Cutting fluids are widely used in cutting because of their functions such as cooling, lubrication, cleaning, and rust prevention. In the use of cutting fluids, there are often problems such as deterioration, odor, corrosion, foaming, and skin allergies. Here, we will discuss the problems in the use of cutting fluids and their countermeasures in light of the practical experience in our work. United Precision Services | Bost Heavy Duty Machines
First, the problem of deteriorating quality of cutting waves
The main reason for the deterioration of the cutting fluid is that the cutting fluid contains a large amount of bacteria, and bacteria in the cutting fluid mainly include oxygen-consuming bacteria and anaerobic bacteria. Oxygen-consuming bacteria live in mineral-rich environments such as water, concentrates of cutting fluids, and oil leaked from machine tools. Under aerobic conditions, they split into two every 20-30 minutes. The anaerobic bacteria survive in an oxygen-free environment and split into two per hour. Metabolism releases SO2, smells rotten eggs, and the cutting fluid turns black. When the bacteria in the cutting fluid is greater than 106, the cutting fluid will become odor. United Precision Services | Bost Heavy Duty Machines
(1) Bacteria enter the cutting fluid mainly through the following channels:
1) Bacterial intrusion during the formulation process, such as bacteria in the water used to prepare the cutting fluid.
2) Bacteria in the air enter the cutting fluid.
3) The transport of the cutting fluid is caused by the transfer between the workpiece processes.
4) The operator’s bad habits, such as littering dirty things.
5) Poor cleanliness of machine tools and workshops.
(2) Methods for controlling bacterial growth
1) Use high quality, stable cutting fluid.
2) Prepare the concentrate with pure water, not only easy to formulate, but also can improve the lubricity of the cutting fluid, and reduce the amount taken away by the chips, and can prevent bacterial erosion. United Precision Services | Bost Heavy Duty Machines
3) When used, it is necessary to control the ratio of the concentrated liquid in the cutting fluid not too low, otherwise it is easy to grow bacteria.
4) Since the oil used in the machine tool contains bacteria, it is necessary to minimize the leakage of oil from the machine into the cutting fluid.
5) When the pH of the cutting fluid is between 8.3 and 9.2, bacteria are difficult to survive. Therefore, new cutting fluid should be added in time to increase the pH.
6) Keep the cutting fluid clean. Do not allow the cutting fluid to come into contact with dirt, food, tobacco and other contaminants.
7) Frequent use of bactericides.
8) Keep workshops and machine tools clean.
9) If the device does not have a filter device, it should regularly remove the oil and remove the dirt. United Precision Services | Bost Heavy Duty Machines
Second, the corrosion of cutting fluid
(1) Cause of corrosion
1) The proportion of concentrate in the cutting fluid is low.
2) The pH of the cutting fluid is too high or too low. For example, PH> 9.2, aluminum corrosion. Therefore, a suitable pH should be selected based on the metal material.
3) Dissimilar metal material contact.
4) Place the workpiece on paper or wood.
5) Parts stacked.
6) The amount of bacteria in the cutting fluid is excessive.
7) The humidity of the working environment is too high. United Precision Services | Bost Heavy Duty Machines
(2) Methods for controlling corrosion
1) Prepare the cutting fluid with pure water, and the proportion of the cutting fluid should be used according to the recommended value in the cutting fluid specification used.
2) Use anti-rust solution if necessary.
3) Control the number of bacteria to avoid bacteria.
4) Check the humidity and pay attention to control the humidity of the working environment in a suitable range.
5) To avoid contamination of the cutting fluid.
6) Avoid contact with dissimilar materials, such as aluminum and steel, cast iron (magnesium), and copper. United Precision Services | Bost Heavy Duty Machines