UV ink characteristics and quality difference analysis (2)

Third, UV ink and traditional ink contrast <br> Advantages

â—† Most UV products do not require the use of solvents, 100% solids;

â—† Improve printing quality: through the composition of high-density cross-linked polymer, the resulting structure has a high degree of toughness, stain resistance, anti-wear and anti-solvent properties;

â—† Offset does not need to spray powder; printed paper can be processed immediately;

â—† UV ink has a good thixotropy, can be high-precision printing of high-line printing lines;

â—† UV ink can print ice, refraction, matte, Zou and other special effects under certain printing conditions;

Shortcomings

â—† UV ink prices higher than traditional ink products;

â—† It is not completely odorless. After curing, it will leave a certain taste;

â—† need to consume more energy;

â—† UV products have a certain degree of danger. Most UV products have no irritation to the skin before drying. Skin gloves and eye protection goggles should be worn during operation to reduce hazards.

â—† The printing process is harder to master than the traditional printing process, and the adaptability to the substrate is not as good as that of the solvent-based ink;

â—† poor adhesion, to increase adhesion must be preceded by a layer of UV primer;

Figure 3 UV offset printing drying device schematic

â—† Strong ultraviolet radiation will cause 3 oxygen molecules to become 2 ozone molecules, and exhaust pipes will be required to remove ozone from the work area.

â—† After the UV ink is printed on the paper, the ink is not well removed and the recovery of waste paper is affected.

Fourth, UV ink types and printing process characteristics

At present, many special effects in printing require the use of UV inks. They are widely used in printing methods such as lithographic printing, flexographic printing, screen printing, gravure transfer printing and even computer inkjet printing. The commonly used UV inks include: UV plastic ink, UV metal ink, and UV. Matte ink, UV fragrance ink, UV ice ink, UV foam ink, UV crystal ink, UV expansion ink, UV transparent ink, UV disc ink, UV refraction ink, UV three-dimensional raster ink, UV wrinkle ink, UV scratch ink, UV Flexible inks, UV reflective inks, UV printed circuit board inks, and more. The UV ink printing process differs from conventional printing in that its main features are as follows:

offset printing

The PS plates, rubber rollers, and rubber blankets used in UV offset printing are different from normal offset printing. The printing unit must be equipped with a complete set of UV ink drying equipment, usually including UV drying device, electric cabinet, water cooling device, exhaust device; UV ink because of its strong corrosive, very high requirements on the rubber roller, ink roller must choose the printing machine must Adaptation with UV ink; can not always change the use of UV inks and general oily inks, if you need to change must be cleaned; UV ink ink balance tolerance is very narrow, easy to cause ink emulsification in the printing, easy to dirty version, affect the stability of the printing quality Sex; UV inks have high viscosity after printing, lack of leveling, and the phenomenon of ink film surface roughness; printing speed can not be too fast, controlled at 5000 ~ 8000 printing / hour; four color UV ink drying difficulty is different from the general The order of UV color printing is black, cyan, yellow, and magenta.

Flexo-printed UV flexo inks require lower viscosity than offset printing inks. UV flexo inks have a slightly higher viscosity than water-based inks or solvent-based flexographic inks. To prevent penetration when the substrate is a paper or other permeable substrate. The countermeasures for applying the primer are often taken; when using a UV flexo ink, the screen angle of the anilox roller is preferably 30° or 60°; the roller must be resistant to UV ink; the plate is preferably UV ink resistant The media.