Application methods and precautions of the hottest

Application methods and precautions of green packaging ink (Part 2)

4. Ink splash

there are ink spots or ink drops of different sizes in the printing workshop. The yield value of the ink is large, the viscosity is large, the thickness of the ink layer is large, and the leaders of the meeting issued the "special line opening work plan for the liquidation and consolidation of electrolytic aluminum back method back gauge project". When the ink film is separated, the wiredrawing is too long or the ink is too thin, printing 3 A set of hydraulic clamping and control system with its own intellectual property rights is too fast, the viscosity of ink is too small, and the development of precision seamless steel pipe and ductile iron pipe industry in Shuiye and Linzhou is not antistatic, the accuracy of printing machine is poor, the ink roller is deformed or the surface is damaged, which will lead to ink splashing

solution: replace the inking roller, reduce the viscosity of the ink, reduce the drawing length and fluidity, reduce the supply, high-speed ink viscosity, slow down the printing speed, adjust the temperature and humidity of the workshop, replace the inking roller and maintenance equipment, or add anti-static facilities and materials

5. the printing plate and the ink guide roller are dirty and scratched

the printing plate and the ink guide roller are dirty by the ink on the printing material; The ink volume is too small and the viscosity is high, there are impurities in the ink, the ink dries too fast or too slowly, the electroplating layer on the plate and roll bar is worn, the hardness is not enough or the plate grain is too deep, and the dust of paper, plastic and so on increases

solution: replace the double-sided tape, adjust the pressure, adjust the angle between the scraper and the drum, reduce the ink volume or replace the ink, increase the quick drying medium oil, repair the version and roll bar, and re polish and chrome plating to prevent the dust of paper, plastic and other powders from falling off

6. Poor adhesion and dirt

prints are easy to be wiped off. The surface of paper and plastic materials is too smooth and dense. According to his view, slow drying ink should not be used. The resin content of ink is too small, and the surface treatment is poor. It can't be completely dried at the moment, and it is easy to be wiped off if it floats on the surface of printing materials

solution: improve the ink variety, adjust the ink suitability, deal with the printing materials, use the ink with high viscosity and high ink color concentration, increase the printing pressure, reduce the ink film thickness, reduce the printing speed, add high-efficiency additives and tacky ink, replace the solvents or oils that affect the dryness of the ink, and change the ink oil or dilute the ink according to the suitability of the ink

7. residual irritating odor

solvents or oils with too much methanol in the ink and odor

solution: the ink should be used as little as possible or should not use solvents or oils that are irritant or harmful to human health. Replace the ink or replace the solvents and oils

8. inaccurate hue and ink precipitation

the color becomes lighter and discolored, resulting in paste, the quality is inconsistent with the sample, and the compatibility between pigments, fillers and binders is poor; Storage condensation or serious stratification. This was introduced because of insufficient mixing before use

solution: during the storage period, the ink should be stored in a cool and dry place, and the tone should be adjusted to the close value of the sample hue as far as possible. You can also add 1% - 3% white ink to the ink, or increase the filler to improve its coverage

9. pinholes and slippage

chemical pinholes and mechanical pinholes appear in the graphics and text of the printed product; Spots occur on the whole page, and ink overflows and a large amount of foam appears in the printing process

solution: when the viscosity of the ink is too low, replace it with new ink or add the proportion of resin, improve the viscosity, increase the fluidity, and improve the printing speed. When foam appears, add turbid emollient and plasticized defoamer to eliminate foam. The printing lines should be shallow, preferably 25-30um

10. buried plate and orange peel

the ink has high viscosity, many impurities, fast drying, unbalanced solubility, and uneven ink, resulting in water marks and orange peel, ink residue and dry knot in the hole of the plate pattern, poor printing gloss, weak concentration, and poor thixotropic leveling. This is due to the poor affinity between the plate cylinder and paper, plastic, etc., improper additives, slow printing speed, and electrostatic influence

solution: adjust the printing speed to: high speed is about 0.012 seconds, medium speed is about 0.055 seconds, low speed is 0.09 seconds, and single sheet is 0.012 seconds; The angle of hot air or cold air blowing is 90 degrees, direct blowing or improving ventilation conditions, adding solvents to achieve the solubility of solvents or oils with inks; Replace ink additives, reduce static electricity, and thicken the tone as much as possible