Wettability investigation of stainless steel fibers with mineral oils using the modified method for liquid penetration kinetics

The modified Washburn equation and the lipophilic/hydrophilic (L/H) ratio are most commonly used for the wettability characterization of fibers. Therefore, this liquid penetration method was applied for the wettability investigation of stainless steel fibers with mineral oils and the lipophilic/hydrophilic (L/H) ratio was obtained. As test liquids mineral oils and water were used. It was found that the range of L/H ratio values was vastly broad (from 1048340 to 37802) concluding that this liquid penetration method was not suitable for these particular fibers. Consequently, in this study a modified method was developed defining a novel route to filter media wettability characterization and establishing the lipophilic/lyophobic ratio (LLR). As the new reference liquid the medical, white oil was selected. By using polar mineral oils the interval of the LLR ratio for stainless steel fibers ranged from 1 to 28. It can be concluded that the suggested LLR ratio, was adequately selected as a measure of wettability for stainless steel fibers with mineral oils. The LLR ratio exponentially increased with the increase of the neutralization number and viscosity of investigated mineral oils. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172022]