Can lubricating grease be diluted with base oil before it becomes hard?
December 11, 2021
Grease, commonly known as butter, we can tell from the name that it is used for lubrication. Many experienced masters know that no matter whether it is a large car or a motor shaft in a factory, as long as it involves rolling and friction, it needs to be lubricated. Due to its high temperature resistance, oxidation resistance, long life characteristics and unique stickiness Attached paste characteristics are widely used. Below, let's share some doubts that are prone to occur during the use of automotive grease!
1. Lubricating grease becomes hard (increased in consistency) after storage, can it be used after being diluted with Base Oil?
After most greases are stored for a period of time, the consistency (that is, the measured value of penetration) becomes larger, that is, it becomes hard. If it does not exceed 1 consistency number, it can be used directly without affecting general lubrication. If the consistency changes greatly, it means that the base oil is separated too much, which may increase the frictional resistance of mechanical parts during lubrication and increase the consumption of mechanical power, so it is not suitable for direct use. Some users add base oil to the hardened (or thickened) lubricating grease to dilute the grease to make the consistency of the grease smaller (that is, soften). This method is not suitable for users because of the lack of necessary homogenization treatment procedures. , The stability of grease colloid becomes worse, and the increase of oil separation will affect the use. When the thickened grease has little change in other physical and chemical properties, the same base oil can be added in the production plant, and after the homogenization process is processed and analyzed and tested, it can be used. 2. What are the changes in the quality of grease during use? How to judge intuitively? Due to the influence of the external environment (such as air, water, dust or other harmful gases, etc.) in the working parts of the grease, and the relative movement of the working parts to produce mechanical forces (such as punching, shearing, etc.), two changes will occur ①Chemical changes: The components of the grease (base oil, thickening agent) may undergo oxidative deterioration due to the effects of light, heat and air. After the base oil is oxidized, a trace amount of organic acids, aldehydes, ketones and lactones will be generated. In addition, fatty acids and organic metal salts in the thickening agent may decompose to form a small amount of organic acid, etc. Therefore, acidic substances (increased acid value of the grease) will cause corrosion of the lubricated parts, and even rust, and loss of lubrication. , Protective effect. ②Physical changes: due to mechanical action, the structure of the grease is deteriorated or even destroyed, the consistency of the grease is reduced, and the lubricating effect becomes poor, or the sealing condition of the mechanical lubricating parts is not good, resulting in the mixing of dust, impurities and moisture in the grease to lubricate The fat quality has deteriorated. Judgment method: grease with naked eyes or hand feel dust, mechanical impurities, or whitening, lightening due to emulsification of grease mixed with water, or obvious reduction in consistency, or obvious smell of oil rancidity, etc., can indicate lubrication Lipid spoilage. 3. What matters should be paid attention to in the storage of lubricating grease? Grease is a colloid, and the structure of the grease will be affected by various external factors during use and storage. When storing in the warehouse, the temperature should not be higher than 35℃, and the packaging container should be sealed to prevent leakage of moisture and foreign impurities. After opening the barrel to take samples or products, do not leave holes in the packaging barrel. The grease surface after taking the samples should be smoothed to prevent pits, otherwise the base oil will be squeezed by natural gravity and penetrate into the sample left Pits, and affect the quality of the product. 4. Can different types of grease be mixed? If the base oil type is the same (such as petroleum lubricating oil or other base oils of the same type), greases made from different soap bases or thickeners are generally not suitable for simple mixing. For certain types of grease, such as calcium-based grease and sodium-based grease, or lithium-based grease and lithium complex grease, etc., they can be mixed with each other. Generally, they will not cause too much performance change and will not affect their use. However, extreme pressure grease contains various active components. When mixed with each other, the additives will be mixed together, which will cause the colloidal stability or mechanical stability of the grease to deteriorate and affect its performance. Before mixing different types of grease with each other, the performance of the mixed grease should be measured, and then use it when it is confirmed that there is no obvious effect.
