Preparation of Enzymatic Starch and Effect of Surface Sizing on Properties of the Paper

In this experiment, we use corn starch as the main raw material and use Mid-Temperature a-amylase to modifie it. The influnce of temperature and time to viscosity of the enzymatic starch were discussed. In this way, we can get the optimal conditions about enzymatic modification. According to testing properties of the paper ,we know about its surface sizing effect. At last,we explored the influnce of AKD to surface sizing. The results showed that the optimal conditions are as follows: the optimal enzyme reaction temperature of 65 °C and the ptimal enzyme reaction time of 20min under the condition that the substrate concentration of 20%, the dosage of enzyme of 0.02%, the dosage of calcium chloride of 0.04%, pH 6, gelatinization temperature of 95 °C, and gelatinization concentration of 10%.Under this condition, the viscosity of starch paste is 11mPas. Compared with original paper, sizing increased by 16.20%, burst index increased by 10.50%, tensile index increased by 12.60%. The AKD can significantly improve the degree of sizing, compared with the original paper, the degree of sizing increased by 26.5%.