Paperboard Repulpability Assessment under Standard Laboratory Disintegration Conditions
Standard laboratory disintegration assesses paperboard repulpability by measuring defibering rates, fiber yield, and screen reject fractions under fixed shear.
Repulpability Assessment
Fibre Disintegration
Testing pulp dispersion under controlled hydrodynamic shear determines how rapidly secondary paper packaging breaks down in water during recycling. Industrial pulpers rely on mechanical rotor action to separate bonded cellulose webs without fracturing individual chemical fibres. A repulpability assessment measures the percentage of retained material captured on a designated screen slot after a fixed disintegration period.
Non-dispersible barrier coatings or wet strength resins extend the required breakdown duration beyond standard mill tolerances.
Yield Loss
Quantifying rejects from standard repulpability testing isolates the actual papermaking fraction recovered from converted packaging laminates. Standard disintegration protocols subject printed folding boxboard or coated containerboard to mechanical agitation in tepid water for ten minutes. Residual flakes remaining on a two millimetre mesh screen represent non-recoverable stock that enters municipal waste streams instead of the pulper vortex.
Extruded polyethylene layers or hot melt adhesives typically generate fibrous clumps that lower overall recovery percentages during automated screening.
Screening Efficiency
Calculating the mass balance of rejected constituents determines whether specialized wet end additives disrupt standard secondary fibre processing cycles. Processing plants measure ovendry weight differences between initial sample inputs and final accepts passing through slotted basket extractors. Coated paper stocks possessing high cross-linked polymer content frequently blind screening equipment and reduce secondary sorting throughput.
Industrial refiners require clean hydropulper outputs to prevent adhesive agglomeration from fouling downstream paper machine felts.
Calculating Matrix Depth Ratios for Co-Extruded Film Laminates under Pressure
Matrix depth ratios dictate counter-die selection by balancing polymer yield strain against substrate compaction to preserve layer integrity under pressure.