Fiber Distribution
Fiber orientation analysis in recycled containerboard manufacturing establishes the structural axis by measuring directional tensile strength ratios across the web. The gab model evaluates machine direction against cross direction fiber alignment during the wet end forming phase on high speed Fourdrinier paper machines. High velocity stock jet delivery relative to wire speed creates excessive fiber orientation, which subsequently drives warp during lithographic laminating operations.
Operators adjust slice lip geometry and stock approach flow velocities to control directional ratios within narrow converting tolerances. Unbalanced fiber distribution causes dimensional instability when corrugated sheets absorb moisture during flexographic printing processes.
Surface Tension
Converting facilities measure surface free energy using dyne solutions to verify substrate readiness before applying water based barrier coatings. The gab model calculates critical wetting tension thresholds required for uniform emulsion spreading on unbleached kraft linerboard surfaces. Low surface energy values cause crawling and pinholes in functional coatings, leading to moisture barrier failure in refrigerated food packaging environments.
Corona discharge treatment modifies cellulose hydroxyl groups to elevate surface energy above minimum converting specifications. Residual sizing agents from recycled pulp furnish often depress dyne levels unexpectedly during continuous production runs.
Burst Resistance
Mullen burst testing quantifies the hydraulic pressure sustained by corrugated board before structural rupture occurs under multi directional stress. The gab model predicts stack compression strength performance based on combined linerboard basis weight and flute profile geometry. Heavy duty shipping containers require specific bursting strength minimums to withstand static warehouse loads during extended supply chain transit periods.
Low lignin content in recycled fibers reduces overall tensile elongation, which directly impacts dynamic puncture resistance on packaging assembly lines.
