Photoinitiator Migration Limits in Food Contact Print Finishes
Photoinitiator migration limits demand complete photopolymer conversion or functional containment to keep extractable residues below 10 parts per billion.
UV-LED 395nm
Curing Technology
Monochromatic light source emitting ultraviolet radiation at a wavelength of 395 nanometers provides efficient pinning and curing of specialized inks on paperboard substrates. Utilizing uv-led 395nm technology allows printers to target the specific absorption bands of modern low-migration photoinitiators. This solid-state light source replaces traditional mercury arc lamps, which emit a broad spectrum of light and heat.
It offers a more controlled and sustainable curing process.
Energy Efficiency
The high intensity of the 395nm wavelength ensures deep penetration into thick ink layers, which promotes uniform curing from the surface to the board interface. Unlike mercury lamps, which require warm-up time, LED systems turn on and off instantly. This reduces energy consumption during print runs and minimizes the idle time of the press.
The narrow spectral output also means that less heat is directed at the paperboard.
Substrate Protection
Reducing the heat load during the curing process is particularly beneficial for preserving the moisture content and flatness of paperboard sheets. High temperatures from mercury lamps can cause the board to dry out, which leads to warping and cracking of the crease lines during folding. By using this cool-curing LED technology, converters can maintain the dimensional stability of the paperboard throughout the printing run.
This ensures that the blanks feed smoothly through high-speed folder-gluers and automated filling lines. This improved handling reduces waste and increases the overall efficiency of the packaging production line.