Surface Sizing

Performance Metric

Sheet integrity gains stability through the formation of a physical bond between the sizing solution and the cellulose. Print density depends upon the restriction of dye migration into the internal voids of the substrate. Operators monitor the cobb value to verify that the layer successfully impedes liquid absorption during the folding or gluing stages of production.

Lower cobb values indicate a tighter sheet structure suitable for high ink density applications. High moisture levels require a greater amount of polymer to maintain dimensional stiffness across the converting line. Consistent performance relies on the thermal setting of the sheet as it exits the sizing press.

Production Boundary

Mechanical constraints at the size press dictate the volume of chemical solids transferred to the moving web. Metering rods or blades act as the primary control mechanism to ensure even coverage across the width of the machine. Changes in temperature at the dryer section alter the viscosity of the fluid and modify the final distribution of the coating across the fiber surface.

Inadequate drying results in sheet blocking where the substrates stick together in the master roll. Differences in fiber morphology demand adjustments to the concentration of the sizing bath to reach the desired target. Precise control of the evaporation rate allows for the development of a smooth finish that supports high fidelity printing.

Uniformity in the application of the sizing agent remains the definitive factor in the success of the finished substrate.