New Zealand tech turns pine into hardwood

Accoya - which uses a kind of natural alchemy to turn pine into sustainable hardwood - has humble origins in New Zealand.

Accoya treated pine is a sustainable alternative to hardwood. Photo / Supplied
Accoya treated pine is a sustainable alternative to hardwood. Photo / Supplied

Element Advertising Promotion: Accoya Wood, which uses New Zealand-grown, FSC-certified pine trees and technological know-how developed in our very own Scion research plant in Rotorua, is changing the future of timber.

British company Accsys Technology, which manufactures Accoya, is using a kind of natural alchemy called 'acetylation' to turn fast-growing, sustainably-managed softwoods like pinus radiata (pine) into wood with the properties of slow-growing, tropical hardwoods without the accompanying deforestation and habitat loss.

The proprietary revolutionary acetylation process essentially pickles the wood in vinegar (acetic anhydride). Water-loving hydroxyl compounds are sucked out and replaced with naturally occurring acetyl groups.

This makes the timber three times more stable than conventional timber and long lasting - the product claims the top durability rating of class-1 and the Timber Research and Development Association in the UK states that Accoya will have a minimal service life of 70 years above ground.

It has many uses, but, because it won't warp or crack, it is ideal for doors, windows, weatherboards and decking.

The process contrasts with that of conventional timbers - slathered in copper chromium and arsenic (CCA), a rot-preventing pesticide chock-full of heavy metals.

The use of CCA-treated timber has been restricted in Australia since 2005 and in 2003 the United States banned its usage in residential builds. CCA can be inhaled when treated timber is burnt.

Chris Wiffen, joint managing director of Timspec, who are the official distributors of Accoya in New Zealand, says the product's popularity is ramping up despite the upfront cost being up to three times more than conventional timbers.

In Europe, sales shot up by 80 per cent to €13.9m in the first half of the year, compared with the same period a year ago. In New Zealand, they have increased by over 50 per cent.

"The renewable nature, durability and stability of Accoya have huge benefits in multiple product sectors. The cost over the life of the structure is often cheaper when using Accoya, because it outperforms cedar, teak and many other treated softwoods and hardwoods," he says.

The pine opportunity

Given that the acetylation process works best with New Zealand-grown pine, New Zealand processing companies such as Tenon, which supplies a large proportion of pine to Accsys Technologies, are well placed to reap the benefits.

Wood is cut into lumber and then kiln-dried using renewable, geothermal energy and supplied as sawn timber, rather than logs, which adds value.

Tenon technical development manager Wayne Miller says that as demand grows for Accoya, both here and overseas, more opportunities for the country will be created - including the possibility of establishing an acetylation plant right here on New Zealand soil.

Chris Wiffen (left) and Rex Holmes, joint managing directors at Timspec, by the boardwalk made with Accoya timber at La Rosa Reserve in Green Bay. Photo / Supplied
Chris Wiffen (left) and Rex Holmes, joint managing directors at Timspec, by the boardwalk made with Accoya timber at La Rosa Reserve in Green Bay. Photo / Supplied

Closing the Accoya loop

Accoya Wood is the only wood product to have earned the top eco-certification, Cradle to Cradle Gold. This rigorous accreditation assesses a product's lifecycle while examining its impacts on environmental and human health, and evaluating its recyclability.

The eco-ethos is also present in Accoya's factory in the Netherlands. Here, the low-energy acetylation process has been streamlined so the main by-product (acetic acid) can be returned to chemical companies and reused. Eventually, the factory aims to transform acetic acid into acetic anhydride onsite, creating a system with no waste.

Accoya holds several other eco-distinctions including the prestigious Green Label of the Singapore Environment Council, which awards environmentally friendly products sold in South East Asia, and was deemed 'excellent' by green building materials portal The Futurebuild.

Additionally, it boasts a low carbon footprint (it is shipped to the Netherlands, has a low weight and a long lifespan, and Accoya window frames have been independently proven to be carbon negative) and meets Japanese food safety testing standards.

Accoya projects

Given its long lifespan and low maintenance requirements, Accoya was used instead of concrete and steel to build a four-lane traffic bridge in the Netherlands in 2008. The 30-metre-long, 12-metre-wide structure can support a load of 60 tonnes and was so successful that another bridge was promptly built upon completion. Tenon won the contract to supply 1200 cubic metres of lumber (around $1m worth of radiata pine) for both projects.

Accoya has also been used in Auckland Council's new boardwalk at La Rosa reserve and in a decking project at the University of Waikato, with both companies selecting Accoya for its longevity and environmentally friendly ethos.

For more information about Accoya, visit accoya.com or timspec.co.nz. For weekly Element news sign up to our newsletter. We're also on Facebook and Twitter.

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