Printing ink printing failure (in)

Third, the main reason for the blurred imprinting trail is: the ink contains coarse hard particles or mixed with dust, paper dust, plastic shavings, etc. The second is the smear caused by a small defect in the blade and the ink film is too soft.
Treatment method: First, exchange the ink with high softening point or filter ink; Second, clean the ink ink bucket or barrel mixed with dust, paper scraps or plastic crumbs; Third, cover the ink immediately after use, or install a new one on the ink bucket. Top cover; four is to replace the scraper or scraper blade behind a 1 ~ 3MM thick rubber or plastic foam sheet to improve its scraping ink elasticity.
Fourth, the main reason for the pinhole is that the rough surface of the substrate is not smooth or the printing plate is stained; the second is that the active agent in the ink is too much or the ink is not ripe (the bubble is not disappeared) completely, often called a chemical pinhole. (Different sites and different areas and different numbers of pinholes).
In addition, faults called mechanical pinholes are pinholes in the same area and the same size and number of the same substrate, often appear repeatedly, and rarely disappear during the printing run-in period.
Treatment methods: First, exchange substrates (clean or unstained); Second, control the amount of active agent in the ink system or add about 0.2% of defoaming plasticizer in the ink for 48 hours (excessively can cause ink film The craters are difficult to level.)
To solve the mechanism pinhole fault method: First, change the printing plate or the printing machine to open and run after a period of time and then open the printing, the second is to adjust the printing pressure.
Fifth, the network is missing or defect The general cause of the failure is: First, the viscosity of the ink is too high; Second, the ink film drying is too fast; Third, there are particles in the ink; Fourth, the ink leveling is poor; Insufficient printing pressure; Sixth, the circumference of the printing plate sleeve is not even and not clean.
Treatment method: First, the ink viscosity should be adjusted between 25 ~ 30S/25 °C · 4 cups between the coating is appropriate; Second, the ink is added in the printing when the slow-drying thinner; third is to prevent the ink from drying prematurely in the plate version of the hole (Add wetting additives); Fourth, add 1% to 3% leveling (such as ethers) or adjust the pressure so that the substrate tension is controlled at 0.05; Fifth, change the plate or polish the surface of the plate. .
VI paste version (in the non-graphic area)
The main reason for the paste version is: the ink system has a low softening point or a low PH value. The second is that the viscosity of the ink is too high, the scraper does not scrape the net, the hardness of the scraper blade is too strong and the toughness is not enough, or the angle of the scraper is not correct. Third, the cold wind is insufficiently blown or the angle is not good during printing (when it is severe, the printed matter may be adhered); Rough is not smooth. Treatment method: First, replace the ink with a higher softening point, or choose a PH value close to neutral; the second is to dilute the ink or add an eraser behind the doctor blade (foam can also be used, its thickness should be 1 ~ 3MM The third is when the hot air blow (the temperature should be depending on the ambient temperature 30 °C or 35 °C or 40 range three levels) after blowing the blot, adjust the cold blowing angle (should be 25 °, 30 °, 35 °, 40, respectively) ° is good; four is to replace the printing plate.
7. The reason for the adhesion of the printed product is that the temperature is high and the printing speed is high, so that the solvent in the ink film is not completely evaporated (relatively speaking), or after the hot air blow, the cold air blow is insufficient and not ripened, but also due to the ink The fast and slow volatilization rate is too high (causing the surface to be wet inside); the fourth is that the ink system invades the water molecules or mixes with substances that promote the oxidation properties (such as lead, cobalt, and manganese salts), so that after printing The ink layer gradually oxidizes (releases) stickiness during storage.
In addition, when the ink is stored in the factory, it is stored in poorly ventilated warehouses, especially if the softening point of the linking material is low or the anti-skid anti-slip agent component is too small, followed by the gravure pattern of the gravure plate being too deep and the ink film thickness of the printing ink will appear after transfer. Stick back. Processing method: In the season of gas temperature, the printing speed is slowed down or anti-adhesion aids are added in the ink; the second is to use the fast, medium, and slow mixed solvents and use as little solvent as possible to adjust the ink; third is when the heat After blowing, increase the cold air blow or adjust the air blow angle; fourth is to measure the thoroughly dried ink film and re-adjust the printing machine speed according to the drying time; cap the ink fountain or bucket or cover the ink at any time to prevent water molecules Intrusion and prevention of oxidation of metal salts; Fifth, the ink is stored in a ventilated, dry, moisture-free low-temperature warehouse; Six is ​​re-plate (print depth is 25 ~ 45cM is better, replace the printing ink with a higher softening point.
Eight, ink film crystallization and difficult to overprint the general performance of: the previous ink film is difficult to print after the second or third color ink, the surface has formed a crystallized (ie vitrification) / mainly due to two The nature of the ink is different or the components are different, and the re-dissolvability (ie poor affinity) is poor; the second is to add too much silicon lubricant in the ink system, especially in hot weather; third is the lack of formation of the surface of the composite ink after film formation Micro-coarse surface matte or anti-adhesive, anti-static agents cause the surface to be too smooth; the fourth is the printing plate hole (graphic pattern depth) is too shallow or ink flow is too high or due to high viscosity and so on.
Treatment method: In the ink system, increase the amount of true solvent to increase its re-dissolving affinity, replace the ink with the same color as the previous color (the same brand and manufacturer), and secondly, use the ink containing silicone lubricant as much as possible. In one color, the second or third ink is printed when it is slightly tacky. Add appropriate amounts of matte powder (without affecting its surface gloss as a standard) or subtract anti-stick and antistatic doses in the compound ink, replace the printing plate or remake the depth of the 25-45 μm graphic plate, or select the content High viscosity and low viscosity inks regularly eliminate plate ink knots. (to be continued)