Green Matter: New molding technology mushrooms into a packaging success

Magic mushrooms, indeed: its inventors are hailing it as a true natural polymer, "tested and tried over millions of years and guaranteed not to clog up the ecosystem." Mycobond, a new material that is being marketed as the green replacement for expanded polystyrene in protective packaging applications, is based on the natural capabilities of fungi to break down and digest dead organic material. Mycobond depends on the mycelium, or root structure of the mushroom, to transform these waste products into a strong mycological composite.

Developed by a company called Ecovative Design that was founded in 2007 by Rensselaer Polytechnic students Eben Bayer and Gavin McIntyre, the new material is currently being produced in a pilot production plant in Green Island, NY. However, plans have already been announced to expand soon to new regional facilities. Ecovative investors 3M, Rensselaer Polytechnic Institute and the Dutch-based Doen Foundation are providing the backing needed to scale up production of the new material.

To date, Ecovative has launched two products in which the new mycological composite is applied. The first was an insulation material called Greensulate, developed while the two founders of the company were still at school. The second product, EcoCradle, won a Diamond Award for Excellence in Innovation, Cost/Waste Reduction and Sustainability this year at the DuPont Awards for Packaging Innovation. EcoCradle is a protective packaging product that is grown, not manufactured, from renewable resources. Its production is said to require only an eighth of the amount of energy and creates just a tenth of the carbon dioxide compared to that used/generated during production of conventional foam packaging, and unlike conventional materials it is fully biodegradable. It is flame retardant, moisture and impact resistant, and has good insulation properties.

So how does it work?

EcoCradle starts out as a mixture of woody biomass composed of agricultural byproducts, such as oat hulls, rice husks and seed burrs, which is then inoculated with mycelia. The mycelia act as glue, breaking down the lignum and cellulose in the biomass and bonding it into a strong, lightweight material. The manufacturing process is virtually energy-free as the growth takes place at room temperature in the dark. The process takes place in a customized plastic tool, called a 'grow tray', which enables parts to be produced to customer specification - just like in the plastics industry. Only here, it's the organism that does the work, not the equipment.

It takes five days to grow a part. Eben Bayer explains: '"It's a controlled, tunable process. Depending on the feedstock, we can vary densities and material properties according to the customer's needs."

After five days, the part undergoes a sterilization treatment to stop the growth. A steam-heat process is currently used, although the company is working on a new, less energy-intensive sterilization method using natural oils, such as cinnamon bark and oregano - with fragrant results. To quote Gavin McIntyre: "The biological disinfection process simply emulates nature in that it uses compounds that plants have evolved over centuries to inhibit microbial growth. The unintended result is that our production floor smells like a pizza shop."

The technology developed by McIntyre and Bayer takes the concept of biopolymers to an entirely new level. Bayer: "We use only local, open feedstocks to put into the tools. Because we believe in local manufacturing, we have created formulations for all around the world using local byproducts. And because the process is self-assembling, it can be done anywhere in the world as there's no need for expensive equipment to set up a production facility."

Ecovative is already producing custom protective packaging products for several companies, including Steelcase and Dell. Moreover, the company is looking to develop prepackaged kits to allow customers grow their own products by 2013.