a angle decreases as the exposure time increases. The exposure time is long and the characters and lines are firm. After washing and drying, the characters are not easy to drop, and they are not easy to bend. However, the printed version is not thorough enough in a small area, which gives the impression that something is not washed clean; The exposure time is short, and the angle a increases. After the washing and drying, the light is cut off and the lines are bent. The heavy words and lines are washed away. If you do not know the correct exposure time, you can use a small piece of media, select a different exposure time for exposure, rinse, dry, watch the publication of the slope, you can determine the correct exposure time. Tianjin Ketai PVA-500 plate exposure time is about 5 ~ 7min.
2. When rinsing and drying the resin plate, the flushing time should be shortened as the flushing water temperature rises. However, the water temperature cannot be too high. Generally, the flushing water temperature of domestically produced plates is set at 45°C. The washed plate can be placed directly in the drying room of the plate making machine. The temperature is set at 90°C for 15 to 20 minutes.
3. After exposure, the prepared plate is directly exposed to the exposure room of the plate making machine for post-exposure. The post-exposure time is generally equal to or greater than the first exposure.