Skateboards made out of harakeke?

Professor Kim Pickering from the School of Engineering at the University of Waikato was the winner of the 2008 KuDo^s Award for Environmental Science, sponsored by Environment Waikato. Kim’s research investigates natural materials like harakeke (flax) that can be used to make composite materials that have less of an environmental impact than traditional structural materials like plastic and rubber.

The background

It's important that we recycle and reuse what we can, so that we have enough natural resources to support the lives of future generations.

Kim Pickering, a materials engineer from the University of Waikato, is looking to natural resources to make composite materials that are sustainable. Kim wants to make materials that have less of an environmental impact than traditional structural materials like plastic and rubber.

For Kim’s research, she uses materials that are environmentally friendly. These materials come from sources that are easily replenished and are recyclable. She uses natural fibres like hemp, wood and harakeke because these fibres are strong, stiff and lightweight. Kim mixes these fibres with plastic to get a sturdy structural material that can be used to make things like furniture, surfboards and skateboards.

The problem

The problem that Kim noticed is that current structural materials like glass fibre, for example, use lots of energy and resources to make and some are not even recyclable. Some plastics that we use are made from oil and it’s not certain how much longer the world’s oil supply will last, so we definitely need sustainable alternatives – and fast!

So Kim’s research sees her working to replace synthetic materials like glass fibre, plastics and rubber with more sustainable materials.

The solution

One approach for Kim has seen her looking at adding the natural fibres to a plastic made from corn gluten meal (a product of corn that is processed for animal feed), and what’s so amazing about this is that the result is completely biodegradable.

Kim says that this new material could be used to make pots for seedlings that can be planted straight into the ground and left to break down, giving nutrients to the roots of the small seedling. This saves having to remove the seedling from the pot, which can damage its roots, and then having to recycle (or just throw away) the plastic pot.

Other areas of work for Kim have seen her using hemp in recyclable plastics instead of glass. Recycled plastics containing hemp or other plant fibres can be used for things like the inside panels of cars or in furniture. This area of work meant that Kim and members of the Waikato Composite Research Group were invited to develop a composite material that used hemp to make the cabin sole (the deck inside the cockpit) of the Earthrace boat.

Research breakthroughs like this mean that we are getting closer to not having to rely on petroleum-based products (like most plastics) as we use natural resources like hemp, wood and harakeke.

So, where to from here for Kim? Amongst other things, she’s attacking the mountains of used rubber tyres filling up landfills worldwide. She’s working with rubber ‘crumb’ (rubber milled down to a size of a few millimetres) to see what plant fibres can be added to natural rubber, because as Kim says ‘There are so many things that have tyres on them. If you could make the material a bit more resilient and hard-wearing, then they’ll last longer and you’ll have less recycling to do in the long run.’

In 2017 Kim was awarded the Scott Medal for her development of composite materials that are more sustainable, read more about this on the Royal Society's website here.

Read Kim’s views on plastic in the article The future of plastics: reusing the bad and encouraging the good.