EVALUATION OF PERMITTIVITY AND SURFACE TENSION OF ORGANIC AND SYNTHETIC LUBRICANTS

Abstract

In the metal-working industry lubricants are one of the many components which ensure the quality of finished goods. During operation the imbalance of lubricants’ components is being observed by reason of contamination by bacteria, mold fungi and microalgae. These factors result in both low-quality metalworking and allergic diseases of plant personnel. The present methods register these changes not very efficiently and for a long time. On frequencies of dispersion of free water permittivity the microwave dielectrometry makes it possible to estimate structural and functional state of a biological system in real time according to the change of bound and free water quantity on macromolecular complexes. The aim of this work is the determination of efficiency of control of biological contamination of organic and synthetic lubricants via permittivity and surface tension and also structural and functional characteristic of the microflora. In this work we have carried out measurements of permittivity and surface tension of organic and synthetic lubricants (freshly prepared and worked-out) by means of microwave dielectrometry. Biological analysis of the microflora’s morphological particularities has been fulfilled by calculation of bacterial colonies with subsequent determination of cells via a microscope. According to the experimental data the increase of bound water in the system of worked-out lubricant and microflora in comparison with freshly prepared samples was observed. We revealed the decrease of permittivity and surface tension in synthetic worked-out lubricant perhaps by reason of contamination by gram-positive nonspore-forming bacteria. According to the fulfilled measurements the lubricants’ quality control can be a marker for a timely replacement of low-quality lubricants and for a decrease of defective goods.

Keywords

• biological contamination
• lubricants
• microwave dielectrometry
• surface tension