by Design and engineering consultancy Callum is urging automakers to rethink the materials they use for interiors.
The challenges all transport industries face when it comes to becoming more sustainable are enormous, and while there has been some focus on vehicle interiors, it seems that car manufacturers can go much further.
Industrial design and engineering firm Callum conducted feasibility studies for car interiors made from foods you’d find in your pantry, like coffee, eggs, walnuts, rice, and lentils.
As part of a self-initiated project, the Warwick-based studio investigated whether food, clothing and plastic waste could be turned into useful materials for car interiors. The short answer is yes, they can.
Callum used the interior of a Porsche 911 as the basis for a series of renderings based on material properties and feasibility research. The company’s creative lead, Aleck Jones, says the car was chosen because its “simple finishes and simple elements” could easily accommodate sustainable alternatives.
At the beginning of each project, Callum conducts “Material Review Sessions” led by Color Material Finish (CMF) designer Charlotte Jones to decide if a product could be more sustainable. Aleck Jones says this helped them build “a catalog of interesting products” and an extensive library of materials.
While more unorthodox sustainable materials are already being used in fashion and interior design, they are not yet widely adopted by automotive companies, although there have been some isolated breakthroughs, particularly in recycled plastic.
Charlotte Jones says the purpose of this study was to ask how to get them into the automotive sector, adding that “once someone has done it, there will be a chain of followers” trying to do the same to achieve what will lead to more extensive testing of these materials.
Callum worked with fabric manufacturers such as Camira Fabrics, Ottan and Planq on the study. According to Charlotte Jones, some of these manufacturers are already testing automotive-grade materials, and others who had no prior knowledge of the subject were approached by Callum and encouraged to think about it.
What are the materials?
Working with green tech company Ottan, Callum created a list of materials made from food waste that can replace plastic while still meeting a car’s design, environmental and construction requirements.
Eggshells mixed with resin can produce a smooth, opaque material that can be customized to a glossy or matte finish. The material meets temperature and wear specifications and could therefore be used as a trim frame for window switches. Adding walnut shells to the mix would increase the recycled content from 78% to 84% without compromising properties.
Callum discovered that outdated rice and lentils could create a smooth, translucent material that could be used for illuminated areas of car interiors, such as lamp covers. Other by-products such as coffee pulp have been found to have flame retardant properties, making them well suited for glossy dash inserts.
Used textiles that would otherwise have ended up in landfill could offer “a blend of wear resistance, comfort and color fastness” that could be used in seating materials, Callum says. Charlotte Jones describes how companies like Dutch sustainable furniture brand Planq combine shredded denim with potato or cornstarch and press it into “a hard veneer that could be used for seat shells or dashboards”.
Callum chose a material made from marine waste from fabric manufacturer Camira for the seat center panels, as well as a soft material called Féline, made from recycled polyethylene terephthalate (PET) bottles. Both materials are without weight disadvantage and can be recycled after use. The carpets have also been chosen for their sustainable properties and are made from Econyl, a durable fabric made from nylon or fishing nets.
For now, the application of these materials in a car is just a concept, but Charlotte Jones says Callum’s design study aims to show “there can be other ways” and advocates helping manufacturers and suppliers “identify technical alternatives”. .
She adds that some of the suppliers they’ve worked with are already on board and are “chasing the auto industry” to join them on this next step.
“It costs more to be sustainable”
The process of turning byproducts into usable materials “isn’t a two-minute job,” which makes them more expensive, says Aleck Jones. Working on a smaller scale for high-end customers means “you can factor the cost of sustainable materials into the product cost,” he adds, arguing that using unique sustainable materials creates a “far more interesting product” for customers are willing to pay for.
Charlotte Jones adds that although “it currently costs more to be sustainable,” hopefully consumers will start prioritizing green choices rather than cost or looks.
“If you’re doing a small project, the cost of each material is a lot higher because you’re only using a small amount, but if you use it consistently you can spread some of the cost across other projects as well,” Charlotte Jones explains. For example, Callum is very familiar with flax in its various forms and uses it in several projects.
Flax fiber is derived from the bast or skin of flax plant stems and can be used in place of carbon fiber. In addition to being renewable, with a lower carbon footprint, flax is lighter than carbon fiber and known to be better for vibration dampening (reducing vibrations from an ergonomic, industrial, or electrical system).
Years ago, carbon fiber was a “really high-quality, very expensive product” but has gotten a lot cheaper, says Aleck Jones, who thinks sustainable materials can benefit from the same falling costs versus rising supply and demand curves.
Planet about aesthetics
In the automotive industry, many design decisions are based on aesthetic values, which can be problematic when it comes to adopting sustainable materials. The studio’s popular flax material is sustainable, but its natural brown color “isn’t a good option for high-end interiors,” says Aleck Jones. He adds that he recently spoke to a supplier who found a way to tint the flax a light gray shade that would be more desirable for a car interior and showed how further development could bring a breakthrough.
Materials like coffee pulp can have a similar high quality finish to wood veneer, proving that not all sustainable materials look less desirable. Another byproduct identified by Callum is purple carrot pulp, which produces a mulberry-like color for trim. Tree leaves can also be recycled into a dark, smooth finish that offers an alternative natural finish to wood veneers for the center console or dashboard, the consultancy has found.
Aleck Jones says that “not all sustainable materials need to be something to show off” and can be clad with something more visually appealing or of higher quality.
“Who will do the tests?”
Any material entering a car is subject to applicable safety regulations. Callum does self-testing, but doesn’t have the capacity to subject materials to the same rigorous testing that automakers do. Aleck Jones says: “We have done as much background research as possible, looked at the technical data sheets and talked to the suppliers”.
According to Charlotte Jones, some suppliers are being prevented from selling more sustainable materials because by the time the materials go to the bigger companies, they are expected to already meet automotive regulations. So the question is, “Who is going to do the testing?” she says.
The end goal of the study is to show automakers that sustainable materials are viable for use in car interiors and to encourage them to “do whatever tests are necessary to see if they can use them,” says Charlotte Jones. She hopes approved materials will be readily available to consultancies like Callum, as well as suppliers, manufacturers and engineers.
“Automotive must create the change”
With most automakers already thinking about electrification, hydrogen propulsion and alternative fuels, sustainable car interiors could be next. Charlotte Jones believes that since the conversation is already happening, “it may only be five years away” but “the auto industry needs to make the transition.”
