Starch Selection for Surface Sizing

Many kinds of native and modified starches are being used on the size press.207 The governing factors are dispersion viscosity, film formation and resistance to retrogra-dation. For low-cost applications, native corn starch is depolymerized in the paper mill by enzymic or thermal-chemical conversion. In-plant converted starches are 

Anionic starches, obtained by carboxymethylation of corn starch, provide improvements in film strength, pick resistance, opacity and air-leak density. They are used 

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