Measuring Specular Gloss Changes during Standard Paperboard Rub Tests
Measuring specular gloss changes before and after standard rub tests quantifies surface coating durability using exact optical angle decay metrics.
Wax Additives
Frictional Reduction
Performance-enhancing formulation compounds incorporated into ink, coating, and varnish systems reduce the friction coefficient of the dried film surface. The use of wax additives protects printed paperboard packaging from scuffing, abrasion, and marking during high-speed folding and filling operations. These compounds migrate to the surface of the ink film during the drying or curing phase, forming a thin protective layer that resists mechanical shear.
Their presence allows the folding cartons to slide smoothly through conveyor guides without scuffing the print.
Dispersion Chemistry
Formulations use synthetic waxes like polyethylene, polytetrafluoroethylene, or natural carnauba wax suspended in liquid carriers. The selection of wax additives depends on the print process and the curing mechanism, such as water-based, solvent-based, or ultraviolet curing. Particle size must be carefully controlled, as too large a particle will reduce gloss and cause piling on the printing plate, while too small a particle will fail to provide adequate rub protection.
Converting Performance
Applying these slip-control compounds prevents blocking when printed sheets are stacked under pressure in a pallet. Integrating wax additives helps converters maintain high production speeds on automated folder-gluers, where excessive friction slows down the line and causes board jams. Maintaining the correct concentration ensures that the finished packages can be filled and shipped without surface damage.