Caustic Soaking: A Pilot Plant Trial, 1995 Recycling Symposium Proceedings
Sue Freeland
Weyerhaeuser Paper Company
Laboratory studies of caustic soaked OCC have shown as much as 22% increase in short span compression. This pilot plant trial found reduced pulping and refining energy will achieve mill specified strength requirements. System yield was significantly improved largely due to better defibering in the pulper. The improved yield more than offsets the cost of the sodium hydroxide, while the strength of caustic soaked OCC is comparable to virgin fiber. Caustic soaking does not appear to adversely effect the freeness of OCC.