The commission of the machine tools manufacturers had commissioned Cetim to carry out an instruction file around the problems of filtration and follow-up of machining machines.

A study on filtration was decided, with two working phases including the research of information and the preparation of the test phase, object of this synthesis.

Manufacturers of machine tools for machining must provide filtration systems that are best suited to the "machined material/cutting fluid" couples used by the machine tool customer..

The question is whether there is a way to detect when it is necessary to change the cutting fluid with a new preparation, and therefore to define the degradation criteria.

The object of the study, summarized here, is :

• To better understand and adapt filtration systems to machining machines and to provide manufacturers with recommendations for systems adapted to different operations.
• To produce a guide for the choice of filtration systems.

The scope of work concerns the two types of fluid commonly used: soluble oil by abundant watering or whole oil.

Microlubrication has not been chosen because it would require a separate study.

While the progress made in the field of machine tools and cutting tools makes it possible to improve productivity, the use of high-performance cutting oils of consistent quality also contributes to this improvement by increasing the service life of the tools.

As the search for better productivity requires ever more severe machining conditions and maximum tool life, it is becoming increasingly important to choose the right coolant and to maintain its lubricity and cooling capacity.

In order to meet these last two conditions, it is essential to eliminate the impurities resulting from machining (metal microchips) contained in the oil and to stabilize its temperature.

Maintaining the characteristics of the coolant and its temperature over time depends mainly on the regularity of operation of the filtration/cooling system.

Since good or bad operating regularity is a direct consequence of the choice of equipment and its sizing, it was necessary to produce this practical guide.

Access to the complete document (in French version) is given here :

https://www.cetim.fr/mecatheque/Resultats-d-actions-collectives/Filtration-des-fluides-de-coupe

The objectives of this guide are as follows:

• To provide technical information on solid/liquid separation.
• To provide technical information on refrigeration.
• To present the main equipment available on the market.
• To give the main conditions to be taken into consideration before any purchase.
• To facilitate the dialogue with the supplier of filtration/refrigeration installations.

Since the approach to the acquisition of a filtration/refrigeration system must be adapted on a case-by-case basis according to the company's context, it is important to point out that this guide is not intended to replace filtration and refrigeration professionals.