The use of UV inks or UV varnish may cause swelling of the general printing ink roller, blanket, or resin plate. In severe cases, peeling or surface cracking may occur. Therefore, it is very important to select an appropriate UV coating or resin plate and resin plate. important.
Many UV ink suppliers will recommend a standard, such as blankets using nitration or nitration material can be mixed with oily, UV ink or coating oil. The natural rubber and polymer ethane materials do not apply UV inks and coating oils.
EPDM rubber blankets are suitable for UV inks and coatings, but not for general ink-based inks. EPDM blankets cannot use petroleum-derived lotions, and special lotions should be purchased. The principle of choosing the ink roller of the printing machine is also such a principle. It is not always possible to change the UV ink and the general oily ink. If it is necessary to change, all the residual chemicals must be removed.
The UV lamp and intensity are sufficient to completely dry the UV ink or varnish of the print, which must be determined according to the printing speed, ink film thickness, and ink color. The UV lamp must be installed in consideration of the type of printer and the printed product.
BASF uses a suitable "industrial medium-pressure mercury lamp" or "microwave H-bulb" for UV ink and coating oil design. If the first single color is cyan and the ink film thickness (1.20-1.40 g/m2) is printed at a speed of 100 m/min, two 120 W/cm medium-pressure mercury bulbs should be used. If the color density is high and the dark color is printed on one or two superimposed colors, the overall drying difficulty is increased, which is caused by the fact that the UV light is quickly absorbed by the dark ink. In general, the difficulties in drying four-color UV inks are magenta, yellow, cyan, and black. Therefore, the order of UV color printing should be black, cyan, yellow, magenta. The opaque color is also very difficult, it reflects the UV light back. Metallic, gold and silver have the same problem.
An excessively aged lamp cannot dry UV ink or coating oil and cause printing difficulties. The UV lamp must be replaced after 1,000 hours of use. If you feel that the print cannot be dried at the normal printing speed, you must consider replacing the UV lamp so as not to affect the print job.
Without a reflector, approximately 80% of the UV light will not be applied to the print due to diffusion. Therefore, the UV lamp must be fitted with a reflector to focus on the print.
The reflector must be clean and maintained in time to maintain its best function. Some paper dust or dust attached to the reflector will affect the efficacy of the UV lamp reflection. When not using the UV lamp, the UV lamp cover should be closed.