Application methods and precautions of the hottest

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Application methods and precautions of green packaging inks

in order to catch up with and surpass the world's advanced level, China's ink industry system was comprehensively promoted by the "748" project signed by Premier Zhou Enlai in the mid-1970s, and was developed and established to meet the needs of printing and export packaging by the early 1980s. It has developed from a few ink varieties before and after liberation, such as glue, lead, and reputation, to bright, fast curing, rotation Plastic, water-soluble gravure printing, electrostatic copying, light curing, etc., more than 20 kinds, up to more than 300 colors. In the late 1990s, which will enter the 21st century, the trend of "eliminating white pollution and developing green packaging" has become an important part of the environmental protection industry

the water-soluble ink for green packaging printing has been printed on the surface of the absorbent material of web paper for nearly ten years. Modern technology has been used to directly introduce domestic efficient additives and pure natural resin rosin into the ink system, so that flexible packaging plastic films, plastic woven bags, calcium plastic cartons, etc. are rotating at a high speed It has become a reality that multicolor printing inks flooded the market and began to be printed and popularized on the surface of non absorbent materials (plastic, aluminum foil, etc.). When printing, it is slightly different from the traditional ink manufacturing process and technical indicators for the same purpose at home and abroad, but the principle of completing printing and packaging is the same

according to the composition of different pigments, auxiliary binders, fillers and auxiliary substances, there are two categories of liquid and slurry inks with certain fluidity, and their application classifications are as follows: according to the classification of printing plate types, there are flexible relief printing inks, intaglio printing inks, hole printing inks and roller coating printing inks

according to the main components of inks, there are web and paperboard printing inks, alcohol soluble printing inks and water-based printing inks

according to the purpose of the ink, there are paper printing ink, plastic ink, etc

in a word, green packaging printing ink is an industrial product serving packaging products, which can be used for printing newspapers, magazines, food, packaging printing and decoration. At present, paper and plastics can be printed with green ink, and a mature new ink product system with Chinese national style has been formed. Although it started late and has broad prospects, application methods and precautions have been placed on the agenda of people in the printing industry. Therefore, according to the problems explored in the past few years, we now master the essentials of use, the faults to be prevented, and the ways and means to solve them. First and second, for the reference of packaging colleagues

in colloidal chemistry, the property that reduces the surface tension of solvents is called surfactant, and the substance that can reduce the surface tension of solvents is called surfactant. According to this theory, rosin soap is often used as a surfactant for pigments, and the experimental data that rosin and non-polar polyolefins are compatible at high temperature significantly change the interfacial tension of the system, so that it has firm adhesion without corona coarsening. In our daily packaging and printing business, green packaging ink is relatively thin, and most of it is used in flexible rotary relief, rotary concave, rotary round screen printing and rotary water-soluble printing paperboard of single pneumatic diaphragm pump. In order to overcome the influence of normal packaging and printing caused by ink delamination and precipitation in summer and ink gelation and thickening in winter, we added inorganic and organic efficient dispersion materials with shape structure and ionic state containing OH hydrophilic alcohol group in the lattice to the components of the ink, which strengthened the destruction of electrolyte and kept the ink in a stable state. Although sometimes, like other printing inks (stratification or precipitation, it can be restored by stirring a little for 1-3 minutes), many factors, such as ink quality, printing materials, operator skills, etc., will cause the occurrence of faults, which can not be distinguished for a moment, so the above situation is summarized as fault phenomenon cause remedial measures. So that colleagues in the packaging industry can take preventive and remedial measures when using them, and expect the whole industry to feed back improvement opinions in time. In the future, we should focus on breaking through the bottleneck of new material utilization, breaking through regional and system boundaries, improving the formula and process design of green packaging printing ink, and doing our best to create brilliance

the picture and text are blurred/the printing ink layer is thin, the picture and text are inked, the strokes are not clear/the amount of ink is small, the ink is hard, the printing pressure is small, the ink transfer rate and adhesion are poor (sometimes even dry in the layout, ink roller or gravure hole), the black ink is even difficult to operate in the printing process, the surface of the substrate is rough/adjust the amount of ink, viscoelasticity, adhesion fastness, improve the printing speed and reduce the printing pressure, Increase the ink viscosity and add high-efficiency hyperdispersive additives to improve the transfer rate of the ink, adjust the printing pressure and select surface slippery materials, dilute the ink viscosity (apply - 4 cups for no less than 15 seconds, preferably about 25 seconds), and improve the drying speed. Crumple and rub dirty/imprint inking, resulting in dirty prints/large printing pressure, poor layout elasticity or deformation and smoothness of the press roll/adjust the ink drying speed or reduce the ink consumption, reduce the pressure of the press roll, change the flexo and correct the press roll

dirty and biting/the back of the printed matter is dirty by the previous ink or overprint adhesion, or the ink on the conveyor belt of the impression roller is transferred to the next printed matter/the ink is too sticky, the dryness is too slow and uncomfortable, the second color is easy to stick off the first color, the conveyor belt surface is not clean or swollen, the printing pressure is too large, the machine speed is too fast, or the thickness of the two sides of the printing material is different or the winding force is inconsistent/improve the dryness (speed) of the ink, Add quick drying solvent or oil, increase the proportion of lubricating and anti adhesion agent in the ink (96:4), increase the hot or cold blowing or slow down the printing speed and extend the printing stroke, select absorbent or surface roughening materials, improve the surface absorption of the printing materials, and pay attention to that the stacking load of the prints should not be too high and heavy

ink splash/there are ink spots or 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 and the ink film are separated, the drawing is too long or the ink is too thin, the printing machine speed is too fast, the ink viscosity is too small and non-static, the accuracy of the printing machine is poor, and the ink roller is deformed or the surface is damaged/replace the inking roller (according to the ratio of the plate line and the inking roller one, it is appropriate to choose 1:4), Reduce the viscosity of the ink, reduce the drawing length and fluidity, reduce the ink supply, adjust the viscosity, slow down the printing speed, adjust the workshop temperature and temperature, replace the ink roller and maintenance equipment, or add anti-static facilities and materials. The printing plate and the ink guide roller are dirty and scratched/the printing plate and the ink guide roller are dirty with the ink on the printed 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 the roller bar is worn or the hardness is not enough, or the plate statistics show that the deep, paper, plastic and other dust increase/replace the double-sided adhesive tape, adjust the pressure and the angle between the high-speed scraper and the roller, reduce the ink volume or replace the ink, and increase the fast drying solvent or oil, Repair the plate and roll bar, re polish and chrome plating to prevent the dust of paper, plastic and other powder from falling off

poor adhesion and dirt/printing products are easy to wipe off/the surface of paper plastic materials is too smooth and dense, so it is not suitable to use slow drying ink. The content of ink resin is too small, and the 5V supply voltage is most often used at the surface. It can not be completely dried at the moment, and it is easy to wipe off floating on the surface of printing materials. It is commonly known as skin scorched bones/improving the variety of ink, adjusting the adaptability of ink, processing the printing materials, and using ink with high viscosity and high ink color concentration, Increase the printing pressure, reduce the thickness of the ink film, reduce the printing speed, add high-efficiency additives and if it does not refer to zero stress, adjust the pointer position to increase the viscosity of the ink, replace the solvents or oils that affect the drying gradient of the ink, and replace the ink or diluent. You should know the adaptability of the ink

residual irritating odor/the proportion of methanol in the ink is too large and the solvent or oil/ink with odor can be reduced or not used at all/replace the ink or replace the solvent or oil that is irritating or harmful to human health. The color tone is not correct and the ink precipitates/the color becomes lighter and discolored, resulting in paste, the quality is inconsistent with the sample/the compatibility between the color, filler and the connection is poor, condensation or serious stratification (up, thin and down)/insufficient mixing before use, the ink should be stored in a cool and dry place with ventilation during the storage period, and the color tone can be adjusted or changed to the approximate value of the color phase of the sample, or 1-3% white ink can be added to the ink or filler can be increased to improve its coverage. Pinholes and slippage/chemical pinholes and mechanical pinholes appear in the print pattern/or spots occur on the full plate, and ink spills and a large amount of foam appear in the printing process. When the viscosity of ink/ink is too low, it is necessary to change new ink or add resin proportion to improve viscosity, increase fluidity, improve printing speed, add wetting and plasticizing defoamer to eliminate foam, and it is appropriate to change the deep plate pattern to 25-30 microns. The embedded plate and orange peel/ink have high viscosity, many impurities, fast drying, unbalanced solubility, and uneven ink/resulting in the reproduction of water lines and orange peel and the residual and dry ink in the hole of the plate pattern, which also leads to poor printing gloss, weak concentration, poor thixotropy and leveling, poor affinity between the plate roller and paper, plastic, etc., inappropriate additives, slow printing speed and electrostatic influence/high speed is 0.012 Seconds or so, what is the medium speed About 055 seconds, 0.09 seconds at low speed, and 0.012 seconds for a single sheet (the time required for ink transfer to the substrate). The angle of hot or cold air blowing is 90 degrees. Direct blowing or improve the ventilation conditions, add its solvent to achieve the solubility of solvent or ink and ink, replace ink additives, reduce static electricity and adjust the tone as much as possible to achieve gray balance. (Liu Jiaju)

from China's packaging industry 1999/5

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