Fruedenberg 2538 Separator: Summary of Characterization Studies and Regression Analyses

The original study of 2538 separator was undertaken to generate a database from production lot testing and to further characterize separator fabric performance. Prior reports on this study focused upon Thickness, Weight, and Electrolyte Retention. The specific concepts of an Indexed Electrolyte Retention versus Bulk Electrolyte Retention, and the Film- Size-Factor were introduced. These concepts were discussed but not completed due to anomalies in the Weight Test.

This paper resolves those anomalies in the Weight Test and proposes adjustments in the results of the Thickness Test. Both are necessary to allow use of the Indexed and Bulk Electrolyte Retention as a measure of free-state separator fabric performance for predicting compressed-state fabric performance. Thereafter, the results of Air Permeability, Wettability, and Capillarity are characterized. Analytical charts, statistical summaries and discussion of the Shewhart Analyses are provided. Additional analytical studies center on developing a similar correlation of Air Permeability to the above Film-Size-Factor. These new studies are also summarized and reported. One recent outcome of this investigation is a more relevant separator test with substantially improved test techniques.