Capillary Sorption Anomalies under Dynamic Surface Tension Gradients in Recycled Paperboard Substrates
Dynamic surface tension gradients in recycled paperboard cause capillary stalling, uneven ink penetration, and severe converting spoilage.
Marangoni Gradients
Surface Dynamics
Liquid film instability arises from local differences in surface tension during the drying of coatings. Marangoni gradients represent these mass transport phenomena where fluid moves from regions of low surface tension to areas of higher tension. This mechanism dictates the uniformity of pigment distribution on paper substrates after the application of aqueous formulations.
Controlled variation in these forces prevents the formation of orange peel textures or drying defects in high speed production environments.
Coating Physics
Thermal or concentration imbalances drive the flow patterns within the fluid phase as it settles on the web. As solvents evaporate from the surface, concentration profiles establish regional disparities in interfacial energy. These gradients exert a physical pull on the underlying liquid, forcing material toward zones that resist movement.
Printers adjust surfactant concentrations to manage this internal transport and maintain film integrity against aggressive drying conditions.
Production Consequences
Precise management of interfacial flow ensures that additive distribution remains consistent across the entire width of the substrate. Any localized failure to regulate these forces results in craters or uneven gloss levels that degrade the final print quality. Operators verify chemical compatibility between base stock and coating components to minimize uncontrolled movement of the fluid.
Surface energy stability maintains the final structural cohesion of the applied layer throughout the manufacturing process.