Verifying Board Caliper before Cutting Brass Embossing Tooling
Verifying true substrate caliper under standard foot pressure before cutting brass embossing tooling prevents fiber shearing, smashed matrixes, and costly die remakes.
DIN 53121 Board Tolerance
Flexural Rigidity
Standardization of two-point bending test methods establishes reproducible physical parameters for evaluating the flexural rigidity of paper, paperboard, and corrugated board. Under European testing guidelines, din 53121 board tolerance defines acceptable limits for bending resistance measured at a fifteen-degree deflection angle. The test determines structural stiffness essential for carton top-load strength and automated feeding.
Standard scope excludes flexible plastic films and lightweight tissue papers below fifty grams per square meter.
Anvil Span
Test procedures fix clamp geometry, bending length, and motor rotation speed to eliminate operator measurement error. Standardized test spans of ten, thirty, or fifty millimeters accommodate various board calipers and structural weights. Bending resistance values correlate directly with folding box performance during high-speed cartoning line erection.
Fiber orientation affects results, requiring separate measurements in machine direction and cross-machine direction. Deviations from standard testing temperatures alter fiber elasticity and invalidate comparative laboratory results.
Variance Limit
Quality control standards specify upper and lower stiffness boundaries for delivered paperboard rolls and sheets. Mill delivery specifications allow stiffness variations within plus or minus five percent of target nominal values. Boards falling below minimum thresholds buckle under compressive loads during automated filling.
Rigorous testing prevents press jams and packaging failures in retail environments.