Heat treatment furnishes designers with opportunity

By PAM GRAHAM

Forget genetic modification. The latest thing in wood is thermal modification.

The idea, originally from Europe, has been applied to New Zealand conditions by Carter Holt Harvey's ideas factory, Fibre-gen, and turned into furniture by a three-man design company, Locusresearch of Tauranga.

The heat treatment means there is no need for chemicals.


Pine is baked at high temperatures in an oxygen-free kiln to reduce its water content. This makes the wood resist water and decay-causing fungi, and darkens its colour.

"Our focus is on sustainable product development, and for us it is a major improvement to have something that does not have chemicals pumped through it, or is not a tropical hardwood," said Timothy Allan of Locusresearch.

"It's a more intelligent way to do it.

"Instead of treating the symptom by putting in chemicals, they are preventing the moisture from getting in there."

The graduate of Wellington Polytechnic's design school is passionate about the company he started in 2002 - and about what can be achieved when designers and manufacturers work together with new technology and sustainably managed materials.

"Very few countries are like New Zealand with sustainable, well-managed plantation forests," he said.

With the right design, technology and product development formula, wood from those forests could fetch $6000 per cubic metre instead of $100 per cubic metre as a log.

In this case, his company has taken the waterproof property of the thermally modified wood and designed furniture that can be transferred freely between indoor and outdoor areas.


Examples, made by Waihi-based Elliott Furniture, are on display at the Eon Design Centre in Freemans Bay until July 11.

The exhibition also features items made from Green Seal-brand wood, which is hardened by injecting cellulose material into wood cells.

The "pouring of wood into wood" to strengthen it was featured at the Metaform 03 exhibition last year.

The concept of thermally modified timber originated in Finland and is so new in this market that it does not yet have a brand name.

Fibre-gen chief executive Mark Smith said Carter Holt was talking to other end users, some of whom were international, about the product.

The wood was suitable for joinery because it was stable and did not warp in humid conditions.

"The Europeans are telling us that radiata pine is a very good species for this technology," he said.

The applications are part of an industry-wide search for ways to add value to the output from New Zealand's pine plantation estates.

Other examples are Tenon's Taupo Clearwood - pine sawn and glued to present a straight grain.