Efficient curing of adhesives using laser light

Summary form only given. Within the last years, ultra-violet radiation is being increasingly used for the initiation of polymerisation reactions, mainly because of the high efficiency and the high curing velocity of this type of initiation. Light curing provides a number of economic advantages over the operations usually used: rapid through-cure, low energy requirements, room temperature treatment and non-polluting and solvent-free formulations. The field of applications for this technique is restricted mostly to surface treatment processes, because the penetration of UV light into organic materials is limited. For faster cure rates, lasers should be a light source that provides a quasi-instantaneous polymerisation, and allows operation at extremely high speeds. Laser-initiated radical and cation production offers several remarkable advantages in comparison to conventional UV initiation, resulting mainly from the large power output available, the narrow bandwidth of the emission and the spatial coherence of the laser beam, which can be finely focused visible laser radiation results in rapid curing of thick sections of polymers.