Imagine washing your clothes in plastic beads. A start-up in Leeds, U.K. last week demonstrated a washing machine that does just that and in the process promises to use 90% less water and 30% less electricity than conventional machines.
To get the stains out, the machine uses polymer beads made of Nylon 66 originally for rifle stocks and a fraction of the water conventional machines consume. What's more, there's no rinse or spin cycle. Xeros' prototype machine was shown in action at The Clean Show which ended yesterday in New Orleans.
"Nylon 6,6 or 6-6 is a straightforward polymer to make tool cases, carpets and injection-molded components. Stains are attracted to the [moistened] nylon beads. We use just enough water to make the clothes damp and between one quarter and one tenth as much detergent," says Nathan Wrench, the washing machine's program manager. Wrench is a mechanical engineer with Cambridge Consultants, an engineering firm hired by start-up firm Xeros Ltd. to develop the machine. Xeros plans to license the design to washing machine manufacturers and make the polymer beads and custom detergent itself (in the show demos, Wrench said he used Tide).
The technique works especially well with fine fabrics such as cottons and linens, producing a clean shirt in 30 minutes instead of the usual 45. And there's no plastic odor with the addition of some fragrance, according to Wrench.
Skyrocketing water and sewerage bills will make the machine if successful in the upcoming 18 months of trials very appealing to strapped retail and commercial laundries."They just tell you how water and sewerage bills are going up and up," says Wrench. "When you tell them they are reducing their carbon footprint by 40%, they're interested but when they hear a savings of 30%, they're really interested."
The initial focus will be commercial businesses, but after that, home units could be built. We have to be careful not to promise too much," says Wrench. Other applications could be in the area of industrial processes, but Wrench is cagey. "Let's leave that at a bit of hint at the moment."
The economics are compelling. A 20 kilo (50 pounds) load in a conventional machine will use at least 200 liters of water. The Xeros machine uses one tenth of that. Less water means less electricity for heating. What's more, the beads stay hot from washing to washing resulting in another electricity savings.
Heated beads draw stains and dirt into their center, but are good for an estimated 500 washes before they have to be recycled, according to Wrench. "The dirt needs to be removed and then the beads can be ground up with a little bit of fresh polymer and made into a new mix. It would effectively be a closed-loop recycling system," he says.The beads will be closely examined in the upcoming tests.
Beads for washing were one a serendipitous discoveries by Leeds University chemist Stephen Burkinshaw who for 25 years has studied how to color fast dyes in fabrics. He knew nylon and cotton together did not hold dyes very well so he reversed the process and voila, nylon beads for washing.
"It was one of these nice stories where a problem becomes an opportunity," says Wrench.