UV inks and water-based screen printing inks will be very popular in the market, and most of the inks used in China are solvent-based inks. The solvent-based ink is a volatile dry ink, which has a slow drying time and requires 8 hours of natural drying. In the drying process, 60% of the solvent must be volatilized. This serious pollution, under the slogan of “returning to the natural environment first”, is not only subject to the strict regulations of the government departments, but also by the neighbors. The screen printing factory also does not want to use it. Therefore, it is inevitable that UV inks and water-based inks will occupy the screen printing market in the future.
First, screen printing ink (UV ink) market trends
At present, the ink for screen printing accounts for the mainstream of volatile dry inks in terms of output and variety. However, the output of UV inks has increased year by year, and the increase is large. The output exceeds the volatile dry screen printing ink, which is only a matter of time. Due to the increase in the types of oligomers, prepolymers, and polymerization initiators in UV screen printing inks, UV screen printing inks are more widely applicable and can be used for screen printing of various substrates. The occupancy rate is bound to increase.
1. Screen printing ink (UV ink) is suitable for various printing materials. Paper, coated paper, wood products, synthetic paper, polyvinyl chloride (PVC (4565, -60.00, -1.30%)) 1 propylene (PMMA), acrylonitrile-butene-styrene terpolymer, acrylonitrile - Styrene copolymer, styrene (PS), ABS, polycarbonate (PC), polyester (PET), polyurethane, treated polyethylene, treated polypropylene, plastic (7860, -190.00 , -2.36%) Coating surface, polyethylene plastic (PE), wood product coating surface, coated metal plate, glass (883, 11.00, 1.26%) ceramic, thermosetting resin.
2. Screen printing ink (UV ink) has strong functional performance. Screen printing inks (UV inks) are suitable for the high quality, diversification and special-shaped products that require special processing.
1) physical: liquid crystal display screen, resistive soldering; electrical insulation, electrical, electric field, magnetic, etc.; thermal temperature foaming, temperature, pearl, fluorescence, night crystal, thermal transfer and so on.
2) chemical, medicinal corrosion, ethanol stripping, etc.; biochemical antibacterial, anti-fouling, etc.; absorption, adsorption, reaction, water repellency, oxidative corrosion.
3) surface decoration: crystal glue, metal etching, matt wrinkles, non-glare, mirror metal, etc.; three-dimensional, thick film printing, Braille, crystal pattern, wrinkles, broken graphics, coral patterns.
Second, the trend of water-based printing ink market
Among the volatile dry printing inks, water-based printing inks developed in the 1980s have received much attention due to their environmental friendliness. At the beginning of the development of water-based printing inks, they were once noticed, but they were not popular because of the poor water demand of the stencils and the wrinkling caused by the paper absorbing water when printing on paper. After entering the 1990s, the above problems were gradually resolved. With the advent of new water-based printing inks using urethane emulsions, the variety has also increased.
Objectively, because the function, use, price, equipment and supply of (water-based printing ink) are superior to screen printing inks (UV inks), traditional printing inks will gradually disappear in the screen printing ink market in the future. Replaced by water-based inks and UV inks, and finally water-based inks completely occupy the market. Commercialized water-based inks have been consistent with the principles of simplicity, practicality and economy. The three shortcomings that existed before have now been overcome.
1. Drying problems of screen printing water-based inks.
The biggest disadvantage of aqueous printing inks is that they are slower than solvent. In theory, the evaporation energy of water is 4-5 times larger than that of oil. How to improve the drying property is a comprehensive problem. After years of research, the composition of water-based printing inks has been completely improved. 1 First, the water content of the past aqueous printing ink was reduced from 70% to 30%. 2 is to superfine the aqueous printing ink, so that the water-based ink which can only be printed by 150 mesh screen can be printed by 300 mesh screen. In this way, the printing film is thinned and the drying is accelerated. 3 is to reduce the viscosity of the aqueous printing ink without impeding the printing effect, reduce the surface tension, and promote the capillary phenomenon to improve the effects of evaporation drying and osmotic drying. 4 is the most important, there must be a high-performance infrared dryer. Because infrared light is radiation energy, it has penetrating power, can directly interact with the molecules in the ink, and simultaneously heats inside and outside, promotes instant drying. Now it uses water printing ink for color printing, instant drying between color and color, 150 °C Just 5s. This drying speed is almost as fast as screen printing inks (UV inks).
2. The problem of the subsequent printing of water-based printing ink
Past water-based printing inks for water-absorbing objects (porous objects) such as cloth (cotton, hemp, wool, enamel, polyester, nylon and blended fabrics), paper (paper, cardboard), wood (wood, wood, plywood) Leather (leather, artificial leather) and the like are good, but the substrate with a hard surface is then difficult. Nowadays, because the fixing agent for water-based printing inks is made of acrylic, polyester and polyester, it has a omni-directional function for non-absorbent substrates, substrates with smooth and hard surfaces, and objects that have been difficult in the past. Excellent adhesion. Such as water cloth, synthetic paper, thick canvas, rigid PVC, PVC, stickers, PVC cloth, artificial leather, acrylic, ABS, AS, PET, PS, glass, hard aluminum foil, stainless steel and so on.
3. The problem of full water-based printing ink Although the past water-based printing inks have been aqueous, most of them have been added with 10% to 15% of the solvent in order to improve the softness, vividness and prevention of bleeding of the printing ink. Nowadays, water-based printing inks have overcome the above problems and are all water-based printing inks. The development of water-based printing inks has become a hot topic for screen printing companies. Because the country has regulations on environmental protection, screen printing practitioners have awakened themselves and have refused to use solvent-based printing inks for their own health. Neighbors of the screen printing factory will call the environmental protection part as long as there is a little smell; for orders received from export traders such as toys, garments, furniture, curtains, etc., it is often stated that non-toxic printing ink processing is required; When you are wearing a shirt, you also learn to touch it with your hands. If you print with water-based printing ink, you should also ask if the customer is printing for water-based printing ink. Another reason is that the prepress of the screen printing has been processed by the computer. From design, text, pattern, combination to four-color film output, special items can be delivered in one hour, screen plate (four-color version) pick-up on the same day, high-performance four-color screen printing machine, high-efficiency infrared instant dryer Supply, creating conditions for the use of water-based printing inks.