How an innovative resin solution solved an LED lens issue

Jon Lawson


In a recent project, a well-known manufacturer of electro-chemicals was tasked with providing an innovative solution for a complex LED assembly issue. The customer, a leading manufacturer of street lighting and high-bay luminaires in India, had been experiencing problems with the attachment of individual lenses to the elements of multiple LED arrays. The function of these lenses is to scatter or focus light from the arrays, as required, and while some of them are held in position by fasteners, most are secured in place with a locking mechanism. The locking mechanism is perfectly adequate when the luminaire is placed in situ but it tends to loosen during transportation, leading to the lenses becoming detached and causing damage to the array.

The use of cyanoacrylate adhesives was considered as an alternative means of attaching the lenses but this solution was rejected on the grounds that this caused fumes during application process, which posed a health hazard to the workforce. The customer then decided to try a clear adhesive that it had been using in other areas of production, but this took too long to cure, ultimately delaying its tight production schedule.

A fast curing, clear adhesive was deemed the only solution and, aware of Electrolube’s reputation for solving seemingly intractable manufacturing problems for electronics manufacturing clients, the customer approached Electrolube India, confident that it would be able to suggest a suitable product.

Following an assessment of the customer’s needs, which specified manual mixing and dispensing, Electrolube India’s technical team decided that Electrolube’s UR5634 polyurethane resin would more than meet the requirements of this application, particularly as it offered an exceptionally fast cure time when mixed and had the required stable optical clarity so vital for LED applications.

Semi-rigid resin

UR5634 is a two-part, semi-rigid aliphatic polyurethane resin specifically formulated to be optically clear, ensuring its ultimate suitability for LED encapsulation and potting applications. It is clear and transparent, which makes it the resin of choice for both aesthetically decorative LED luminaires and those that must have effective protection against adverse environmental conditions.

When used as a potting medium or encapsulant, UR5634 performs reliably in all weather conditions and offers good acid and alkali resistance. Since the resin is an aliphatic polymer, it is strongly resistant to yellowing when exposed to UV light, making it especially useful as an outdoor LED encapsulant or for use in other applications where it may be exposed to direct sunlight.

Offering a fully bespoke solution for its customer, Electrolube delivered the UR5634 resin in 50ml twin cartridges for easy mixing and fast cure, along with a suitable dispensing gun for ease of handling. The solution also provides complete flexibility for the customer should they wish to embark upon future design changes.

Julia Vorley is with Electrolube.


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