Cutting Fluid Aerosol from Splash in Turning: Analysis for Environmentally Conscious Machining

Abstract

The generation of airborne particulates from cutting fluids in machining operations poses, a potential threat to machine operators. The primary mechanisms through which cutting fluid atomises to form liquid aerosol are splashing upon impingement on a solid workpiece, spin-off away from a rotating workpiece or tool, and evaporation due to high cutting temperature. This paper presents a quantitative model to describe the concentration and size distribution of aerosol resulting from the splash atomisation of cutting fluids in a lathe turning operation. In this analysis, the main parameters that govern the aerosol formation are the workpiece diameter, nozzle height, cutting fluid properties, and cutting fluid flow rate. The model first examines the fraction of splashed mass in relation to the total flow rate of cutting fluid based on the calibration of the splash parameter. The model further determines the statistical variation of the liquid droplet size due to unaccounted disturbances. The aerosol concentration is then expressed in terms of the product of the splash parameter and the fraction of total droplet volume of a specified size. The validity of the model is experimentally established based on light-scattering aerosol measurement carried out on a horizontal lathe with various jet heights, part diameters, and fluid flow rates. The results of this study can be used to estimate the amount of aerosol from a machining process, and to provide a quantitative basis for process optimisation, fluid planning, and machine design in achieving given environmental standards.