Wet end starch addition for papermaking

摘要

Partially gelled starch is sprayed onto the wire section and is fully cured during the drying process. This gives better retention than head box addition, higher concs. of starch can be used, the starch is fully cured even at low drying temps. and carriers need not be used. Starting materials are pref. maize-, tapioca-, milo-, wheat- or potato starches. The solids content of the spray is pref. 10-40 wt.% and temp. 70 degrees C. with a Stein-Hall viscosity of 15-50 secs. at pH 8-13. Other additions may be made at the same time e.g. borax, carboxymethyl cellulose, PVA, paraffin or synth. resins, fillers etc.