Thomas Norrby

Additive influence on wear and friction performance of environmentally adapted lubricants

Abstract In this paper, the influence of concentration level and chemical composition of three different additive types on friction and wear coefficient are presented for a synthetic ester base fluid and a mineral base oil. One extreme-pressure (EP), two antiwear (AW) and two yellow metal passivator (Cu-passivators) additives were used. Factorial experimental design was used as the basis for a systematic evaluation of wear rates under mixed and boundary lubrication conditions. A total of 33 different lubricant blends were tested in a Plint and Partner High Frequency Friction Machine. For the synthetic ester, the extreme-pressure (EP) additive, containing phosphorus and nitrogen, was found to be much more effective in reducing wear than either of the two antiwear (AW) additives tested. In fact, the AW and Cu-passivator additives made little or no contribution to the wear protection in most of the cases studied. A synergy effect between the three additive combinations was observed only for the reference mineral oil blend. A significant difference between the antiwear performance of the test lubricants was found. This study suggests that the traditional “AW” and “EP” labels associated with commonly used additives are poor aids when designing of ester based lubricants.

Environmentally adapted lubricants – where are the opportunities?

Environmentally adapted lubricants (EALs) have been a slowly growing segment of the lubricants business since the early 1970s. The evolution of environmental thinking has led to the change of focus, from biodegradability to renewability. In the future, the focus will be more on fuel economy and lower emissions. Technical development drivers include the availability of suitable base fluids and additives for lubricants formulation and the adaptation of technical standards, OEM specifications and eco‐labels. Important non‐technical development drivers include environmental management tools and eco auditing. Environmental policy, and procurement guidelines for cities and government organizations, clearly has a large impact. EALs have been repeatedly heralded as one of the few future growth segments of the lubricants business, hence the relatively large increase in R&D activity over the last decade. In sales terms, growth has been slow, limited by high cost and several other factors. For a good future development, both technical and political hurdles must be overcome.

Environmentally adapted lubricants in Swedish forest industry – a critical review and case study

During the last ten years, a gradual conversion from mineral oil based hydraulic fluids to environmentally adapted lubricants (EALs), has taken place in the forest industry in Sweden. The current market share of the EALs is ca. 80 percent of the mobile hydraulic fluids utilised. The original driving force of this change can be traced to end‐user demands, especially paper and pulp consumers in Germany. The Swedish standard SS 15 54 34 was in 1997 supplemented with environmental criteria derived from the “Ren Smorja” (“Clean Lubrication”) environmental project in the city of Goteborg. The reliable third‐party validation offered by SP (Swedish National Testing and Research Institute), the present stewards of the “Clean Lubrication” list, has proven to be another important factor. By comparison to the German Blue Angel Eco‐labelling scheme, the Swedish SP‐list approval is somewhat easier to attain, and has provided a flexible base for the development of new products.

Environmentally Adapted Lubricants, Vehicles for Change in the Transformation to Sustainable Industrial Practices

Environmentally adapted lubricants : vehicles for change in the transformation to sustainable industrial practices