Compatibility of Filter Materials Used with Ionic Liquids’ Uses in Hydraulic Drive Control Systems and a Filterability Test

Abstract

Developments in the field of ionic liquids have led to industrial applications within various industrial processes, as they can be tailored to a specific purpose of use. Due to certain excellent physico-chemical properties, the first industrial applications also appear in the field of hydraulic drives. In these cases, efficient filtration of the hydraulic fluid is extremely important, as the safe, reliable, as well as long-lasting and economical operation of a heavily loaded hydraulic system depends on the efficiency of the filter and the cleanliness of the fluid. In the case of ionic hydraulic fluids, the question of compatibility with the materials of hydraulic components, including filters, arises. The chapter addresses the issue of compatibility of ionic hydraulic fluids with all filter materials, including the filter material that does the actual filtering. At the forefront of the discussion is the issue of incompatibility with cellulose-based filter material, which is considered the most effective when filtering conventional hydraulic fluids. The discussion is also related to off-line filter devices and the standardised filterability test, which prescribes cellulose filter membranes, and the resulting problems of practical and credible implementation of the standardised filterability test.