Advanced concurrent technologies for ecological production of dies and moulds

The result is an ecologically self-sufficient and a highly efficient, maintenance free filtering system. Currently, the state-of-the-art filters, either electrostatic precipitators or oil mists filters have a far lower efficiency rate as far as filtering vapours, odours, and heavy metals are concerned. They also need a heavy maintenance schedule; commonly more than once a week. The result being that over time, efficient filtration suffers progressively because maintenance is no longer done. The advantages of our system include: -Cost effectiveness. -The disposal of the saturated adsorbents. -Ecologically self-sufficient and highly efficient. -Maintenance free.

The EDCM machining strategy can be used in the mould and die-making industry sector. The EDM process can be used for roughing and pre-finishing. For this purpose water-based dielectrics should be used because of the lower hazardous potential and the better technological results as compared to hydrocarbon dielectrics. For finishing, the ECM process can be applied. The ECM process enables the thermally influenced white layer to be removed completely, which will improve the material characteristics like fatigue strength and potential for coating.

Electrolyte waste treatment consists of two principal steps including demineralised water flushing and electrolyte concentration. An optional ion exchange unit was investigated to reduce heavy metal content in recycled electrolyte solution. The method is suitable for any ECM wastes (dry or wet, low- or high-electrolyte content). Processing is carried out under mild condition of temperature and normal pressure. A two-stage washing process reduces water usage. The procedure is easily adapted for existing ECM sludge / electrolyte separation systems. Only some simple and commercially available equipment is necessary. Free of electrolytes, solid residue can be reused in metallurgical processes. For more information concerning this result, please refer to the following titles which relate to the same project: Water-Based Dielectric Waste Treatment Hydrocarbon-Based Dielectric Waste Treatment Water-Based Dielectric For Sinking And Wire-Cutting EDM Hydrocarbon-Based Dielectric For Sinking EDM Grinding Coolant Sludge Recycling Hybride Process-Energy Source (SEDCM Generator)

Extraction by liquid CO(2) under mild conditions (room temperature, pressure of 50-60 bars) has been tested as the most promising process for hydrocarbon dielectric sludge treatment. Based on bench-scale experiments, a demonstration plant was constructed at SEPAREX. The unit was sized to treat batches of sludge from 20 kg to 60 kg. The extraction and dielectric separation is performed without any fluid decompression. The dielectric is precipitated in the series of high performance, cyclonic separators. Gaseous CO(2) is then condensed and recycled to the extraction autoclave. The demonstrated performance test with dielectric sludge containing more than 57% of dielectric and considerable amount of fine particles, resulted in a high level of dielectric recovery (99%). A solid residue discharge under pressure has also been demonstrated. To be economically profitable, waste extraction by CO(2) must be performed at higher capacity units equivalent to more than 1000 tons per year. The proposed technology based on CO(2) is a clean, environmentally-friendly process and does not generate any hazardous and toxic products. For more information concerning this result, please refer to the following titles which relate to the same project: Water-Based Dielectric For Sinking And Wire-Cutting EDM Hydrocarbon-Based Dielectric For Sinking EDM Water-Based Dielectric Waste Treatment Grinding Coolant Sludge Recycling Hybrid Process-Energy Source (SEDCM Generator) Electrolyte Waste Treatment

The newly designed water-based dielectric, will make spark erosion more flexible in use, more economic, safer and will reduce its negative influence on environment and health. With this new specially designed high powered, EDM-fluid, it is possible to get a 100% increase of metal removal and a significant decrease of electrode wear in comparison to usual hydrocarbon products. The advantages of the new EDM-fluid are: -Not flammable, no flashpoint -Very low oral toxicity (> 5000 mg/kg ratio) -No irritating effects on eye and skin -Biodegradability > 70% according to OECD 301A -Minimal ecological toxicity (LC50 fish, EC10 bacteria > 30 g/L) -Low water endangering class WGK 1 -Minimal smoke emission under spark erosion conditions -Slightest corrosion on ferrous metals -Twice greater metal removal in comparison to hydrocarbon dielectrics -Better surface quality than common used water-based dielectrics at roughing and finishing -After spark erosion; the melted and solidified zone is extremely thin. There are therefore practically no micro-cracks in the solidified zone -A special technique for the regeneration of the used ion-exchanger-resins is developed -The amount of waste of water-based dielectrics can be reduced by the separation of water with an ultra-filtration or reverse osmosis unit An interesting effect of the new water-based dielectric is, that it can also be used in wire cutting EDM-machines with an great increase of the cutting rate. There are more than 15000 wire cutting machines in Europe. Also the new anticorrosion additive for water-based EDM-fluids can be used in every wire cutting machine. For more information concerning this result, please refer to the following titles which relate to the same project: Hydrocarbon-Based Dielectric For Sinking EDM Hydrocarbon-Based Dielectric Waste Treatment Water-Based Dielectric Waste Treatment Electrolyte Waste Treatment Grinding Coolant Sludge Recycling Hybride Process-Energy Source (SEDCM Generator)

A new approach to the problem of grinding coolant sludge recycling includes extraction by liquid or supercritical CO(2) � a technological solution already proved for hydrocarbon-based dielectric sludge. Bench-scale experiments with both fluids, yield the oil which meets all specifications for such a product (e.g. Sintogrind 353 grinding oil). Fully recyclable �green� solvent and lack of hazardous wastes are the most important features of the method. To became competitive with disposal cost of metallurgical waste, large-scale installation of recycling units capable of 2000 Tons of waste per year have to be considered. For more information concerning this result, please refer to the following titles which relate to the same project: Water-Based Dielectric Waste Treatment Hydrocarbon-Based Dielectric Waste Treatment Water-Based Dielectric For Sinking And Wire-Cutting EDM Hydrocarbon-Based Dielectric For Sinking EDM Hybride Process-Energy Source (SEDCM Generator) Electrolyte Waste Treatment

A concept to control three-phase rectifier units with sinusoidal current consumption was developed. This circuit concept is mainly interested in applications which have a high total harmonic distortion of the input currents, and have a power factor deviating strongly from unity which is caused by short current drain with high amplitudes. The principle of this procedure is the recognition of the operating state of the rectifier unit, following from it the selection and the call of a suitable driving characteristic for the rectifier. The data of the driving characteristics is stored (e.g. in an EPROM). Therefore measurement of the line voltage and of the line current is not necessary. A pilot sample for the supply of a 6 kVA load was built up and proved at the University of Magdeburg.

A measuring instrument was developed for photographic investigation of single pulse spark erosion.The installation consists of a single pulse generator, a test cell, a positioning system (< 1 µm) and a flashlight unit. The camera system can be selected depending on investigation emphasis.The measuring system is especially suitable in order to analyse photographically the discharge phases in the nanosecond field. The system approves defined initial conditions that are achieved by pre-erosion (electrode double system), dielectric movement and electrode positioning. The delays between the starting conditions and the main discharge can be chosen freely in steps of 1 nanosecond. A HSF camera (High Speed Frame Camera) which an exposure time of 5 nanoseconds to 1 microsecond in 1 nanosecond steps, was used for investigations of the spark erosion in dielectric fluids. The optical resolution for this equipment is limited at 1,3 µm pixel resolution.

The development of high power EDM synthetic hydrocarbon dielectrics has led to a new synthetic dielectric liquid which has a 30% better removal rate and less electrode wear in comparison to common used hydrocarbon based dielectrics. Starting out from the described investigations, a multifunctional fluid was developed, which is a high performance EDM-fluid as well as a high speed grinding fluid for machining of polycrystalline diamond tools in a special designed EDM-HSG-machine. EDM synthetic hydrocarbon dielectrics have to following advantages as apposed to common hydrocarbon dielectrics: -Synthetic base fluid with high thermal stability -Very low evaporation rate (14 % in 22 h at 107°C acc. to ASTM D 972) -High flashpoint (150°C according to ISO 2592) -Optimal kinematic viscosity for roughing applications -Biodegradability > 80 % according to CEC L-33-T 82 -Low oral toxicity (> 2000 mg/kg ratio) For more information concerning this result, please refer to the following titles which relate to the same project: Waterbased Dielectric For Sinking And Wire-Cutting EDM Hydrocarbon-Based Dielectric Waste Treatment Water-Based Dielectric Waste Treatment Electrolyte Waste Treatment Grinding Coolant Sludge Recycling Hybride Process-Energy Source (SEDCM Generator)

The hybrid process-energy source works according to the principle of a pulse-current supply. Current-voltage characteristics of the most different machining processes (EDM and ECM) can be realized by the modular construction of the power units and of the ignition units. One specific case of application is the Sinking Electrical-Discharge-Chemical Machining. Working voltages of 0Volts to 40Volts at current amplitudes to 2 kAMP are possible. The current rates of rise can be adapted to the optimal process characteristic in consideration of the interface conditions between energy source and machine. For eroding, the values for EDM are up to 100 AMP/µs and for ECM up to 500 AMP/msec.The modular construction allows a continuous current-enlargement and a multi-channel machining (two-channel). The voltage can be increased by a varied connecting to the power units. For this hybrid process-energy source, changes in the process control strategy can be made by the corresponding models in software. The process analysis and the generator control system are implemented in a micro-controller and PLD's. The nature of the process-energy source makes a more extensive use possible for other applications. The boundary parameters are the connection parameters of the machine systems. For more information concerning this result, please refer to the following titles which relate to the same project: Water-Based Dielectric Waste Treatment Hydrocarbon-Based Dielectric Waste Treatment Water-Based Dielectric For Sinking And Wire-Cutting EDM Hydrocarbon-Based Dielectric For Sinking EDM Electrolyte Waste Treatment Grinding Coolant Sludge Recycling

Due to specific properties of water-based dielectric wastes, their treatment by demineralised water has been developed. Superiority of dielectric extraction in moving bed column was proven. With almost total dielectric recovery, water consumption can be drastically reduced. Furthermore, the system is easily realised in continuous mode. The demonstration unit capable of 200 kg of sludge per day was constructed at SEPAREX. Well suitable for all water sludge with good settling properties, it yields dielectric-free metal residue and high concentrated dielectric solution to be recycled after simple clarification. Extremely cost-efficient, the process can be easily adapted to the existing filtration system of EDM machines. For more information concerning this result, please refer to the following titles which relate to the same project: Hydrocarbon-Based Dielectric Waste Treatment Water-Based Dielectric For Sinking And Wire-Cutting EDM Hydrocarbon-Based Dielectric For Sinking EDM Grinding Coolant Sludge Recycling Hybride Process-Energy Source (SEDCM Generator) Electrolyte Waste Treatment

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