Virgin Sulphate Grade
High-purity, multi-layered paperboard manufactured entirely from bleached virgin chemical kraft pulp provides superior brightness, hygiene, and mechanical strength for premium packaging. Solid bleached sulphate, widely designated as SBS board, is produced using chemical pulping processes that remove lignin, resulting in a substrate free from mechanical fibre contaminants and recycled impurities. Both the outer surfaces and the internal core plies consist of refined bleached chemical pulp, typically finished with one or more layers of mineral pigment coatings on the print side.
The material serves luxury packaging, cosmetics, pharmaceutical cartons, and direct food packaging sectors. The specification boundary stops when economy recycled chipboard or unbleached kraft grades are selected for cost-sensitive structural applications.
Converting Characteristics
Clean chemical fibre composition delivers high tensile stiffness, exceptional tear resistance, and consistent ply-bond strength across high-speed converting runs. During die-cutting and creasing operations, solid bleached sulphate delaminates cleanly within its internal layers, producing sharp, defect-free fold hinges that maintain their structural form without coating fracturing. The ultra-smooth coated surface provides high ink holdout, wide colour gamuts, and precise dot reproduction for demanding sheet-fed offset, UV flexographic, and digital print technologies.
Its neutral odour and taint profile makes it standard for chocolate, confectionery, and dairy packaging where volatile organic compounds cannot be tolerated.
Performance Verification
Quality control protocols assess solid bleached board against strict standards for brightness, whiteness, surface roughness, and Taber stiffness. The high purity of the virgin chemical furnish ensures uniform dimensional stability and predictable hygrothermal performance during high-speed rotary printing and hot foil stamping. Because the furnish contains no recycled secondary fibres, the board displays superior consistency in caliper and formation across both machine direction and cross-machine direction.
High internal tear resistance and structural purity guarantee reliable carton performance on automated high-speed pharmaceutical filling lines.
