PLA bicycle helmets

For this booming market, many products are imported to Europe from Asia that are not ecologically sustainable. Researchers at the Fraunhofer Institute for Chemical Technology ICT in Pfinztal near Karlsruhe have now developed an alternative as part of a project funded by the Fraunhofer Future Foundation.

New bicycle helmet made entirely from biopolyester PLA
The product design of bicycle helmets focusses on functionality for good reason. Until now, this has been at the expense of recyclability and leaves a considerable ecological footprint – especially when the helmets are manufactured in Asia from mass-produced petroleum-based plastics: The helmet shell is made from polycarbonate (PC), the foam core from polystyrene foam (EPS), add-on parts are often made from polypropylene (PP) and straps from nylon (PA). In most cases, such a structure does not allow for material recycling at the end of the product's life, both technically and economically. As a result, the helmets are usually incinerated after their three to five-year service life.

If we scrutinise the principle of manufacturing each component from a specific material, we arrive at new, sustainable production approaches. The PIMMS project, funded by the Fraunhofer Future Foundation, demonstrates one such approach. As part of this project, various sports articles have been developed that consist of just one material. The biobased and recyclable plastic PLA is particularly suitable for this. Thanks to its technical properties and competitive price, it has been established on the market for several years. PLA has a material footprint up to eight times smaller than the materials used to date.

Bicycle helmet prototype
The bicycle helmet is an ideal prototype for the new material and design concept, as it must guarantee high functionality, in particular high energy-absorption with low weight. Wearing comfort, price, and appearance are also crucial for market success. As part of the one-and-a-half-year market-oriented project, the Fraunhofer ICT developed particle foams, thermoforming films, fibres, and composite materials made exclusively from PLA in cooperation with industrial companies (Comfil ApS, Elas A/S, WSVK, Polyola SAS). Their production and processing require precise and customised process control. Thanks to the broad-based cooperation, the PLA helmet could be produced in the same high-volume process as the conventional petroleum-based bicycle helmet. This lays the foundation for a competitive market launch of the new helmets.

The material's resistance to normal environmental influences during use has already been positively tested. The standardised external test, which is intended to prove the helmet's suitability for use, is still pending. A life cycle analysis (LCA) will also quantify the improved carbon footprint of the mono-material bicycle helmet, which is suitable for recycling, compared to the petroleum-based design across production, use and end-of-life. AT

www.ict.fraunhofer.de

Translated from German PR.