AKD sizing agent is one of newly-developed products in our company for the purpose of avoiding defects such as slow ripening, easy to be under machine moisture regain, high cost, ect.. Common AKD emulsion using amylum as emulsifier, which cause low retention rate, large dosage, slow ripening. A100 neutral polyester sizing agent adopts a new type of polymer emulsifier that our company developed independently which takes the petroleum resin as main raw material, and is supplemented by other cationic surfactant,. The emulsifier is polymer, high cationic charge density and thus the emulsification has highly efficiency, uniform dispersion, and small particle size. The manufactured AKD sizing agent ripens fast with high efficiency and small dosage. General resistance to water penetration under the machine is up to 60 seconds, The dosage of per ton paper that compared with the ordinary AKD products can be reduced more than 15%.