Over the past few months, the r-LightBioCom project has made great progress in developing sustainable composite materials using natural and basalt fibres. Project partner Hochschule Kaiserslautern (University of Applied Sciences) has created an innovative mix of flax, hemp, and basalt fibres with a polypropylene (PP) matrix. Using a special pressing technique, they have turned this material mix into high-performance, eco-friendly composites. Tests have shown substantial improvements in bending strength and impact resistance compared to traditional composites, marking a significant step toward more resource-efficient, high-performance materials for various industries.
Composite materials are widely used in industries such as aerospace, automotive, construction, and medical technology due to their outstanding properties. However, conventional composites containing carbon or glass fibres pose significant environmental challenges. Their complex structure makes recycling difficult, often leading to large volumes of waste that end up in landfills or incineration. Moreover, current recycling methods typically recover only fibres with reduced mechanical strength, while the resin matrix is discarded or burned. This limits the sustainability of these materials and increases their environmental impact. In response to these challenges, recent efforts have focused on making composites more sustainable, especially through the use of eco-friendly and recyclable materials.
The r-LightBioCom project aligns with these efforts, aiming to develop high-performance, sustainable composite materials with sustainable manufacturing and recycling processes alongside advanced optimisation tools. Within the project, various sustainable fibres are being investigated, including two natural fibres (flax and hemp), one inorganic primary fibre (basalt), and three recycled high-performance fibres (recycled carbon, glass, and aramid fibres). While the use of natural fibres in composites has been widely studied, the incorporation of basalt fibres in sustainable composites is still relatively underexplored.
Innovative Material Combination made of Natural and Basalt Fibres based on PP-Matrix
Over the past few months, project partner Hochschule Kaiserslautern has successfully developed and tested hybrid nonwoven materials made from flax, hemp, and basalt fibres with polypropylene as matrix. Afterwards, the resulting hybrid nonwovens were transformed into composite materials by applying compression-moulding techniques. The basalt fibre content in the nonwoven fabrics was 20%, with fibres sourced from four different suppliers to assess their impact on mechanical performance. The results are promising: differences between the supplied fibres were minimal, and all tested variations led to significant improvements in material properties, compared to composites made solely from natural fibres and PP.
What makes this innovative material approach unique is the combination of natural and basalt fibres. While flax and hemp are valued for their light weight and CO₂ neutrality, basalt fibres, considered to be a high-performance material, enhance strength and corrosion resistance. Another advantage is the environmental friendliness of basalt fibres. Unlike glass fibres, basalt fibres do not require chemical additives in their production, as they are made from pure volcanic rock. This makes them sustainable and resource-efficient.
A further innovative aspect is the use of long basalt fibres, approximately 100 mm in length, which have largely been unexplored Previous research has primarily focused on short basalt fibres, known as „chopped fibres,“ typically ranging from 4 to 12 mm. Hybrid nonwovens and composites with longer basalt fibres have rarely been studied. These longer fibres not only provide new mechanical benefits but also open up a broader range of potential applications across various industries.
Sustainability Through Regional Sourcing and Improved Recycling
This innovative material approach, which combines natural and basalt fibres in composites, represents a major step towards more sustainable lightweight materials. The use of locally source natural fibres helps reduce supply chain lengths and lowers the carbon footprint. While basalt fibres have typically been used as short fibres, processing them into longer, nonwoven structures enable superior mechanical performance and broader industrial applications.
Another key advantage of this material combination is its improved recyclability. Project partner FeyeCon has successfully recycled the developed composite materials, recovering both natural and basalt fibres from the recycled material. Early tests suggest that these composites can be recycled effectively without significantly degrading fibre quality. However, further research is needed to refine recycling methods and ensure consistent fibre performance after recovery.
Future Prospects
In the coming months, r-LightBioCom’s further research efforts will focus on optimising the material composition, fine-tune manufacturing processes, and conduct comprehensive mechanical testing. The goal is to further enhance both the performance and sustainability of these advanced composites. A particular emphasis will be placed on gradually replacing the polypropylene (PP) fibres with recycled PP fibres (rPP). This will increase the proportion of sustainable components in the composites, making a significant contribution to environmental protection.
