MecWash Systems Ltd. has completed the installation of a further aqueous-based component cleaning system at MAHLE Powertrain Ltd. in Wellingborough.  The MecWash Midi offers both environmental and performance advantages, and features one of the most comprehensive, integral jetting arrangements the company has ever designed.  The MecWash Midi is dedicated to cleaning aluminium V8 engine blocks and heads for a prestige automotive manufacturer and has the capacity to clean 30,000 individual machined ‘engine sets’ per year.

“Each set, which comprises two cylinder heads and a block, features a wide range of machined elements, all of which have to be cleaned of machining oil and metal swarf to meet the customer’s specifications,” explains Phil Knightley, Production Engineer at MAHLE Powertrain.  “Clearly, this places great emphasis on the capability of the cleaning station, which fulfils a vital role between machining and both leak and porosity testing procedures, ahead of packing and despatch.     

“The decision to work again with MecWash, who have supplied a number of units for MAHLE in recent years, was centred on the company’s ability to meet this complex cleaning requirement in the required time-frame, and to

do so in an environmentally responsible way as a result of the aqueous-based design,” he adds.   MAHLE Powertrain operates an Environmental Management System in accordance with the international management standard, ISO 14001.

Engine sets are loaded into purpose-designed fixtures and then onto individual trolleys that incorporate a steel roller system for ease of handling.  Both were also supplied by MecWash Systems.  These trolleys are brought to the front-loading unit and latched into position before an operator rolls each set into the 800 mm deep drum, which is at the heart of the MecWash Systems’ design.  The wash chamber rotates the components in accordance with a six-minute wash programme, which can be tailored using the PLC.  Each cycle subjects the components to a flood wash, external and internal jetting as well as hot air and vacuum drying – with the process fully meeting the customer’s exacting cleanliness specification.

“As the fixtures are loaded into the drum, they locate on a central spigot through which the wash solution is distributed to no less than 200 individual nozzles,” comments John Pattison, Managing Director at MecWash Systems.  “This not only delivers the optimum amount of cleaning solution, but also directs it at critical areas, to achieve the highest possible level of cleaning performance.”

The need to ensure the jetting arrangement complemented the engine block and cylinder head designs were clearly critical during the development

programme and one that pays testimony to the co-operation between the designers at both MAHLE Powertrain and MecWash Systems. 

“We used a series of CAD drawings to overlay the three different components – blocks and cylinder heads – into the wash space so that jet positioning could be determined,” continues John Pattison.  “The swarf flushing is optimised by the selected arrangement, utilising the power of the high volume pressure pump.”

Because all machine designs from MecWash Systems incorporate aqueous-based cleaning solutions, environmental issues that are associated with alternatives such as solvents, become irrelevant.  Moreover, due to the filtration system, the wash solution is re-used repeatedly, with MAHLE Powertrain anticipating a changeover and disposal on a three-monthly basis only.  

“We assessed a number of alternative systems during the specification phase, but concluded that the MecWash design optimised both our performance and environmental objectives – particularly given the high quality and high profile application within which the unit operates,” adds Phil Knightley.  “Moreover, the company’s ability to supply the machine, the fixtures, the trolleys and the chemical, meant there was an automatic interface between each of these key elements. 

“MAHLE Powertrain has developed a worldwide reputation for the quality of its engineering and its commitment to meeting environmental obligations.  We are confident that the latest MecWash Systems’ facility will enhance

our capability in both areas, and help enable us to meet future high volume output for one of the most prestigious automotive manufacturers in the industry,” he concludes.