PAPERMAKING PROCESS Russian patent published in 2005 - IPC

FIELD: paper industry.

SUBSTANCE: invention relates to technology of manufacturing paper from aqueous suspension containing cellulose fibers and optional fillers. Process comprises separately adding to suspension cationic processing polymer with one or several aromatic groups and anionic polymer with one or several aromatic groups. The latter is selected from polymers prepared according to stepped molecule growth mechanism, naturally occurring polysaccharides and aromatic polymers and modifications thereof, provided that, if anionic polymer is polymer prepared according to stepped molecule growth mechanism, then it cannot be anionic condensation polymer based on melaminesulfonic acid. Another condition that could be alternatively fulfilled is that anionic polymer is not anionic polystyrenesulfonate or anionic condensation polymer based on melaminesulfonic acid. Suspension is then molded into sheet and dehydrated on screen.

EFFECT: improved dehydration and/or retention during making of paper from all types of fibrous pulps, including those with high content of salts, and increased strength of dry paper.

19 cl, 10 tbl, 11 ex