1. Observe the sample
Sample inspection in printing. Soon after entering the official printing, the amount of ink to be determined at the time of printing is somewhat different and should be checked frequently and adjusted. When the printing speed remains constant, the amount of ink and the amount of water are in stable condition, the sampling inspection shall be carried out according to the proportion of 500~1000 pieces/time.
Put in a warning note. In the formal printing, for the occurrence of the failure, as a kind of mark, should be clamped into a slender warning note, in order to facilitate the inspection in the post-process.
2. Notice the change of water
Pay attention to the change of water in the initial stage of printing. Testing-run when the water and into formal on water after printing, how many will be some changes, you must pay attention to the sample for any side ghosting, carry water, one side note settlement plate yield.
Pay attention to the change of water in the official printing process. Please pay close attention to the machine body heat and ventilation to the effects of water within the workshop, alcohol education version should pay attention to wetting system cooling device, control the temperature of the good wetting liquid, too little water, can make the printing plate up dirty. Excessive water will cause ink emulsification, a series of problems. For example, the printing products have no luster, the paper is retractable and the printing is not allowed, delaying the drying of ink.
Pay attention to the change of ink
Pay attention to ink of ink. Ink of ink from the gap between the ink bucket roller and the ink scraper, is caused by the ink's self-gravity and naturally squeezed out. Therefore, ink amount of ink in ink, directly affect the output of ink. So, be careful to keep a certain amount of ink in the ink. In addition, printing ink has a thixotropic property. When placed in inks for longer, the liquidity will gradually deteriorate, so it is necessary to use the ink knife to stir in the ink, or to install the ink agitator.
Prevent the ink from drying on the machine. The ink on the ink roller and ink on the ink can be dry when it is stopped for long periods of time like eating and resting. Can be sprayed with a dry inhibitor to prevent drying.
The density of the printed material varies with the amount of water, room temperature and machine speed. Check with standard samples frequently. Notice to prevent inhomogeneity of ink color.
The pH value of wetting liquid is maintained, and the pH value of wetting solution can be easily influenced by the addition of the auxiliary agent in the ink. If the pH value increases, the printing plate will become dirty, so pay special attention to it.
Pay attention to the back of the dirty
The dirt on the back is caused by the slow drying of the ink, the thickness of the ink layer and the high degree of smoothness of the paper, so that the ink on the surface of the printed sheet is glued to the back of the printed sheet.
5. Pay attention to the reshadow failure
The so-called ghost image is the wrong movement of the image printed in a printing plate, which can see double and triple figures in the printed sheet. There are many reasons, such as paper, teeth, roller, rubber cloth, printing speed, ink viscosity and other factors are very complicated. The following methods can be used to check for reasons and to deal with them.
Double printing, observe the accuracy of the overprinting, and check the side gauge drawing force, the paper, the paper wheel, the paper machine parts to check and adjust.
Check the tension of the rubber cloth, the new rubber cloth is easy to relax, and pay attention to the partial tightening, but not too tight.
Check roller packing and printing pressure.
Check the paper's fitness. The paper is poor, especially in the mouth part of the paper, it is easy to have heavy shadow, so it should be checked.
Reduce the viscosity of ink. The ink viscosity is high, the paper can not smooth the rubber cloth, so that the tip of the paper is unstable, resulting in heavy shadow. Can reduce the viscosity of ink properly.
The adjustment of the teeth. The poor adjustment and maintenance of the teeth is one of the main causes of heavy shadow. Therefore, the adjustment and maintenance of the teeth should be done regularly to keep the work in good condition.
6. Pay attention to check the overprint situation
Take out 20~30 prints continuously, break the edges of the paper, check the front and side rules and make sure that they are accurate.
Pay attention to other work
The supplement of ink, stirring and moistening liquid.
Remove dirty homework. Because of ink residue, paper powder, paper wool and other loot on the plate or rubber cloth, and reflected on the paper, it is necessary to remove the dirty. In addition to the dirty work normally should be stopped. Unless there is a device that can remove dirt during operation. It is absolutely forbidden to remove the dirty while running.
To clean the rubber cloth, the eraser and the gelatinize work. When the blanket of ink, paper powder, powder of powder and influence ink transfer, must stop to clean the rubber cloth, the operation should pay attention to safety. Safety should also be noted for scrubbing and gelatinize operations.
Notice the abnormal phenomenon of the printing press. Pay attention to the sound, heat, vibration and smell of the machine. Check the current meter and keep an eye on the abnormal situation of the printing press.
Viii. Pay attention to confirm the printing number
At the end of the printing, it is necessary to confirm whether the printing number is consistent with the production construction sheet. If there is a shortage, the production manager shall inform the production manager and arrange the reprint in a timely manner.