Cutting carbon footprints with Cake: Swedish firm evaluate paper-based replacement for plastic components
The drive towards a carbon-neutral future has long focused on the direct emissions of engines and the shift to electric power but even the complete elimination of exhaust fumes is only a partial step towards a greener future.
For a more complete solution firms need to reduce the emissions from manufacturing – and Swedish e-bike firm Cake is looking at replacing plastic parts with paper to achieve that.
The company have joined forces with fellow Swedes at PaperShell AB, a start-up focused on turning paper into a durable, wood-like material that can be moulded like plastic or carbon fibre.
Despite its roots in paper, the final material is a water-repellent and fire-resistant cellulose fibre. This allows it to be used in both wet and hot environments without the need to add flame retardant chemicals, and promises a combination of strength and density that should allow it to be both tough and lightweight when replacing plastic.
“PaperShell aims to make components that are more environmentally friendly than press moulded veneer, as weather-resistant as plastic and strong as fibre composites,” said the company.
The material is sculpted by press moulding, where it’s clamped between two shaped moulds under pressure to form its final, three-dimensional shape, or bladder moulding where it’s put into a female mould and an inflatable bladder is inserted to force it towards the walls of the mould.
Like plastic, it can also be moulded with a variety of finishes – gloss, satin, matte, rough or patterned, with logos or pictures embossed into the surface if desired – and it can be either left with that surface or given a painted finish.
Unlike plastic, it’s also biodegradable over time, and it can be recycled in the same way as wood. PaperShell claims that its environmental impact is a fraction of that of more conventional materials. Measured by ‘kgCO2-equivalent per kg’ – a yardstick of the environmental impact including material production, manufacturing, and end-of-life – PaperShell comes in at 0.65 kgCO2-eq, compared to plastic such as polypropylene which rates 4.95 kgCO2-eq or glass-fibre reinforced plastic at 25.05 kgCO2-eq.
Stefan Ytterborn, founder and CEO of Cake, said: “We’re excited to work with PaperShell and hope that we can play a crucial part in finding a material that can minimise or even eradicate the use of conventional plastics in our motorcycles. This is a collaboration that ultimately will benefit the entire vehicle industry and beyond.”
Although the initial focus is on replacing plastic components, PaperShell’s weight-to-strength ratio may also allow some metal parts to be switched to the new material. Although only half as strong as aluminium, it’s also half the weight, so provided there’s space to increase a component’s thickness, parts that are made of aluminium could also be replaced with PaperShell versions.
PaperShell was only established in 2021, after three years of work on the idea, but the company’s pilot plant in Tibro, Sweden, can already make 60,000 components per year. In 2023, the company plan to open a flexible manufacturing plant that can turn out more than ten times that many, annually churning out as many as 700,000 planet-friendly parts.
Some will eventually be destined for motorcycles, and by 2025 Cake hope to use PaperShell components to develop a bike with the smallest possible carbon footprint.
Anders Breitholtz, CEO at PaperShell, said: “We can’t think of a more perfectly challenging testbed for our material than the industry-leading electric off-road motorcycle and look forward to developing further PaperShell’s inherent resistance to fluids, UV-radiation, weather and fire.”