Why add surface sizing agent? What's the benefit?

In recent years, with the transformation of the paper industry to neutral paper making, cheap calcium carbonate series fillers have been widely used in neutral paper making, and the addition of styrene and acrylic surface sizing agent can reach 30% to 40% of the total pulp weight, and may be higher. With the increase of filling amount, there are more and more problems such as poor sizing effect, low tensile strength and surface strength, and even abnormal production.

These problems have seriously damaged the economic interests of production enterprises and printing units. How to make up for the defects caused by filling has become the concern of many papermakers in enterprises.

Surface sizing is becoming more and more important and is highly valued by the paper industry.

Surface sizing is a good way to increase the printability of paper. Surface sizing can increase the water resistance of paper, increase the physical strength index of paper, better change the phenomenon of hair loss and powder loss in the printing process, and increase printing efficiency and printing quality. Therefore, in order to obtain higher surface strength, printability and paper stability, it is necessary to use surface sizing and select a better surface sizing agent to increase the quality of the paper.

At present, there are many kinds of chemical auxiliaries for styrene and acrylic surface sizing agents, which can be roughly divided into two categories: natural polymers and synthetic polymers.

Natural polymer products have the advantages of wide source, low price and easy biodegradation. It has always occupied an important position in the surface sizing agent market.

Starch, guar gum, cellulose and hemicellulose, shellac, gelatin, chitin and sodium alginate are the main natural polymer sizing agents used in the production of cultural paper.

In recent years, the surface sizing agent of synthetic polymer styrene propylene has been developed rapidly because it can give better properties to paper. At present, the choice of surface sizing agent is mainly based on the purpose of surface sizing.