Eliminating Photoinitiators in UV Curing

Presented by Mark VandenBosch, IST America

UV curing of inks, coatings, silicones, and adhesives is an established, fast, and energy-efficient method for crosslinking reactive systems. It is widely used in industrial applications including printing, tapes, wood processing, and industrial surface coating because UV curing enables high production speeds, compact process design, and the development of durable surface properties. Despite these advantages, conventional UV curing depends heavily on photoinitiators and remains sensitive to oxygen inhibition at the coating surface. Oxygen inhibition can reduce cure efficiency, limit line speed, and negatively affect final coating performance. To compensate, processors often rely on inertization with nitrogen and/or increased photoinitiator loading. While effective, these approaches can increase process complexity, cost, and the risk of undesirable side effects such as odor, yellowing, migration concerns, and formulation constraints. At the same time, the industry continues to face pressure related to raw material availability, regulatory scrutiny, and the need for lower-migration and lower-emission curing technologies. These factors have driven interest in curing approaches that can reduce or eliminate reliance on conventional photoinitiator chemistry while maintaining industrially relevant performance. The work described here examines a curing approach based on intensified short-wave UV output designed to enable direct activation of reactive carbon double bonds under ambient conditions. The development goal was to create a practical UV curing route that avoids the need for inertization and does not require additional curing technologies such as excimer or electron beam systems. The resulting platform was evaluated together with formulation strategies intended to support photoinitiator-free or significantly reduced photoinitiator curing in both 100% UV and water-based UV systems.