Microbiological Analysis of Coolant Used in Machining

Abstract

The subject of microbiological tests of coolants presented in the work is the cutting fluid (emulsifying oil) of Fuchs ECOCOOL 68 CF3. The liquid was taken from the tanks of three different numerically controlled machines (Lasertec 65, MillTap 700, CTX beta 1250 TC), used with different intensity. The five most characteristic and popular media were used in the study: nutrient agar - plain, TSA medium (tryptone-soy-agar), medium with dichloran, rose bengal and chloramphenicol, Sabouraud agar with Chloramphenicol, Czapka agar. The incubation time was dependent on the type of microorganisms. After the specified time, the plates inoculated on the medium were subjected to visual observations and under the Leica DM 500 microscope. As a result of the observation, the following types of microorganisms (fungi and bacteria) were detected: Aspergillus Niger Tiegh, Candida Albicans, Saphylococcus Aureus, Micrococcus Luteus and Escherchia Coli and Citrobacter Freundia. The assessments were made in fixed periods. The results are presented as a function of the intensity of the use of cutting fluids. Microbiological analysis of machining fluids will allow for optimizing the time periods of using coolants and will also contribute to the protection of the operator's health and indirectly "extending the life cycle" of the technological machine.

Keywords

• microorganisms
• metalworking fluids
• cnc machining
• cooling and lubricating properties