In this paper were discussed the properties of sized paper made by surface sizing at the size press of a paper machine after removal of rosin and alum from the wet end.
Oxidized starch and certain synthetic polymers were used for the surface sizing to impart water and ink resistance to paper. A waterleaf sheet was surface-sized at the size press, and the properties of the surface-sized paper were evaluated at our laboratory and pilot plant scale experiments.
By the surface sizing techniques, the surface sizing solution penetrated deeply into the waterleaf sheet and showed its performance satisfactorily. In other words, the surface-sized paper showed a better writing quality, greater bursting strength and higher pick resistance than the internally sized paper. It was also found that the surface sizing techniques made it possible to use calcium carbonate as a filler of an excellent optical property.