Multi Site Chain of Custody Credit Ledger Fundamentals
Multi-site chain of custody credit ledgers centralize certified fiber allocations across eligible sites under strict conversion and 24-month expiration limits.
Fiber Loss Ratio
Material Yield
Pulping mass balance evaluation measures the proportion of usable wood pulp solids discarded through reject streams during stock preparation. Fiber loss ratio expresses the dry weight of rejected cellulosic material relative to total dry fiber entering the repulping process. Deinking operations and mechanical screening remove contaminants, yet short fibers and fines inevitably exit alongside heavy rejects and stickies.
A lower ratio indicates efficient stock cleaning, whereas elevated values signal mechanical attrition or incorrect screen slot sizing. The metric applies strictly to solid organic fiber content rather than dissolved organic solids or inorganic filler loadings.
Processing Effect
Recycled containerboard mills monitor reject streams from coarse screens, reverse cleaners and flotation cells to isolate processing inefficiencies. Fractionation screens separate long softwood fibers from short hardwood fragments, but incorrect rotor speeds carry prime long fibers directly into tailing lines. Adjusting shower pressure and reject flow rates restores fiber separation, cutting organic waste sent to sludge dewatering systems.
Higher feed consistency in pulping vessels protects fiber length from mechanical shearing, lowering fine generation in subsequent washing stages. Flotation deinking systems require delicate bubble size control, because aggressive aeration entrains useful fiber alongside ink particles.
Mass Balance
Extreme mechanical cleaning settings maximize brightness at the expense of cumulative yield loss. Fiber loss ratio tracking stops at the wastewater clarifier inlet, where suspended solids transition into environmental effluent management.