Plastics filters for EDM have long life

Plastics filters for wire and die-sinking EDM machines cover a filter fineness range of 1 to 25 micron, have up to 30% less weight than comparable metal filters and have long service life.

Mann+Hummel will extend the range of its large-size H34 series with the addition of new plastics filters.

The new filters for wire and cavity-sinking EDM filters cover a filter fineness range of 1 to 25 micron, have up to 30% less weight than comparable metal filters and are characterised by a long service life.

The new filters will improve the ability of EDM machine operators to match the filtration to the respective process.

At the 2006 Bi-Mu Italian machine tool trade fair in Milan, Mann+Hummel, the development partner and series supplier to the international automotive and mechanical engineering industries, presented its complete range of plastic large-size filters for wire and die-sinking EDM machines.

Additions to the range include the H 34 2090 and the H 34 1390/1.

Mann+Hummelwill extend its range of products for European EDM machines for OEM and aftermarket with the H 34 2090, which has a filter fineness of 3-5 micron.

The new filter in plastic offers EDM operators a weight advantage and improved economy compared to the H 34 2240 metal version.

The H 34 2090 in plastics therefore replaces the H 34 2240 in metal.

For Japanese manufacturers, Mann+Hummel will present the H 34 1390/1.

This is an economic alternative in plastics to the corresponding metal filter.

The H 34 1390/1 plastic filter from Mann+Hummel achieves the same peformance levels regarding filter fineness and service life obtained by the conventional metal version.

A new filter medium with a mixed-fibre fabric enables a filter fineness range of 1 to 2 micron and ensures clean dielectric fluid right from the start thanks to a high initial separation efficiency.

The implementation of new double bellows technology and the deflection of the dielectric fluid into the plastic end cap enable a large filtration surface area and result in a longer service life.

Mann+Hummel recommends use of this filter in wire-EDM processes with the highest requirements for purity of the dielectric fluid.

Such requirements are especially present for surface finishing processes.

There are further versions of this filter with filter finenesss of 3-5 micron, 10 micron and 25 micron.

The filter fineness range of 3-5 micron represents the quality level mostly used for wire EDM machining where standard materials such as tool steel are processed.

The version with 10 micron satisfies the requirements for filter fineness on cavity-sinking EDM machines.

And last but not least, the 25 micron filter offers excellent performance, service life and filtration quality for processes with critical materials such as aluminium or copper.

In addition, all the filters benefit from the advantage of up to 30% less weight against comparable metal filters.

As a result customers save money on the costs for transportation and disposal.

The filters also have integrated handles to facilitate handling during fitting and removal and are equipped with splash protection to ensure higher process reliability.

During product development Mann+Hummel works together with machine manufacturers to optimise the process parameters.

The EDM filters are internally tested and validated for specific process parameters on an EDM machine under long-term service conditions.

In order to achieve high quality EDM results, the filtration of the dielectric fluid has to be matched to the process.

This involves separation of the coarse particles and reducing the amount of contamination.

The coarser the filtration, the more contamination remains in the dielectric fluid which in turn leads to corrosion and electrolytic elution.

Therefore, in wire and cavity-sinking EDM processes, a high filter fineness is an important factor in order to reproduce a defined surface quality and achieve high process reliability.

Filters of inferior quality compromise the results of the machining process and lead to blocked cleaning nozzles, dirt particles in radiators and piping, and can cause high consequential costs.

* About Mann+Hummel - the Mann+Hummel Group is an international company.

In 2005, the company achieved sales of EUR 1.38 billion.

The Mann+Hummel Group currently employs around 9,500 people at 41 locations worldwide.

The company develops, produces and sells technically complex automotive components such as air filter systems, intake manifold systems, liquid filter systems and cabin filters for the automotive industry, and filter elements for vehicle servicing and repair.

For general engineering, process engineering and industrial manufacturing sectors the company's product range includes industrial filters, filter systems, and materials handling systems and equipment.

Mann+Hummel's customers come from a large number of sectors, with series production for the automotive industry occupying a key position.