How to distinguish whether high temperature grease is high temperature resistant?
As the working environment of machinery and equipment is becoming more and more demanding, the demand for grease is also increasing. However, in some high-temperature working conditions, ordinary grease cannot meet the requirements of use. Therefore, in this case, the best solution is to use high-temperature grease, which can not only provide excellent lubrication to the equipment, but also prolong its service life. But with so many grease products on the market, how should we distinguish whether it is a high-temperature-resistant grease?
1. The reason why high temperature resistant grease can provide excellent lubricating performance under harsh working environment is inseparable from its composition. Its main components are polytetrafluoroethylene thickened perfluoropolyether oil with high chemical stability and special anti-corrosion additives.
2. The biggest difference between high temperature resistant grease and ordinary grease is in the temperature range of -50~250℃, while the national standard drop point of general grease is about 180 degrees, so it can be distinguished by temperature Identify.
3. High temperature resistant grease has excellent film forming, bearing capacity and lubricating performance, and can provide excellent anti-wear lubrication protection at high temperatures, and it is more than 3 times that of general grease.
4. High temperature resistant grease is suitable for the lubrication and anti-friction of extremely high temperature and high load bearings, gears, guide rails, cams that ordinary grease cannot withstand, and has a longer life than ordinary grease.
5. High temperature resistant grease can effectively resist salt water and most cleaning agents, and will not dry out or form harmful impurities under high temperature and high load. It has good stability and can effectively extend the lubrication time and oil change interval.
6. It has a wide range of uses, suitable for lubrication of film stretch stenter bearings, heat setting machine conveyor belt bearings, corrugated paper machine bearings, hot air blower bearings, hot oil pump bearings, and high temperature motor bearings.
Why does grease flow under high temperature conditions?
1. Grease has a low dropping point, and when the temperature is higher than the dropping point temperature, the grease will melt and flow out.
2. Lubricating grease has poor mechanical stability and cannot be restored to its original state after shearing. After repeated shearing, it will become thinner and flow.
3. Grease colloid has poor stability. After the grease is sheared or oxidized, it will cause a large amount of oil separation.
Causes of grease coking under high temperature conditions?
1. Under high temperature conditions, the light components of the grease Base Oil evaporate quickly, and its heavy components will oxidize, carbonize or shrink into coke under the action of high temperature, high pressure and metal catalysis.
2. For greases made of inorganic thickeners or greases added with solid anti-wear agents, when the light components of the base oil are exhausted, the heavy lubricating oil components are encrusted with inorganic thickeners or solid anti-wear agents Forms hard coke.
3. Due to poor sealing or long service life, dust and grease will form hard scales and abrasive particles under high temperature and high pressure.
Measures to avoid grease flowing or coking under high temperature conditions
1. Choose a grease with a dropping point of 30°C higher than the working temperature and good mechanical stability and colloidal stability.
2. Choose grease whose base oil component is synthetic oil.
3. Strictly abide by the lubrication management regulations, formulate a scientific, regular and quantitative replenishment plan, and replace the old grease with new grease on time.
