New Developments in Soluble Oil Manufacture

THE TERM "SOLUBLE OIL," whilst well established in engineering practice is a misnomer, the oils are not soluble but emsulifiable and are blends of mineral oil with a suitable emulsifier. To illustrate this it might even be said that a very crude soluble oil is formed when soap is rubbed into oily hands. Certainly a crude emulsion results when the hands are subsequently rinsed. Modern soluble cutting oils are much more complex than this, the emulsifier usually consisting of a blend of petroleum sulphonates with soaps of fatty acids. Since this emulsifier may not readily form a homogeneous blend with the mineral oil some "coupling" or "linking" agent is often necessary to prevent separation and to ensure rapid and even dispersion of the oil when it is added to water.