Surface Cohesion
Polysaccharide solutions increase the internal bond strength within paper structures by facilitating chemical links between adjacent cellulose fibers. This starch binder functions as a critical component in size press operations where fluid penetration governs the pick resistance of the finished substrate. Surface sizing treatments modify the porosity of paper webs to improve surface finish and printing fidelity.
Application of these aqueous mixtures occurs while the sheet remains in a moist state during the drying cycle to guarantee optimal distribution throughout the interstitial spaces.
Internal Load
Mechanical adhesion depends upon the gelatinization temperature and the viscosity grade of the chosen starch derivative. Manufacturers modify native starches through oxidation or enzyme conversion to control the molecular weight of the polymer chains. Low viscosity formulations travel deeper into the fiber network while higher viscosity versions remain at the surface to create a denser barrier against ink penetration.
Each grade requires a precise balance of heating cycles to prevent premature thickening that ruins the application uniformity.
Performance Parameter
Sheet performance relies upon the retention of these additives during the drainage phase on the paper machine wire or the subsequent surface coating process. High levels of binder improve the surface strength of the sheet and reduce the incidence of linting during offset lithography. Excessive inclusion leads to brittleness that causes cracks in the folds of finished packaging products.
The ideal addition rate balances the mechanical requirements of the printing process against the material cost of the coating mixture.
