Extending the Useful Life of Metalworking Fluids in a Copper Wire Drawing Industry by Monitoring Their Functional Properties

Abstract

Three metalworking fluids (MWFs) from a copper wire drawing industry were monitored for a 2-year period by studying changes in their functional properties: two semisynthetic oil-in-water (O/W) emulsions used in smoothing and wire drawing processes and one synthetic fluid used in the casting process. The parameters measured included zeta potential, droplet size distribution, surface tension, contact angle, foaming power, and optical characterization of the creaming stability. Experimental results showed that zeta potential, droplet size distribution, and creaming stability are the key parameters for monitoring the life span of MWFs and extending its life cycle. Surface tension, contact angle, and foaming power showed large variations with time and did not adequately reflect the changes in functional properties of the MWFs. Furthermore, the influence of several parameters on the properties of MWFs with the purpose of reducing the foaming power was studied. Commercial concentrates and several types of water (decalcified, tap, and distilled) were utilized to formulate the fluids and their properties were compared to those of the plant MWFs.