Have you ever wondered what happens to old carpets, after they're thrown away? For the most part, they're incinerated, with only about 20 percent of the material being recycled. Given that over 700 million square meters (837 million square yards) of carpets are produced in Europe every year, with the U.S. reportedly producing ten times that amount, that's a lot of burning floor coverings. Dutch companies Bond Textile Research, Best Wool Carpet, and James wanted to change that, so they commissioned a research team from Spain's Universitat Polit├Ęcnica de Catalunya (UPC) and Austria's University of Graz to come up with a solution. The result was a new type of wool carpet that is reportedly cheaper and lighter than traditional products, and that can be completely composted when worn out.

The research project is called "Erutan," which is "nature" spelled backwards, as the idea behind it is for carpets to return back to nature.

One of the first steps in the making of the biodegradable carpets is to obtain wool from New Zealand sheep that have grazed on organic, pesticide- and heavy metal-free pastures. That wool is then subjected to an enzyme-based treatment, to remove any impurities it might contain. It is then spun, and cross-linked to the base of the carpet.

With traditional wool carpets, even though the wool itself may be biodegradable, the latex backing that holds the carpet together is not. According to UPC, that latex is expensive, makes up 70 percent of the carpet's weight, and must be applied using a high-temperature vulcanization process. Instead of latex, the new carpets are backed with a biodegradable paste made from natural phenolic compounds.

This paste is polymerized using oxidative enzymes, in a process that sees the carpet first being kept at a temperature of 45C (113F) for 15 minutes, followed by an additional 15 minutes at 95C (203F). The vulcanization process required for the latex backing, by contrast, requires a temperature of 100C (212F), and is claimed to use 50 percent more energy.

Presumably, naturally-sourced dyes could be used to add color to the carpets.

The UPC researchers claim that when no longer wanted, the carpets could be shredded and turned into organic material, such as fertilizer. Mohawk Industries, one of the largest carpet manufacturers in the U.S., has reportedly shown an interest in the technology.