Solid Bleached Sulfate Board Bending Stiffness Evaluation Methods
SBS bending stiffness scales with the third power of caliper and dictates carton bulking resistance, requiring verification via ISO 2493 load-cell testing.
Matrix Scoring
Quantitative Assessment
Numerical values assigned to individual substrate properties establish a weighted hierarchy for comparison across diverse paper stocks. Matrix scoring employs these relative weights to rank sheets based on performance metrics such as tensile strength, brightness, and ink holdout. A numerical result derives from multiplying each raw measured value by a designated coefficient of importance.
This output permits a direct comparison of divergent physical characteristics when selecting raw materials for high volume lithographic runs.
Operational Calibration
Engineers define the primary coefficients through historical process data recorded during stable print production cycles. Each variable receives a value that reflects the impact on runnability and final visual output. High coefficients attach to parameters that cause immediate press downtime while lower values address cosmetic deviations that remain within acceptable commercial tolerances.
Managers adjust these coefficients to match the specific requirements of a new production line or a modified coating chemistry. The calculation creates a single index that represents the fitness of a specific substrate for a targeted end use.
Performance Threshold
Industry standards dictate that a finished score must fall within a set variance to qualify a batch for high speed converting equipment. Variations occur due to fiber distribution and coating thickness across the web. A low result indicates a lack of mechanical stability that potentially compromises the integrity of a folded package.
Consistent application of these formulas stabilizes the supply chain by removing subjective evaluation from the inspection process.