The difference between emulsion, cutting oil and cutting fluid
October 05, 2022
Emulsion is a high-performance semi-synthetic metalworking fluid, especially suitable for the processing of aluminum and its alloys, but not for lead-containing materials, such as some brass and tin-like metals. This product has a long service life and is completely unaffected by oil leakage and mixed oil. It is best to use soft water for deployment. Cutting oil is a special kind of lubricating oil, which is prepared by mixing low-viscosity lubricating Base Oil with some animal and vegetable oils, antioxidants, anti-wear agents, and rust inhibitors. Cutting fluid is a cutting fluid in which the oil is diluted with a large amount of water, usually containing 5 to 20 percent of the oil, and its dosage accounts for about 95 percent of the total cutting fluid. Water-based cutting fluids are generally divided into emulsions (soluble oils, Soluble Oil), microemulsions, and chemical aqueous solutions. The latter two are called semi-synthetic and fully synthetic in the market.
In terms of lubricating performance, the lubricating performance of oil-based cutting fluids is better than that of water-based cutting fluids. However, the cooling effect of water-based cutting fluid is significantly better than that of oil-based cutting fluid. Generally speaking, slow cutting requires higher lubricity of the cutting fluid. When the cutting speed is lower than 30m/min, cutting oil needs to be used. Emulsions combine the lubricity and rust resistance of oil with the cooling properties of water, and are therefore effective for high-speed, low-pressure metal cutting operations that generate large amounts of heat. The cutting oil with extreme pressure additives is effective for cutting any material when the cutting speed is not higher than 60m/min. During high-speed cutting, due to the large heat generation and poor heat dissipation effect of the oil-based cutting fluid, the temperature in the cutting area will be too high, resulting in smoke and fire. In addition, because the workpiece temperature is too high, it is easy to produce thermal deformation, which affects the machining accuracy of the workpiece, so water-based cutting fluids are often used. Compared with oil-based cutting fluids, emulsions have the advantages of greater heat dissipation, cleaning and economy, which are beneficial to operator hygiene and safety. Therefore, metalworking plants are more willing to use emulsions. In fact, except for materials that are particularly difficult to machine, the emulsion can be used for almost all light and medium-duty cutting operations and most heavy-duty machining. The emulsion can also be used for complex grinding such as thread grinding and groove milling. The disadvantage of the emulsion is that it is easy to cause bacteria and mold to multiply, and the active ingredients in the emulsion will be chemically decomposed and odorous and deteriorated, so generally, less toxic organic fungicides should be added. The advantages of chemically synthesized cutting fluids are economy, fast heat dissipation, strong cleaning and excellent workpiece visibility, easy to control machining dimensions, and their stability and anti-corrosion ability are stronger than emulsion fluids. Poor lubricity will cause sticking and wear of the moving parts of the machine, and the sticky residue left by chemical synthesis will affect the movement of machine parts and cause rust on the overlapping surfaces of these parts.
