Cationic starch plays a significant role in paper coating:

1- Improves coating water retention: It enhances the water retention capacity of the coating, slows down the penetration of water into the paper, ensures uniform distribution of the coating on the paper surface, improves the smoothness and gloss of the coating, and prevents issues such as uneven coating and drying spots caused by rapid water loss.

2- Enhances pigment binding: Its cationic properties allow it to tightly bind with negatively charged pigment particles, fixing the pigments more effectively on the paper surface, reducing pigment shedding and migration during subsequent processing and use, and improving color vibrancy and printability.

3- Improves paper surface strength: It forms a film with certain strength on the paper surface, enhancing the bonding between surface fibers, making the paper more wear-resistant and resistant to linting and dusting during printing, thereby improving print quality and reducing the occurrence of printing defects.

4- Optimizes coating rheology: It adjusts the viscosity and rheological properties of the coating, ensuring good fluidity and spreadability during the coating process, adapting to different coating methods and process conditions, and improving coating efficiency and uniformity of coating application.

During use, cationic starch should be prepared into a paste of a certain concentration and added to the coating preparation process using appropriate equipment. The dosage and application method should be determined based on factors such as paper type, coating requirements, and production processes. The typical dosage ranges from 1% to 5% of the total coating weight to fully leverage its role in paper coating and enhance paper quality and performance.