Impact Resistance
Energy absorption capacity defines this mechanical property of high density paperboard and corrugated fibreboards. Dynamic fracture toughness measures the energy required to propagate an existing crack under high strain rates during high speed automated converting or case forming processes. Testing involves subjecting a pre-notched specimen to a sudden blow to calculate how much force the substrate absorbs before total structural failure occurs.
Material science models confirm that fibre length and moisture content influence these values significantly.
Processing Limits
Industrial high speed packaging lines demand boards that handle rapid mechanical stress without splitting along the score lines or edges. Dynamic fracture toughness determines the acceptable speed of blank feeding and folding operations because it dictates the energy threshold at which a micro-crack transitions into a catastrophic failure of the substrate. If the loading speed exceeds the material ability to dissipate internal energy through plastic deformation the carton integrity collapses during the brief interval of a folder gluer pass.
Low values indicate a brittle failure mode where sheets shatter under impulse loads rather than bending.
Structural Integrity
Manufacturers verify that paperboard stocks maintain consistent performance across varying ambient conditions to ensure line uptime. Accurate assessments allow converters to adjust machine settings for stocks with lower tolerance for rapid crack growth or high speed folding impacts. Engineering specifications for premium substrates often require a baseline value that ensures the board withstands the shock of pneumatic ejection or sudden stopping on high speed conveyor belts.
The ability to resist sudden energy spikes governs the reliability of the finished box design during heavy duty transit and automated fulfillment cycles.
