Folding Torque

Crease Geometry

Crease delamination depth directly controls the magnitude of force required to rotate a board panel through ninety degrees. Deep matrix scoring fractures internal fibre bonds, reducing bending resistance while preserving the outer liner integrity. When folding torque remains excessively high, carton panels bow outward during gluing, which causes misalignment in downstream packing lines and jams inside automatic filling equipment.

Fibre stiffness varies with moisture content, meaning low relative humidity increases panel stiffness and requires higher folding energy. Mill scoring tools must balance male knife width against female groove dimensions to achieve predictable resistance levels across machine direction and cross direction folds.

Speed Impact

High-speed erecting lines magnify rotational resistance due to viscoelastic recovery inside the compressed paperboard matrix. Bending force spikes during initial panel deflection before declining to a lower steady resistance level. Measurement thresholds lose accuracy when line speeds exceed the response frequency of sensor arms.