Coated Folding Boxboard Crease Quality Audit Procedures
Crease audits verify internal mechanical ply shear through moment ratios between thirty and fifty percent without top coating fracture under dye staining.
Coated Folding Boxboard
Boxboard Grade
Multi-ply paperboard substrates featuring pigment-coated top surfaces provide the structural and visual foundation for consumer folding cartons. Multi-layer construction combines bleached chemical pulp outer layers with mechanical or recycled middle plies to balance stiffness and weight. Coated folding boxboard offers a smooth printing surface paired with mechanical strength required for scoring, die-cutting, folding and high-speed packaging erection.
The grade designation excludes solid bleached chemical boards and unbleached kraft containerboards.
Multi-Ply Architecture
Layering distinct pulp types creates an efficient structural effect across the sheet profile. Bleached chemical pulp on outer faces yields high tensile strength and creasing durability, while bulkier mechanical pulps in inner plies maximize bending stiffness at low overall weight. Pigment coatings applied via blade or air-knife coaters fill surface voids without compromising structural stiffness.
This layered composition minimizes fiber mass while maintaining carton compression resistance.
Surface Receptivity
Ink absorption and print fidelity depend heavily on the mineral coating formulation applied to top plies. Calcium carbonate and clay pigments bound with synthetic latex form a micro-porous structure that controls ink vehicle penetration. High brightness and surface smoothness enable accurate color reproduction across offset litho and gravure printing processes.
Excessive coating binder migration can reduce ink drying rates and create surface picking during press runs. Proper balance between coating absorbency and surface strength prevents ink set-off in delivery piles while ensuring strong adhesive bonding during carton gluing. Embossing and high-tack ink transfer remain stable under controlled surface strength settings.
Creasing Rule Selection for Coated Folding Boxboard Conversion
Selecting steel creasing rules and matrix channels for coated FBB requires matching board caliper and CTMP core shear limits to prevent surface cracking.