Recently received a lot of information about dilution of water-soluble metalworking fluid. Add water first? Or add water after? With tap water? Or mineral water? Let's take you to know today about dilution method of water-soluble metalworking fluid.
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The use concentration of water-soluble metalworking fluid is usually 5%~15%. The diluent can be divided into two types, one is semi-synthetic or emulsion, and the other is fully synthetic. For emulsions and semi-synthetic liquids, the concentrated solution is added to water when preparing diluents, while for full synthetic liquids, the order of addition has no effect. Dilution method For metalworking fluid whose diluent is semi-synthetic or emulsion, if the concentrated solution is added to the water during the dilution process, it will form oil-in-water emulsion, which is also the ideal state for dilution. If water is added to the oil, a part of it will form oil-in-water emulsion.
It is well known that oil and water are immiscible, and the "emulsifier" added in the metalworking fluid can make the oily formula melt with water. These emulsifiers are a special surfactant. One end of the molecule is hydrophilic, and the other end is lipophilic, making very small oil droplets suspended in water. The amount of emulsifier, the type of oil and the mixing method determine the size of the oil droplets of the emulsion. The size as small as possible is easier to penetrate to the cutting point and reduce the consumption of the processing fluid taken away by the parts. If water in oil emulsion is formed, its shape cannot be changed, resulting in unstable emulsion performance, uneven mixing, easy delamination and shortened tank life. In addition, the processing tool will also wear rapidly due to insufficient lubrication, resulting in a decline in tool service life. For the processing of fully synthetic products, emulsification has been generated in the concentrated solution, so there will be no mixing problem, and no matter how mixed, the product performance will not be affected. Water quality selection No matter how excellent the performance of metalworking fluid is, it needs good operation methods and supporting materials to make it fully play its role. From the perspective of metalworking fluid, high-quality dilution water should have the following characteristics: Less bacteria: When the tap water comes from the water plant, it is usually 10 per milliliter ² To 104 bacteria, while groundwater or surface water may be many times higher. No suspended particles: Water often has suspended substances. In the well water, we often find sand and other pollutants. Due to the pipe pollution of tap water, there may be rust fragments left in the water. Less minerals and other chemicals: Minerals and high levels of nitrogen can cause many problems. In metalworking fluids, many of the components with key chemical properties are anions. When these chemicals contact with cations, they will react. The reaction products are often insoluble in water, making the effective substances lose some or even all of their functions. These insoluble substances are residues often found on machine tools. Therefore, it is better to use soft water with less calcium and magnesium ions to dilute water-soluble metalworking fluid. The better the water quality is, the better the dilution effect is, and the "inferior" water source cannot be used because of cost saving, which may lead to poor stability of metalworking fluid, serious corrosion of machine tool and processing workpiece, and ultimately the loss outweighs the gain. Matters needing attention When diluting water-soluble metalworking fluid, it is better not to premix in the tank, but to add the diluted working fluid into the tank. In order to ensure the optimal performance of the processing fluid and the stability of the concentration, the liquid tank is regularly supplemented with diluent. In case of artificial dilution, vortices can be generated by stirring. Pour the concentrated solution into the vortices and keep stirring to fully mix.
