Fluid Types The main types of cutting fluids fall into two categories based on their oil content:
Soluble oils (also called Emulsion fluid) are composed of a base of petroleum or mineral oil combined with emulsifiers and blending agents Petroleum or mineral oil combined with emulsifiers and blending agents are basic components of soluble oils (also called emulsifiable oils). The concentration of listed components in their water mixture is usually between 30-85%. Usually the soaps, wetting agents, and couplers are used as emulsifiers, and their basic role is to reduce the surface tension. As a result they can cause a fluid tendency to foam. In addition, soluble oils can contain oiliness agents such as ester, extreme pressure additives, alkanolamines to provide Òreserve alkalinityÓ, a biocide such as triazine or oxazolidene, a defoamer such as a long chain organic fatty alcohol or salt, corrosion inhibitors, antioxidants, etc.
Synthetic fluids (chemical fluids) can be further categorized into two subgroups: true solutions and surface_active fluids.
Semisynthetics fluids(also called semi_chemical) contains a lower amount of refined base oil (5-30%) in the concentrate. They are additionally mixed with emulsifiers, as well as 30-50% of water. Since they include both constituents of synthetic and soluble oils, characteristics properties common to both synthetics and water soluble oils are presented.