Cutting fluids water-based emulsions

However, its cooling properties can be utilized when other materials are added to improve machining performance. One of the most common water-based cutting fluids is the so-called soluble oil, which, in fact, is not a true solution but an oiTin-water emulsion in which very fine droplets of oil are suspended in water. Such a fluid has very effective cooling power and the petroleum oil and its additives provide its lubricating and protective properties. 

Water from towns main supplies is usually suitable for the preparation of water-based cutting fluids. That from factory bore holes is also generally suitable, although occasionally it contains excessive amounts of corrosive salts. Water from rivers, canals and ponds usually contains undesirable contaminants, and should be tested before use. A good first test is to mix a small quantity of emulsion and allow it to stand for 24 hours in this time, no more than a trace of the oil should separate. If serious separation occurs, the water should be analyzed to indicate the sort of remedial treatment required. 

There has been much activity in this field of corrosion inhibition in recent years which appears to have been prompted by health and safety requirements. As with engine coolants, the use of nitrites, particularly where amines may also be present, needs to be considered carefully. Nitrites have been widely used in cutting, grinding, penetrating, drawing and hydraulic oils. Suggested replacements for nitrites and/or amines make use, inter alia, of various borate compounds, e.g. monoalkanolamide borates. Molybdates have also been proposed in conjunction with other inhibitors, e.g. carbox-ylates, phosphates, etc . Water-based metalworking fluids usually contain other additives in addition to corrosion inhibitors, e.g. for hard-water stability, anti-foam, bactericidal proderties and so on. Thus, claims are made for oil-in-water emulsions with bactericidal and anti-corrosion properties. 

Chem. Descrip. Hydroxyethyl-s-triazine CAS 4719-04-4 EINECS/ELINCS 225-208-0 Uses Preservative, bactericide, bacteriostat, fungicide for water-based prods, incl. adhesives, polymer emulsions, fountain sol ns., paints, metalworking, sol. cutting fluids and coolants and other prods. Features Water-based effective against yeast stable to light and at pH 6-10 nonflamm. nonexplosive Regulatory EPAreg. no. 49403-16... 

Uses Emulsifier, thickener, wetting agent, dispersant, solubilizer, stabilizer for cosmetics and pharmaceuticals demulsifier in petrol, industry detergent ingred. antistat for polyethylene and resin molding powds. metal treatment emulsion polymerization surfactant in latex-based paints, aq.-based syn. cutting fluids and vulcanization of rubber Properties Colorless liq. m.w. 5500 ref. index 1.4613 water-sol. sp.gr. 1.04 vise. 850 cps HLB 15 cloud pt. 65 C (1%) pour pt. 18 C surf, tens. 40.3 dynes/cm (0.1%) nonionic 100% act. 

As shovvm in Table I, petroleum emulsions may be desirable or undesirable. For example, one kind of oil-well drilling fluid (or mud O is emulsion based. Here a stable emulsion (usually oil dispersed in water) is used to lubricate the cutting bit and to carry cuttings up to the surface. This emulsion is obviously desirable, and great care goes into its proper preparation. 

Water lubrication is used in some niche applications such as reservoir pumps, and oil-water emulsions are often used for metal cutting, taking advantage of the effectiveness of water as a coolant. In the mining industry, hydraulic fluids are frequently based on water so as to exclude flammable materials from underground working areas. Interest in water lubrication is also high in the food, textile, and pharmaceutical industries, where product contamination by oil is a concern (1). 

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