Mushroom composite foam
A biodegradable material made from mushroom roots and seed husks could replace plastic foam.
To produce the biocomposite (Ecocradle), developers at Ecoactive Design in New York, USA, have used locally sourced agricultural waste. The feed stocks are pasteurised and then inoculated with mycelium (mushroom ‘roots’). Eben Bayer, Co-inventor of the technology, Mycobond, explains, ‘Over the course of 5-7 days, this mycelium spreads throughout the loose agricultural matter and acts like a biological resin, gluing everything together. After this growth process, the parts are dried out in a low temperature oven. This stops the growth of mycelium.’
The material, which has already been used for ready-to-assemble office furniture packaging and audio products may be used as a substitute for expanded polypropylene (EPP) and extruded polystyrene foam.
Bayer adds, ‘The material has outperformed traditional EPP packaging in a gauntlet of tests, including drop, vibration, scratching, temperature swings and humidity. It has also now been tested to ASTM standards, including water sorption where results were equal to conventional foam.’
He also claims the material has further environmental benefits as it can be industrially and domestically composted with a degradation rate of two weeks to three months, and is grown in moulds made of recycled bottles. Bayer add that the foam uses an eighth of the energy consumed by synthetic materials.
However, a full lifecycle assessment (LCA) is yet to be completed. Furthermore, Bayer says the estimation depends on the agricultural feedstock chosen, the product being made and the location of the facility.
John Williams, Polymers and Materials Manager at National Non Food Crops Centre, UK, says, ‘Waste-based material is a positive step and is key to sustainably maximising the non-fossil material chain.
'Yet, as with any process using agricultural waste, you have to be transparent about your LCA. Are we sure this waste is not otherwise being used by other industries already and will it be used in the future as an energy feedstock?
‘The waste material is low cost at the moment but increasing usage of agricultural “waste” materials will change this dynamic. A fully qualified and thorough LCA is the only way to verify energy saving claims and whether feedstock is best used for this application.’
Research is now in progress on the use of plant-based essential oils to cut the energy consumed in steam technology to the feedstock. The company is developing further blends of the material with the US Department of Agriculture, to be facilitated in different parts of the country using local feedstock. ‘If you're making these materials in the south, we could use cotton gin trash or rice husks. In the north, we could use buckwheat hulls or oat husks,’ adds Bayer.
The next priority will be increasing automation and development of a turnkey manufacturing system that can be franchised for regional production of the material.