Autumn has arrived and as the weather turns a little cooler we may forget that July 2023 saw the hottest month ever recorded. In starting this blog my goal was to talk about global trends in composites. It seems increasingly clear that many (all?) of the global trends in composites are to some extent now driven by the effect of climate change. I bring up the subject with some hesitation. We now live in a world where raising such issues as climate change are not necessarily perceived as commentary on science but considered an issue of political bias. In talking about what the impacts of climate change have on composites my hope is whichever position you take, that you will agree and recognise how policy, economics, decision-making and consumer behaviour are changing. That the effect on our industry is clear whether or not you believe in the underlying root cause.
Sustainability and composites
One of my own personal challenges when considering sustainability and composites are the inherent contradictions. Take one example, aircraft. For sure, flying is not sustainable. Burning so much fuel and releasing so much CO2 can’t be considered sustainable but acknowledging the reality that people want and need to travel, making aircraft airframes lighter, and making composite jet engine fan blades lighter achieves more sustainability than not doing it. Perhaps sustainability in this context means wasting less material and increasing “buy-to-fly” ratios. But in another contradiction this is still applied to materials made from energy-intensive carbon-fibre and hydrocarbon based thermoset resins.
Electrification and the role of life cycle analysis
Another example might be electrification. Is it more sustainable to keep using my 20 year old polluting diesel engine vehicle or to buy a new electric car with “zero emissions” but having mined the earth’s natural resources to build the vehicle and the 100s of Kgs of batteries inside. All I know is that I don’t know where the balance falls and that while not perfect, the use of Life Cycle Analysis tools is going to become a huge driver in what we determine to be “net beneficial” to the environment. Everything will be about trade-offs and over what time scales, and the validity of the data used. We at Airborne see an increasing need from our customers for Industrialisation Partnership to help them in, for example, reshoring analysis, to help build the case for investment in local automation by considering the full LCA impact of their supply chain before and after.
New transport forms and the advantages of composites
Another key driver for composites use is the emergence of new transport forms. Entrepreneurial start-ups created by investment liquidity from the credit crunch and covid aftereffects along with disruption from electrification technology improvements has allowed new companies to challenge the established ones with new concepts such as micro-scooters, skateboard chassis vehicle platforms, and EVTOLS. As start-ups, all are unaccepting of previous paradigms. Lower initial volumes are ideal for composites where lower tooling costs and more geometrical freedom allow fresh ideas to be realised. Capital requirements are lower with lower cost tooling, and the design freedom, lightweight and ability to use “sustainable” materials such as thermoplastics and bio-materials appeals to the consumer driven segments. For many of these companies navigating the challenging trade-offs between tooling, design, materials, qualification, part cost and scale-up requires third party support and again here, Airborne’s Industrialisation Partnership has been formed to support customers through these decisions in an informed way.
RTM vs. prepreg: a shift towards infusion
As all markets focus on material cost, buy-to-fly ratios, and higher production rates, RTM as competition to prepreg is gaining more and more adoption. Lower cost/Kg materials and avoiding batch processing such as autoclave in favour of pressing means structures in all markets looking at infusion/RTM. Typically materials are trending towards multiaxial and stitched UD. Higher fibre areal weights mean less plies to deposit and lower cost per Kg to weave. While structures may become less optimised, and in highly weight sensitive applications (space, high end aerospace) the use of higher modulus UD materials will surely continue in any market where some optimisation can be sacrificed for cost improvement then infusion will trend up.
Airborne are ready for this through the development of Automated Ply Placement. This automated preforming solution is able to convert material at high rate into 2D preforms suitable for 3D forming via hot drape forming or double diaphragm forming and is compatible with infusion/RTM. The same technology can be used for prepreg too, with solutions for backer removal so whichever technical direction is chosen, we’ve got you covered.
The rise of thermoplastics
We can also see that Thermoplastics use will grow considerably. Technical, processing and economic challenges have always existed with thermoplastics. Cost effective materials with high structural and thermal performance are hard to find. Processing can be challenging especially with the effects of crystallinity. But the attraction of material which can be reprocessed or reformed without significant loss of format or properties can only drive significant increased use. The challenge will be to achieve the design requirements but perhaps the most significant challenge is rate. Heating (to anywhere between 200C and 400C), cooling at controlled rate and to a de-mouldable temperature and achieving the necessary rate is the biggest challenge. Automated Ply Placement (APP) also enables this trend to allow preforming cells with high rate pressing to achieve the needed output for commercial aerospace programs and we hope to make more announcements on this later in the year.
Whether or not sustainability is driving this, or just good old-fashioned economics, it’s clear that maximising use of lower cost materials, wasting less, and manufacturing more efficiently is never going to be unpopular. Whether in the early phases of evaluating how to achieve such results, or ready to invest in the solutions, Airborne is perfectly placed to support.
Feel free to contact any of the commercial team or myself to discuss further.