An extremely high level of component cleaning - which exceeds a target that calls for just one particle of 100 microns in size per 100 ml of wash down fluid - is now being achieved by one of the country's leading manufacturers of hydraulic components as a result of MecWash Systems' technology. A new installation of a MecWash Midi at Hydraforce in Birmingham is combining the company's acclaimed rotational washing technology with ultrasonics, to meet the highly stringent cleanliness specifications.

Manufacturers of a wide range of hydraulic valves, primarily for customers in the
off-road and agricultural vehicle sector, Hydraforce is using the installation for cleaning six separate component designs, including a new transmission manifold for a leading manufacturer of construction equipment.

The manufacturing process sees machining followed by resin impregnation which can, under some circumstances, cause machined residue to adhere to the component. The MecWash Midi uses ultrasonics to dislodge this material before the aqueous washing process removes it, resulting in a highly cleaned component that is then ready for transfer onto the build line.

Andy Fellows is Manufacturing Engineer at Hydraforce and highlights the specific objective that the installation is able to meet for one of the company's most important customers -

"We are required to clean the components to meet precise customer specification," he says, "which calls for no more than one particle above 100 microns in size to remain in 100 ml of wash-down fluid drawn from a one litre sample. Early results using patch pull through tests have indicated that these highly stringent aims are actually being exceeded by the MecWash installation," he points out.

The use of ultrasonics in combination with the rotational, high volume, single chamber wash process - for which MecWash Systems has gained a leading reputation in its field - adds a further significant dimension to the cleaning process.

The surface scrubbing action caused by the ultrasonic sound waves loosens ingrained and adhered contaminants such as casting sand, graphite, lapping pastes and polishing compounds - as well as machining residue as in this case - allowing the powerful flushing action at the heart of the MecWash flood/spray washing process to remove the maximum amount of waste material.

Apart from the high quality results, the design also offers significant efficiency and environmental gains over more conventional ultrasonic installations. Traditionally, these have seen a long line of open top dip tanks which, because they could require up to three times the footprint of the MecWash unit, would place significantly more pressure on available floor space. Moreover, although effectively loosening waste material, the conventional approach would offer no means of removing it from the solution - with an inevitable gradual decrease in cleaning quality.

The blocks, as with the other components that are processed through the MecWash Midi, are held securely in purpose-designed jigs. These are then front loaded from an adjacent roller conveyor into the wash unit in pairs, with the door closed and the drum indexed through 180º each time. The company also has the option of locating smaller components into baskets, sub-divided with nylon partitions, which are also clamped in pairs into the drum mechanism.

An automatic wash process lasting 10 to 15 minutes then follows with the resultant wash solution filtered back into the system for future use. To date, in the first few months of operation, Andy Fellows reports no more than one filter change has been required. Alongside this, the environmental benefits compared with solvent alternatives make for the optimum operating environment and avoid the risk of inappropriate discharge to the drainage system.

"Hydraforce has also specified the unit to allow retro-fitting of both vacuum drying and direct jetting connections," comments MecWash Sales Director Paul Young. "This will enable the company to enhance the performance of the equipment, particularly as the direct jetting operation allows us to provide 'the ultimate wash' for more complex components - even those with multiple blind holes and galleries. Our belief, therefore, is that this is an installation that not only meets the company's stringent requirements today but which is designed to allow them to build further on their success in the future."

With a wide range of metals processed - including aluminium, steel and brass - and a long list of hydraulic valve designs, the need for the highest level of production quality is central to the Hydraforce track record. Its use now of a MecWash Midi - which builds on the advantages the company has gained for several years from a Mini system from the same supplier - is set to help Hydraforce maintain its leading position in this highly specialist sector of the manufacturing industry.