Surface Sizing Agent is a synthetic copolymer of high molecular emulsifier and styrene ester monomer. It mixes well with starch and provides the starch coating with excellent cross-linking strength and hydrophobic property. It's featured by low consumption, free odor, low foaming, long foam inhibition period and excellent film forming, and it can significantly improve the water resistance capability and ring pressure strength of corrugated paper and cardboard paper. It is a sufficient substitute for internal sizing agent and has no maturation period. It is applicable to various types of surface sizing machines. Advantage: Low consumption, low sizing than internal (pulp) sizing and AKD type of surface sizing. The paper can be fully cured after reeling down. Strong water-resistant performance. Features: The cationic surface sizing agent needs some aluminum sulfate to perform well. The product series adapt to all high and low speed paper machines. Good Moisture Resistance, effectively prevent the reduction of RCT. Anionic the surface strength for culture for cultural paper.