Ph.D. Thesis Defense by Zhong Chen
Tuesday, January 30, 2001

(Dr. Steven Liang, advisor)

"Cutting Fluid Aerosol Generation and Dissipation in Machining Process: Analysis for Environmental Consciousness"

Abstract

The use of cutting fluids has raised increasing concerns with regard to environmental intrusiveness and occupational hazards. Cutting fluids are often applied in machining and grinding operations. It often produces mists, smoke, gases and other particles that are incompatible with the shop floor environment. Current National Institute of Safety and Health (NIOSH) in a manufacturing environment is set at 0.5 mg/m3 total particulate as a permissible exposure level for personnel. Unfortunately, most of the current study on the fluid effects has been experimentally based. However, the amount of fluid escape from the cutting zone into the shop floor environment depends strongly on the fluid properties and the operating parameters of the manufacturing process. Therefore, measurement data without analytical understanding of the contamination process often reflect only a minimum set of information and typically are not easy to extend to new conditions, various fluids and different processes. To facilitate machining and grinding process planning and fluid selection in meeting the requirements of productivity and environmental compatibility, a quantitative and scientific modeling of aerosol generation is essential. The mechanisms primarily responsible for the creation and dissipation of cutting fluid aerosol will be examined.  Based on the description of fluid motion, modeling of atomization, and treatment of statistical variation, the airborne particulate concentration and size distribution are quantitatively expressed in terms of fluid properties, fluid application conditions, cutting process parameters, as well as machining time. This research will result in a new and original way to model aerosol generation that will enable optimal usage of fluids in machining process for the environmental consciousness. The analytical models will be verified using experimental method with various manufacturing conditions and different cutting fluids.