Core Construction
Paperboard engineered with a white pigment-coated top liner over mechanical pulp middle layers and a pigment-free cream or manila back liner provides high bending stiffness at lower basis weights. Designated in European packaging standards, gc2 boxboard utilizes groundwood or thermomechanical pulp in its inner plies to maximize sheet bulk. The top surface receives double mineral coating to ensure clean ink receptivity for offset and flexographic printing processes.
The reverse side retains the natural yellowish tone of mechanical wood fibers.
Yield Advantage
High specific volume achieved through mechanical pulping allows boxboard converters to meet stiffness specifications while reducing overall sheet weight compared to solid bleached grades. Incorporating mechanical fibers into gc2 boxboard creates a thick internal network that pushes outer tensile layers further apart, increasing section modulus. Structural yield advantages enable carton manufacturers to reduce transport mass and raw material consumption in dry food packaging applications.
Higher bulk decreases total sheet density without sacrificing panel rigidity.
Application Barrier
Structural limitations of mechanical pulp plies restrict exposure to wet environments where moisture absorption causes thickness swelling. Uncoated back liners on gc2 boxboard absorb moisture faster than coated alternatives, making the grade unsuited for direct contact with wet chilled foods. Varnishing or poly-coating extends functional utility in frozen food carton conversion.
