From red to clear under UV light 08 July 2024

The latest Master Bond adhesive, UV15RCL, is a low viscosity, cationic type UV curing system suitable for various bonding and sealing applications. Thanks to its special colour changing feature, users have a visual indicator for when the UV light has reached the polymer. 

Originally a red colour, the material changes to clear once exposed to UV light, although Master Bond highlights that this change in colour does not indicate a full cure. By giving immediate visual feedback, UV15RCL offers processing and handling advantages over conventional systems. For bonding and sealing applications, the product adheres well to metals, glass, ceramics and many plastics, including acrylics and polycarbonates.

Curing under UV light typically takes 30 – 60 seconds with a broad spectrum UV lamp emitting light with a wavelength range between 320Nm – 365Nm. The minimum energy required for this curing process is 20 – 40 milliwatts per cm2.   

The adhesive features a high glass transition temperature (Tg) of 90°C to 95°C, however, when post cured for 1 – 2 hours at 125°C, the Tg can increase to 125°C to 130°C. UV15RCL has a service temperature range from -80°F (-62.2°C) to 350°F (176.7°C). This non-solvent based system also cures tack free and has a low viscosity of 115 cps – 350 cps, making this material ideal for spin coating. Additionally, the adhesive is an excellent electrical insulator, with a volume resistivity exceeding 1,014 ohm-cm. 

UV15RCL is available in a wide range of packaging options, including syringes, ½ pint, pint, quart and gallon containers.   

Deputy Editor

Claire Aldridge Deputy Editor t: +44 (0) 1727 743 889


Having spent a decade in the fastener industry experiencing every facet – from steel mills, fastener manufacturers, wholesalers, distributors, as well as machinery builders and plating + coating companies, Claire has developed an in-depth knowledge of all things fasteners.

Alongside visiting numerous companies, exhibitions and conferences around the world, Claire has also interviewed high profile figures – focusing on key topics impacting the sector and making sure readers stay up to date with the latest developments within the industry.