FIELD: textile, paper.
SUBSTANCE: full bleaching/extraction of craft cellulose fibres is carried out with a chorine agent. Afterwards fibres are washed and exposed to contact in solution with at least one optical bleach (OB) upstream the mixing box and the discharge box of the machine. Fibres in solution have consistency from 7 to 15%, pH of solution in process of contact of fibres with OB makes from 3.5 to 5.5, temperature of contact makes from 60 to 80°C, and time of contact is from 0.5 to 6 hours. Additional contact of OB with fibres is carried out in the device for coating application or in the gluing press. Contact may be carried out at the stage of storage, both at high density and low density of the craft-cellulose fibres, and also at the stage of refinement.
EFFECT: improved whiteness and brightness of fibres when using lower quantity of OB.
19 cl, 11 dwg, 12 tbl, 6 ex
