The hottest ink technology is in progress

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Progress in ink technology (Part 2)

3 progress in water-based ink technology

by 1970, the main use of water-based ink was kraft board offset printing production line for corrugated box industry. This kind of ink has gradually replaced moisture curing alcohol soluble letterpress printing ink

they are colored rosin maleic acid or fumaric acid semiester alkyl alcohol amine solutions. The major progress that has an impact on the future development in the 1970s is the development of alkali soluble acrylic acid copolymers, which cure faster, and improve the dryness and wet friction resistance of inks on paper and wood substrates. The intermediate colloid and lotion polymer were further developed, thereby improving the film-forming performance of polymer solution

the development trend of material technology is shown in Figure 3, and the drying mechanism is shown in Figure 4. Table 1 shows the performance comparison between solvent based and water-based inks, indicating that the water-based system has both advantages and disadvantages. By the 1980s, color chips and color paste concentrates that are easily dispersed and dissolved in suitable aqueous media were developed

surfactants can improve pigment dispersion and printing performance

the "three campaigns" of introduction, commencement and production have achieved rich results. The use of water-based systems has made limited progress in the following two aspects

(1) in terms of ink dryness, it takes more energy to volatilize water than organic solvents with similar boiling points

(2) the adhesion, mechanical wear resistance, heat resistance, water resistance and durability of water-based inks on impermeable packaging substrates are generally not as good as the corresponding organic solvent based products

in the 1980s, the enthusiasm for developing water-based systems on a wider range of substrates was not as enthusiastic in Britain and Europe as in the United States, and the United States Environmental Protection Agency (EPA) began to impose restrictions on the emission of organic solvents. In the United States, statistics show that the sales of water-based inks have increased, and more and more water-based offset printing and gravure printing inks have been used to print polyethylene, polyethylene coated plates and some film materials

in the UK, water-based photographic intaglio inks with low odor were developed in the early stage for printing chocolate and dessert packaging boxes and for printing water-based photographic intaglio varnishes on alcohol soluble inks on food and candied fruit packaging materials. In fact, the market and application of these types of waterborne varnishes are increasing year by year, not only limited to the field of offset printing and gravure printing, but also extended to the application of assembly line surface coating (see Figure 2)

corrugated boxes have been printed with kraft board with a large number of water-based offset printing inks. Now it also includes high-quality four-color intermediate tone printing (pre coated with white lining) on white substrates before Corrugated processing. There is no doubt that the more water-based inks are used, the more their defects appear. Researchers need to continue to study, improve and expand the available varieties of waterborne polymers that can improve their dryness and printing properties on plastics and other impermeable substrates. Mainly considering the activity, for example, it will still be a challenge to achieve the balance between the activity of cross-linked polymer system and the stability required for high-speed printing

through the wider use of synthetic resins, film-forming polymers and organic solvents in liquid ink formulations, it is possible to meet the printing needs on a wider range of substrates and laminated structures, while the range of aqueous systems is narrower, and the available polymer materials are more limited

then, with the mandatory control of VOC emissions by legislation, how should we choose? In terms of route debate, solvent recovery system has been used in intaglio printing of publications for a long time, but this is not feasible in the field of packaging printing. In this case, a large number of different solvents need to be recovered and fractionated before reuse. Some articles discussed various controversial views in detail, discussed the advantages and disadvantages of various technologies, and discussed the impact of various factors, including capital and operating costs. The solvent treatment can adopt biological method or thermal decomposition, and the catalyst can be added or not. The biodegradation system uses the dispersion medium to adsorb VOC in a humid environment, and then uses specific bacteria that take it as food to decompose VOC. Its advantages are low operation cost and capital into the joint venture of China Polyurethane Association and Yantai assimilation waterproof and thermal insulation engineering Co., Ltd., Wanhua energy saving science and Technology Group Co., Ltd., Beijing Maohua polyurethane building materials Co., Ltd., Shanghai Huafeng PUEN Polyurethane Co., Ltd Zhejiang Keda new building materials Co., Ltd., Jiangsu Lvyuan new materials Co., Ltd., Beijing Hangyu thermal insulation building materials Co., Ltd., jingcarbon Weiye (Beijing) Technology Co., Ltd., Wuxi Jieyang Energy Saving Technology Co., Ltd., Nanjing hongbaoli new materials Co., Ltd., Shandong Lianchuang energy saving new materials Co., Ltd. and other 11 enterprises have moderate cost and long service life because most thermoplastic materials will not be interrupted in this experiment. But on the other hand, the mutation of VOC concentration, composition or flow speed may stop the work of bacteria. This technology is suitable for low concentration VOC. The thermal oxidation incineration technology has the advantages of high concentration VOC degradation, high efficiency, moderate capital cost and good compatibility with the fluidity, concentration and composition changes of the released solvent

as for the printing press and converter for flexible packaging, thermal incineration equipment has been installed, so it is unlikely to switch to the newly developed water-based ink

it is expected that the interest in hydration in printing inks for paper and cardboard box substrates will increase. In fact, some types of plastic films and films have been used, and future research should focus on methods to improve printing dryness

there are many factors that affect the dryness and quality of the final ink. What matters is the air flow rate and optimal temperature for different ink and substrate mixing systems, and how much is the influence of relative humidity on the evaporation rate of water

knowledge of the "drying curve" (see Figure 5) helps to understand what happens at different volatilization stages. It is urgent to develop accelerated drying technologies such as microwave and radio frequency radiation curing

4 development trend and application of thermosetting silk offset lithographic printing ink

here is a brief description of the changes in the formulation of thermosetting silk offset printing ink in recent years. A detailed study was carried out in the 1970s to save printing energy by drying the prepared ink at the lowest possible furnace temperature. At that time, there was no special legislation on solvent emission. However, the new ink used low odor High boiling trend? By chance? Point of petroleum solvent, and introduce a small amount of water into the ink to form a water in oil lotion, which will not affect the lithography performance. This makes it possible to adopt a temperature lower than the usual furnace temperature. Despite these advances, some local departments still insist on solving the solvent problem by discharging from the chimney of the drying furnace. In fact, incineration equipment has been installed, especially in factories in areas with many buildings

this enables ink manufacturers to have a wider choice, such as using high boiling point petroleum distillate (hbpf) solvent to prepare ink, and using a new generation of polymer resin developed in recent years

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