What is hard water?
Hard water refers to water containing trace elements of minerals such as calcium, magnesium, calcium and magnesium. The hardness of water refers to the amount of calcium and magnesium in the water. The dissolution of 1 grain of calcium and magnesium into one gallon of water indicates that the hardness of the water is 1 GPG. Usually, we say that the water with a content of 0.5 GPG or less is soft water, and the increase of 3.5 GPG for 0.5 or more is one unit, that is, the water content of 0.5 to 3.5 calcium and magnesium is micro-hard water, and the water containing calcium and magnesium is 3.5 to 7 GPG. For medium hard mass water, the water containing 7 to 10.5 GPG calcium magnesium is hard water and so on. It is a very hard, very hard mass water. The tap water that we usually use in our daily lives is called ordinary hard mass water. The extremely hard quality water is groundwater and river water containing more than 10.5 GPG of calcium and magnesium.
The amount of calcium and magnesium directly affects the amount and quality of the cutting fluid dissolved in water. The higher the content of calcium and magnesium, the lower the solubility of the cutting fluid, and the more water containing calcium and magnesium, the more the fatty acid combination with the cutting fluid is produced. This is particularly important for cutting fluids of emulsified oil type with fatty acid as the main raw material. Therefore, a synthetic type of Idawell cutting fluid containing less fatty acid is often selected in hard water.
Thirdly, the raw material rust inhibitor, emulsifier and lubricant in the cutting fluid are generally produced from fatty acids. After the cutting fluid is mixed with hard water, these fatty acids react with calcium and magnesium in the water to form another compound, which reduces lubricants, emulsifiers, The amount of rust inhibitor should be affected, which seriously affects the efficiency of emulsification, lubrication and rust prevention of cutting fluid.
The hard water resistance of the cutting fluid refers to the adaptability of the cutting fluid in hard water. It can also be understood that the cutting fluid is not easily reactive with calcium and magnesium.
How to improve the bad phenomenon of cutting fluid in hard water?
First, choose to use soft water with soft water, or soften the water. Water softening treatment can be divided into physical methods and chemical methods. The physical method is to purify by adsorption and filtration of activated carbon and nano-permeable membrane; the chemical method is to soften water by chelation of calcium and magnesium in water by chemical products such as EDTA and trisodium phosphate to form a chelate which is not easily reacted with fatty acid. effect.
Second, the use of fully synthetic cutting fluids with good hard water resistance.