Water Based Coatings That Keep a Pack inside the Fibre Stream
Water-based dispersion coatings achieve food barrier requirements while maintaining full fiber repulpability and standard mill recovery yields.
Core-Shell Polymer
Thermal Threshold
Aqueous dispersions of core-shell polymer particles establish the barrier integrity of specialty paper coatings during high-speed drying cycles. Synthetic latex architecture pairs a rigid glassy inner domain with a softer rubbery outer stratum to modulate film formation under thermal stress. Glass transition temperatures dictate the minimum film formation temperature of the aqueous suspension, controlling how particles coalesce into a continuous barrier layer during calendering.
Premature coalescence clogs doctor blades on the coater head when drier temperatures exceed the specified threshold for the outer stratum.
Converting Rheology
Shear thinning behavior governs fluid dynamics as coating formulations pass through fountain applicators onto continuous paper webs. Viscosity profiles respond predictably to mechanical agitation inside the fluid head, preventing streak formation across heavy packaging boards. Particle morphology restricts swelling in water-based printing inks, preserving dimensional stability during flexographic application.
Surfactant concentration at the particle periphery stabilizes the colloidal suspension against mechanical shock during high-shear pumping operations.
Barrier Performance
Oxygen transmission rates decline significantly when these heterogeneous particles form a dense laminar film across porous cellulosic substrates. Crystallinity within the rigid core restricts gas permeability, protecting sensitive food contents from oxidative degradation inside laminated folding cartons. Moisture vapor transmission rates depend directly on the spatial distribution of the hydrophobic outer phase within the dried binder matrix.
Pigment binding efficiency improves because the compliant outer stratum deforms around clay and calcium carbonate platelets during consolidation.