Given the increasing popularity of UV curing adhesives, it is interesting that ThreeBond have recently introduced the 30F-404 one-component adhesive which can be cured by UV and/or visible light between 200 and 400nm.

ThreeBond have noted that there are application factors that favour a visible light-curing adhesive over an exclusive UV cure process. The 30F-404 offers a way of dealing with this, e.g. in situations where the substrate attenuates UV light. Engineering plastics for example intended for outdoor use usually have an ultraviolet-absorbing agent added to prevent deterioration. This makes it difficult to bond such materials by using ultraviolet-curing resin.

Typical applications for the 30F-404 include adhesion and sealing of electrical/electronic components while providing excellent mechanical and chemical resistance – cure is effected within seconds with no VOC emission, offering potential cost savings and greater security/reliability performance. In particular, ThreeBond suggest 30F-404 is suitable for plexiglass/plexiglass bonds, glass bonding, hard coating of keys, fixing of LCD pins, fixing injection needles, balancing of electric motors, fixing of wires, coating PCBs and component encapsulation.

While it is understood that UV light has a higher energy level and so faster cure potential than visible light, it is often found that the longer wavelength of visible light enables deeper penetration and so a cure to a deeper level than just UV light alone. This deep penetration and response to visible light have facilitated modelling applications using visible light lasers for curing.