Bond Resistance
Standardized test procedures measure the wet strength retention of paper substrates subjected to controlled immersion cycles. Scott Bond ISO 16260 defines the internal bonding strength perpendicular to the plane of the paperboard sheet. Laboratory dynamometers apply tensile forces through aluminum blocks adhered to opposite faces of the sample until delamination occurs.
The resulting energy absorption value quantifies the internal cohesion of the cellulosic network before fiber pullout degrades performance. Production facilities monitor this metric during multi layer board manufacturing to prevent delamination failures during high speed converting operations. Caliper variations across the web alter the applied pressure distribution during adhesive curing, changing the recorded failure load independently of pulp quality.
Cross directional uniformity depends heavily upon refining intensity applied during stock preparation and press section water removal rates. Wet end chemistry parameters directly influence inter fiber bonding potentials by modifying surface charge distributions. Starch add rates alter internal strength properties without necessarily improving tear resistance or stiffness parameters.
Tensile Energy
Mechanical converting machines demand predictable internal cohesion to withstand severe bending stresses during folding carton erection. Scott Bond ISO 16260 ratings establish the minimum structural threshold required for folding boxboard destined for heavy duty packaging applications. Board grades failing to meet specific internal bonding minimums fracture along crease lines when subjected to automated packaging machinery speeds.
Laminated packaging structures rely upon this standard to guarantee that paperboard layers remain intact under high peel stresses. Converting plants reject stock exhibiting localized weak spots because adhesive application during window patching causes immediate substrate delamination.
Ply Bond
Standardized testing protocols isolate internal fiber bonding from surface picking phenomena during offset printing runs. Scott Bond ISO 16260 provides converters with an objective benchmark for predicting how substrates interact with viscous inks. High tack inks exert perpendicular pulling forces on top liner surfaces during blanket release cycles.
Paperboard with inadequate internal strength suffers blistering or picking when ink tack exceeds the fiber network cohesion limit. Production auditors utilize these laboratory measurements to establish acceptable operating windows for multi color printing presses. Substrate moisture content fluctuations alter internal bonding values significantly by softening hydrogen bonds between adjacent cellulose fibers.
