Automatic Measurement of Zeta Potential and Drainage, 1992 Nonwovens Conference Proceedings

A new instrument is described which automatically measures the zeta potential and drainage of fiber slurries. A streaming potential measurement is made by passing liquid through a pad of fibers while simultaneously measuring the potential across the pad. It is used to calculate the zeta potential of papermaking furnish. Specific filtration resistance is assessed by measuring the volume of liquid that passed through the pad over a period of time. The lower the specific filtration resistance, the better the drainage on the paper machine wire. The total volume of liquid which passes through the pad can be measured to the third decimal place, and can be expressed as "drainage in milliliters". Controlling wet end chemistry at the zeta potential which produces maximum drainage can result in maximizing retention and formation in the Microparticulate and other wet end chemistry processes. Results are reported of Microparticulate Process experiments with bleached kraft furnish and recycle newsprint.