METHOD OF PRODUCING BAST-FIBRE BLEACHED PULP Russian patent published in 2016 - IPC D21C5/00 

FIELD: pulp industry.

SUBSTANCE: invention relates specifically to production of cellulose from bast raw material intended for chemical processing. Method involves cleaning bast fibre in a solution containing 10-20 g/l of sodium hydroxide and 2-5 g/l surfactant for 40-50 minutes, acidification in a solution containing 3-8 g/l sulphuric acid for 30-50 minutes, alkaline boiling in a solution containing, g/l: 15-30 of sodium hydroxide and 3.5-7.0 stabiliser for 120-180 minutes, bleaching in solution of hydrogen peroxide for 90-150 minutes, intermediate washing and drying, as bast fibre cottonised bast fibres are used produced by machining with subsequent aerodynamic fractionation, with linear density 0.81-1.24 tex and length of up to 15 mm, and mass fraction of fibres with length 3-7 mm is not less than 70% stabiliser used is sodium sulphite or sulphide.

EFFECT: technical result consists in recycling primary processing fibre crops due to use unspinnable fluffy fibres and production of cellulose with high wetting ability and high output.

4 cl, 2 tbl