Use UV printing precautions

Ink roller, blanket or resin plate

The use of UV inks or UV coatings may cause general printing ink rollers, blankets, or resin plates to swell. Swelling may result in peeling or surface cracking. Use appropriate or specific UV-specific blankets and resin plates. It is very important.

Many UV ink suppliers will recommend a standard range. For example, a nitrocellulose or nitrified material used in blankets may be compatible with oils, UV inks, or coatings. Natural rubber and polymeric ethane materials are swollen and cannot be applied to UV inks and coating oils.

Rubber blankets made of EPDM are particularly suitable for UV inks and coatings, but may not be suitable for general ink-based inks. EPDM blankets, in particular, cannot use petroleum-derived lotions, and special lotions should be purchased. In the same way, choosing the ink roller of the printing press is based on this principle. It is not always possible to alternately use UV inks and general oil inks. If the ink needs to be changed, it must be cleaned very cleanly to remove any chemicals that may remain.

UV tube

The arrangement of the UV lamps between the units and the working intensity of each setting make the UV ink or varnish of the printed matter fully and properly cured. It depends on the printing speed, the thickness of the ink film, and the color of the ink. In general, only the specialized UV technology suppliers in the printing industry will carefully consider the type of printing press and various finished product requirements for printing, and recommend suitable UV systems.

BEST-UV uses a suitable standard for "Industrial Medium Pressure Mercury Lamps" or "Metal Halide Lamps" for UV printing and coating applications. If the first color (such as cyan), printing standard ink film thickness (1.20-1.40g/m2), speed 100m/min, the use of two 120W/cm medium pressure mercury lamp curing. If we change the color density of the high, dark color printed on 1-2 overlay color, the difficulty of the overall curing is greatly increased, this is because the UV light is quickly absorbed by the pigment of the deep ink. Generally, the difficulty of curing four-color UV inks is magenta, yellow, cyan, and black, so the color sequence in UV color printing should be black, cyan, yellow, and magenta. Some deployment colors/spot colors are also very difficult to cure, such as green in yellow and cyan tones, opaque colors that reflect UV light back, and so on. Similarly, metallic colors such as gold and silver have the same problem.

The precise and stable control of the temperature of the UV lamp at work also has a direct impact that cannot be underestimated. At present, the strong exhaust cooling method is difficult to meet the specific requirements in the face of the application of UV printing high-variation (color, material, speed, etc.). The BEST-UV system uses a water circulation cooling system, combined with air-cooled, strong exhaust, and can ideally achieve various forms of UV curing. And to prevent the lamp, radiator, line overheating and short circuit.

UV lamp quartz tube wall temperature is generally about 800 °C (according to certain changes in power regulation), paper dust, air particles, fingerprints and stains on the lamp once the high temperature work process will become permanent Residues, affect the emission of UV light. Therefore, it is very important to carry out the daily maintenance of the lamp regularly (a soft cloth with a proper amount of anhydrous alcohol for the entire week). Power-attenuating lamps can cause printing problems, so they must be replaced in time to avoid affecting the overall operation.

The limited life of the UV lamp, usually 75% radiation intensity, the output efficiency is reduced, it is difficult to achieve effective curing. The BEST-UV system has a clear indication of lamp usage, status, and whether it needs to be replaced.

Reflector

If no reflector is installed, about 80% of the UV light does not act on the print due to diffusion. Therefore, the UV lamp must be equipped with a reflector and focus on the direction of the printed matter. The importance of the reflector cannot be ignored.

The reflector of the BEST-UV lamp box is cooled by a water circulation system to ensure precise temperature control during operation. The reflector must be cleaned and maintained. Paper dust or powder dust attached to the reflector will affect the efficacy of UV light reflection. Normally, the BEST-UV shade automatically shuts off the light box to prevent dust when UV is not used.

Source: Shanghai Limengde Co., Ltd.