So, what are the alternatives?
When considering conventional lithium soap as the single most dominant grease thickener technology, anhydrous calcium has quickly emerged as the most obvious and viable alternative.
Already established as a reliable multi-purpose technology for a wide range of loss-lubrication applications as well as suitability for environmentally sensitive formulations, its superior water resistance in combination with a more stable supply chain are just a few reasons behind its growing popularity.
On top of that, recent comparative studies with equivalent lithium-based formulations have also revealed some unexpected advantages of anhydrous calcium technology that will further enhance its value from both a performance and a sustainability perspective.
Comparative study – anhydrous calcium and lithium
For this study 2 samples of each thickener technology were prepared using a combination of Group II and Napthentic Oils to provide base oil viscosities of 110 cSt and 220 cSt at 40°C.
All were produced to an NLGI 2 consistency and additive-free with the exception of 0.5% antioxidant in those samples run on the FE-9 Life Test.
An extensive range of common grease tests were used to compare the grease properties and performance, but here, I will focus on those that enable a degree of correlation with sustainability driven values and benefits.
When it comes to product endurance and durability, the mechanical (or shear) stability of the grease as determined by its thickener is of primary importance. Extended worked penetration (ASTM D217) and Roll Stability (ASTM D1831) tests are both used to determine the mechanical stability of a grease based on measurements of consistency before and after test.
Figure 4: ASTM D 5707 SRV Friction & Wear Test. Comparative Coefficient of Friction Traces
Equally interesting were the comparative wear scars on both ball and disc that again highlighted superior protection from the calcium based technology.
Figure 5: ASTM D 5707 SRV Friction & Wear Test.
Comparative Ball & Disc Wear Scars
Figure 3: ASTM D 1831 Roll Stability Tests. Standard & Modified Methods
Conducted on dry samples and with 10% water, the calcium grease demonstrated better mechanical stability with its advantage being greater under the more severe conditions.
Low friction and wear reflect a lubricants potential to enhance energy efficiency and prolong component life.
For this element of performance, an SRV (ASTM D5707) 2 hour wear test was conducted with noticeable difference in the coefficient of friction traces observed which again favoured the anhydrous calcium technology.
Figure 2: Comparative 220 cSt Samples; Anydrous Calcium on left & Lithium on right
LUBE MAGAZINE NO.188 AUGUST 2025
23
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 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64
