Lube-Tech
Introduction Biobased greases are no longer considered new. For nearly 25 years numerous products have been commercially in use and on the market. Many of the commercially popular biobased greases are used in niche end uses like rail curve, drill rod, wire rope and other lost-in-use applications. But there are also biobased greases that are used in vehicle bearings and chassis and reside in the equipment for an extended period of time. Those applications present the possibility of comingling biobased greases with other greases. That is when a truck terminal, for example, regreases the bearings of a truck with a different grease than the grease that is already in the bearing, a small amount of the old grease will remain and will comingle with the new grease. This report is an excerpt of a full study that was presented and published earlier in the NLGI Spokesman. Using the ASTM D6185 test methods, the grease mix ratios ranging from 0-100 at selected increments were tested.
ASTM D6185 “Standard Practice for Evaluating Compatibility of Binary Mixtures of Lubricating Greases”. This method provides a protocol for evaluating the compatibility of binary mixtures of lubricating greases by comparing their properties or performance relative to those of the neat greases
PUBLISHED BY LUBE: THE EUROPEAN LUBRICANTS INDUSTRY MAGAZINE
No.132 page 1
Grease Compatibility for Biobased-Biodegradable Greases
Dr. Lou A. Honary, President, Environmental Lubricants Manufacturing, Inc.
comprising the mixture. The standard properties to be tested are: (1) ASTM D566 Test Method for Dropping Point (or Test Method D2265); (2) ASTM D217 Test Method for Shear Stability using a Grease Worker instrument and by 100,000-stroke worked penetration; and (3) by ASTM D217 Test Method for Storage Stability at Elevated-Temperature by change in penetration after being worked 60-strokes in a Grease Worker.
Two test approaches can be used. In one approach, two greases are mixed at a ratio of 50:50 by mass and then evaluated for changes in their dropping point, shear stability and storage stability. If the mixture passes all three tests, then the 90:10 and 10:90 mixtures are also prepared and tested the same way. However, if the 50:50 mixture fails any of the three tests, then the 90:10 and 10:90 mixtures are not further tested. Incompatibility is most often revealed in the test results of 50:50 mixtures and no testing of mixtures with smaller ratios would be necessary.
In a second approach initially three mixtures are made at 10:90, 50:50, and 90:10 and all three mixtures are tested concurrently. No matter which approach is used, if any of the three mixtures fail any of the primary tests, the greases in that mixture are
LUBE MAGAZINE NO.161 FEBRUARY 2021 25
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53
