Economy wash

Granule technology could mean new-style washing machines use less water and save energy

Researchers claim to have developed a method of laundering clothes that uses as little as a cup of water in each load but gives the same results as a conventional washing machine.

The process, developed in Leeds University’s School of Design by Prof Stephen Burkinshaw, an expert on textiles and dyeing, is based on the use of plastic granules or chips which are washed with the clothes to absorb dirt and remove stains, using less than two per cent of the water of a normal wash. The clothes also emerge from the process almost dry, thus reducing the need for tumble-driers and saving energy.

To commercialise the technology, the university has launched a spin-out company, Xeros, which is working with some of the biggest names in the washing and dry-cleaning industries to build a working machine. Among the company’s directors is Martin Gregson who has experience in the dry-cleaning and solvents industries, most recently as technical director for Johnson Service Group.

A typical washing machine uses about 35kg of water for every kilogram of clothes that are washed as well as large amounts of energy to heat the water and to dry the clothes afterwards. With environmental concerns becoming increasingly urgent and water an increasingly scarce resource, there is a pressing need to reduce the amount of water and energy used for washing clothes.

According to Waterwise, a UK NGO focused on decreasing water wastage in the UK, washing machine use has risen by 23 per cent in the past 15 years, up from three times a week in 1990 to an average of four times a week per household today. On average, this accounts for 13 per cent of daily household water consumption, or 455 million litres of water daily — enough to fill 145 Olympic-sized swimming pools.

In tests in controlled laboratory conditions, carried out according to worldwide cleaning industry protocols, the process showed it can remove virtually all types of everyday stains as effectively as existing methods, while leaving clothes as fresh as normal washing. It has even been shown to be suitable for delicate items such as embroidered articles and wool. The company believes the new technology could be on the UK market as early as next year.

The Xeros technology could benefit other industrial processes such as wastewater treatment and hard surface cleaning such as during metal degreasing. It could be used in the textile industry during the dyeing process to remove unwanted excess dyes.

Tests are also underway in commercial dry cleaning facilities to see if the technology is suitable for that market. If successful, this would allow dry cleaning firms to stop using the solvent perchloroethylene that has been linked with certain types of cancer and is now facing a ban in various states in the US. Xeros believes that removing the need for this could make its technology very attractive to this market by saving money and improving safety.

‘The technology is not all that complicated,’ said Dr Rob Rule, director of Xeros. ‘We are working on creating a finished washing machine, but so far tests have been carried out using existing machines and simply replacing water with the plastic chips. Now we need to automate the process.

‘One issue is creating the ability to recognise when the chips have absorbed so much dirt they must be replaced,’ said Rule. ‘We have used them up to 100 times in tests and they are still all right, but you would probably have to change them every six months or so, depending on how much washing you do. However, while we cannot say what they are made of, they are not expensive and can easily be mass produced.’

As well as reducing energy use through tumble-drying, reducing the amount of water to be heated creates energy savings. ‘The plastic chips are heated, but they have a much lower heat capacity than water,’ explained Rule.

The potential revenues for machines based on the Xeros technology are considerable. There are more than two million washing machines sold in the UK annually, valuing the market at around £1bn. Although the company cannot yet confirm what the price of the machine would be, it said the process contains nothing that would make the technology prohibitively expensive. Meanwhile, the company has recently secured an investment of just under £500,000 from the university’s commercialisation partner, IP Group, conditional upon certain milestones being met.

Julia Pierce