Causes and solutions of ozone generation in UV printing

UV printing uses VOC UV ink, and UV ink 100% participates in the curing reaction. Therefore, compared with traditional solvent-based gravure printing, screen printing and ordinary offset printing with aromatic hydrocarbons, it is more in line with the requirements of green environmental protection. However, the UV printing process will produce pungent odors, including some pungent odors on the final printed product. How to eliminate this pungent smell has always been a problem for printing companies.


Ozone is generated during UV printing

UV ink is irradiated by ultraviolet light and uses ultraviolet light of different wavelengths and energies to cure itself. Therefore, ultraviolet light plays a key role in the UV printing process. The wavelength range of ultraviolet light generated by the UV curing device is 200~425mm. Among them, short-wave ultraviolet light below 275mm easily produces ozone when it comes into contact with oxygen in the air, which is a major source of irritating odors. From the perspective of reaction mechanism, short-wave ultraviolet light will decompose oxygen molecules in the air, thereby producing free oxygen. Due to the imbalance of positive and negative electrons carried by free oxygen, it will combine with oxygen molecules to produce ozone. This ozone often cannot be decomposed by itself, and will not only float in the air, but also remain on the surface of the printed matter (the printed matter is adsorbent and will retain some odors).

Ozone at a certain concentration has the effect of disinfection and sterilization, but its pungent smell is annoying. And studies have shown that excessive intake of ozone will not only irritate the human respiratory tract, cause sore throat, chest tightness and cough, cause bronchitis and emphysema, but also cause dizziness, headache, vision loss, memory loss and other neurotoxic symptoms.

How to eliminate ozone

In response to the problem of ozone generated by short-wave ultraviolet light, printing companies can reduce the accumulation of ozone by modifying the air suction and exhaust methods of the equipment or the ventilation facilities in the workshop. However, when the equipment uses a high-power air suction and exhaust device, the UV lamp will not turn on normally due to too low temperature. At this time, ventilation in the workshop is particularly important. The ideal solution is to install an ozone filtering device in the workshop and use a catalyst to chemically react with the ozone in the workshop to convert ozone into oxygen. It not only improves the air quality in the workshop and ensures the health of workshop workers, but also reduces ozone emissions and avoids atmospheric pollution.