Adhesive for motor magnets can be fixed with light

“HT2990 is designed for use in multiple processes, including magnet bonding and magnet stacking in electric motor manufacturing,” according to the company.

This is a dual-cure adhesive: Heat is the main way that it is cured, but accessable parts of its can also be cured in 5 to 10s using light .

“In magnet bonding, light-fixation creates an already-cured outer layer that helps keep everything in place – the adhesive does not seep outside or onto the motor laminations,” said Delo. “In magnet stacking, supplementing heat curing with light fixation lets you forego having to keep magnets under a jig in the oven to reach the desired bond-line thickness.”

Final curing at 150°C takes 30 minutes, or 60 minutes at 130°C – in an oven or via induction heating. Light-based fixing can allow this heat curing to be delayed until a later step in manufacturing.

At room temperature, compression shear strength can reach 70MPa on steel. Glass transition is at 165°C and, at 180°C, tensile shear strength of 7MPa on aluminium is claimed by the company which said: “This is equivalent to 70g/cm² of force, a very secure bond.”

Huntsman (Araldite) recently announced a suite of adhesives for automotive battery construction.