Words by Sophie Chua, Patent Technical Assistant, Mewburn Ellis
The composites industry has established itself as an essential partner to aerospace manufacturing. The need for advanced composites in the eVTOL market is even more acute as light-weighting is essential for electric vehicles. Not only is there a need for these aircraft to have lighter components, but their designs need to also comprise fewer components.
What makes the eVTOL industry so exciting for the composites industry is the extent to which composites can play a part in eVTOL aircraft structures; on average approximately 70 per cent of an eVTOL aircraft’s weight is composite material, compared with a Boeing 787 which has approximately 50 per cent of its structure made from composite material.
Thermoset resins are currently the most used resin type in the aerospace industry. Given the race to get eVTOL vehicles certified as quickly as possible, manufacturers are turning to proven materials as a first step, rather than leaping to brand new innovations straightaway. It is not surprising that more than 90 per cent of eVTOL manufacturers are entering into certification with thermoset-rich platforms.
However, we are likely to see a transition to the use of thermoplastics, particularly fibre- reinforced thermoplastics. Thermoplastics facilitate significantly lighter-weight vehicles at higher production rates due to their reduced cycle times.
Furthermore, the inherent recyclability properties of thermoplastics improve sustainability, an ongoing initiative of the composites industry. Although the transition is expected to be gradual, key composite materials suppliers such as Toray are already marketing thermoplastics for eVTOL application.
Vertical Aerospace is an example of a manufacturer making significant use of thermoplastics. Their flagship aircraft VX4 has components like rotor blades, battery enclosures and brackets made using thermoplastic prepregs.
The prototype has successfully undertaken piloted test flights and is now in the next stages of the flight test programme. Vertical have built an experienced team and partnered with big industry players such as Rolls Royce to help them to achieve certification and scale-up of their pioneering aircraft.
The demand for composite materials is expected to significantly increase as plans for eVTOL vehicle manufacturers to scale-up production take shape, and is estimated to reach $673 million in 2030 (up from an estimated $36.2 million in 2024).
With the shift towards thermoplastics and a need to develop thermoplastic manufacturing solutions for larger structures, a re-evaluation of the current supply chain may be required to keep up with the demand.
Clearly, the eVTOL and composites industries are on an upwards trajectory, and it will not be long before we are able to take a commercial flight aboard an eVTOL aircraft. In such a rapidly evolving industry, it will be fascinating to see the way in which new innovation drives advances, and the way in which intellectual property around those innovations might allow one or two companies to ‘fly higher’ from a commercial perspective.
The industry has already created opportunities for several manufacturing and supply partnerships who are now incredibly close to delivering a new era of mobility.