Quantitation of Fatty Oil in Cutting Fluid by Single Reflection ATR Spectroscopy

Introduction

Cutting fluid is a type of lubricating oil that is used to suppress the generation of heat or friction when cutting metal, and it is distinguished as either water-insoluble or water-soluble depending on its composition. If it is water-insoluble, it is further classified into four types according to its fatty oil content, total sulfur content, and corrosiveness to copper. In JIS K 2241 Cutting Fluid (Supplement 1), two types of fatty oil content tests are described for water- insoluble cutting fluid analysis, the saponification test method and the infrared spectroscopy method. The test method using an infrared spectrophotometer specifies that a calibration curve be generated using standard samples consisting of paraffin solvent spiked with rapeseed oil, and that quantitation of the carbonyl group in the cutting fluid be conducted. This is the same method as the analysis of fatty acid methyl esters (FAME) in biodiesel, which is described in EN 14078 and ASTM D7371. Here, we introduce the determination of fatty oil content using an infrared spectrophotometer in accordance with JIS K 2241.

August 21, 2013 GMT