Folding Boxboard Internal Ply Shear Stiffness Standards during Die Cutting
Core shear stiffness governs folding boxboard creasing performance; correct values enable middle ply delamination while preventing outer coated liner failure.
GC1 Boxboard
Paperboard Specification
Premium virgin-fiber boxboard grades featuring pigment coatings on both top and reverse surfaces represent the highest visual standard for consumer packaging. Primary fiber construction delivers high brightness, purity and odor neutrality required for sensitive goods. GC1 boxboard designates a fully bleached virgin fiber folding boxboard with a white reverse side suitable for interior printing.
The classification stops at uncoated reverse grades and recycled-content boards.
Material Composition
Bleached chemical pulp constitutes both outer layers and internal plies, creating a uniform white fiber matrix throughout the sheet thickness. Chemical pulping removes lignin completely, preventing sheet yellowing over extended storage periods. The absence of mechanical pulp lowers bulk compared to mechanical-center boxboards, requiring slightly higher grammage to achieve equivalent bending stiffness.
Double-blade coating on the top side yields exceptional smoothness, while a light coating on the reverse side stabilizes back-side printing.
Print Performance
Dual-side surface coating enables complex two-sided print layouts and high-end finishing applications. Synthetic latex and mineral pigment formulations prevent ink show-through while delivering high gloss and color fidelity. Excellent ply adhesion prevents delamination during foil stamping, embossing and high-tack ink transfer.
Lower bulk demands precise creasing matrix calibration to avoid cracking along fold lines during carton assembly. High purity and chemical neutrality make this board ideal for luxury cosmetics and pharmaceutical cartons. Surface properties support consistent ink trap and crisp detail rendering across multi-color print runs.
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.