Vegetable oil-based lubricants are slowly being introduced into the industrial market. While these products are advertised as being green and biodegradable, they have major deficiencies that greatly affect their performance in critical machinery.
The largest concern with these products is their lack of oxidative stability. While this is a benefit for meeting biodegradability standards, it is a negative for system reliability due to the increased possibility of sludge formation. In a hydraulic system, this sludge formation can lead to fouled control valves and increased operating temperatures – further exacerbating the issue.
Additionally, vegetable-based oils are sensitive to metal catalysts. In one application, the switch from a stainless steel to a yellow-metal-containing valve in a soybean oil storage vessel lowered the oxidative life of the oil by 1 month. The ability for vegetable-based oils to be easily catalytically degraded by metals further increases the risks of sludge formation.
Due to these products being derived from food-products, microbial growth in the product is also a major concern. Compared to other biodegradable products on the market – vegetable-based products are far more likely to develop microbial growth issues. This growth can be controlled with antimicrobial products. However, recent changes to chemical safety guidelines with the Global Harmonized System (GHS) mean these antimicrobial products are very strictly controlled and require specialized handling, storage, and disposal. Products that are not based on vegetable oil do not have this concern.
SLFi… Technical Support Department