Curing coatings using UV light is an established industrial process – particularly in the wood, plastics, printing, and electronics industries. However, the trend is increasingly shifting away from conventional mercury vapor lamps towards modern excimer lamps. These offer not only ecological advantages but also improved process control and surface quality. In this article, we explain the technical background, application areas, and advantages of excimer-based UV curing.
Technical Basics
Curing with UV radiation without heat input
In UV curing, a liquid coating or coating material is polymerized – i.e., hardened – within seconds by exposure to UV light. Mercury vapor lamps emit broadband UV light, which often results in high thermal stress.
Excimer lamps, on the other hand, produce monochromatic UV radiation with a precisely defined wavelength, typically 172 nm (xenon), without significant IR components – and are therefore cold, but high-energy. This VUV (Vacuum Ultra Violet) radiation causes:
- Photolytic cleavage of molecular bonds
- Initiation of polymerization even without photoinitiators
- Uniform matting or texturing of painted surfaces
- Increased adhesion and surface hardness
Excimer lamps are easy to meter, integrate inline, and reach full power immediately after being switched on – ideal for industrial processes with high cycle times.
Applications
Furniture industry, electronics, printing and plastics technology
Excimer technology is now used in many areas of UV curing, especially as an alternative to classic mercury UV lamps:
Wood and furniture industry:
- Matting of Acrylic and UV lacquers without chemical matting agents
- Improved surface feel for floors, panels, and fronts
Printing industry:
- Curing of inks and lacquers on packaging, labels, or films
- Integration into high-speed offset or flexographic printing lines
Plastics processing:
- UV curing of coatings on profiles, films, or housing components
- Improved scratch resistance and chemical resistance
Electronics manufacturing:
- Curing of insulating or protective lacquers with minimal heat input
- Suitable for temperature-sensitive components
The compact design and low heat generation of excimer lamps make them ideal for temperature-sensitive substrates or complex geometries.
Advantages of excimer technology compared to mercury lamps
Switching to excimer technology offers numerous technical and environmental advantages: Mercury-free: Complies with RoHS and EU regulations for phasing out mercury technologies, making it future-proof. No special disposal required
- Cold operation: No substrate heating – ideal for heat-sensitive materials
- Instant radiation: No preheating time, no standby mode necessary
- Precise control: Monochromatic emission for precisely controllable processes
- Surface optimization: Combination of matting, cleaning, and adhesion improvement
Additionally, the need for photoinitiators is eliminated, which is particularly advantageous for food-related applications and environmentally friendly processes.
Conclusion: Excimer technology for future-proof UV curing
Replacing conventional mercury lamps with excimer lamps is more than just an ecological upgrade. The technology offers a real advancement in the quality, energy efficiency, and process reliability of UV curing processes. For companies focused on sustainability, performance, and regulatory compliance, excimer curing represents a modern and future-proof solution.
Are you looking for a solution for mercury-free UV processes? We can advise you!
Our team at the Radium TECH Application Center supports you in converting your UV curing processes to excimer technology. From system integration to spectrum customization – together we implement innovative, emission-free drying and coating solutions for your production.