Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/957021
22 | March - April 2018 | www . machinerylubrication.com these requirements? A recent study of new, deployed and in-service greases showed that very few met these requirements, and some were down- right filthy. "Deployed" grease refers to a grease that has been removed from its original packaging but not yet placed into a machine housing or component. is includes grease in an auto-luber reservoir or loaded into a grease gun awaiting transfer to the machine. Figure 1 shows the initial results of this study, presenting the partic- ulate content in milligrams of debris per gram of grease, of particles greater than 10 microns. An approx- imate equivalent for the Mil Spec aircraft grease requirement would be approximately 0.1 milligram per gram. Of the greases tested, only two in their new packaging met this target, while seven others failed. Some were close, but others had nearly 100 times this amount of particulate. e new packaging samples are highlighted in blue, showing values ranging from 0.07 to 8.5 milligrams per gram for particles greater than 25 microns. Controlling Contami- nation in Grease When there is too much particu- late in your oil, the course of action is clear: filtration of the lubricating oils through the application of multiple technologies. However, when you have dirty greases, the path forward is not so clear. Grease cannot be filtered effectively after formulation for two main reasons. Mixing and flow of a fluid is necessary when introduced to a filter to ensure uniform opportunity to remove particulate from the fluid, which is not typically achievable with grease. Secondly, normal filtration methods generally disrupt and break down the grease's thickener, which is designed to give it consistency and keep it in place within the machine. Therefore, you must ensure the cleanliness of greases in their manu- facturing, packaging, handling and Figure 2. Moisture levels in new greases (green), from grease guns (orange) and from the machine (blue) 80% of lubrication professionals do not have a grease analysis program at their plant, according to a recent survey at MachineryLubrication.com 16000 14000 12000 10000 8000 6000 4000 2000 0 319 679 925 1285 1356 3654 4026 4331 4817 5081 5488 1341 1629 2075 2098 2165 4808 7564 8890 8577 15781 15944 Polyurea Mineral Base Oil Elec. Motor Grease Aluminum Complex Synthetic Lithium Complex Mineral Base High-Water Washout Lithium Complex Synthetic Base Oil Unknown Grease Type Lithium Complex High-Temp. High-Visc. Mineral Base Lithium Complex High-Temp. High-Visc. Mineral Base Lithium Complex High-Temp. High-Visc. Mineral Base Lithium Complex Mineral Base High-Water Washout Calcium Sulfonate/Carbonate Complex Synthetic Base Food Grade Calcium Sulfonate Mineral Base High-Temp. Calcium Sulfonate/Carbonate Complex Synthetic Base Food Grade Lithium Complex Mineral Base High-Water Washout Calcium Sulfonate Mineral Base High-Temp. Lithium Complex High-Temp. High-Visc. Mineral Base Lithium Complex High-Temp. High-Visc. Mineral Base Lithium Complex Synthetic Base Oil Lithium Complex Synthetic Base Oil Lithium Complex Synthetic Base Oil Lithium Complex Mineral Base High-Water Washout Calcium Sulfonate/Carbonate Complex Synthetic Base Food Grade Calcium Sulfonate Mineral Base High-Temp. Moisture Content (ppm) GREASES