Single Sided Lamination Curl against the Flatness Filling Lines Need
Single-sided lamination curl is controlled by balancing nip heat, reverse dampening, decurling bar tension, and conditioning board to filling line humidity.
Web Tension Strain
Mechanical Deformation
Longitudinal elongation occurs when pulling forces act across moving continuous paper rolls during slitting and printing. Continuous processing machinery measures web tension strain as the proportional stretch experienced by paperboard between driven draw rollers. Excessive tension exceeds the elastic limit of the fiber web, causing permanent elongation, web breaks, and core-crushing rewind defects.
Elastic Behavior
Paperboard behaves as a viscoelastic material, exhibiting immediate elastic stretching followed by time-dependent plastic deformation under constant load. As the continuous substrate travels through tension isolation zones, load cells monitor mechanical resistance and signal drive motors to modulate rotational speed. If tension exceeds the yield point of the base paper, fiber-to-fiber hydrogen bonds break, permanently altering sheet caliper and creasing properties.
Insufficient tension allows the web to wander laterally, introducing color-to-color register errors and edge bagging across converting nips. Closed-loop tension control systems maintain uniform elongation across variable reel diameters to preserve structural board integrity.
Rewind Integrity
Winding finished rolls under improper strain creates internal stress gradients that deform the paperboard over storage periods. Rolls wound too tightly suffer from burst centers and reel dishing, while loose winding causes telescoping and web slippage during downstream converting unwinds. Precise tension profiles ensure smooth roll unwinding without substrate snap on automated high-speed corrugating and printing lines.