Filtration: the key of successful EDM

Modern industry is full of processes for machining materials. Among these techniques, EDM stands out for its ability to shape hard, complex parts with unrivalled precision.

The EDM process requires electricity, an electrode, a workpiece (which must be conductive) and a dielectric fluid. Unlike other machining methods, EDM requires no direct contact between the components. How is this possible? Thanks to the conductivity of the materials. When the gap between the electrode and the workpiece is reduced, an electrical discharge occurs between the two conductive elements. As it passes through the dielectric fluid, this electric current creates a "bubble" which then implodes. This micro-implosion works locally on the surface of the part. With successive discharges, several craters form on the surface, leading to continuous erosion of the part until the desired shape is obtained.

There are two main types of EDM: wire EDM and sinker EDM.

Dielectric fluids play an essential role in the EDM process. These insulating fluids have three key functions that guarantee efficient and safe operations:

1. The dielectric fluid provides electrical insulation, preventing electrical discharges from being dispersed between the electrode and the workpiece.
2. It cools the electrode to prevent premature wear and stabilises the temperature of the workpiece.
3. The dielectric fluid removes machining particles from the gap to ensure a clean surface finish.

Dielectric fluids are therefore proving to be invaluable allies in the field of EDM, guaranteeing high-precision operations and increasing machine life. However, a dielectric fluid is only fully effective if it is clean. Good filtration of the fluid is therefore essential.

• Preserve machining quality: Dielectric fluid filtration eliminates particles present in the liquid. By capturing the metal residues generated during erosion, it prevents the build-up of undesirable deposits on the electrode and the workpiece. This guarantees constant precision in the machining process, avoiding surface defects and dimensional variations caused by the deflection of electric arcs due to the presence of contaminants.
• Maintain equipment performance and durability: By removing unwanted particles, dielectric fluid filtration protects the fluid flow channels. This prevents clogging of the cooling and lubrication circuits, helping to maintain equipment performance. Filtering also prevents debris from accumulating on the electrodes, causing premature wear. In other words, dedicated EDM filters extend the life of your electrodes.
• Preventing short circuits and accidents: Metallic particles in the dielectric fluid can cause short circuits between the electrode and the workpiece. Rigorous filtration eliminates these contaminants, ensuring adequate electrical insulation and preventing malfunctions that can damage electrical components. This also helps to ensure safe operations and avoid potentially dangerous incidents in the workplace.
• Reduce costs and downtime: By maintaining a clean, filtered dielectric fluid, machining operations are more reliable and consistent. This reduces rework, minimising production costs. In addition, by preventing blockages and malfunctions, filtration of the dielectric fluid reduces downtime for maintenance and equipment replacement, improving overall workshop productivity.

Electroerosion is not the only area of expertise for HIFI FILTER® in the industrial sector. We also offer products dedicated to filtration in areas such as machining, cutting, plastic injection and printing. Together, we ensure that all the fluids involved in the operation of your machine tools are filtered, guaranteeing the reliability, durability and optimum performance of your equipment.