Starch in the wet-end

Abstract

Starch has been used in papermaking almost since the invention of paper. The global paper industry consumes almost 5 million tonnes of starch per year, making starch the third most important raw material in papermaking. Roughly 20% of this is used in the wet-end. Cationic starch is the major wet-end starch. The phenomena involved in starch adsorption and the selection of cationic starch need careful consideration, as do the proper preparation and application of starch. The criteria for the use of native, anionic and amphoteric starches are also considered. An additional source of starch in the wet-end is returned size press starch, which can have a significant influence on wet-end operations and machine runnability. © 2009 Springer Science+Business Media B.V.