The effective way to improve the printing resistance of PS plate and

The PS version's resistance to printing force is the number of copies that can be actually printed on a PS version within a certain quality tolerance. To increase the printing resistance of the PS version is to effectively increase the machine operation rate, reduce the auxiliary time, save the plates, and increase the economic efficiency.

therefore. Every printing company is looking for ways to increase the PS version's resistance to printing.

First, improve the printing resistance of the PS version from the printing process.

1. Correctly grasp the pressure between the plate cylinder and the blanket cylinder. Because the pressure of the plate cylinder and the blanket cylinder is too great, it will aggravate the wear of the printing plate, thus reducing the resistance to printing. The normal pressure is 0. 1mm.

2, do not use aging rubber. Because the rubber will be aged after a long time, the rubber will lose its elasticity, the fat-sensing ability will decline, the ink transfer performance will be poor, and the printing ink will be light. It is believed that the pressure is small, the pressure of the rubber cylinder increases, and the wear of the printing plate is accelerated.

3, correctly master the ink roller and water roller pressure. Because the pressure of the ink roller or the water roller is too large, the contact between the plate and the plate is generated during the imprinting process, and the surface of the plate is thus worn by impact. The ink roller and plate pressure should be adjusted to 5mm (Pressure bar width of the plate by the printing roller) The pressure of the water roller and the plate should be adjusted to 5-6mm (The bar width of the water roller on the printing plate. Front plate The water roller pressure should be slightly larger than the back plate roller pressure.

4, a reasonable choice of paper, ink and other materials. Because the quality of the paper is poor, the powder is lost, the hair is lost, and the gold powder is attached to the surface of the rubber or printing plate to increase the wear of the printing plate and reduce the resistance to the printing force. In addition, if the ink pigment or filler particles are coarse, it will also increase the grinding resistance of the printing plate.

5, correctly grasp the fountain solution PH value. Because the pH of the fountain solution is too small, ie, the acidity is too strong, it will erode the oxide layer on the surface of the printing plate and reduce the resistance to printing force. The pH of the fountain solution is generally controlled between 5-6.

Second, improve the endurance from baking process

(1) Normally, the PS plate is printed on the machine after exposure, development, drop of dirt, and gluing. However, since the inked portion is composed of unseen photosensitive wood, the photosensitive layer will continue to decompose during the printing process due to the effect of light, and the corrosion resistance and adhesion of the film layer will gradually decrease. The force of India can only reach about 5-10 million. In order to improve the endurance of the PS plate, apply a layer of protective agent to the PS plate after exposure, development, and lowering the dirt, and bake at a constant temperature of 240°C±10°C5- In 8 minutes, the developer is used for the second development, so that the endurance can be increased by about 1 time. Because the PS plate was baked, the photosensitive group in the photosensitive layer disappeared. The resin in the photosensitive layer is thermally cross-linked. Fastness and tightness increase. As a result, the solvent resistance and wear resistance of the PS plate are greatly improved, thereby increasing the printing plate resistance of the PS plate.

(b) The following points must be noted when baking the PS version:

1, in addition to dirty after the PS plate surface coated with a baking plate protection solution, generally each off the PS plate with 20 ml, to be coated evenly, there can be no stripes, if the coating is not uniform, after baking version There will be traces, dirty parts of the blank, affecting the quality of printing or even scrapped.

2, control the baking sheet temperature and time. The temperature is controlled at 240 °C ± 10 °C, baking time 5-8 minutes, if the temperature is too high or too long, causing the photosensitive layer carbonization, aluminum plate deformation. The temperature is too low or too short, the degree of curing is not enough, from Less than the role of baking version.

3. The wiping cloth used for wiping baking solution should be clean, and should not be mixed with the cloth used for rubbing the peach. It should be rubbed with a special cloth. When baking the protective printing plate, the plate must be thoroughly cleaned before it is baked. After the protective rubber can not be wiped off and dirty.

4, baking version must keep the entire layout temperature is the same, otherwise it will affect the resistance force.

5. After the baking version, the PS plate must be developed for a second time. The baking plate protection solution is then applied and the printing plate protective glue is applied.

6, must be carefully removed before baking, because the baked PS version is difficult to remove dirty.

7. Before the PS plate is baked, it must be coated with a protective liquid, otherwise, after the high-temperature baking, the microporous part of the closed hole will open, which will easily lead to dirt.

8. After the baked PS plate is taken out, it should be cooled naturally. Avoid water cooling to avoid deformation of the aluminum plate base.

Third, drying PS version of the relevant matters needing attention

(I) Improve contact between printing plate and printing plate

In order to make a good contact between the printing plate and the printing plate, the following points must be noted:

1, should pay attention to the maintenance and maintenance of the machine, the glass and rubber pads on the plate printing machine should be frequently cleaned;

2. Always check the pumping pressure of the vacuum pump;

3, often check whether the rubber pad is deformed, whether it is partially arched upwards or loose;

4, the use of the film thickness of the same film;

5, cut collage collage printing film must be repair personnel to trim the edges with a knife, transparent adhesive tape does not stick too close to the pattern.

(B) Correctly grasp the exposure time

Because of the lack of exposure will cause the blank part of the dirty, and over-exposure is tailored to cause network points to shrink. The correct exposure time can be controlled by the continuous scale and small dots in the GRTTGMS color bar. (The different exposure time of PS plate from different places of origin)

1, using a continuous adjustment ruler to control the exposure time

0.6D level; completely disappears

0.9D level; appears but not complete on the plate

1.2D level; complete in the version

2.5D level; entire in the version

2. Control the exposure time with the small outlets used in the garden ring

1% dot disappeared
2% of the dots appeared
4% outlets appear completely
6% of outlets completely appear

(3) The temperature, concentration and development time of the developer are properly grasped (there is a special developer for different PS plates)

1, the developer temperature is best controlled at 20 °C

2. Insufficient development (short development time or low developer concentration) or fatigue of the developer, there will be photosensitive film residue on the blank part of the layout, resulting in the upper dirt;

3. If the developer is too thick or the development time is too long, the sealing layer will be damaged. Causes poor hydrophilicity, oxidation when shut down, and the printing plate starts to float after booting.

4, manual flushing should pay attention to cleaning the remnants of clean medicine.