New development ECOCUT FT 7 WSO
ECOCUT FT 7 WSO is the latest addition to the FUCHS portfolio of integral cutting and grinding fluids. It is an innovative product with GTL (Gas-To-Liquid) technology. After intensive development in the laboratory, this product has been successfully tested on several customers over an extended period of time. This product is particularly recommended for carbide grinding and one of the most important requirements for its development was to improve the dissolving characteristic of Cobalt.
Cobalt in Carbide
Cobalt is used for the metallic bonding of carbide alloys. It is classified as a carcinogen according to CLP regulations. In manuals, rules and regulations (for example: TRGS 561 or BGI/GUV-I 790-024) increase the precautions for handling materials containing Cobalt. Cobalt can be separated from carbide alloys when in contact with oil and then dissolved in that oil. Contact between humans and Cobalt-enriched oil should be assumed to be a health risk.
Development
During development, great emphasis was placed on the choice of additives. On the other hand, the prevention of Cobalt dissolution was optimised. However, components should be used that will not lead to further restrictions because they will be classified according to CLP in the future. To optimise the dissolution of Cobalt, a method was used in which Cobalt powder and oil are stirred at a set temperature for a set period of time. The test was carried out with 3 products: 1 oil without a Cobalt inhibitor additive, the predecessor ECOCUT FT 7 WSE and the new development ECOCUT FT 7 WSO. Figure 1 shows the results of these tests. ECOCUT FT 7 WSO does not dissolve Cobalt compared to the other two products.
Customer case study
Two grinding machines were filled at a FUCHS customer with ECOCUT FT 7 WSO in February 2024. Both machines grind carbide tools for grinding. These are ground in several steps with diamond grinding discs. During the tests, the grinding fluid was carefully analysed in the laboratory. Cobalt content was one of the most important measured values. This is the lowest value measured by this method. On the other machine, there was hydraulic oil contamination in the grinding fluid. As some hydraulic oils strongly favour the dissolution of Cobalt, an increase in the Cobalt content was detected here. In the next step, an additive1 was added to dissolve and agglomerate the Cobalt to reduce it in the system. The use of this additive successfully inhibited Cobalt.
ECOCUT FT 7 WSO has also been in use at another customer since May 2024. It is used in an unfiltered system for grinding cemented carbide on circular saw blades. Here too, no dissolution of cobalt has been detected as of the date of publication of this article.
1ECOCUT PLUS CL 7
ECOCUT PLUS CL 7 is a filling additive. It can therefore be added to a system that is already filled with grinding fluid. If Cobalt is already dissolved in the grinding fluid, adding this additive will cause the Cobalt to precipitate and be filtered out. Regular addition can also prevent the Cobalt from dissolving again. If a grinding fluid is being used that does not have a Cobalt inhibitor, the dissolution inhibition performance of Cobalt can be achieved by regularly adding this additive.
IMPORTANT!!!
If the Cobalt content in the fluid is already high, an excessive amount of ECOCUT PLUS CL 7 could result in too much Cobalt precipitating at once, potentially blocking the filters in the filtration system. In this case, it is necessary to dose the product with the assistance of FUCHS Application Engineers.
Summary
It can be stated that with ECOCUT FT 7 WSO, the system can remain Cobalt-free for a long time without the need for additional additives. The ECOCUT FT 7 WSO can be used in all applications in which the ECOCUT FT 7 WSE. The hydraulic fluid may (depending on the additive system used in the hydraulic fluid) favor the dissolution of Cobalt. ECOCUT PLUS CL 7 prevents and reverses the dissolution of Cobalt.
