sustainability case study

Coffee, eggs, walnuts, rice and lentils could be just as likely found in your future car’s interior as your shopping basket.

Our designers and engineers went beyond materials already under consideration to identify fresh sustainable options that customers could benefit from. Using a retromod Porsche 911 interior as the basis for the research, the team led by Charlotte Jones and Ian Callum identified coffee pulp, eggshells, red lentils, walnuts and rice as viable materials for a car interior in 2030.

the materials

food waste.

With thousands of tonnes of food wasted every day in the UK alone, we consulted with green-tech company Ottan to determine the most appropriate materials capable of replacing plastics yet still meeting the rigorous design, environmental and engineering requirements of a car. Solutions identified that could meet the temperature and wear specifications included adopting 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 of Ottan’s material increases to 84 per cent from 78 per cent.

Out of date rice or lentils can be turned into a smooth translucent material, ideal for illuminated areas of the car such as lamp covers or illuminated switches.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.

Keen to demonstrate that sustainable materials can still offer vivid colours, we 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.

clothing waste.

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 Charlotte Jones, head of materials and sustainability at CALLUM. “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 SMS design study was created by CALLUM to illustrate that there is another way, and we can support manufacturers and suppliers identify engineered alternatives that end consumers are increasingly looking for.”

plastic waste.

The seat centre facings in this design study use Camira, a fabric made from marine plastic waste such as polyester, whilst the bolster surfaces are covered in Féline, a soft material produced from PET bottles. Each offers no weight penalty, another factor considered for the restomod upon which the study is based, and crucially each can be recycled again if needed. For the carpet, Jones proposes Econyl, a material that uses nylon carpets or fishing nets to create a new hard-wearing fabric.