Test Method for Water Washout Resistance of Lithium-Based Grease No.1
Lithium-Based Grease No.1 is a general-purpose grease prepared by thickening mineral oil with lithium 12-hydroxystearate soap and adding additives such as antioxidants and rust inhibitors. It exhibits excellent mechanical stability, oxidation stability, and water resistance. Its penetration is 320 mm (0.1 mm), density at 23℃ is 1.1 g/cm³, and it is suitable for use in environments ranging from -20℃ to 120℃. This grease is widely applied in textile machinery, heald frames of water-jet looms, and other low-load equipment.
Experimental Purpose
In the fields of chemistry and scientific research, the water washout resistance test is of great significance for greases. This test can evaluate the structural stability and adhesion capacity of the product under water washout conditions. By simulating actual working conditions (such as rain erosion), it quantifies the grease loss, emulsification degree, and consistency change of the grease, so as to judge its ability to maintain lubricating effect in humid environments.
Experimental Equipment
①SH116 Grease Water Washout Resistance Tester
②Auxiliary equipment such as graduated cylinders, distilled water, cleaning solvents, and drying ovens
Experimental Procedures
1.Inspect the instrument and equipment to ensure they are dry and free of contamination. Connect the power supply and keep all switches in the off state.
2.Take the sample, add 4.00g±0.05g of the grease sample into the pre-weighed ball bearing, install the pre-weighed protective plate into the bearing sleeve, and fix it on the sleeve frame of the water storage tank.
3.Inject no less than 750ml of distilled water into the water storage tank, with the water level below the bearing sleeve. Start the water circulation pump to bring the water temperature to the experimental temperature.
4.Adjust the flow system to stabilize the water flow at 5ml/s±0.5ml/s, and adjust the position of the nozzle.
5.Start the motor and run the bearing at a speed of 600rpm±30rpm for 60min±5min.
6.Turn off the motor and heater, remove the experimental ball bearing and protective plate, and place them on the pre-weighed watch glass.
7.Separate the ball bearing and the protective plate, dry them in an oven at 77℃±6℃ for 15 hours, cool them to room temperature, weigh them, and measure the grease loss with an accuracy of 0.01g.
8.Repeat the experiment 1 to 3 times and perform the calculation.
Experimental Results and Analysis
In the experiment, the water washout loss of Lithium-Based Grease No.1 was 2.40%, which meets the specified value in the standard SH/T 0109.