This label die cutting machine or label die cutter adopts flat bed high accurate die cutting, label feeding and sheeting controlled by touch screen micro-computer, the two sides of printed mark and longitudinal tracked by three photoelectric eyes. Die cutting rewind waste edge side paper, sheeting can finish at one time. It is suitable for die cutting paper label, film label and holographic label etc. This machine is necessary auxiliary label die cutting machine for the flexo printing machine or continuous screen printing machine.
Most of the light sources of UV or UV/EB flexo ink drying systems are medium-pressure mercury lamps. The following five problems should be noted during actual use:
1. Heating management of the drying system. Although the drying and curing principle of UV or UV/EB flexo inks is to use UV (ultraviolet) light or EB (electron beam) to illuminate the ink for instant drying and curing, UV light occupies only 20% of the light energy emitted by mercury lamps. %. IR (infrared) light accounts for 60%, and visible light accounts for 20%. Therefore, the energy generated by the IR fiber must be removed because the mercury lamp can produce 800 degrees of high temperature under illumination.
Both photo initiators and pigments in UV inks absorb the energy of UV light. Studies have shown that different pigments in inks have different ability to absorb UV light. Milky yellow and magenta flexo pigments can be cured by absorbing a small amount of UV light, so their drying performance is good; while cyan and black flexo pigments absorb more. UV light can be dried and cured to save energy.
In addition, avoid UV light with UV and UV/EB flexo inks. Since the UV flexo ink is UV-illuminated, the remaining (under-reacted) photo initiator continues to react for 6-24 hours, the so-called post-polymerization. If the light is excessive at the beginning, the UV ink film will become harder and harder until it is brittle, and it should not be processed at the same time as the quality of the printed product.
2. Keep the drying system clean. Foreign practice has proved that the flexo printing process using UV flexo inks requires strict working environment. If the working environment is in poor condition and the special working space has a low plot, the better drying device will not achieve satisfactory drying effect.
3. Replace the UV lamp in time. The service life of the UV lamp should be used according to the rated life specified by the manufacturer. When it exceeds its rated life of 1000-2000 hours, the lamp should be replaced even if the lamp still emits light, because the ability of the UV lamp to emit a UV lamp is far from satisfactory.
4. The reflected light unit must be kept clean and the mirror should be highly polished to improve reflection. Therefore, keeping the reflector clean is a prerequisite for ensuring reflection.
5. When using UV flexo inks, you must pay attention to radiation protection. UV radiation is harmful to the human body. In fact, the UV light energy is relatively small, and a UV or the like can be appropriately closed or covered with a thin film of lead material or the like.