Application of the most popular green packaging in

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Application of green packaging ink

the water-soluble ink for green packaging printing has been applied to the absorbent material surface of web paper for more than 10 years. Using modern technology, the domestic high-efficiency additive and pure natural resin rosin are directly composed and introduced into the ink system, so that the ink can be used in the printing of flexible packaging plastic film, plastic textile bag, calcium plastic carton, leather and other materials, as well as on the surface of non absorbent materials. During printing, although the manufacturing process and technical indicators are slightly different from those of traditional domestic and foreign ink with the same purpose, the principle of completing printing and packaging is the same

according to the composition of different pigments, auxiliary binders, fillers and additives, and the two categories of liquid and slurry inks with certain fluidity and fluidity, there are three application classification methods:

according to the classification of printing plates, there are flexible relief inks, intaglio printing inks, hole printing inks and roll coating printing inks

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

there are paper printing inks, plastic inks, etc. according to the use of inks

in a word, pure 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, plastic and leather can be printed with green ink, but due to the late start, there are many defects in the application methods. For this reason, the author will provide reference for packaging colleagues according to the outline and key points, fault prevention and solutions in recent years

in colloidal chemistry, the property that reduces the surface tension of a solvent is called surfactant, and the substance that can reduce the surface tension of a solvent is called surfactant. According to this theory, the rosin soap can be used as a surfactant, and the experimental data of compatibility between rosin and non-polar polyolefins at high temperature can significantly change the interfacial tension of the system, so that it has a firm adhesion without corona treatment

in the daily packaging and printing business, the green packaging ink is relatively thin, which is mostly used in flexible rotary relief, rotary intaglio, rotary round screen printing and rotary water-soluble printing paperboard of single pneumatic diaphragm pump. In order to overcome the problem of ink delamination, frequent ink gelation and thickening in winter and affect the normal packaging and printing, we have added inorganic and organic efficient dispersing materials with shape structure and the ionic state of - Oh hydrophilic alcohol group in the lattice to the components of the ink, which has strengthened the vicious cycle of anti electrolyte and kept the ink in a stable state. Although sometimes it is like looking for links, the occurrence of faults caused by factors such as ink quality, printing materials, operator skills and so on can not be distinguished for a moment. Therefore, the above situation is summarized as fault - phenomenon - cause - remedial measures. It is expected that colleagues in the industry will give timely feedback on improvement opinions, break through regional and system boundaries, and improve the formulation and process design of green packaging printing ink, so as to create brilliance

common ink faults and solutions:

1. the picture and text are fuzzy

the printing ink layer is light, and the picture and text strokes are not clear; The ink quantity is small, the ink property is hard, the printing pressure is small, and the transfer rate and adhesion of the ink are poor. Therefore, the requirements for the system stiffness of the black ink are not high enough to agglomerate in the printing process, which is difficult to operate, and the surface of the printing material is rough

solution: adjust the ink dosage, viscoelasticity and adhesion fastness, improve the printing speed, reduce the printing pressure, increase the ink viscosity, add high-efficiency hyperdispersive additives to the ink to improve the ink transfer rate, adjust the printing pressure and select surface smoothing materials, dilute the ink viscosity, and improve the ink drying speed

2. crushing and smearing

inking results in dirty prints, large printing press, poor layout elasticity or press roll degeneration and smoothness

solution: adjust the ink drying speed or reduce the ink consumption, reduce the pressure on the pressure roller, and replace the flexo and correct the pressure roller

3. sticking and biting

the back of the printed matter is stuck or overprinted by the previous ink, or the ink on the impression roller conveyor belt is transferred to the next substrate; In the ink, the dryness is too slow, the second color is easy to stick to the first color, the surface of the conveyor belt is not clean or inflated, the printing pressure is too large, the machine speed is too fast, the thickness of the printing materials on both sides is inconsistent or the winding tension is inconsistent

solution: improve the initial dryness of the ink, increase the proportion of lubricating anti adhesion agent and in the ink, add quick drying solvent or oil to increase the heat or cold blowing or slow down the printing speed and extend the printing stroke, select absorbent or surface roughened materials to improve the surface absorption of the substrate, and pay attention not to stack the prints too high or too heavy

4. ink splash

there are ink spots or ink drops of different sizes in the printing workshop. The ink has large yield value and viscosity, the ink layer thickness and ink film separation are too long or the ink is too thin, the printing speed is too fast, the ink viscosity is too small and not anti-static, the printing machine accuracy is poor, the ink roller is deformed or the surface is damaged, which will lead to ink splash

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 workshop temperature and humidity, 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 materials; 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 adhesive 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 oil, repair the plate 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

the printed matter is easy to be wiped off. The surface of paper and plastic materials is too smooth and dense, so it is not suitable to use slow drying ink. The ink resin content is too small, and the surface treatment is poor. It is easy to be wiped off if it cannot be completely dried at the moment and floats on the surface of the printing material

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 ink dryness, and change the ink oil or dilute the ink according to the ink suitability? Br 7.

residual irritating odor

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

solution: use as little or no irritant or harmful solvents or oils as possible. Replace the ink or replace the solvents and oils

8. inaccurate color tone and ink precipitation

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

solution: during the storage period, the ink should be stored in a cool and dry place, and the color tone should be adjusted to the approximate value of the sample hue as far as possible. 1% can also be added to the ink - 3% white ink should be used to implement the development strategy of high efficiency and green plastic granulator, or the filler should be increased to improve its hiding power

9. pinholes and slippage

chemical pinholes and mechanical pinholes appear in the printed text; There are spots on the whole page, and the ink overflows and a large amount of foam appears during the printing process

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

10. embedded plate and orange peel

this particle size range is located in the transition area at the junction of atomic clusters and macro objects. The ink has high viscosity, many impurities, fast drying, unbalanced solubility and uneven ink, resulting in water marks and orange peel. The ink remains and dries in the hole of the plate. The printing gloss is poor, the concentration is too weak, and the thixotropic leveling is poor. This is because the affinity between the printing plate cylinder, paper and plastic is not good, The auxiliary agent is not suitable for printing due to slow speed and electrostatic influence

solution: adjust the printing speed as follows: high speed is about 0.012s for vulnerable parts of hydraulic material testing machine, medium speed is about 0.055 seconds, low speed is 0.09 seconds, and single sheet is 0.012s

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