Light-cure adhesives contain photoinitiators that start polymerization under UV or visible light, commonly around 365 or 405 nm. Cure is near instant and only happens on demand, which suits medical devices, optics, electronics and glass bonding. Light has to reach the bondline, so at least one part must be transparent; secondary heat or moisture cure handles shadowed areas, and oxygen can leave the exposed surface tacky.
Bump the lamp intensity, the UV-cure on the needle hubs is coming out tacky on top.
Also heard as
- light-cure adhesive
- UV adhesive
- LCA
Related terms
Oxygen inhibition
Air at the surface blocking the cure of free-radical adhesives, leaving them sticky where exposed.
Cure
The chemical reaction or physical change that turns a liquid adhesive into a solid that carries load.
Wicking
Describing very thin adhesives that run into already assembled joints by capillary action.
Fixture time
The time until a bond is strong enough to handle or unclamp the assembly without moving the parts.