Anton Paar’s RapidOxy 100: Optimising the quality and lifetime of environmentally acceptable lubricants

Oct 24 2024

Environmentally acceptable lubricants (EALs) have a reduced impact on the environment and contribute to improved environmental protection and sustainable development.

Bio-components may improve the eco-balance; however, some may have a negative effect on important characteristics of the lubricant and therefore need to be supervised. One of the drawbacks of EALs may include limited high-temperature performance due to inferior oxidation stability. As eco-friendly lubricants are expected to degrade in the presence of oxygen over time, their shelf-life may also be shorter compared to that of mineral oils. The serious effect of degradation by oxidation can compromise their properties as well as impair their quality and performance.

To assure and maintain product quality and safety during the lifetime of an EAL, Anton Paar provides a unique instrument solution – RapidOxy 100. It features accurate pressure monitoring and a unique measuring principle to artificially accelerate the oxidation process by using increased temperature and an excess of pure oxygen. It fully complies with ASTM D8206 and measurements are fully automatic after a set-up taking less than five minutes.

Demonstrating the effectiveness of the test, the table below shows the test results of a variety of EAL sample types of different producers, e.g. hydraulic oil, gear oil, chainsaw oil, universal oil, motor oil, concrete mould release oils, and high-performance oil:

Product type	RO 100 140 °C 1. Test	RO 100 140 °C 2. Test	RO 100 160 °C 1. Test	RO 100 160 °C 2. Test
Hydraulic oil	389.93 min	415.48 min	114.20 min	114.63 min
Mold oil	41.23 min	41.77 min	16.55 min	16.05 min
Universal tractor oil	1015.5 min	1015.58 min	316.70 min	324.38 min
Gear oil	902.5 min	883.72 min	262.65 min	258.28 min
Universal oil	802.78 min	798.63 min	241.70 min	239.68 min
Chainsaw oil	128.72 min	129.72 min	39.80 min	39.48 min
Chain saw oil	27.17 min	26.88 min	19.25 min	19.32 min
Hydraulic oil	265.77 min	265.63 min	64.40 min	64.70 min
Gear oil	1666.13 min	1616.08 min	709.85 min	745.78 min
Hydraulic oil	366.77 min	369.27 min	86.32 min	86.22 min

The measurement results demonstrate that the oxidation stability of each lubricant clearly reflects its intended use and area of application. Chainsaw oil has low oxidation stability, as fast decomposition after use is a desired property. Gear oil, on the other hand, must have high oxidation stability. Some gear oils additionally contain organosulfur compounds, as well as pressure additives and oxidation and rust inhibitors, all of which lead to even higher oxidation stability. The high repeatability is one of the major benefits when it comes to measuring with RapidOxy 100.

Further investigation of the oxidative behaviour is possible with the powerful OxyLogger 100 desktop software: Automatic calculation of activation energy and oxygen consumption, estimation of shelf life, and many more useful features take product stability to a new level.

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