I saw an article in Composites World this week about the use of flax fiber composites for body work for a NASCAR BEV. This means two things to me. First, NASCAR is actually living up to their promise to become sustainable – natural fibers and an electric race car – pretty amazing stuff. Just 10 years ago nobody would have believed this, but here’s proof.
Courtesy of Composites World 10 July 2024
In 2023, NASCAR made a commitment to achieving near zero carbon emissions by 2035, and this flax fiber body work on their first EV race car is a good start. The body work is made using flax fibers developed by a Swiss company called Bcomp. This company was created because of the 2022European Green Deal which ended up with mandates that EU-manufactured products from construction materials to textiles would be made using sustainable, recyclable, or recycled materials. I have talked about this in previous posts and that the Europeans are well ahead of us in this regard, but hopefully we are on a path toward catching up here in the US.
Another industry adopting flax fiber especially is closely related to NASCAR, the auto industry. In several cars in all classes, but primarily a bit higher end vehicles, flax fiber is used for interior door panels, dash boards, seat cushions, and the like. Primarily the flax has found itself in interior door panels. It is light weight, strong, and when made into a composite with usually a thermoplastic, it has sufficient stiffness and strength to handle rough use. And, maybe more importantly, it acts as a sound deadening material, keeping the interior of the car quieter, a nice feature in a BMW. This again is happening more in Europe than in the US. This is not only because of the European regulations, it is also because France is the leading grower of flax as a country, with about 75% of the world supply. The Alliance for European Flax-Linen & Hemp is headquartered in Paris for good reason – France is where they grow the stuff.
Here in the US, Hexcel has launched a natural fiber sustainable prepreg they call HexPly® Nature Range. This was done in 2022 and they paired their new flax fiber product with their own partially bio-based epoxies. This prepreg is intended to be a direct drop in replacement for prepregs currently used in the marine, automotive, wind energy and winter sport applications. They are targeting the growing demand for sustainable composites, especially in renewable energy, sporting goods, and the automotive industry. And as I have been writing about these demands are driven not only because of new governmental regulations but also consumers increasingly interested in “green” products wherever they can find them.
In France and Germany, Porcher Industries (Eclose-Badinères, France) and Saertex (Saerbek, Germany) have also announced flax fiber based composites products for the industrial market. Porcher Industries is focusing on the automotive market with a flax fiber thermoplastic prepreg intended to be used for interior door panels, exterior shrouds in the engine compartment, trunk linings, etc. Saertex is focusing on marine and leisure (sporting goods mostly) markets with a flax fiber non-crimped fabric. Bothof these companies are in partnerships with Terre de Lin which claims to produce as much as 15% of the world’s supply of flax fiber. Since the stuff is grown in France by and large that does make sense. Terre de Lin manages about 700 farms and handles flax production from cradle to grave so to speak. They provide the seeds for their farmers to grow, process the harvested flax, and manufacture fibers specific to the composites market. Of course, I’m sure that they also harvest and sell flax seed because it is a staple in the European diet.
And there is a company in our native California that is also providing a flax fiber based
composite. Lingrove in San Francisco started producing its flax fiber / bio-based resin product they call Ekoa to replace wood. Originally it was to replace wood in ukeleles and guitars, but they have expanded to sporting goods, and recently started selling Ekoa into the building materials and automotive markets. They provide prefabricated panels and interior veneers made from Ekoa that is made to look like natural wood. This is again driven by demand in the marketplace, where customers are looking not only for the aesthetic value of their building interiors, they are also looking for sustainable materials.
Another interesting use for natural fibers is for bullet proof vests. Natural fibers can have much the same properties as the traditional Kevlar in these personal protection wearables, while at the same time saving weight because natural fibers are less dense than Kevlar. They are also easier to process because the fibers are larger so it does not take as many to make a vest. Tests were performed on pineapple leaf fiber, water hyacinth fiber, salak frond fiber, hemp fiber, and bamboo fiber. The only fiber that failed that test was the pineapple leaf fiber, the other four survived and demonstrated performance on par with Kevlar. These four fibers had excellent tensile strength and also excellent impact strength when made into a vest using traditional methods of construction.
Finally, I want to talk a little bit about medical applications of composites. As many of you already know, composite materials in general have made quite a bit of headway in medical applications. There has been dental implants that are composite materials because you can make a synthetic tooth out of a discontinuously reinforced composite that is far more realistic and tooth like than you can out of any other material. And, fairly recently, carbon composites have replaced titanium for skeletal implants like hip and shoulder replacements. This is because of a number of reasons, including the fact that the organic matrix as well as the carbon fiber can be made to be far more bio-compatible than titanium so the implant won’t be rejected. In addition, composites have the unique property of enabling the tailoring of stiffness and strength where you need it, so it also can be made to mimic the structure of the bone, so the patient may not even notice much change in motility once the implant sutures heal up and the implant is accepted and integrated into the skeleton. Very recently natural fibers have also been integrated into these skeletal composites because of their enhanced flexibility over traditional fibers as well as their bio-compatibility. They are after all just plant parts, so they are biological materials to start with.
In addition to skeletal composites, in recent years flexible composites made using natural fiber and bio-compatible resins have been used for soft tissue repair. These applications run the gamut from use as stents and arterial wall reinforcements to open weave scaffolding that the body’s tissues can incorporate to rebuild wounded areas. Some of these materials are intended to remain in the body, while others are intended to be consumed by the body as fuel as the body rebuilds the structure using its own tissue cells. There is even work going on to build scaffolding out of natural fibers to rebuild bone in areas where the loads can be more controlled than in something like a femur. Since natural bone has this sort of structure, it is a fairly obvious, albeit somewhat challenging, path for the clinician to take to make the skeleton of their patient as close to original as possible.
That’s about it for this week. I hope everyone that reads these posts enjoys them as much as I enjoy writing them. As usual I will post this first on my website – www.nedpatton.com – as well as on LinkedIn. And if anyone wants to provide comments to this, I welcome them with open arms. Comments, criticisms, etc. are all quite welcome. I really do want to engage in a conversation with all of you about composites because we can learn so much from each other as long as we share our own perspectives.
I also wanted everyone to know that I am working on my second book. This one is about what I have been writing in these newsletters for the last 6 months or so – sustainability of composites and a path to the future that does not include using fossil fuels for either the raw materials or the process energy to make composites. Stay tuned to this space and I will let everyone know about my progress as I write this one. I’m about three chapters into it at this point and I know what I want to write. And now that life is settling down a little bit I have time to devote to just writing.
Finally, I still need to plug my first book, so here’s the plug. The book pretty much covers the watershed in composites, starting with a brief history of composites, then introducing the Periodic Table and why Carbon is such an important and interesting element. The book was published and made available last August, and is available both on Amazon and from McFarland Books – my publisher. However, the best place to get one is to go to my website and buy one. I will send you a signed copy for the same price you would get charged on Amazon, except that I charge $8 shipping. Anyway, here’s the link to get your signed copy: https://www.nedpatton.com/product-page/the-string-and-glue-of-our-world-signed-copy. And as usual, here’s a picture of the book.
Comments