Cutting fluid analysis

CUTTING FLUID : ANALYSIS & DIAGNOSTIC

Cutting fluid is a lubricant designed specifically for metalworking processes. There are different technologies of cutting fluids : synthetic, semi-synthetic, mineral or vegetal based emulsions, etc.

This aqueous base liquid evolves regularly over time, depending on product losses (projections, evaporation), pollution, percentage top up, etc. It is therefore necessary to monitor regularly  the conditions of the cutting liquid.

Analysing the physico-chemical characteristics of cutting fluid allows : to check the concentrations of the product, to guarantee a good lubrication necessary for the quality of the surface conditions, to reduce oil change, to limit the maintenance costs of oil change (destruction, cleaning, filling, etc.), and to control the machining costs (tool consumption, scrap rates, etc.).

In addition to an economic aspect, the cutting fluid monitoring also enables to control the quality of the working environment and thus to prevent the risks to the health of the operators.

Analyses and checked points

Bath stability

• Aspect
• pH : indicator of stability of the emulsion, NFT 78-103
• Salting out 24h : indicator of stability and  presence of tramp oil
• Bacteria : development of microorganisms is a degradation factor of the soluble, NF M07-070

Concentrations

• Refractometry concentration
• Acidimetry concentration: measurement of concentration by alkaline reserve
• Concentration by acid breaking: calcul of the concentration by measuring the quantity of oil contained in the emulsion

These 3 complementary methods each measure a characteristic of the emulsion. The interpretation of the results of the three methods thus ensures an accurate diagnosis.

• Tramp oil content: estimation by calculation of pollution from lubricating oils.

Complementary analysis 

• ICP (Spectrometry),  NFT 60-106
• Hardness of the bath
• Chlorides: corrosion control
• Solid impurities content: quantifies the filtration quality of the cutting liquid,  ISO 4405 (modified)

Others tests

The tests below are not part of the classic  sequences but can be carried out according to the wishes or problems encountered.

• CNOMO foaming test
• Corrosion (IP287)
• Measurement of formaldehydes, nitrites,  … (prevention of health risks)
• Test Reichert
• 4 balls test
• Ability to separate tramp oil
• Surface tension
• …

Interpretation of results and diagnosis

From results of analyses transmitted by our laboratory, our team of diagnosticians-consultants will provide you with a detailed and reliable diagnostic on the condition and properties of your cutting fluid. We also propose customised recommendations to assist you in the conditional maintenance of your equipment.

This post is also available in: French