Boxing clever - sustainable wooden packaging

Wood Focus magazine
,
29 Apr 2013

Call it traditional, call it hardheaded, wood can still take some knocking. David Webb of Norbord Europe, headquartered in Scotland, discusses the role of engineered sustainable materials in packaging.

The properties that made wood the obvious choice for our forefathers are still relevant to modern packaging needs. Wood is probably the oldest packaging material still in common use. It is cheap, strong and easy to work, which is why for centuries dry goods have been transported safely in wooden boxes and crates, and wet goods in barrels. Today, we are capable of enhancing wood’s properties to make it tougher, lighter and more durable. A recent example is oriented strand board (OSB).

Without doubt, the most familiar use of wood in modern packaging is for the ubiquitous pallet, a product remarkable for its simplicity and yet indispensable to modern trade. Over the years, new materials have emerged and found a niche in the packaging industry – but not to the detriment of timber’s share. Metals, and in particular steel, are useful for their strength but are heavy and expensive. Plastic is fairly cheap, but the tooling required to create complex moulds is expensive and all too often it can be influenced by fluctuating oil prices. Plastics also lack some of the qualities required for fresh foodstuffs. This is one reason why citrus fruits are still shipped in boxes made from poplar wood and why raw coffee beans are transported in natural sisal sacks.

One of the most compelling reasons to use wood is environmental. Plastics and metals are finite resources and, while most are recyclable, they are not genuinely renewable. They also have significant carbon footprints. In comparison, softwood grown in sustainably managed forests is a renewable resource. New trees are planted as mature ones are harvested and, as they grow, these young trees absorb atmospheric carbon dioxide and store it in their fibres. This CO2 remains locked away long after the tree is felled and its fibre used to make a wood-based panel.

In addition, ensuring that woodbased packaging comes from a sustainable source is now easier thanks to certification schemes such as those operated by the FSC and the PEFC.

After natural sawn timber, one of the most common wood-based packaging products is plywood. Once a cheap material, it must be made from veneers shaved from prime quality large-diameter logs, increasing its cost. Plywood cannot match the consistency of modern alternatives, since it includes imperfections such as knots and splits. For this reason, an increasing number of manufacturers are now choosing OSB instead of plywood. OSB’s lower cost (compared to softwood ply) has, in the past, been misinterpreted as an acknowledgement of poorer quality. But this is far from the case. Its low price is due to it being made out of forest thinnings – small-diameter logs that have few alternative uses.

Instead of using expensive veneer sheets, as plywood does, OSB uses relatively small strands of wood that are layered in specific orientations and bonded together with a resin under high heat and pressure. This structure gives the board multi-directional strength and eliminates weak points in the resulting product. OSB also has excellent impact strength and its construction means it holds screws and other fixings securely, even near the edge of a board.

In Germany, the use of OSB in packaging is increasing, particularly in the automotive industry where its strength and versatility make it suited to transporting high-value components, such as engines. At a time when the packaging industry is frequently the target of criticism over its perceived role in generating waste, the use of low-carbon, recyclable and sustainable materials such as OSB could help reduce its overall environmental impact.