Product Details
Water based black ink is a black ink made with water as solvent. With the enhancement of environmental protection awareness and the development of new varieties of water based resin, water based ink has become the most promising ink variety because of its unique advantages. water based ink which is eco-friendly have entered the mature stage and transition to the recession stage, while water based inks are in the growth stage, with rapid development and increasingly perfect variety and quality. It is very likely to completely replace other inks and occupy the printing market.
Many solvent inks used for packaging, newspaper and magazine printing use aromatic compounds such as benzene, toluene and xylene as solvents. After the solvent volatilizes, it not only pollutes the air, but also is a carcinogen. There are usually two options to reduce the pollution of solvent ink: one is to install a solvent recovery device to recover the volatile benzene solvents or adopt a microbial or bacterial treatment system that feeds on VOC; The other is to replace aromatic solvents with solvents with low toxicity and low pollution. With the further improvement of environmental protection requirements, the development and application of water based ink comply with this development requirement. In recent years, with the relevant cooperation in raw material production, ink manufacturing, paper manufacturing, printer design, drying and printing equipment manufacturing, it is possible to prepare high-performance water-based black ink, the quality is continuously improved, and it is more and more widely used.
Preparation Technology of water-based black ink
After weighing the carbon black, connecting material, water and additives according to the quantity, put them into the mixing barrel in a certain order for mixing. The mixing speed starts to be low to prevent the pigment toner from flying. After mixing for 20 minutes, stir at high speed for 10 minutes to open the carbon black lump.
Pass the above and dispersed water based ink into a horizontal sand mill for grinding. When the fineness of carbon black meets the requirements, stop grinding to become water based ink.
Performance
Ink viscosity: 50-105mpa · s (25 ℃ rotary viscometer);
Initial dryness: 10-20mm / 15s (25 ℃);
Dryness: no more than 160S / 100 μ m (25℃)。
Application
The aqueous black ink prepared by the above method is suitable for flexo and gravure printing. This water based ink has good printing adaptability, wet friction resistance, high gloss and good adhesion. It can be used for printing on different kinds of paper and plastic films, such as publishing paper, packaging paper, corrugated paper and other substrates. It is also suitable for high-speed printing. The application of water based black ink can reduce air pollution . Therefore, it is of great significance to vigorously develop and promote water based ink.
Characteristics of printing conditions and application methods of water based black ink
The printability of water based black ink is affected by objective conditions such as printing conditions, substrate surface characteristics, ambient temperature and humidity, storage time and so on. Therefore, some additives need to be used to slightly adjust the ink to obtain good printing effect. Additives commonly used in waterborne black ink include pigment, pH stabilizer, slow drying agent, defoamer, diluent, etc. it is necessary to be familiar with the characteristics and application methods of additives in printing.
1. Pigment is used to deepen the color, and its dosage should generally be controlled at 0 ~ 30%. If it exceeds 30%, the content of binder in ink will be too low, resulting in a stable decline in adhesion and performance.
2. PH stabilizer is used to adjust and control the pH value of water based black ink to stabilize it at 8.0 ~ 9.5 and protect the printing state of water based black ink. At the same time, it can also adjust the viscosity of water based black ink and dilute the ink.
3. Slow drying agent is used to reduce the drying degree of water based ink. Slow drying agent can prevent and slow down the drying speed of water based ink, prevent the ink from drying on the printing plate, and reduce the occurrence of printing faults such as blocking and pasting. The amount of slow drying agent should generally be controlled at 0 ~ 10% of the total ink. If the amount is too much and the ink is not dried thoroughly, the printed matter will stick dirty or produce peculiar smell.
4. Aqueous black ink diluent is mainly used to reduce the color scale, and the dosage is unlimited. However, adding a large amount of diluent may lead to a slight increase in ink viscosity. At this time, a small amount of diluent can be added at the same time for adjustment.
5. Dilution is mainly used to reduce the viscosity of ink. The dosage should be controlled within 3%, so as not to reduce the color scale of ink and keep the pH value of ink unchanged. Diluent shall be added slowly while stirring to prevent low viscosity. If more diluent is added or diluted with tap water with high hardness, bubbles will be generated. Defoamer should be added at this time.
6. The main reason for the foaming problem in the use of water based black ink is that it uses water as a diluent. When the emulsion is polymerized, a certain amount of emulsifier is needed to make the surface tension of the emulsion system drop.
With the continuous development of the times, people have more and more demand for printing products. The first thing to print products is the design and the samples of printed products. Of course, the most important thing is the regularity of the printing manufacturer and the quality of the printed products. Only with the dual guarantee, the printed products will be recognized by customers. For a formal printing manufacturer, the most important thing is to have experienced printing technicians, And good printing equipment.
People engaged in the printing industry should know that the digital printing process, as one of the important printing processes for the sustainable development of modern major printing manufacturers, occupies an important position in the printing plant. For the printing products printed by digital printing, there are many kinds of water-based black ink in the printing process.
There are four kinds of water-based black ink: dry powder water-based black ink, liquid water-based black ink, solid water-based black ink and electronic ink. Dry powder water-based black ink is mainly made of printing pigment particles, particle electric agent and resin that help charge. The operation principle of the printing ink is that when the negatively charged printing ink powder is adsorbed, an image will be formed in the corresponding, and then transferred to the paper to be printed. Finally, the printing ink toner of the printing paper is heated to fully melt the resin of the toner, and an image will be formed on the printing product.
Surfactant
Only surfactants that can emulsify or wet water-based black ink are selected. The selection can be determined according to the equilibrium value of hydrophilic group and lipophilic group (i.e. h.l.b.). Ink is generally oil in water emulsion, because its printing adaptability is good, storage stable for a long time, so generally choose H.L.B. as 4~6 emulsifier. The commonly used varieties are span (esters synthesized by dehydrated sorbitol and various fatty acids) and tween (adduct of span and ethylene oxide), etc.
Anti pinhole agent
Additives for thin inks and coatings. Sometimes there are many small sunken eye holes on the conjunctiva of printing, called pinholes. Pinholes are easily caused by flexible relief ink, photographic gravure ink, hose roller ink, iron printing inner and outer coatings and finishing oil. Pinhole phenomenon should be treated and overcome according to its causes. For example, as the bubbles enter the ink oil, the bubbles burst during drying to form small holes. The surface tension of thin ink and coating is too large and the wettability is poor, which can not completely wet the pinholes caused by the substrate. Some trioctyl phosphate, tributyl phosphate or silicone oil can be added to reduce the surface tension of the system and better wet the substrate.
Smoothing agent
It is used to increase the smoothness and friction resistance of aqueous black ink conjunctiva, which is conducive to the adhesion and hardness of ink film. Also known as slip enhancer and anti friction agent. Most of these additives are mainly waxes. Containing 1 ~ 3% wax in the ink can significantly improve the smoothness and friction resistance of printing products.
Plasticizer
Additives that can increase the plasticity of polymer materials. It can make the printing film soft and improve the adhesion to the substrate surface.
Preservative
Additives used in water-based inks prone to rancidity.
Spices
It is mainly added to the ink to cover the unpleasant smell of the ink. In some high-level prints, when printing pictures of flowers and fruits, the fragrance of the corresponding flavor type is added to the ink for printing, which can make the shape, color and aroma of the picture similar to the real thing.
http://www.kagemink.com/
Company Profile
