Our planet’s resources are limited. The Earth cannot keep up with the demands of manufacturing, or bear the impact on the environment. With mega manufacturers keen to reduce costs and environmental impact, our research into alternative natural materials could provide a sustainable solution to reduce resource demand, landfill and emissions.
At our School of Mechanical and Design Engineering, Dr Hom Nath Dhakal is pioneering research in sustainable, lightweight composite materials, using plant fibres. Dr Dhakal is an expert in composite materials and leads our Advanced Polymers and Composites research group.
Composite materials are a mainstay of manufacturing. Usually, they take the form of plastics reinforced by manmade materials such as carbon and glass fibres. This combination (compositing) makes the material stronger than it would be on its own.
Aside from the environmental impact of traditional composites, carbon fibres and glass fibres come from petrochemical products – which means there’ll be no more of them when the world’s oil runs out.
Hom and his team are working on a much more radical, far more natural solution – biocomposites using palm fibres.
The way we are using resources currently, we might need another 3 or 4 Earths to meet our demand. We are sending a message to industries that our graduates are capable of using these tools relating to sustainability, using materials efficiently, using less energy.
Converting agricultural waste into sustainable materials
Date palm trees produce a large quantity of agricultural waste, which is burned or land-filled, causing pollution and damaging important soil micro-organisms. Hom says sustainable materials can be produced by using this waste product – and its production requires less energy than conventional glass and carbon fibres.
Hom explains, ‘We are trying to use materials that are biobased and biodegradable after their useful life. We’re making natural composite products using plant based natural fibres as a reinforcement. Flax, hemp and jute fibres are natural, renewable and abundantly available. If we can use them as reinforcements, we are talking about sustainable composites.’
The principle of Hom’s research is combining organic materials with plastics to create composite laminates. The goal is to see these being used for products such as car bumpers and door linings.
The future of transport
In order to reduce emissions from vehicles, the automotive industry wants to introduce lightweight materials, so cars don’t need to burn as much fuel. Plant fibres are lighter weight than carbon or glass, so could be the solution.
Part of Hom’s research is about proving they have the necessary strength. Hom and his team test for factors ranging from strength to endurance – for example, they expose the materials to extreme hot and cold temperatures to find out if biocomposites can withstand harsh environments.
Hom explains: ‘You cannot just say, okay, let’s use all natural materials. They have to fulfil a functional requirement. So, we do certain tests, follow certain standards and come up with certain values for the product – this one has amazing impact resistance behaviour, this one has very good scratch resistance property – so the industrial collaborators will be confident in using these emerging sustainable materials.’
Hom and his team are exploring treatments and processes that could make these materials more safely compatible with plastics. It’s all about achieving the mechanical strength required in a reliable, sustainable way, and minimising the risk of moisture absorption.
‘It’s a long journey,’ says Hom, ‘and we have to have patience and perseverance to make an impact. The challenge is getting consistent, reliable properties. It takes a long time to convince people to use a new class of materials, such as natural fibre reinforced composites for non-structural and structural applications.’
But ultimately, his passion is not about sustaining profit generation in industry. It’s about sustaining life on our planet:
‘The way we are using resources currently, we might need another 3 or 4 Earths to meet our demand. We are sending a message to industries that our graduates are capable of using these tools relating to sustainability, using materials efficiently, using less energy.’