Tensile Strain Measurement in Recycled Paperboard Grades
Recycled paperboard strain measurement requires direct optical extensometry under ISO 1924-3 to isolate true sheet elongation from clamp slippage.
Tensile Strain Measurement
Deformation Quantifier
Mechanical deformation testing measures the fractional elongation of a paper or paperboard specimen subjected to uniaxial tension until tensile fracture occurs. Tensile strain measurement evaluates web runnability, stretch capacity and energy absorption in packaging papers subjected to converting stress. The metric expresses elongation as a percentage of initial gauge length using constant rate of elongation tensile testers.
It governs substrate performance in sack kraft, corrugated fluting and creased packaging lines. The measurement stops applying once plastic yield passes into total structural failure or when multi-axial stress fields distort pure tensile elongation.
Load Elongation
Fibers within the sheet align, stretch and uncurl under tensile loading, transferring stress across the hydrogen-bonded network until bond failure initiates micro-cracks. High tensile strain capacity allows paper webs to absorb sudden tension spikes on high-speed corrugators without breaking. Tensile strain measurement relies on precise extensometers or optical image correlation to record dimensional changes without specimen slippage in the grip jaws.
Fiber orientation, moisture content and refining levels directly govern the total elongation achievable before fracture. Understanding strain limits prevents web snapping during slitting, printing and automated bag filling operations.
Strain Boundary
Inaccurate grip clamping pressure causes jaw slippage that inflates measured elongation values. Tensile strain measurement yields invalid results when non-uniform sample width creates stress concentration points along test strips.