Coffee, eggs, walnuts, rice and lentils could be just as likely found in your future car’s interior as your shopping basket according to a new study by design and engineering consultancy CALLUM. 

Using a Porsche 911 interior as the basis for the research, the team identified coffee pulp, eggshells, red lentils, walnuts and rice as viable materials for a car interior in 2030. 

Options identified that could meet the temperature and wear specifications for an interior included using eggshells mixed with resin to create a smooth, opaque material with either a glossy or matt surface. Application examples include the trim surround for the window switches. By adding walnut shells to the eggshells, the recycled content can be increased from 78 to 84%. 

Out of date rice or lentils can be turned into a smooth translucent material, ideal for illuminated areas of the car such as lamp covers or illuminated switches. As a flame-resistant alternative, coffee pulp could replace traditional plastics for glossy, decorative trim such as dashboard inserts.

Coffee grinds are bound together with resin to create panels

Keen to demonstrate that sustainable materials can still offer vivid colours, CALLUM identified purple carrot pulp that produces a mulberry-like colour for trim parts. Tree leaves can be recycled into a dark, smooth surface offering an alternative natural finish to wood veneers for the centre console or dashboard. 

With seats requiring a blend of wear resistance, comfort and colour fastness, CALLUM opted for preloved materials that would usually go to landfill. “Around the world, we consume roughly 62 million tonnes of textiles a year and around 87 per cent of the total fibre input used for clothing is either landfilled or incinerated,” says CALLUM’s head of materials and sustainability, Charlotte Jones. “Companies such as Planq take jeans, then shred and press them with potato or corn starch to create a hard veneer that could be used for seat shells or dash centres. 

The seat centre facings in the CALLUM design study use Camira, a fabric made from marine plastic waste such as polyester, while the bolster surfaces are covered in Féline, a soft material produced from PET bottles. The carpet is made from a material that uses fishing nets to create a new hard-wearing fabric. 

“More of our customers are starting to think about sustainable projects and put an emphasis on the circular economy. With others, we might nudge them down that path, highlighting the business benefits of making a more sustainable choice,” said CALLUM co-founder and design director, Ian Callum.

Finger on the pulse - lentils can adda splash of colour to switches