Fractionating paper fiber suspensions, to give fiber-enriched and fines-enriched fractions, by wet sieving to obtain long and short fiber fractions and further wet sieving short fiber fraction

摘要

A method for fractioning and processing a paper fiber suspension (S), to give fiber-enriched fiber fraction(s) (R12) and fines-enriched fines fraction(s) (A2) involves a first wet sieving (1) to obtain a long fiber retentate fraction (R1) and a short fiber permeate fraction (A1); and a second wet sieving (2) of the retentate, to enrich fines in the permeate to give the fines fraction (A2) and enrich fibers in the retentate to give a fiber fraction (R2).