Clean and green

Aqueous cleaning of components can deliver excellent results, has advantages for the operator and demonstrates environmental responsibility, according to John Pattison, managing director of MecWash Systems

Increasing competition demands greater efficiency and consistently high quality output from businesses, while fulfiling environmental obligations. The importance of environmental responsibility can often move far beyond the obvious benefits, it can even be a specific customer requirement during the tendering process. In this context, product and component cleaning is a key focus. Cleaning installations not only have to deliver excellent performance, but must also demonstrate greener credentials. Increasingly, many manufacturing and engineering companies are looking towards aqueous cleaning - not just because the concept can deliver excellent results, but because it can eradicate the acknowledged drawbacks of solvent cleaning, not least for the operator.

Solvents Emissions Directive MecWash Systems offers a choice of aqueous component cleaning systems that can be installed either as standalone units or within a manufacturing line. Operating in a range of engineering businesses worldwide, the shift away from solvents that they enable does not only reflect the drive towards quality and environmental improvement, but also helps users meet greater regulatory requirements.

"This was brought into sharp focus by the advent of the UK's Solvents Emissions Directive in 2004 with particular relevance to metal cleaning applications," comments MecWash managing director, John Pattison.

"The SED stipulated that all users of volatile, organic compounds had to operate under licence by the end of October 2007 and drew particular attention to Trichloroethylene, amongst other chemicals, which had been widely used in cleaning applications.

"This has been emphasised more recently when manufacturers and distributors agreed with the EU Commission to sign a voluntary charter not to supply Trichloroethylene to open top degreasers after the end of 2010.As a result, all such users would either have to invest in expensive, hermetically sealed degreasers - and still be subject to emissions checks and future legislation - or move to other systems such as aqueous," he explains.

Similarly, alternative solvent n-Propyl Bromide, which has been promoted as the ideal drop-in replacement for Trike, has been re-classified as a CMR (carcinogenic, mutagenic or toxic for reproduction) - the same category as Trike, and may also be a priority for control or replacement under the REACH EC Directive, which became effective at the start of June 2007.

"From both environmental and production quality points of view, we believe the argument for aqueous-based cleaning has now become overwhelming and, indeed, the success we have enjoyed across our range of equipment pays testimony to this view," adds Pattison.

All MecWash machines are based on a rotating drum within which products and components are held and subjected to spray and flood washing and drying processes. A wide range of components can be accommodated - from those loaded loose in baskets to larger scale items held in purposedesigned fixtures.

"Model selection is often dependent upon the specific component or range of components to be cleaned," continues Pattison, "but each can then be tailored to meet precise application requirements. For example, we can incorporate ultrasonic cleaning or direct jetting - the latter, a reflection of the increasingly widespread use of complex components." Here he highlights applications in the aerospace, automotive and medical industries as being particularly relevant.

"The machining of such components unavoidably creates numerous areas where swarf and other contaminants have become trapped and the combination of our rotational washing technology and highly focused jetting action can often maximise the cleaning performance. Specification requiring removal of particle sizes of less than 100 microns - common on complex engineering components - can thus be readily addressed," he continues.

Recycling system The environmental benefits of MecWash technology are enhanced by the use of a purpose-designed wash water recycling system from the company's specialist division, Aqua-Save Technologies. Aqua-Save units can be specified in either a mobile configuration or built into wash stations and in all cases separate material for disposal from re-useable wash water.

"As a result, typically only 5% of the wash solution needs to be removed from site with the remaining water clean enough, with appropriate permissions, to be discharged to drain," explains Pattison.

With quality component cleaning such a fundamental requirement throughout engineering and with greater acknowledgement of environmental obligations,MecWash believes the argument in favour of aqueous-based cleaning is becoming ever more compelling.Where perhaps 15 or 20 years ago the use of solvents was regarded as the principal option, their use is not only becoming increasingly restricted through regulations, but now has to be seen against the performance capability of units such as those manufactured by MecWash Systems.

"It's a view that is being adopted by more and more of manufacturing industry, both in this country and overseas," concludes Pattison, "to such an extent that we believe aqueous cleaning is now recognised as the most logical and most viable option. From both the production quality and environmental stand point, that has to be seen as a step in the right direction."