The chemicals debate

4 April 2002



Nicholas Marshall listens to the arguments about wash processing chemistry


Has the laundry industry made real progress in its use of chemicals in recent years? The question is still up for debate and prompts varying and sometimes opposing views from the chemicals suppliers.

There has been some emphasis on lower processing temperatures. Advanced formulations have appeared to prove themselves in certain contexts but, achieving first class cleaning results across a broad spectrum of laundry classifications is a complex business. Winning ground in one area can have implications elsewhere and these are not always positive.

Charlie Betteridge, European marketing director, Christeyns, says that the only "real developments" - he uses the words cautiously - in laundry chemicals in recent years have been in bleaches.

Peracetic acid, well established on the continent, has started to be seen in the UK. This is, firstly, an alternative to peroxide and effective at lower temperatures - 60C to 70C instead of 80C to 90C - and, secondly, a disinfectant.

Mr Betteridge notes how, about four years ago, a PAP bleach, effective at 40C to 50C, was brought onto the market.

This has generated considerable interest, and results on polycotton in washer-extractors have been extremely good. Blood and protein staining can be effectively removed. However, he says, formulations are expensive and only work in a relatively low pH range. Furthermore, he has concerns about how practical it is to use with continuous batch washing machines and also about greying.

Christeyns places emphasis on Sanoxy liquid a combined bleach-sour designed to benefit production by increasing throughput and creating savings.

Mr Betteridge considers that development work with laundry chemicals will now move forward through giving more attention to changing wash processes, rather than concentrating on the raw materials.

David Dore at Powles Hunt draws attention to the company's development of a totally reliable powder dosing machine. He contends that all liquid formulations are limited by the solubility of chemicals in water and that it is unusual to find a water-based product that contains more than 25% to 30% active ingredients. Liquid formulations contain up to 80% water and that is expensive in transport terms alone!

In many formulations, he says, the ingredients do not form stable mixtures and can separate to give inconsistent results at higher concentrations - a further limiting factor.

"With dry powder formulations, the customer gets almost 100% active product. Their dry nature enables us to include ingredients mixed together that would be impossible in a liquid formulation."

In contrast, Colin Stubbs of DiverseyLever says that the complete liquid package has developed to a point where results and in-use costs can be equal to or even better than those of the powder equivalent. This has led to much more development in dosing technology, and provided the ability to monitor and measure a process and additions.

  Low temperature

His company's latest development Xtend Technology allows the linen rental market to process linen at low temperatures (50C). It is based on a patented stain removal system that is safe on white and coloured work. The pH of the wash is low, giving good effluent conditions.

According to Patrick Dowling of Alex Reid, one of the most important changes of the past few years has been the move from chlorine bleaches, and their associated environmental problems, to oxygen bleaching. As an example he cites Kreussler's Ottalin Oxy, a highly active product for oxygen bleaching which also has a bactericide effect and is completely biodegradable.

The move to lower temperature washing has also influenced the development of detergents and additives. Mindful of this change, says Mr Dowling, Kreussler developed the Trebon range of products to help launderers obtain good cleaning results. Trebon Plus is a highly concentrated powder detergent for low temperature washing, and Trebon Color, a highly active detergent for coloured work including table linen. It is formulated to protect colour and guard against colour transfer.

P&G Professional is starting to enter the commercial laundry market with its liquid feed system for on-premise operations.which includes programmable pumps with up to 10 programs.

The company offers a range of professional detergents and additives including both oxygen and hypochloride bleach. The company sees the reductions in wash temperature as significant and says that there is a greater understanding of the need to not only use more efficient detergents but also to look at ways of cutting energy and water costs. Additionally, a greater tendency, especially in smaller laundries, towards automated processing includes dosing. This is a step change for many establishments, giving them better control and improved cleaning performance and reducing the amount of re-wash.

Bleaching types

New types of bleaching allow better linen safety, improved cleaning and the use of lower processing temperatures, P&G Professional says.

Klentec considers that the main recent developments have been in the introduction of low temperature oxidising agents and the increased programmability of laundry equipment to give greater wash cycle flexibility.

Continental Clip points to the development of sophisticated multi-enzyme powdered laundry detergents, which allow the processing of garments at significantly lower pH ranges and a lowering in temperature to about 60C, reducing the loss of garment's tensile strength.

The company draws attention to Fabritec's niche product Platinum. Originally developed for the US shirt market it can clean and brighten shirts without the need to scrub colours and cuffs. The results obtained, says Continental Clip, would be hard to achieve at high temperatures using heavy bleaching. Platinum is now also being used for wedding dresses, insurance restoration work and even duvets.

Views on sensible ways forward with laundry processing vary, and the debate over temperatures looks set to continue.

Strange paradox

  At Powles Hunt, Mr Dore comments: "Within the laundry industry, it is a strange paradox that chemicals account for just 2% of cost but the cleaning results are at least 50% due to the formulations and controls of methods!"

He adds that the higher the temperature, the faster the chemicals work, indicating that while low temperature detergent technology is effective in household washing, it is not suitable for industrial applications where high speed and low re-wash rates are essential.

"Control of heat loss and waste water will show far more cost reductions than an unrealistic search for low temperature solutions that fly in the face of the fundamental science of laundry technology," says Mr Dore.

And at Christeyns, Charlie Betteridge considers that temperature is still an important factor in getting linen clean.

Due to special re-use of press water, and the use of fresh water almost only in the pre-wash, Christeyns's Sanoxy system, which relies on a temperature of 70C to 75C in the main wash, can achieve energy savings not only in the washing machine but also in the drying process - which is significantly more demanding in energy terms.

Sanoxy is already in the UK, and now being launched in France and Germany. It achieves savings in water and steam of 25% to 30% and also allows shorter cycles and thus increased capacity. The single Sanoxy liquid product is used in place of a bleach and sour (and often disinfectant). A significant advantage is the system's disinfection of the press.

Alex Reid's Patrick Dowling underlines the skilled approach necessary with lower temperature washing to ensure adequate cleaning and disinfection.

Demands for low temperature, although important, are seen by Colin Stubbs at DiverseyLever as less significant than the demand for less or better water usage. Improved use of water has been achieved by chemical and mechanical means. He says: "The chemical changes to a process to save water are based on bleaching technology and whilst savings can be made there are some obvious potential downsides." A mechanical method such as ultra filtration is still expensive with a long pay-back time, he notes.

Best practice

DiverseyLever is focusing on "best practice" and points out that the UK laundry industry remains very "anti-preventative maintenance". Water and steam leaks, and poor valves and controls, are often evident. The company advocates attending to the basics, before moving on to "new technology".

Continental Clip says that Fabritec is currently looking at how heavily soiled high visibility items can be cleaned in an industrial process using low temperatures and new "environmentally friendly" degreasing chemistry. Work with this is in its early stages.

Klentec observes that developments in washing machine technology mean that temperatures, water levels and cycle times can be set freely to save energy.

In some cases, to ensure high quality cleaning, the wash time may need to be extended to offset the result of lower temperature or dip level.

Klensafe is a peroxy carbonate additive for low temperature processing, designed to be coloursafe. Other offerings include Klenstar high quality liquid starch; Klencom high quality softener/sour; and Klendet, a liquid detergent that gives extremely effective soil removal and water softening performance.



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