Summer is here, and microbiological problems begin to plague many people who are fighting on the front lines of metalworking. Corruption of cutting fluid can lead to a series of problems, such as emulsion stability, lubricity, rust resistance decline, odor, worker complaints of allergies and so on.
Microbial Problems in Metalworking Fluids The metalworking industry contains large amounts of water suitable growth temperature The temperature in the range of 10-40℃ is suitable for the growth of a variety of microorganisms suitable nutrient source Organic components in the metalworking industry Microbial source The water used to dilute the concentrate, the water in metalworking fluids is high in composition, and although some are treated, they contain large numbers of microorganisms. dirt, dust Multiple sources of air, floors, metalworking parts, and more Worker: Worker's skin, clothing, etc. Contaminated machining fluid remaining in the previous system On-site diagnosis of microbial problems in metalworking fluids Should be "seeing, hearing and asking" √ hope Observe the on-site use environment and preliminarily determine the source of pollution Observe whether the appearance of the cutting fluid has changed Observe if there is a problem of foam growth Observe whether the nozzle, filter tube, etc. are blocked Observe whether there is mold growth in the headspace of the machine tool Do the first step → observe the scene → find the problem → prescribe the right medicine √ smell The production of bacteria is generally accompanied by the odor of hydrogen sulfide (rotten egg) The formation of mold is generally accompanied by the production of an acid and musty odor √ Ask Inquire about the usage of the on-site processing fluid (such as: usage concentration, fluid change cycle, whether there is any downtime, etc.) Inquire about tool life, defect rate of machined workpieces, etc. √ Cut Test whether the PH value of the processing fluid has dropped On-site microbial culture using bacterial test pieces Take the contaminated solution to the biological laboratory for screening and recovery experiments How to accurately detect the cause? experiment method: Microbial status detection Upon receipt of the samples, the samples were streaked on TSA and MEA media and then placed in an incubator at 30°C and 28°C for 5 days. Medium: Tryptic Soy Agar (TSA) Bacterial Medium Malt Extract Agar (MEA) Fungal Medium Do a good job of cutting fluid maintenance in hot summer In summer, the weather is hot and there is relatively sufficient moisture in the air, which provides good natural conditions for the growth of bacteria. Do a good job of cutting fluid maintenance from the following aspects: Use high-quality, stable cutting fluid; Using pure water to prepare the concentrate is not only easy to prepare, but also improves the lubricity of the cutting fluid, reduces the amount taken away by chips, and prevents bacterial erosion; When using, it is necessary to control the ratio of the concentrate in the cutting fluid not to be too low, otherwise it is easy to cause bacteria to grow; Since the oil used in the machine tool contains bacteria, it is necessary to minimize the oil leakage from the machine tool and mix into the cutting fluid; When the pH value of the cutting fluid is between 8.3 and 9.2, it is difficult for bacteria to survive, so new cutting fluid should be added in time to increase the pH value; Keep the cutting fluid clean, and do not let the cutting fluid come into contact with dirt such as dirty oil, food, and tobacco; Frequent use of fungicides; Keep workshops and machine tools clean; If the equipment does not have a filter device, the oil slick should be regularly skimmed to remove the dirt.
