Virgin SBS against White Lined Chipboard for Retail Facings
Virgin SBS provides superior print brightness, stiffness consistency, and crack-free scoring, whereas recycled board lowers initial cost but adds waste.
Calcium Carbonate Mineral Filler
Mineral Function
Inorganic wet-end additives added to papermaking furnish increase sheet opacity, brightness, and surface smoothness while replacing wood fiber. Calcium carbonate mineral filler represents the primary inorganic loading material used in alkaline papermaking. Ground and precipitated variants alter light scattering properties and improve print receptivity on uncoated fine papers.
The addition threshold stops where internal bond strength degrades below converting specifications.
Furnish Behavior
Loading cellulose networks with mineral particles alters physical paper properties during web formation and pressing. Utilizing calcium carbonate mineral filler decreases fiber-to-fiber bonding area, which lowers tensile strength while increasing sheet opacity. Precipitated forms offer narrow particle size distributions that maximize light scattering at reduced loading levels.
Wet-end retention chemicals bind mineral particles to cellulose fibers to prevent white water accumulation. Excessive filler content reduces stiffness and increases dusting during high-speed offset printing operations. Mill operators adjust filler loading to balance brightness goals against required burst strength values.
Calendering filled sheets flattens mineral particles near the surface, enhancing gloss without extra coating chemicals.
Processing Constraint
Papermaking chemistry restricts mineral loading when operating in acidic environments due to chemical decomposition. Adding calcium carbonate mineral filler requires an alkaline or neutral wet-end pH to prevent carbon dioxide gas release. Surface sizing starch locks filler particles into the web, minimizing surface linting during slitting and converting.
High filler loadings lower drying energy requirements because mineral solids hold less water than cellulose fibers.