What Is Cutting Fluid?

Cutting fluid (coolant) is an industrial fluid used to cool and lubricate tools and machining parts during metal cutting and grinding. The cutting fluid is made of a variety of super-functional additives through scientific compounding. At the same time, it has good cooling performance, lubricating performance, rust prevention performance, degreasing and cleaning function, anticorrosion function, and easy dilution. It overcomes the problems of traditional soap-based emulsions which are stinky in the summer, difficult to dilute in the winter, and poor in rust prevention. It also has no adverse effects on the lathe paint. It is suitable for cutting and grinding of ferrous metals. It is currently the leading grinding product. All indexes of cutting fluid are better than saponified oil. It has the characteristics of good cooling, cleaning, rust prevention, etc., and is non-toxic, odorless, non-erosive to human body, non-corrosive to equipment, and non-polluting to the environment.

The history of human use of cutting fluid can be traced back to ancient times. People in

classification

Water-based cutting fluids can be divided into emulsions, semi-synthetic cutting fluids and fully synthetic cutting fluids.

The classification of emulsions, semi-synthetic, and total synthetics usually depends on the type of base oil in the product: Emulsions are water-soluble cutting fluids that use only mineral oil as the base oil; semi-synthetic cutting fluids contain both mineral oil and chemical synthesis bases Oil-soluble cutting fluid; fully synthetic cutting fluid is a water-soluble cutting fluid that uses only chemically synthesized base oils (that is, mineral oil-free).

Cutting oil

Lubrication of oil-based cutting fluid

Cutting fluids must meet the four goals of cooling, lubrication, cleaning, and rust prevention, so we should start from these four aspects.

Cooling

High water-based cutting fluid has a water content of more than 95% in normal use, and a water content of more than 97% when grinding;

2. Lubrication

It is difficult to choose a standard to judge the performance of cutting fluid, and it is also difficult to establish a test process to evaluate the efficiency of cutting fluid based on this standard. This problem is more complicated to transfer from the laboratory to the factory, but the performance of the cutting fluid can also be evaluated by the following methods.

The daily use concentration is not more than 5%, that is, this product is less than 5 kg plus 95 kg of ordinary tap water. Depending on the conditions used, the use concentration can be 1% -5%; the roughing concentration is lower, and the use concentration can be 1% -3%. (Except for special processes and materials with special requirements)

This method is used as it is used by different manufacturers. But please read the manufacturer's instructions before use.

Throughout the cutting fluid market in the 21st century, some emerging cutting technologies and corresponding products have come out one after another. Faced with the increase of human environmental protection awareness, the market has increasingly higher requirements for the green environmental protection performance of cutting fluids. For example, the use of biodegradable vegetable oils instead of mineral oil as the base oil for cutting fluids, and the use of tungstate, molybdate, etc. to replace toxic additives in water-based cutting fluids have gradually become the research and development direction of scientific and technological personnel.

With the development of the overall technology of the machinery industry, the cutting speed of the machine tool is faster, the cutting load is higher, and the cutting temperature is higher. At the same time, new technologies are constantly emerging to adapt to the processing of new materials. This requires new high-performance cutting fluids to meet the processing requirements. At the same time, according to the requirements of labor hygiene and environmental protection, cutting fluids should not contain substances that endanger human health and the ecological environment as much as possible. China has imported more and more advanced equipment such as CNC machine tools and machining centers. If the cutting fluid used is imported from abroad, it will be inconvenient to transport and costly. Therefore, it is urgent to develop high-performance cutting fluid to replace imported products. In China, water-based cutting fluids are used more and more widely, and have begun to transition from emulsions to synthetic cutting fluids and microemulsions with good performance and long life. The development of high-performance, environmentally friendly, degradable, long-life cutting fluids; researching ways to extend the life of cutting fluids, thereby reducing the waste fluid discharge of cutting fluids, is an important content of cutting fluid research at home and abroad.

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The main ingredients of transparent water-soluble cutting fluid formula include

The main ingredients are: ethylene glycol, sodium tetraborate, sodium metasilicate, sodium phosphate.

Ethylene glycol: Ethylene glycol is also known as "ethylene glycol" and "1,2-ethylene glycol", referred to as EG. The chemical formula is (HOCH ₂ ) , which is the simplest glycol. Ethylene glycol is a colorless, odorless, sweet liquid that is toxic to animals. The lethal dose for humans is about 1.6 g / kg. Ethylene glycol is miscible with water and acetone, but has a lower solubility in ethers. Used as solvent, antifreeze and raw material for synthetic polyester. Polyethylene glycol (PEG), a polymer of ethylene glycol, is a phase transfer catalyst and is also used for cell fusion; its nitrate is an explosive.

Sodium tetraborate: Sodium tetraborate, also known as borax, has a molecular formula of Na ₂ B ₄ O ₇ · 10H ₂ O. It is a very important boron-containing mineral and boron compound. Usually a white powder containing colorless crystals, easily soluble in water. Borax has a wide range of uses, such as detergents, cosmetics, pesticides, and can also be used to configure buffer solutions and prepare other boron compounds. Borax is often referred to as sodium tetraborate decahydrate, namely Na ₂ B ₄ O ₇ .10H ₂ O, but commercially available borax has often been partially weathered.

Sodium metasilicate: Sodium metasilicate is a low-molecular crystal produced by the hydrothermal reaction of ordinary foamed alkali and caustic soda. The products are anhydrous, pentahydrate, and nonahydrate. Among them, the nonahydrate is only available in the Chinese market. Its melting point is only 42 ° C. It is easy to become liquid or paste during storage and is gradually being phased out. However, due to some user habits and some areas that do not care about crystal water, there is still a certain market for sodium metasilicate.

Sodium phosphate: Sodium phosphate (chemical formula: Na ₃ PO ₄ ) is a phosphate and is an inorganic compound. Generally, sodium phosphate refers to sodium phosphate dodecahydrate (Na ₃ PO ₄ · 12H ₂ O). Sodium phosphate dodecahydrate is weathered in dry air, and when it is heated to 100 ° C, it will lose crystal water and become anhydrous.

The main ingredients of the emulsified cutting oil formula include

The main ingredients are: sodium petroleum sulfonate, polyoxyethylene alkyl phenol ether, chlorinated paraffin, lead naphthenate, triethanolamine oleic acid soap, high speed mechanical oil, tall oil sodium salt, sodium petroleum salt, synthetic fatty acid , Polyethylene glycol, industrial machinery oil.

Sodium petroleum sulfonate: Other names: sodium alkyl sulfonate, T702 rust inhibitor, sodium petroleum sulfonate T702; molecular formula: R-SO ₃ Na (R = C ₁₄ C ₁₈ alkyl); structural formula: Among them, R is a straight-chain aliphatic alkyl group with an average of 14 to 18 carbon atoms; solubility: a translucent liquid dissolved in water, relatively stable to acid and alkali and hard water;

Chlorinated paraffin: Chlorinated paraffin is a chlorinated derivative of paraffin hydrocarbon. It has the advantages of low volatility, flame retardancy, good electrical insulation, and low cost. Widely used in the production of cable materials, floor materials, hoses, artificial leather, rubber and other products. And additives for coatings, lubricants, etc.

Lead naphthenate: The preparation method is obtained by metathesis and replacement of sodium naphthenate and lead acetate. First raise the naphthenic acid with water to 90-100 ° C, then slowly add 30% sodium hydroxide solution for saponification until the solution is transparent to obtain sodium naphthenate, and then metathesis with lead acetate to obtain the crude product. Wash with water. Heat dehydration to obtain the finished lead naphthenate.

Triethanolamine oleic acid soap: oleic acid soap has good cleaning ability to animal and vegetable oil, mineral oil, motor oil, paraffin, lubricating oil, etc., and has good antirust ability. The metal cutting fluid can be used as a cleaning part, and at the same time has good lubricity, corrosion resistance of ferrous metals, and good cooling and rust prevention functions. It is used for steel, iron, aluminum, alloy steel, low alloy steel, clock components Other metal processing semi-finished product cleaning agents, have anti-rust effect. As emulsifier in general industry, it has good emulsifying performance for mineral oil, vegetable oil and wax scale.

High-speed mechanical oil: High-speed mechanical oil is also called high-speed spindle oil. A kind of light mechanical oil. Lower viscosity lubricant. It is obtained by refining petroleum distillates through sulfuric acid or solvent and adding antioxidants. Requires good lubrication performance, low wear on mechanical parts; good stability, not easy to deteriorate for long-term use; light color, does not pollute gauze. It is mainly used for the friction parts of textile machinery with high speed and light load, such as the thrust bearings of spinning machines, twisting machines, roving machines, and knitting machines. It is also suitable for the lubrication of other high speed and low load machinery and some automatic control instruments. . The main quality indicators are viscosity, flash point, and freezing point.

Synthetic fatty acids: Synthetic fatty acids are fatty acids made by chemical synthesis of petroleum products. Used as raw material for making soap. Its carbon number is 10-18, and the lower carbon number is used in other industries. The raw materials for the production of synthetic fatty acids by the paraffin oxidation method are C21-28, normal paraffins (commonly known as paraffin) having a distillation range of 350-420 ° C, and normal paraffins having a distillation range of 320-450 ° C are also useful. The production process is shown in the figure. No picture

Polyethylene glycol: non-toxic, non-irritating, has good water solubility, and has good compatibility with many organic components. They have excellent lubricity, moisture retention, dispersibility, adhesives, antistatic agents and softeners. They are used in cosmetics, pharmaceuticals, chemical fiber, rubber, plastics, papermaking, paint, electroplating, pesticides, metal processing and food processing. There are extremely wide applications in the industry.

Anti-rust extreme pressure emulsified oil formula contains the main ingredients

The main ingredients are: chlorinated paraffin, sulfurized oleic acid, barium petroleum sulfonate, oleic acid, triethanolamine, and mechanical oil.

Chlorinated paraffin: Chlorinated paraffin is a chlorinated derivative of paraffin hydrocarbons. It has the advantages of low volatility, flame retardancy, good electrical insulation, and low cost. It can be used as a flame retardant and PVC auxiliary plasticizer. Widely used in the production of cable materials, floor materials, hoses, artificial leather, rubber and other products. And additives for coatings, lubricants, etc. The metered liquid paraffin was added to the reaction kettle, and thionyl chloride was added dropwise with stirring. After refluxing for 5-7 hours, the excess thionyl chloride was recovered at normal pressure. The water and NaOH aqueous solution were sequentially washed under reduced pressure and dehydrated to a water content of less than 2%, and the output was a finished product.

Barium petroleum sulfonate: Barium petroleum sulfonate is currently used as a corrosion inhibitor in China. According to different use conditions, the general addition amount is 1-10%. It has excellent resistance to moisture, salt spray, salt water and water displacement, and excellent rust resistance to a variety of metals. It is suitable for use as rust preventive in rust preventive grease, such as the preparation of replacement rust preventive oil, inter-process rust preventive oil, storage oil, dual-use lubricant and rust preventive grease. The static corrosion test of petroleum barium sulfonate is better, and it has no corrosion effect on steel, brass, copper, aluminum alloy, zinc and other metals.

Oleic acid: Oleic acid is a monounsaturated Omega-9 fatty acid found in plants and animals. The chemical formula is C ₁₈ H ₃₄ O ₂ (or CH ₃ (CH ₂ ) ₇ CH = CH (CH ₂ ) ₇ COOH). Hydrogenation of oleic acid gives stearic acid. The double bond trans isomer of oleic acid is called transoleic acid. As a chemical reagent, as a chromatographic comparison sample and for biochemical research, verify calcium, ammonia, copper, and determine magnesium and sulfur.

Triethanolamine: Refining method: The triethanolamine content of industrial products is more than 80%, and the rest contains less than 1.0% water, less than 2.5% ethanolamine, 15% diethanolamine, and a small amount of impurities such as polyethylene glycol. During purification, ethanolamine was distilled off with water vapor, and sodium hydroxide was added to precipitate triethanolamine as an alkali metal salt. After separation, the mixture was neutralized and distilled under reduced pressure to obtain a pure product.

Mechanical oil: Petroleum lubricating oil distillate, degreasing , solvent refining, and white clay treatment. Usually only antioxidant additives are added. Mechanical oil is divided into high-speed mechanical oil and ordinary mechanical oil, which are used for the lubrication of general machinery such as textile machinery spindles and ordinary machine tools. The classification of "mechanical oil" has been cancelled in the existing lubricant classification, and the required lubricant can be selected by referring to the characteristics of the L-AN category.

Modern mechanical processing is developing in the direction of high speed, strength, and precision. The development of super-hard and super-strength difficult-to-machine materials has also made the difficulty of cutting increasingly difficult. These two reasons lead to a significant increase in friction and friction heat during the cutting process, which requires the metalworking fluid to have better lubrication, cooling, cleaning, and rust prevention performance in order to obtain the ideal machining surface. Mineral lubricating oil has superior lubrication and rust prevention performance, but poor cooling and cleaning performance. Emulsions and water-based cutting fluids have excellent cooling and cleaning performance, but poor lubrication and rust prevention performance. In addition to all the properties of emulsions, water-based cutting fluids also meet or exceed the requirements of emulsions for their lubrication, cooling, and rust prevention performance. Therefore, water-based cutting fluid has become the development direction of improving processing performance in mechanical processing at home and abroad.

Adding oil-based additives and extreme-pressure additives to water-based cutting fluids is an effective way to improve the lubrication and rust prevention performance of water-based cutting fluids. Nonionic surfactant H synthesized from rosin, maleic anhydride, polyamines and other raw materials has excellent lubricating and antirust properties. Trihexanolamine oleate is an excellent oily additive. Nonionic surfactant H and oleic acid are used. Triethanolamine ester and other water-based cutting fluids have excellent lubricity, rust prevention, cooling and cleaning properties. It is a major breakthrough for water-based cutting fluids.