Lubricants have a finite life and degrade whilst in storage. Ideally a container of lubricant should remain in storage only for 1 year once it has been opened and use of the contents commenced.
Grease lubricant degradation occurs for a number of reasons:
Oxidation: contact with air will cause oxidation of the oil in the grease. How quickly and how readily oxidation occurs is dependent on the grease type. The grease base-oil type and the additive package influence the rate of oxidisation and regardless of the type of thickener, the thickener increases the rate of oxidation of the oil in air.
Environmental conditions have a big impact on the storage life of greases. Generally, greases such as lithium-based multi-purpose greases should not be stored for more than 1 year. This is based on storage conditions being dry and about 200C. However, the storage period is dramatically lowered with increased temperature and in broad terms, a 100C increase in storage temperature will double the oxidation rate and reduce the storage life by 50%.
Water contamination increases the rate of oxidation. Once a grease container is opened it is always susceptible to water contamination. This occurs as a result of condensation caused by daily temperature cycles and from storage in humid conditions; in practical terms therefore, it is almost unavoidable.
Not only does as little as 0.05% of water contamination degrade the grease, causing failure of the grease’s lubrication and protection properties but it will also cause a number of bearing lubrication problems such as breakdown of the oil film strength which reduces the oil’s ability to separate rolling elements under load, corrosion, formation of acids due to the breakdown of EP additives in the grease and hydrogen-induced embrittlement and cracking
Another factor which will reduce the storage life of greases is frequent grease agitation in opened containers. This can occur as grease is removed to fill greasing equipment. This promotes surface area contact with air, which promotes oxidation and emulsifies water from condensation and humidity into the grease. Steel containers, if not suitably prepared for grease storage, will expose the oil content to iron which in the presence of oxygen is a catalyst for oil oxidation.
GreaseMax® automatic lubricators eliminate grease storage issues and prevent the maintenance problems that these cause.
GreaseMax® lubricators provide assured delivery of the fundamental elements of effective lubrication:
- Right place
- Right time
- Right amount
- Right condition
