Threebond launches light curing instant adhesives

Edited by the Engineeringtalk editorial team Nov 25, 2008

Threebond has announced the launch of the 1770 series of light curing instant adhesives, which includes the 1771E, the 1773E and the 1776E.

The company said light curing accelerates the final cure time to approximately 10 seconds (can be up to 24 hours for full cure without light activation) and also deals with issues such as bleaching/blooming and slow curing excess.

It also aids curing in wide gaps, and by using both moisture and light cure ensures a quick, thorough cure where light cure alone would be affected by obscuring non-transparent material.

Threebond said the 1770 series is ideal for electronics and wider industrial assemblies including optics, medical, electromechanical assembly, ornamental products, angling accessories, toys, musical instruments, sporting equipment, jewellery and woodwork.

These are all areas where non-jig placement, followed by quick and complete cure are major production benefits.

For example, advancing component miniaturisation has resulted in single components having extremely fine structures, such that conventional irradiation with sufficient light may often cause problems.

In these cases, the use of an instant adhesive that combines both light and moisture curing is an effective way of providing reliable curing and bonding.

With this increasing miniaturisation, printed circuit boards also use less solder.

But since bonding strength must be maintained, light curing instant adhesives can be used to reinforce solder.

Similarly, for metal-plated plastic components, conventional light curing or anaerobic resins sometimes fail to bond.

In these cases, light curing instant adhesives are often used, due to their bonding capabilities for an even broader range of materials.

The 1770 series adhesives are traditional cyanoacrylates with the benefit of photo-anion-polymerisation to enable curing by ultraviolet or visible light.

This ensures a tack-free surface on curing.

In the case of medical components such as hypodermic needles and syringes, completely reliable bonding and curing is critical in their assembly - light curing instant adhesives help to achieve these high standards.

They are also used for assembly of Braille characters and graphics where other adhesives may suffer incomplete curing of excess material due to oxygen inhibition - such that touching incompletely cured portions may result in skin irritation.

Light curing instant adhesives are not affected by curing inhibition with oxygen and so eliminate the problem.

The benefits of this dual-cure system extend to its substrate suitability, where, for example, non-polar or highly crystalline resins, generally regarded as difficult to bond, can bond strongly.

Instant adhesives generally function also as reactive 'solvents' capable of dissolving the surfaces of certain plastic materials, including acrylic, polycarbonate and ABS.

However, the setting times for acrylic and polycarbonate are known to be relatively slow.

This is due to the mutual solution of instant adhesive and the plastic in the bonding area.

Since they cure instantly, light curing instant adhesives can prevent the dissolution of plastic surfaces in such cases.