Developing new manufacturing processes for biocomposites

Developing new manufacturing processes for composites reinforced with natural fibres and biological resins.

Composites reinforced with biological materials are emerging as a more sustainable and economical alternative to synthetic components like carbon fibre and glass, however their use within structural applications still presents significant technical challenges.

The European BioStruct project is on a mission to solve some of these technical problems through the development and validation of new manufacturing processes for bio-based composites in industrial applications within sectors such as wind energy and maritime. Research centre IDEKO is a prominent participant in the project, contributing its know-how in advanced 3D measurement and vision technologies to improve the precision of production using biocomposites.

BIOCOMPOSITE BENEFITS

Biocomposites are materials that combine natural fibres such as wood, hemp or flax, and offer several advantages over synthetic materials, explains Ibai Leizea, expert in vision technologies in precision engineering at IDEKO.

“Biocomposites have been increasingly gaining ground in providing more sustainable and environmentally friendly solutions compared to synthetic materials, resulting in a lower carbon footprint,” he says. “They are generally lighter than synthetic materials, and this weight reduction can be beneficial in some applications where weight saving is critical. Some biocomposites are biodegradable, which provides an advantage over synthetic materials in terms of disposal at the end of their life cycle.”

TECHNICAL CHALLENGES

Despite their promise, biocomposites also pose their challenges from a manufacturing perspective, particularly in the case of structural applications due to their less regular and solid properties.

“The variability of natural fibres makes it difficult to achieve consistency in the final product, while hygroscopicity can compromise dimensional stability and mechanical properties,” Leizea explains. “Additionally, ensuring effective adhesion between the fibres and the matrix, adapting processing methods to the properties of natural fibres, and guaranteeing durability against environmental factors are complex tasks.”

The main objective of the BioStruct project is to develop new manufacturing processes to boost the use of biocomposites in industrial applications such as a ship’s hull or a wind turbine blade.

“Precision is crucial when handling fabrics made from natural fibres, especially during the cutting and draping of composite parts,” Leizea continues. “This project will provide a deeper understanding of the mechanical properties of bio-based materials to accurately design structural components and enable their use in such applications.”

DRAPING IN DETAIL

The draping manufacturing process is a common method used to produce biocomposite material parts, beginning with the preparation of materials consisting of natural fibres and a matrix material, usually a polymer resin. A mould is prepared according to the desired shape and dimensions of the final composite part, then the natural fibre fabric or mat is cut to the required shape and size and carefully laid up in layers onto the mould. The matrix resin is applied or infused into the fibre layers and then cured to solidify the part. Finally, the part is demoulded, excess material is trimmed, and any necessary additional finishing is carried out.

“Being a new type of fibre with properties different from conventional ones, it requires new inspection methodologies to ensure the quality of these materials,” Leizea explains. “At IDEKO, we leverage artificial vision techniques developed in recent years to perform precise measurements, aiming to provide a response to dimensional control of the parts in this project.”

IDEKO possesses various technologies and sensors to study and determine which can offer the best precision results. “One of the biggest challenges in vision systems is the lighting or reflectivity of materials,” says Leizea. “Therefore, we will seek the best alternatives to provide a solution for end users. Ultimately, the goal is to validate that the geometries of the parts manufactured in this project are correct with this new manufacturing methodology.

MEASURING SUCCESS

The manufacturing process proposed by the project will be validated through two use cases: the manufacturing of a hull for a six-metre electric boat and the production of rotor blades for wind turbines. In both cases, natural fibres and bio-based resins will be used as construction materials, paving the way towards a greener and more sustainable industry.

“Biocomposites are an attractive alternative for the wind energy and maritime industries for several key reasons,” Liezea says. “firstly, their lightweight nature makes them ideal for applications where weight reduction is critical, such as in wind turbine manufacturing and shipbuilding, which can improve efficiency and reduce structural loads. Additionally, their corrosion resistance makes them durable in marine environments, lowering maintenance costs and extending the lifespan of components.”

The success of the project will be measured through several key indicators, including the quality and performance of the manufactured biocomposite parts, their cost-effectiveness, properties, and precision compared to synthetic compounds. The project is due to run until 2026, envisioning a market potential for biocomposites of around €100 million by 2030, which would lead to a significant reduction in greenhouse gas emissions from composites production, estimated at between 2.5-4.3 million tonnes of CO2 per year.