Harnessing the properties of ozone, which achieves high standards of whiteness, softness and appropriate sanitation according to standards with frugal utilities usage (it is effective in a cold wash), for washing textiles is nothing new but it has proved difficult in the past to maintain the ozone in the water long enough for a consistent result.

Recent technical developments in ozone-producing boxes have now made using the process more attractive; but what about the chemistry involved? We take a look at a British collaboration between chemicals manufacturer Ideal Manufacturing and ozone box provider Laundry Efficiency and review Christeyn’s Speed-O chemical and ozone box package.

Ideal and Laundry Efficiency announced their partnership in June last year and in December 2018, Ideal’s founder Dr Mike Kalli told LCN: “Our research is suggesting that we are able to achieve substantial energy savings, a reduction in process time and the extension of fabric life by using a safe, dissolved form of ozone.”

The function of the ozone is to enable effective oxidation (stain removal) and sanitation, he explains. “Ozone used properly is the strongest of all oxidants and we are actively creating a complete range of processes that accommodate both oxidation and sanitation. The consequence will be a dramatic reduction in energy costs, a reduction in process time and thus more effective use of labour.”

Help to decrease costs
Colin Oakley, MD of Laundry Efficiency adds: “We have invested significantly in the development of a new method in which to deploy ozone into the wash process and deliver some incredible savings for the customers we work with. We wanted to build a partnership with chemical experts who focus, like we do, on reducing the cost of laundry production and helping laundry owners who’ve been hit hard with increased utility and staffing costs over the past couple of years.”

One such is Telford Laundry in Shropshire, England. Working with Laundry Efficiency and Ideal, Paul Woodhead, Telford’s managing director, is saving money hand over fist. According to Woodhead, the ozone system has slashed his use of utilities and chemicals; achieves 100% disinfection (not only on the textiles but also in the machines and associated hardware); produces whiter than white linen and towels; and also prolongs linen life. Neither is there any need to use chlorine bleach as ozone is a powerful oxidiser.”

OPL benefits
Meanwhile, Christeyns’ ozone development trail led the company to devise a product for use in on-premise laundries (OPL) in hotels, restaurants, care homes and other facilities. Christeyns’ Speed-O, launched at ExpoDetergo 2018, is a time-saving wash concept for washing light to medium soiled textile in washer extractors up to 70 kg described as “a synergistic combination of new, cold-active laundry chemicals, ozone and a designated cold wash process”.

Christeyns marketing manager Lieve Keppens explains that ozone is one of the strongest available oxidizers ever and has long been used in many areas of water treatment, sterilisation of medical devices and in the food industry. The use in laundries is not widespread, although the physico-chemical properties of ozone can offer a whole range of advantages.
“Cold washing requires significantly less energy and does not waste any time heating the wash liquor. Ozone itself is biocidal and, in combination with the disinfectant Peracid Forte, meets the EN standards (EN 1276, EN 1650 and EN 13704). Since the ozone molecule is unstable, it cannot be packaged, but must be freshly produced on-site. This is done in the Speed-O-Box,” says Keppens.

The new chemicals, Speed-O Wash (detergent) and Speed-O Boost (alkali booster), have been specifically developed to wash at full performance at cold temperatures. The selected surfactants and optical brighteners are not broken down by the ozone, so the products are fully active throughout the washing process.

Reduced dryer times
The ozone molecule intervenes in the wash process in various ways. Ozone opens the fibre structure and makes the fabric softer and fluffier (see illustration, top left). The textile thereby contains less residual moisture after the washing process, so dryer times can be reduced. Ozone also boosts the performance of the laundry chemicals. Dirt deposits adhering to the textile fibre are loosened and chemically broken down.

According to Keppens, the Speed-O system has been picked up really well. “We have installed it in OPLs across Europe – Belgium, the Netherlands, the UK, France, Italy, Germany and Czech Republic. “At the Intercommunal Hospital Centre (CHI), Lys-Hyrome in Maine-et-Loire, France, the use of ozone has transformed the laundry since its implementation in Spring 2018.  The two sites at Vihiers and Chemillé, wash 324 tons of linen annually,” she says.

“Ozone has an important oxidizing power: its use has allowed us to lower the temperature of the washing water to 16°, allowing us to reduce our consumption of water and electricity. In addition, it opens the fibres of the fabric and make it softer,” reports Stéphane Gadeyne, hotel service engineer.