As grease temperature increases, penetration increases until the grease liquefies and the desired consistency is lost. The thickener is described in terms of its chemical and mechanical structure. Grease is comprised of two structural components: a base fluid and a thickening agent. Measures the resistance to oil separation from the thickener. This test demonstrates the insulative properties of dielectric grease, in this case NyoGel® 760G, and proves that grease does not affect conductivity. These mineral oil-based greases typically provide satisfactory performance in most industrial applications. Calcium sulfonate complex grease (CSCG) exhibits the impressive performance including high dropping point, good thermal and oxidative stability, and excellent tribological properties. Effective grease lubrication depends on the grease's consistency. Poor Lubrication Properties Compared to Other Greases (copper grease is primarily an anti-seize grease) Can Interfere with Modern Breaking Systems - (eg: noise fix shims) Copper Can Interfere with Electrical Components - (copper is a conductor and can have detrimental impacts on electrical systems eg: magnetic sensors in ABS braking systems) They are made from emulsified soap with oil and provide parts with what is called thixotropy. Physical Properties of Lubricants. Evaluation of the ability of a grease to withstand water without adversely effecting its ability to properly lubricate components. The most important performance properties are determined by the application. Physical Properties of Lubricants. … General rule of thumb is 50°C below the dropping point should be the maximum operating temperature. Both dielectric grease and "conductive" greases (anti-seize) are insulators. For the components the physical and chemical properties will be given. The National Lubricating Grease Institute (NLGI), defines grease as: “A solid to semi-solid product of dispersion of a thickening agent in a liquid lubricant. The lubrication properties of compound grease with Mn3O4#G nanocomposite additive under heavy contact loads of 600–900 N (3.95–4.59 GPa) were investigated. customercare@fluidlife.com, Lubricant Storage Shouldn’t be an Afterthought, Six Reasons to Perform a Failure Analysis. Grease is used when it is not practical or convenient to use oil. In this study, Mn3O4/graphene nanocomposites (Mn3O4#G) were synthetized using a hydrothermal method as lubricant additives. In addition to its basic components, grease properties, such as penetration or wear resistance, should be taken into consideration when determining the type of grease to use for your specific application. Results should not be used as the upper temperature limit for use. The soap can lend important properties to the grease, such as water resistance, chemical stability, and an improved viscosity index. If requested, your grease supplier should be able to provide grease properties data in their product data sheets. 1. The properties of calcium sulfonate complex greases and their structures. Generally, the base oil’s pour point is considered the low-temperature limit of a grease. ASTM D 217 and D 1403 methods measure penetration of unworked and worked greases. 1. In comparison, grease, by virtue of its rigidity, is easily confined with simplified, less costly retention devices. 2. Dispensability: The ease with which grease may be transferred from its container to its point of (ASTM D1264), Water Spray: evaluates the ability of the grease to adhere to a metal surface when subjected to direct water spray. The lubrication properties of compound grease with Mn3O4#G nanocomposite additive under heavy contact loads of 600–900 N (3.95–4.59 … A true grease consists of an oil and/or other fluid lubricant that is mixed with a thickener, typically a soap, to form a solid or semisolid. Roll stability. Although grease can effectively lubricate machines, lubrication failure may occur under high speed and heavy load conditions. Grease Properties and Tests Dropping Point. Complex greases are made by combining the conventional metallic soap with a complexing agent. They are being selected because of their high dropping points and excellent load-carrying abilities. U.S. Army Corps of Engineers. The characteristics commonly found on product data sheets include the following: Pumpability is the ability of a grease to be pumped or pushed through a system. The thickener is a material that, in combination with the selected lubricant, will produce the solid to semifluid structure. The primary difference between dielectric greases and "conductive" greases is that "conductive" greases and anti-seize greases include some amount of finely-powdered metal. Fluid level does not have to be controlled and monitored. Mechanical stability. physical properties of grease; pumpability, dropping point, mechanical stability, and oil separation. This test is done as some greases tend to separate while in storage. Following are the important properties of a lubricant. The Lithium Grease is mainly used as an ideal metal to metal lubricant in the automotive industry. The depth, in tenths of a millimeter, to which the cone sinks into the grease is the penetration. Density is fundamental physical property of oil. Prolonged exposure to high temperatures accelerates oxidation in greases. RHEOLOGICAL PROPERTIES OF A LUBRICATING GREASE i C. R. Singleterry and E. E. Stone Naval Research Laboratory, Washington, D. C. Received January 30, 1951 INTRODUCTION" McKee (1) has described the construction and use of a worker-con- sistometer for lubricating greases which makes use of the small sample size and the high shear rates of the Hain microworker (2) in connection with … If the temperature of a grease is lowered enough, it will become so viscous that it can be classified as a hard grease. Properties exclusive to grease include dropping point, mechanical stability, water washout, bleed characteristics and pumpability. This makes it a great choice for challenging metal-to-metal heavy load applications. Grease consistency depends on the type and amount of thickener used and the viscosity of its base oil. Dielectric grease, also sold as silicone grease, is good for protecting electrical terminals and insulating components. The results indicate that CB can dramatically improve the conductivities of the greases. The temperature at which the grease starts to melt or drip while heated. Machinery that is not easily accessible for frequent lubrication. Bearings running in a steel mill roll-out table application may be exposed to process temperatures of several hundreds of degrees, and may experience sustained temperatures of 250ºF to 300ºF (120ºC to ±150ºC). A grease's consistency is its resistance to deformation by an applied force. These primarily include enhancing the existing desirable properties, suppressing the existing undesirable properties, and imparting new properties. Bentonite and silica aerogel are two examples of thickeners that do not melt at high temperatures. High temperatures harm greases more than they harm oils. These soaps include lithium, aluminum, clay, polyurea, sodium and calcium. The reaction of grease with oxygen produces insoluble gum, sludges and lacquer-like deposits that cause sluggish operation, increased wear and reduction of clearances. Automotive Uses. Pirro, Wessol. Measure of a grease’s heat resistance – as grease temperature increases, penetration increases until the grease liquefies and the desired consistency is gone. Today, over 80% of the world’s bearings are lubricated with grease. Density. There is a couple ways to determine water resistance. The American Society for Testing and Materials (ASTM) defines lubricating grease as: "A solid to semifluid product of dispersion of a thickening agent in liquid lubricant. HEAT RESISTANCE: Lithium grease demonstrates excellent heat resistance. Grease maintains thicker films in clearances enlarged by wear and can extend the life of worn parts that were previously lubricated by oil. The properties of a grease are determined by the quality of the oil it is made of. The grease should have good stability and not contain metals in any form, and be specifically designed for use as a dielectric grease. Different types and combinations of base fluids and thickeners, along with supplemental structure modifiers and performance additives, combine to give the final product its special lubricating properties. There are few different wear tests that can be done, and each are dependant upon the application of the grease. It also acts to keep deteriorated seals effective.