ASTM D6184 Test Method for Oil Separation from Lubricating Grease (Conical Sieve Method)
1. Scope
1.1 This test method is used to determine the tendency of lubricating grease to separate oil at an elevated temperature. This test method shall be conducted at 100°C for 30 h unless other conditions are required by the grease specification.
1.2 This test method is not suitable for greases having a penetration (Test Methods D217) greater than 340 (softer than NLGI No.1 grade).
1.3 Values stated in acceptable SI units are to be regarded as the standard.
1.4 This standard does not purport to address all the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D217 Test Methods for Cone Penetration of Lubricating Grease
D1742 Test Methods for Oil Separation from Lubricating Grease During Storage
E 437 Specification for Industrial Wire Cloth and Screens (Square Opening Series)
2.2 Government Standard:
Federal Test Method (FTM) 791C Method 321.3, Oil Separation from Lubricating Greases (Static Method)
3. Terminology
3.1 Definitions:
3.1.1 lubricating grease, n - a semifluid to solid product of a dispersion of a thickener in a liquid lubricant.
3.1.1.1 Discussion - The dispersion of the thickener forms a two-phase system and immobilizes the liquid lubricant by surface tension and other physical forces. Other ingredients imparting special properties are often included.
3.1.2 oil separation, n - the appearance of a liquid fraction from an otherwise homogeneous lubricating composition.
3.1.3 thickener, n - in a lubricating grease, a substance composed of finely divided particles dispersed in a liquid lubricant to form the product's structure.
3.1.3.1 Discussion - The thickener can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soap thickeners) which are insoluble or, at most, only very slightly soluble in the liquid lubricant. The general requirements are that the solid particles be extremely small, uniformly dispersed, and capable of forming a relatively stable, gel-like structure with the liquid lubricant.
