TABLE OF CONTENTS Saponification is the process used to develop the grease thickeners, in which fat or fatty acids are used to react with an Alkali to form a chemical soap.
The fat can be of animal, vegetable or synthetic materials, with the alkali being a substance of basic properties. In the grease industry, saponification is considered to be the formation of soap through the reaction of a fat with a metallic hydroxide. This metallic hydroxide is the component by which the grease is classified (e.g. Aluminum, Barium, Calcium, Lithium, Sodium etc.) Figure 4.10c shows the different grease properties for each type of thickener. Lithium based grease is today s most popular choice of grease.
| Type | Approx. Temp Range | Cold Weather Pumpability | Water Resistance | Usual Appearance | ***Note*** |
|---|---|---|---|---|---|
| Lithium | 350F 175C | Very Good | Very Good | Buttery | Most Commonly used grease. |
| Lithium Complex | 375F 190C | Very Good | Very Good | Buttery | |
| Calcium (Lime Soap) | 230F 11 10C | Fair | Very Good | Buttery | |
| Sodium (Soda Soap) | 250F 120C | Fair | Poor | Fibrous | |
| Calcium Complex | 350F 175C | Fair | Good | Stringy | Can bleed and harden in centralized systems. |
| Barium | 380F 193C | Poor | Excellent | Fibrous | |
| Aluminum Complex | 350F 175C | Good | Excellent | Stringy | Can form gel at high temperature, increasing power consumption and reducing wear properties |
| Bentones (Non Soap) | 500F 260C | Good | Good | Buttery | Can blled and harden in centralized systems. Can be highly flammable due to wicking. |
