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.
Continuous Repulpability Testing
Dissolution Metric
Continuous repulpability testing is a laboratory method measuring the time required for a printed packaging substrate to disintegrate completely inside a stirred aqueous suspension. Evaluated pulping duration determines whether coated folding boxboard fragments dissolve into manageable secondary fibres during standard mill hydrapulper processing. Testing halts when rejects passing through a slotted screen plate fall below a defined weight fraction.
Recyclability grading depends directly on complete fiber liberation within standard processing time limits.
Slurry Protocol
Sample squares face mechanical agitation inside a temperature controlled disintegration vessel filled with treated process water matching typical mill alkalinity levels. Dissolved coating binders and surface varnishes release into the liquid medium while cellulose bonds swell and break apart under gentle shear forces. Screening stages separate undispersed plastic laminates or heavy wax barriers from the resulting fiber slurry for dry mass weighing.
Residual flake percentages establish whether specific print run additions hinder subsequent paper machine operations.
Screen Retention
Final sorting phases capture undissolved polymer films and wet strength resin networks that survive prolonged aqueous exposure. Unpulped fractions indicate excessive barrier coating weight or improper adhesive crosslinking during the lamination step of converting. Board mills reject parent reels yielding excess screen residue because oversized fragments plug refining tackle and cause formation defects in recycled paper output.
Residual contamination levels dictate final pricing tiers for recovered secondary fiber bales.