A sensor for microstickies.

Application: A method for sensing microstickies can alert mills to high incoming microstickie loads, help test strategies to remove microstickies, and serve as a quality control tool.

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Because stickies can cause major operational problems, their detection and control has long been an industry priority. While several methods for determining macrostickies--adhesives caught in a 0.006 inch screen--are available, a rapid, consistent procedure for microstickie analysis is unavailable. We propose that the high molecular weight (> 3000 Da) colloidal material in process streams of secondary fiber mills is mainly microstickies. This material can be determined by first filtering a sample and measuring its total organic carbon (TOC) content. The filtrate is then ultrafiltered through a membrane that only allows passage of compounds of MW < 3000 Da. The TOC of this low-MW permeate is then obtained. The difference in TOC represents high-MW (>3000 Da) material, which corresponds to microstickies. A sensor that makes the entire measurement in about 8 min has been built for online use. We have validated this new technique by comparison with two independent techniques using lab-derived samples as well as those collected from several points at six mills. S!

Koskinen, Sung, Kazi, Yang, and Banerjee are with the Institute of Paper Science and Technology, 500 10th Street, NW, Atlanta, GA 30318, USA. Email Banerjee at [e-mail].