The Automotive Sector’s Latest Raw Material Trend: FRPCs

The automotive industry is under fire. It is highlighted as a major contributor of carbon emissions and is demonised as congested, expensive, and a dangerous way to travel.

Yet vehicle manufacturing is actually one of the most innovative sectors of the economy. A place where engineers are given free rein to push the boundaries of technology, design, and raw material sourcing.

One of the latest trends in this field is the application of fibre-reinforced polymer composites (FRPCs) as an alternative feedstock for use in numerous components.

Made from glass, carbon, or natural fibres embedded in a polymer matrix, such as a thermoplastic or thermoset, FRPCs provide numerous advantages over conventional materials, such as synthetic fibres or metals. They can lower feedstock and production costs, and can be more environmentally friendly as they reduce energy consumption in both manufacture and use (due to their lower weight).

That being said, they bring with them their own set of problems, such as difficulties with recycling, challenges in creating a superior surface finish, they often lack the ability to preserve mechanical and physical characteristics in harsh environments, and cannot always guarantee compatibility and integration with other materials.

Why are FRPCs trending among vehicle manufacturers?

Resistance to Corrosion

Since FRPCs do not react with oxygen, water, or other chemicals, they are highly resistant to corrosion giving them a significant advantage over metals, which notoriously rust over time. This is particularly relevant in the automotive sector, where vehicle performance, safety, maintenance costs, and aesthetics are all impacted by corrosion. Consequently, employing FRPCs can decrease a vehicle’s environmental impact while also extending its service life.

Adaptability and General Performance

One of the key features of FRPCs is their high degree of design flexibility, which allows them to be readily moulded, formed into shape, and customised to meet particular needs and applications. This enables the automotive sector to produce innovative designs that can enhance a vehicle's aerodynamics. Furthermore, because FRPCs can create a variety of colours and textures in addition to smooth, shiny surfaces, they can significantly improve a vehicle’s visual appeal.

Low Weight

Due to their higher strength-to-weight ratio, FRPCs can support greater loads with less mass than metals. This weight loss also allows for lower fuel consumption – a key selling point for a vehicle. Additionally, by improving rigidity, damping, and impact performance, it is easy to see why FRPCs are becoming an ever more popular raw material.

FRPC Manufacturing

The method of creating composite materials containing fibres pre-impregnated with a partially cured resin matrix is known as prepreg manufacturing. Compared to conventional composite materials, prepregs offer a number of benefits, such as improved performance, quality, and consistency as well as reduced environmental, waste, and labour costs.

The two primary processes used to create prepregs are the solvent dip procedure and the hot melt process.

The Solvent Dip Method

In this process, the resin is dissolved in a solvent bath before the fibres are dipped into it. A drying oven is subsequently used to evaporate the solvent, leaving the prepreg behind. This allows for low-cost prepregs with a high fibre and low void content to be produced.

The Hot Melt Process

A small layer of heated resin is first applied to a paper substrate. The fibres are subsequently impregnated with the resin while being heated and compressed. This allows for high-quality prepregs to be made with a good surface finish and dimensional accuracy.

To guarantee the best quality and functionality of prepregs, both techniques necessitate meticulous control over the resin viscosity, temperature, pressure, and curing time.

The use of fibre-reinforced polymer composites in automotive manufacturing presents a complex mix of benefits and drawbacks. On the positive side, these lightweight, high-strength materials can significantly improve a vehicle's fuel efficiency by reducing its overall weight. The superior corrosion resistance of composites makes them a durable option, while their design flexibility allows for greater styling innovation.

However, the drawbacks of these materials should not be overlooked. The high initial cost of sourcing and processing composite materials can be a major barrier, especially for smaller automotive manufacturers operating on tight budgets. There are also challenges around recyclability, as composite parts are often difficult to disassemble and reuse at the end of a vehicle's lifecycle. Concerns have also been raised about the potential health and environmental impacts of composite manufacturing, particularly around the release of harmful chemicals and microplastics.

Consequently, carmakers must carefully weigh these trade-offs as they determine the role of fibre-reinforced polymers in their future vehicle designs and production processes. For despite the significant challenges, it is good that the manufacturers have FRPCs available as a feedstock – one that through reduced weight could help lower industry’s carbon emissions and lead towards a more sustainable future.

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