Behind the scenes at Unilever’s world-class laundry detergent testing lab

The Appraisal Lab at our Port Sunlight facility in the UK is where we test our laundry detergents – from Power Brands including Dirt Is Good and Surf – to ensure that they’re exactly what consumers want, whether they’re destined for sale in Belgium, Bangladesh or Brazil.

To find out what’s involved, we spoke to Vincent Mole, our Laundry Product Appraisal Manager.

What equipment do you have in the lab?

We have 80 washing machines available at any one time, including front-loading European automatics and top-loading machines from Asia and Brazil. These machines represent what consumers use at home, allowing us to mimic real-world conditions.

Unlike typical home appliances, our machines collect detailed performance data during each wash cycle. This data enables us to analyse and optimise washing processes and product formulations.

At full capacity, we can run over 700 wash cycles a day.

What sort of tests do we run?

We’re world experts in tough stain removal and this is one of the key functional benefits we test for in the Appraisal Lab washing machines. Analysing everyday stains like tea, coffee, wine and cooking oils, we use high-tech scanners to accurately measure the colour of the stain before and after washing. The data generated tells us to what degree the stain has been removed.

But consumer needs and wash loads vary hugely, so we also look at other aspects of product performance including malodour removal, freshness and fragrance, and ensuring no residues are left in short cold cycles.

How does this fit in with the work we do at our Materials Innovation Factory?

The Materials Innovation Factory (MIF) runs tests in the discovery phase of product innovation. It has the highest concentration of robots doing materials chemistry in the world. These robots operate round the clock, carrying out tests that usually take weeks to complete.

MIF robots are programmed to mimic cycles from different types of machine and water conditions. Using computational science, we can change variables to help us predict how well a product will perform. This is the step we take before testing products in the Appraisal Lab washing machines.

Do we always run the same tests?

We carry out regular studies to identify the critical issues – or ‘pain points’ – affecting consumers, and we constantly adapt our tests to meet these evolving needs.

Persil Wonder Wash is a good example, our biggest laundry detergent innovation in a decade. This is our first-ever detergent designed specifically for short cold cycles, so we were testing everything in 15 minutes. Ordinarily, we’d be testing in long wash cycles.

Water conditions vary across the world. Do we take that into account?

We have our own treatment plant which allows us to replicate different water hardness conditions from very soft like you get in Australia to moderately hard in regions like North America.

Water hardness is about the concentration of calcium and magnesium ions. We take our regular water supply, de-mineralise it, then add back in a blend of these ions to get specific compositions. We can also adjust the water temperature.

From the plant, we can supply the lab with any type of typical tap water from around the world. This allows us to assess the performance of our products just as consumers will use them – mirroring their machines, their water and their conditions.

Why does the temperature matter?

It’s about replicating real-world conditions. Typically, in European countries, consumers use front-loading washing machines that heat up the water. But in places like Asia and South America, where the ambient temperature of the water supply is typically warmer, consumers tend to use top-loading machines, which don’t heat the water.

Getting the temperature right is important, particularly if, for example, we’re testing how well capsules dissolve – they dissolve quicker in warmer water.

How about the types of fabric we use?

There’s an incredibly diverse range of fabrics, so we test across the spectrum. Traditionally, wash loads have been made up of cotton and polyester, and blends of those. But we’re seeing a shift towards more synthetic clothing – such as sports and athleisurewear – so we’re continually adjusting the tests we perform.

What does the future hold for laundry innovation?

One important shift will be how all the data we generate will power AI and predictive modelling technology to develop and test new products.

Take Wonder Wash, for example. Using robotics and AI, we completely ‘rebuilt’ the concept of a laundry detergent in response to consumers who are looking for convenience and energy saving.

Machine learning enables us to generate, capture and share data across our R&D facilities in record time. This will continue to help us create products that solve the laundry pain points of the future.