Quick, cool wash cycles gentler on clothes and microfibres


16-01-2020
 Microscopic microfibres filtered from the test washing loads/ Credit: University of Leeds/P&G

Shorter, cooler washes help clothes look better for longer and release fewer microfibres, shows EPSRC-funded research into washing machines’ impact on clothes and the environment.

Academics from the University of Leeds and specialists from detergent maker Procter & Gamble have wrung out new insight into how laundering clothing affects fading, colour runs and microfibre release.

Every load of washing releases hundreds of thousands of microfibres – tiny strands that are flushed down the drain. Many reach beaches and oceans where they can remain for many years and be swallowed by sea creatures.

Throwaway clothes lasting less than five washes

In what is the first research into wash cycle duration that used both laboratory and real consumer testing, they found that reducing both washing cycle length and water temperature can significantly extend the life of garments and reduce the quantity of dye and microfibres shed into the environment. The findings were published 14 January in the journal Dyes and Pigments.

Report lead author Lucy Cotton, from the University’s School of Design, said: “We are increasingly familiar with the environmental threat posed by throwaway fast fashion, but we also know that consumers claim their clothes can lose their fit, softness and colour after fewer than five washes – this means it’s more likely they will ditch them long before they are worn out.

“Using shorter, cooler washes is a simple way everyone can make their clothes last longer and keep them out of landfill.”

52% less microfibres and 74% less dye

Mimicking average household loads, the researchers washed 12 dark and eight brightly-coloured t-shirts, together with white fabric squares to test colour-fastness.

Conventional domestic washing machines and Ariel pods of biological detergent were used, comparing 30-minute cycles at 25°C, and 85-minute cycles at 40°C (both with 1,600rpm spins) for 16 cycles each. The research was repeated and validated with authentic loads of dirty laundry provided by UK consumers.

A series of tests were carried out on the garments and fabric squares, and the washing machine waste water analysed. Chemical analysis distinguished individual dyes washed out of the clothing, and microfibres were collected and weighed.

The researchers found washing with a quicker, cooler cycle reduced the amount of microfibre release into the environment by up to 52%, and cut dye release by up to 74%. 

Dr Lant, a Procter & Gamble Research Fellow, added: “Advances in detergent technology, especially in sustainable ingredients such as enzymes, are allowing consumers to get excellent cleaning results in colder and quicker washes. It’s well known that these cycles reduce our energy bills and carbon footprint, but our partnership with the University of Leeds is helping us understand how cycles also slow down the ageing of clothes – keeping us looking smart, saving us money replacing garments and helping the environment.”

Further information

The research, "Improved garment longevity and reduced microfibre release are important sustainability benefits of laundering in colder and quicker washing machine cycles" (Dyes and Pigments), was funded by Procter & Gamble and the Engineering and Physical Sciences Research Council, which provided an industrial CASE studentship to Dr Cotton to allow her to conduct her PhD studies.


Image: Microscopic microfibres filtered from the test washing loads
Credit: University of Leeds/P&G

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