PRODUCTION OF PAPER OR CARDBOARD Russian patent published in 2011 - IPC D21H21/10 D21H23/14 D21H17/20 D21H17/29 D21H17/33 D21H17/37 D21H17/45 D21H17/67 

FIELD: textile, paper.

SUBSTANCE: method includes provision of a thick mixture of cellulose suspension, which contains a filler. The thick suspension mass is dissolved to form a diluted mix of suspension, in which the filler is available in amount of at least 10 wt % in terms of dry mass of dissolved suspension mix. The thick mixture of suspension and/or dissolved mix are flocculated. Polymer system of retention/dehydration is used in flocculation. The dissolved mixture of suspension is dehydrated on a mesh to form a sheet, and then the sheet is dried. In this method the polymer system of retention/dehydration contains the following: i) a water-soluble branched anion-active polymer and ii) a water-soluble cation-active or amphoteric polymer. The anion-active polymer is available in the thick mixture or in the dissolved mixture of suspension prior to addition of cation-active or amphoteric polymer.

EFFECT: improved retention of ash relative to complete retention with higher quality of paper.

16 cl, 21 dwg, 32 tbl, 8 ex