Work Item
ASTM WK81992
New Test Method for Measuring the Adhesion and Tackiness Properties of Grease Using the Falex TAA Method
1. Scope
1.1 This test method covers a procedure for determining adhesive and tackiness properties of greases using the Falex Tackiness Analyzing Apparatus TAA. Data from this test can be used to characterize greases with respect to changes in retraction speed and temperature.
Keywords
grease adhesion, tackiness, thread length, pull-off force, separation energy
Rationale
Greases are widely used in industrial and technological applications to reduce friction and wear of components. Indicative examples can be found in construction, mining, transportation and food industry. Their performance in open systems does not only depend on their lubrication properties, but also on their interaction properties with other moving surfaces, particularly how the adhere and how they can transfer through thread formation. That latter property is called tackiness of a grease and not to be confused with the term tackiness for adhesives and glues. It is usually described as the ability of the grease to form threads when two contacting surfaces covered in grease, are separated from each other (such as between thumb and index finger).
There is no established method that correctly quantifies the thread length (tackiness) with sufficient precision and without user bias. This method describes a test instrument and method that allows to measure with high precision the length of grease threads in a repeatable and objective fashion. The method also allows to measure the maximum force needed to pull a probe out of a grease covered surface, which is called maximum pull-off force in the following. It is an indication for the adhesion of the grease to metal surfaces.
This test standard describes the procedure for measuring tackiness and adhesion via the parameters of thread length and maximum pull off force. It reports these ‘tackiness numbers” as a function of retraction speed and optionally temperature, these numbers can be used to describe these properties of a grease and characterize a lubricating grease for use in development or for specification purposes.
The title and scope are in draft form and are under development within this ASTM Committee.
Work Item Status
Date Initiated: 05-25-2022
Technical Contact: Michael Anderson
Item: 001
Ballot: D02.G0 (22-05)
Status: In Balloting