BCTMP Core

Bulk Retention

Caliper gains achieved through this mechanical pulp fraction allow converters to reduce overall packaging weight while maintaining box compression strength standards. Stiff fibres resist crushing under pressure from automatic carton erection machinery and pallet stacking loads in distribution warehouses. Board stiffness declines when moisture absorption exceeds strict mill tolerances because wood polymers soften in humid warehouse environments.

Converters compensate for humidity fluctuations by adjusting creasing depth parameters on rotary die-cutting equipment. Compression resistance drops sharply if the middle layer density falls below mill specification limits during the wet end pressing sequence.

Surface Uniformity

Smooth exterior surfaces require dense chemical pulp outer plies because coarse mechanical fibres would otherwise telegraph through clay coatings and degrade print quality. Papermakers control pore distribution across the web by optimizing headbox jet-to-wire speed ratios during multi-ply sheet formation. Microscopic voids remaining between unrefined mechanical elements absorb liquid paraffin unevenly during barrier treatment applications on high-speed liquid packaging lines.

Printers evaluate dot gain consistency across the substrate to confirm that base sheet formation satisfies high-end graphic reproduction demands. Surface smoothness measurements dictate maximum ink transfer limits on offset lithography presses running coated folding boxboards.