MTU is working with European partners to develop more sustainable 3D printing methods by recycling natural waste materials.
In 2020, the EU adopted the circular economy action plan as part of the European Green Deal – the bloc’s set of measures to reduce net greenhouse gas emissions by 55pc by the end of the decade.
A circular economy, according to the EU, moves us away from the ‘take, consume and throw away’ linear model of production to one based on reusing, repairing and recycling, “in an (almost) closed loop, where products and the materials they contain are highly valued”. In this way, a circular economy reduces pressure on natural resources, supporting biodiversity and the climate, and decouples growth and jobs from overconsumption of resources.
As part of the circular economy action plan, the EU says it aims to make sustainable products the norm and ensure less waste, with a focus on sectors that use the most resources and have high potential for circularity, including electronics and ICT, batteries and vehicles, and construction and buildings.
SiliconRepublic.com recently spoke to some of the people involved in a new EU-funded project that aims to contribute to the circular economy by repurposing natural waste materials for the construction and manufacturing industries.
From farm to factory
Bio-2-Print is a three-year project co-funded by the EU’s Interreg NPA (Northern Periphery and Arctic) programme, and is led by Finland’s Centria University of Applied Sciences with six partners across academia and industry including Munster Technological University (MTU), Luleå University of Technology, Innomost and Future Cast, and currently has 13 associated organisations.
Many biological by-products from agricultural, marine, forestry and industrial processes are discarded or incinerated, leading to lost value and increased emissions, explains project lead Dr Rathish Rajan from Centria University. He gives the example of inner tree bark. Outer tree bark has many cosmetic and manufacturing applications, with the inner bark discarded as a by-product. Other waste or underutilised materials identified by the team include hemp hurds, wool, seaweed and flax stalks.
The aim of Bio-2-Print is to harness these natural waste materials for plastics and concrete production to create more sustainable products and processes.
Rajan has a PhD in plastics technology and as well as being overall lead for Bio-2-Print, he is focused on developing high-performance composite materials using recycled plastics and these natural waste materials.
The overarching aim of the project, Rajan says, is to create a value chain, that is to develop a full lifecycle for sustainable manufacturing using these natural waste materials, from sourcing them to developing new techniques and composite materials to testing, piloting and scaling their implementation.
Creating connections
Creating a value chain means bringing lots of people together and that’s where MTU comes in.
MTU leads the Circular Bioeconomy Cluster and Research Group and works with more than 60 Irish industry members to develop circular and sustainable uses for biomaterials.
Stephen Barry-Hannon, a senior researcher and PM for the Circular Bioeconomy Cluster at MTU, is focused on developing the Bio-2-Print project network and value chain.
The Munster team, he says, will also conduct training on additive manufacturing – also known as 3D printing – a key component in developing sustainable manufacturing, as well as test the scalability of these natural waste materials for real-world applications and evaluate their environmental and economic impacts.
It was through meeting Barry-Hannon at the Circular Bioeconomy Cluster that Future Cast, an Irish non-profit R&D centre for the construction and quarrying industries, got involved in Bio-2-Print.
Concrete plans
Future Cast is investigating the use of natural waste materials in concrete as part of the project. Its chief operating officer Mary Whitney says that the organisation’s mission is to drive sustainability in the construction sector.
Being involved in Bio-2-Print has been “really beneficial”, Whitney says. “We’re delighted to be part of this project to see how we can do our best for the circular economy.”
Geological scientist Dave Plunkett manages Future Cast’s Materials Testing Laboratory.
He says that Bio-2-Print is all about problem-solving. “We had a good kick-off meeting recently in Sligo with a whole group of partners from Finland, Sweden and Ireland, and we discussed the various uses [for these waste materials],” Plunkett says.
In the early stages of the project, the aim is to find and test materials for various solutions to see what might be viable long term and at scale.
Future Cast tests materials in the lab. Image: Future Cast
Plunkett explains that for concrete there are certain standards as regards its strength and durability. Techniques have been developed to add plastics to concrete in small amounts to improve these qualities, and some of these plastics end up in landfill.
“They’re effectively microplastics,” Plunkett says.
If you replaced the plastics with natural waste materials that perform the same functions, you could reduce the amount of microplastics getting into the environment and reduce production emissions, he says.
Though it would only be small amounts that you replace, Plunkett says that the scale of the construction industry – the Irish Green Building Council estimates that concrete accounts for 30-50pc of materials-related emissions in Ireland – means you could make a big impact over time.
In the lab, Plunkett and the team perform advanced weathering tests on concrete and other materials they develop, for example exposing them to extreme high and low temperatures, to measure their performance.
“We have to understand fully how [the natural materials] interact with cement,” Plunkett explains.
“Biological material might decay, it might absorb moisture, it might react to alkaline conditions.”
All these factors must be tested before any new products can be piloted in later stages of the project.
Alongside new product ideas, Plunkett mentions a product already on the market called hempcrete, a biocomposite made from the inner core of the hemp plant mixed with lime, which is a sustainable, carbon negative alternative to concrete, the use of which is growing across Europe.
He says the team are looking at ways to advance the development of hempcrete through 3D printing technologies.
What additive manufacturing can add
3D printing, also known as additive manufacturing, is a critical element of this project, Rajan says.
Additive manufacturing can be more sustainable than traditional manufacturing for a few reasons. It works by building products layer by layer which reduces the amount of excess or waste materials, Barry-Hannon explains. It can also be faster than traditional methods and uses less energy and space.
A major issue with 3D printing is that most printers use plastics made from fossil fuels so Bio-2-Print is developing more sustainable materials that are locally sourced and can be easily integrated into 3D printing processes, with the aim of bridging the gap between circular resource use and cutting-edge digital manufacturing.
“In a nutshell, by successful completion of this project, we will lay a foundation for the transition of industries in the region from a linear to a circular economy model,” Rajan says.
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