The important role of cutting fluid in machining procedure
The cutting fluid has the functions of lubrication, cooling, rust prevention and cleaning, which helps to reduce the wear of machining tools and improve the precision of the machined surface. Usually, it can be prepared with industrial tap water before it can be used. Therefore, machining enterprises first need to master the proportion and concentration range of the solution.
Proportioning solution:
For cutting fluids, the oil-in-water state is the most stable. The proportioning sequence is to inject water first, then add the cutting fluid stock solution, and continue to fully stir. The deployment ratio is usually 1:20=5%,
To adjust the concentration:
When the concentration of the solution rises or falls, it is necessary to supplement the diluted solution to adjust the concentration. Do not add water directly to the high-concentration solution, otherwise the water-in-oil phenomenon will occur and the solution will be in an unstable state. The correct method is to add a 1% concentration diluted solution to a high concentration solution, or add a 6% concentration diluted solution to a low concentration solution to adjust the concentration to maintain the ideal concentration of 5%.
In addition, users need to pay attention to the following four points when using and maintaining cutting fluid:
1. Foaming
Most of the lubrication management personnel directly use tap water to prepare cutting fluid. The hardness of tap water is soft, and when the concentration deviation is encountered, the solution is easy to foam. As long as the concentration is controlled at 5%, the problem of foaming can be basically solved.
2. Oil slick
There are usually two sources of oil slicks. One is that the guide rail oil sprayed regularly when the machine is running is sprayed and washed by the solution and flows to the solution tank; the other is the oil leakage of the hydraulic system of the spindle and tool change. Because of the emulsifier added to the cutting fluid, the oil is easily emulsified. Therefore, once the oil slick occurs, it must be removed in time. The most ideal tool is an oil skimmer, and an oil suction bag can also be used.
3. Stink
When the oil slick covers the surface of the solution, the solution will be in an oxygen-deficient state. Anaerobic bacteria will become very active in a suitable temperature and anoxic environment. When the anaerobic bacteria decompose the oil to obtain food, they will release hydrogen sulfide gas, which is poisonous and dangerous to the human body. In addition, anaerobic bacteria are more sensitive to pH value. The pH value most suitable for the activity of anaerobic bacteria is about 6.8-8.5, and the concentration of the solution is about 2-2.5%. To prevent the activity of anaerobic bacteria, the concentration of the solution should be maintained at the level of 5%.
4. Skin allergies
The PH value that human skin can contact hovers around 7, and both acidic and alkaline solutions will irritate the skin, resulting in allergies. It is recommended that users wash off with soap or hand sanitizer as soon as possible after contact with cutting fluid, preferably with hand care products.
In recent years, the state has vigorously promoted the concept of green development, and clearly stipulated that cutting fluids cannot contain halides such as chlorine. The main source of these substances are additives, and their attachment to the product also makes it impossible to pass the environmental certification.