Scientists urge farmers to grow wood substitute

The fibres of kenaf, a plant native to east-central Africa, can be used to replace those of wood, with the intention of reducing the demand for fibres harvested from trees. However, says Professor Poo Chow, a wood engineer at the university, what is needed now is demand from industry for the product, though that could soon change in a country were each inhabitant uses 700 pounds of paper a year, and where the paper industry produces more than 200,000 tonnes of paper and paperboard per day.

Chow is currently researching the viability of using varying blends of both virgin and recycled plastic, combined with kenaf, cornstalks or corncobs, and of just using kenaf on its own. Though corn is a primary crop in Illinois, and would have further value added to it with this new use, the virtues of kenaf are as yet virtually unknown.

“Growing kenaf lets you produce a fibre similar to that made from wood, but you can do it in 150 days,” said Professor Poo Chow, of the University of Illinois at Urbana Champaign. “Compare that with the time it takes to plant and grow a tree to maturity. We know how to grow kenaf in Illinois. You don’t have to buy new equipment, just modify existing machinery.”

Kenaf grows up to 10-15 feet high, into a forest of narrow poles and leaf-coloured branches, says Chow, with yields per acre on a test plot in Southern Illinois as high as seven tonnes of dry fibre.

Chow has used an injection-moulding process with a blend of 40% cornstalk and 60% polypropylene plastic, which produced a wood-like product of a quality similar to pile and demolition wood.