Characteristics And Application Of Water - Based Ink

The biggest feature of water-based ink is to reduce the emission of organic volatiles (voc) into the atmosphere, thereby preventing air pollution, improving the printing environment, and greatly reducing the risk of fire. It can completely eliminate some toxic substances in solvent-based ink to the human body and packaging goods pollution, improve the overall environmental quality. Especially suitable for food, medicine and other hygiene requirements of strict packaging and printing products.

At present, the main applications of water-based ink are flexible printing and gravure printing. According to the data, 95% of the narrow flexographic paper prints in the United States are printed with water-based ink, 80% of gravure paper prints are printed with water-based ink. In recent years, our country is developing rapidly, but there is still a big gap between its application and foreign countries.

Whether the application system of water-based ink can be appropriate is an important economic factor affecting the quality of its printing products. The control index of water-based ink mainly includes fineness, viscosity, drying speed and PH value.

In flexographic printing, the transfer of water-based ink and the control of ink volume is undertaken by the aniline roll, so the fineness of the aniline roll must be selected according to the product conditions. In field printing, about 300 lines of aniline roll are generally selected, and the ink layer is thicker, but 600 lines of aniline roll need to be selected for 150 lines of fine layer printing. The number of aniline rolls is generally 4 times the number of printing lines. For better printing clarity and resolution.

Viscosity is the most important control index in the application of water-based ink, it is a kind of performance to prevent fluid flow. Because viscosity directly affects the transfer of ink and printing quality, so the control of ink viscosity is very important. In the printing process, the viscosity of water-based ink is too low will cause color, dot increase, uneven ink and other problems; On the other hand, if the viscosity of water-based ink is too high, the transfer performance of ink will be poor, easy to produce problems such as stain plate.

Flexible version of water-based ink generally do not use dilution directly, viscosity can be in 30 "-45" \\u002F25℃ range (coated with 4 # cup). The viscosity of flexographic waterborne ink for cartons can be lower. As long as the water stabilizer is added regularly, the viscosity can be controlled basically. Gravure water-based ink according to the traditional custom usually with ethanol and water 1:1 diluent dilution, its viscosity is generally controlled at 15 "-25" \\u002F25℃.

Water-based ink technology is usually alkaline (mainly by amine substances to maintain), the PH value of general water-based ink should be controlled between 8.0-9.5 is appropriate, if the use of water-based ink PH value is too high, will affect the drying speed of Chinese ink; If the PH value is too low, the viscosity of the ink gradually increases, the drying speed of development is getting faster, easy to cause a variety of printing plates and roller blockage, causing the page dirty.