Light cure adhesives

The adhesive contains photo-initiators which can absorb light of a specific wavelength and a specific intensity. These photoinitiators are activated by a specific wavelength of light and a specific intensity of light and they form free radicals. The free radicals initiate polymerization of adhesive. After radiation with sufficient light the adhesive is finally polymerized.

Fluorescent performance has been validated over the shelf life of Henkel fluorescent products in the uncured state. While no long term studies have been completed to evaluate fluorescence performance in the cured state, (e.g. months or years), it is known that the ability to fluoresce continues for at least 24 hours after the adhesive has been cured. For most manufacturing processes, this is more than sufficient to allow for part inspection. It is expected that the adhesive will continue to fluoresce beyond this time period.

In general, Henkel products subjected to standard sterilization methods, such as EtO, Gamma Radiation (25 to 50 kiloGrays cumulative), auto-clave show excellent bond strength retention. It is recommended that customers test specific parts after subjecting them to the preferred sterilization method. Consult with Henkel for a product recommendation if your device will see more than 3 sterilization cycles.

The photo-initiators contained in our adhesives are activated by a a specific wavelength of light. We do our best to match that photo-iniator’s peak absorbance to the spectral output of our equipment. The ability of the adhesive to cure at all is based on the compatibility of the light source that the photo-initiator is exposed to and the wavelength that inherently excites the photoinitiator. We also know the capability of our equipment – output intensity and corresponding wavelength, so we can do our best to make recommendations for what settings on our equipment will give you the best bond strength.