Zero-added formaldehyde (ZAF) for safer construction and healthier buildings

Norbord is the world’s largest manufacturer of OSB and has recently invested £95m in a new plant in Inverness, Scotland. A new family of products is a development of the most popular OSB brand in the building and interior design arena and comprises SterlingOSB Zero 3, SterlingOSB Zero Tongue and Groove, SterlingOSB Zero SiteCoat, SterlingOSB Zero Fire Solutions and SterlingOSB Zero StrongFix. It is a precision-engineered OSB3 board for structural use in load-bearing and challenging conditions; as well as being hugely popular in the aesthetics-led interior design industry. BBA approved and designed for humid, wet conditions, it now contains zero added formaldehyde and so is unique in the market.

Unlike traditional oriented strand board (OSB) containing urea-formaldehyde (UF) or melamine-urea-formaldehyde (MUF) binders, the new SterlingOSB Zero family from Norbord uses a methylene diphenyl diisocyanate (poly-urethane MDI) resin to bind the thousands of strands that make up each board. Formaldehyde is a known carcinogen that can pose a health risk, especially when the board is being sawn, drilled or sanded.

As well as being healthier, a ZAF board offers superior performance compared to conventional low-emission boards made with UF or MUF. The MDI binder has better mechanical properties including a stronger internal bond and a lower modulus of rupture than UF/MUF boards. A ZAF board is more moisture resistant (subject to less swelling in humid environments such as kitchens and bathrooms) and is stiffer and less prone to ‘creep’. The pMDI resin in a ZAF board is suitable for hot and humid climates, unlike boards containing UF or MUF resins. Boards made with pMDI binders also contain less resin – and hence more wood – than traditional boards, meaning they are ‘greener’.

SterlingOSB Zero is even more environmentally-friendly to produce. The pMDI binder cures at a lower temperature than UF/MUF resins so less heat energy is consumed during manufacture. It is also safer to produce since pMDI resin uses water as a catalyst in the curing process; UF/MUF resins need the addition of ammonium nitrate – an explosive chemical – to harden.

Like all Norbord OSB products, SterlingOSB Zero is made from forest thinnings taken from sustainably managed forests. All of Norbord’s production sites in Europe are able to produce wood-based materials that are certified according to the guidelines of the FSC or PEFC.

For further information on Norbord, please call 01786 812 921 or visit www.norbord.co.uk.