Thin line bending of solid photosensitive resin plate during plate making

When using a solid photosensitive resin plate in the production of forms or thin lines of work, the most prone to plate-making failure is the wavy bending of the resulting thin plate lines. This is especially the case with domestically produced plates. This is not due to the issue of quality of the plate. It can be overcome as long as the correct plate making method is adopted.
Domestic plates are made of polyvinyl alcohol, which is highly water-absorptive. The photopolymerization occurs after the plate is exposed. Although the exposed part is insoluble in water, it still needs to absorb a lot of moisture during the process of rinsing. Because it is a linear work piece, the polyvinyl alcohol that absorbs water expands gradually, and the stress along the straight direction increases. When it is large to a certain extent, lateral deformation occurs, resulting in wavy bending of the lines. It can be seen that water swelling during the flushing process is the cause of line bending. Therefore, in the process of plate making, trying to reduce the water absorption rate of the plate after exposure can effectively overcome the bending phenomenon of the lines.
The exposure of a full plate, due to a complete photopolymerization reaction, the water absorption rate is significantly reduced, can effectively overcome the thin lines of bending, so in the production of thin lines of live work, should be appropriate to extend the exposure time. Sometimes, the phenomenon of fine line bending still occurs when the exposure time is increased, which is caused by the following reasons.
1. The water temperature is too low and the rinse time is too long, resulting in increased water absorption of the plate.
2. When the film is made, the density of the light-transmitting portion is relatively high, so that the transmittance of ultraviolet rays is reduced, and the plate material is not sufficiently exposed.
As long as the former raises the temperature of the water to between 45 and 50°C and moves faster when brushing, a qualified plate can be produced. The latter situation is often the use of sulfuric acid paper made by a laser printer, which is caused by excessive lengthening of the printing process or excessive development time. In order to copy the qualified film, you can use a laser printer to print two sheets of the same sulfate paper or polyester film, re-coil them together, stick them together with adhesive tape, and copy the density of the light-transmitting part of the negative chart with this document. Very low, there is no thin line bending phenomenon in the resin version.
If the phenomenon of thin line bending in the plate after washing is not serious, it can be slowly dried at 60°C, and it can be straightened naturally after 30 minutes.
If it is too late to re-produce the film, you can use multiple development methods to produce a qualified plate, that is, the plate is washed in a higher water temperature (such as 50 °C) 1min, and then dried, immediately after drying 1min And then dry. Although this method is more troublesome, it can eliminate the need to remake the film and save the total plate making time.
In some cases, fine line bending can occur when the plate has a high moisture content. In this regard, one is to increase the amount of exposure to make up for; the other method is to tear off the cover film before plate making, put the plate under the condition of 50 °C, and then dry it for about 30 minutes before exposure.
If the black light on the plate making machine is used for a long time, a large decrease in the amount of ultraviolet radiation will cause underexposure, resulting in a thin line of curvature. In this case, replace the new lamp.
The above situation has noticed that the phenomenon of thin line bending that occurs when using domestically produced solid tree tire platemaking can certainly be overcome.