June 18, 2015 – UV curable adhesives have a lot going for them. As single-component systems, they eliminate the possibility of mixing errors. They’re also easy to dispense, with many bonding and potting products available in syringe dispensers. Conventional UV curable adhesives, however, can also have a dark side—literally.
Because these adhesives need direct exposure to UV light, any section of the bondline or potting cavity that remains in darkness won’t cure. This need for a line-of-sight to the UV light source has ruled out many applications with opaque materials. UV curables have also run into trouble when applied in deep, shadowed cavities or cross sections.
The good news is that advanced UV curable adhesives and potting compounds can sidestep some line-of-sight issues by offering secondary curing mechanisms.
Take our Illumabond 60–7155, for example. This one-component epoxy cures primarily under either a black or high-intensity UV light source, but it also offers:
- Dark cure capabilities for shadowed sections. After an initial exposure to the UV light source, Illumabond 60–7155 will continue to cure in the absence of light. This capability allows the adhesive to be used when potting or joining substrates with shadowed areas.
- Secondary heat cure for underexposed sections. If needed, Illumabond 60–7155 can also undergo a secondary heat cure, which makes it possible to cure sections that haven’t been adequately exposed to the UV light.
- Viscosity optimized for deep sections. With a viscosity of 1,000 cps at 25º C, Illumabond 60–7155 can flow into and cure in sections up to 3/4 inches deep. In these deeper sections, 60–7155’s dark cure capability also comes into play.
Illumabond 60–7155’s other properties include a water clear color as well as good weatherability and resistance to moisture and chemicals. When properly cured, 60–7155 has a rigid, smooth, and glossy surface finish. It bonds to a variety of metal, plastic, paper and ceramic substrates.
Learn more about Illumabond 60–7155’s physical properties and cure requirements here.