Cooling lubricant treatment: How to extend the service life of your cooling lubricant

Cooling lubricants are an essential process medium in the metalworking industry. They are responsible for dissipating heat and reducing friction during machining processes. This makes them indispensable for a smooth work process and optimum product quality. However, once they have been used, they are expensive to dispose of, usually after just a few weeks. One solution: cooling lubricant treatment with specialised filtration solutions. In this article, you can find out how to best treat your cooling lubricants with our filter systems and thus significantly extend their service life.

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Filtration Knowledge

·5 Min. Reading time

The tasks of cooling lubricant

An essential process in metalworking is mechanical processing, such as machining or grinding. During these processes, heat is generated by the friction between the tool and the workpiece, and chips and metal particles are produced.

This is where the cooling lubricants come into action: their task is to reduce friction and heat production and to dissipate the resulting heat. They also remove the metal chips produced, which can then be briquetted and recycled.

Why is a good cooling lubricant preparation important?

A well-functioning cooling lubricant treatment system is essential for optimum cooling and lubrication performance during the production process. Thoroughly cleaned coolants ensure better surface qualities during machining and ultimately higher product quality. Careful cleaning of cooling lubricants also significantly extends their service life. Cooling lubricant preparation therefore makes a significant contribution to cost-benefit efficiency in the metalworking industries.

However, reconditioning is not only useful for economic reasons – it also protects the environment considerably. Without the right cooling lubricant management, the cooling lubricants only last a few weeks and then have to be disposed of as hazardous waste. By carefully cleaning the cooling lubricants, they can remain in the production cycle for a long time. Good coolant preparation also helps to conserve resources and reduce CO2 emissions by increasing efficiency. It is therefore both cost-efficient and sustainable.

What makes cooling lubricant treatment necessary?

During the work process, cooling lubricants absorb a wide variety of residues such as aluminium, steel, copper and other metal chips as well as abrasive abrasion and other impurities. These must be regularly filtered out of the cooling lubricants so that they can continue to fulfil their task as lubricants.

Cooling lubricants also change through their use. For example, through the heat they dissipate, through changes in the preparation water, or through mechanical stress and oxidation. These changes are reflected in the pH value, concentration or bacterial infestation. It is therefore important to carry out regular tests. We have summarised how and at what intervals they should be carried out in our article on checking cooling lubricants. However, most of these tests can only be carried out with a cooling lubricant that has been prepared by filtration.

FAUDI filtration solutions as effective cooling lubricant cleaning systems

FAUDI has developed various solutions for efficient cooling lubricant maintenance – different systems are used depending on the area of application, quantity and degree of contamination.

Cooling lubricant treatment with BELT FILTERS

FAUDI vacuum filters can be used universally – in cooling lubricant treatment and beyond. They are suitable for cleaning cutting, grinding and rolling oils, emulsions and aqueous solutions. The separation range is between 20 and 100 μm, depending on the material to be machined, the type of machining and the filter material used. The modular design of the FAUD filter allows the filtration capacity to be customised from 100 l/min to 20,000 l/min. As a result, they are suitable for a wide range of waste quantities and types of contamination.

Our FAUDI pressure belt filter is also ideal for cleaning the same process media. This filter can also be used universally and can be optimally adapted to the respective conditions thanks to its modular design – with separation ranges between 30 and 100 μm. A special feature here is that filter finenesses of up to 10 μm are also possible thanks to the optional precoating with additional filter aids. This system can therefore also be used for very fine contamination of the cooling lubricant.

Our FAUDI folding belt filter is a fully automatic cooling lubricant filter with a high throughput capacity. Thanks to the special design of our filter, a particularly high filter cake of up to 15 cm can be built up, which further increases the separation performance. Filter areas of 1 m² to 2.5 m² per filter are possible.

FAUDI inclined belt filters are particularly advantageous when a high filtration performance is to be achieved in a limited space. They can be used as decentralised filter systems on the machine tool or as stand-alone filter systems. They are used for slightly smaller quantities of cooling lubricant to be cleaned, with a filtration capacity of 30 l/min to 800 – 1000 l/min.

Cooling lubricant treatment with cartridge filter systems

FAUDI cartridge filter systems are also popular for the treatment of cooling lubricants. They are particularly economical for large volume flows. However, we also offer a compact design for medium-sized operations.

A system with a particularly high dirt holding capacity is our patented regenerable microfilter with a filter surface area of 2.5 – 73 m² per filter dome. The filter cartridges can be completely cleaned by backwashing. This makes the system particularly durable and sustainable. Our compact system can be used economically from volume flows of 50 l/min.

Our FAUDI backflush filter also works without filter aids. The filtration performance can be individually adjusted to 250 l/min to 20,000 l/min. The filter surface can also be easily removed at a later date. This makes our backflush filter very sustainable.

Our precoat filters, which are also available in a compact version, are suitable for particularly finely contaminated cooling lubricants. With the right filter aids, ultra-fine filtration can also be carried out here. Depending on the dirt content of the cooling lubricant to be filtered and the filter aid, filter finenesses of between 3 and 10 µm can be achieved. The filter elements are also completely cleaned here by automatic backwashing. This makes all our cartridge filter systems particularly sustainable.

Further processing of residual materials

Good cooling lubricant maintenance already contributes significantly to closed production cycles and the conservation of resources. A further step in this direction can be taken by using systems for chip and sludge processing. Metal grinding sludge – a mixture of fine metal chips, cooling lubricant, abrasive abrasion and impurities – as well as moist metal chips can be further processed in our briquetting and screw presses. They are used to press out the cooling lubricant remaining in the moist residual material and to press the metal swarf into usable briquettes.

This makes them doubly economical: by enabling the metal briquettes to be sold as recyclable material and by reducing the need for fresh emulsions. If you want to know how you can utilise our presses profitably, we recommend our blog posts on how briquette presses and screw presses work.

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Cooling lubricants are indispensable in all metalworking industries – from the automotive and aviation industries to the machine tool and rolling/steel industries. Cooling lubricant preparation that is ideally customised to your application is beneficial for your metalworking operation in many ways:

  • Increased quality: an increased cooling lubricant quality has a positive effect on the quality of the machined surfaces
  • Cost savings: closed circuits reduce the costs for fresh cooling lubricants and disposal
  • Sustainability: a long service life of cooling lubricants conserves resources and avoids hazardous waste

In most cases, it is therefore worth investing in good cooling lubricant management. We will be happy to advise you on the best solution for your filtration task.