Recycled Board Delamination Testing under High Strain Rates
Dynamic high strain rate testing exposes inter-ply strength loss in recycled board that standard static Z-tensile tests miss, preventing carton converting failure.
Mill Quality Certification
Attestation Instrument
Official production documentation issued by a paper or board manufacturing facility validates that a delivered reel lot matches contractual, physical, and chemical specifications. This document, termed a mill quality certification, records measured batch data from mill laboratory testing, including basis weight, caliper, moisture content, Cobb sizing values, and short-span compression results. The paperwork provides traceability from the base reel back through specific raw material inputs, forming wire configurations, and roll slitting operations.
Commercial procurement contracts require this instrument for release, verifying that the delivered substrate complies with agreed technical delivery conditions before converters mount reels onto presses. The validity of the record ends where secondary off-site converting, sheeting, or re-moisturization alters the physical properties established at the paper mill reel winder.
Testing Verification
Certified values reflect sample sweeps excised from cross-machine web sections at designated intervals during manufacturing runs. Automated online scanners supply real-time continuous basis weight and moisture profiles, while offline laboratory tests establish burst strength, bending stiffness, and surface roughness parameters. Each certification details test results against standard tolerances, highlighting departures from the target grammage or porosity limit.
Statistical quality control determines whether out-of-spec sections require rejection and re-pulping or pass through customer-approved tolerance bands. When moisture content veers outside the agreed delivery window, the document proves the deviation occurred during mill winding rather than improper warehouse transit.
Supply Chain Settlement
Commercial print shops and carton fabricators verify certification parameters to set die cutting pressures, ink drying curves, and folder-gluer setups without extensive trial runs. When board fails during folding or delaminates on filling lines, the certification serves as the evidentiary baseline for commercial damage claims. Claims investigators evaluate listed mill values against testing laboratory findings to determine whether failure stemmed from base sheet variance or improper converter processing.
Without this formal mill attestation, converters bear liability for running sub-standard material, forfeiting contractual recourse against board producers for downtime and packaging defects.