Fiber Resistance
Structural integrity under axial loading defines this property for linerboard and fluting media. Short span compression represents the maximum force a sample sustains across a gap of point seven millimeters before buckling failure. It measures the potential of a substrate to resist vertical collapse when formed into the walls of a corrugated box.
Engineers rely on these results to predict top-to-bottom compression strength in finished packaging.
Testing Procedure
Equipment grips the specimen firmly on both sides of a precision gap to prevent bending. Actuators apply force in the machine direction or cross direction until the fibers snap under the concentrated stress. Standard protocols mandate constant humidity and temperature control because moisture content alters the bonding strength of the cellulose network significantly.
High values indicate a dense sheet capable of maintaining structural shape despite external weight or stacking pressures.
Performance Expectation
Mills adjust refining energy or chemical additives during the papermaking process to optimize these values for specific board grades. Heavyweight liners usually offer higher resistance than lightweight counterparts, though sheet formation and fiber orientation also dictate the final result. Manufacturers verify this metric to ensure the container remains rigid during distribution cycles.
A high short span compression value ensures structural stability in stacked storage conditions.