FIELD: paper-and-pulp industry.
SUBSTANCE: invention is directed to preparing secondary fiber and can particularly be used in manufacture of paper and cardboard. Method comprises pulping of secondary fiber in presence of alkali metal hydroxide, sodium silicate, hydrogen peroxide, to which phosphorus-containing acid compound is added. The latter is selected from group consisting of sodium polyphosphate and sodium phosphate. Consumptions of sodium silicate, hydrogen peroxide, and phosphorus-containing acid compound are, respectively, 0.5-2.0%, 0.5-2.0%, and 0.1-1.0% based on the weight of dry fiber.
EFFECT: improved whiteness of fibrous material.
1 tbl, 4 ex
| Title | Year | Author | Number |
|---|---|---|---|
| METHOD OF PREPARING SECONDARY FIBER IN PRODUCTION OF CELLULOSE-CONTAINING FIBROUS MATERIAL | 2005 |
|
RU2298058C1 |
| METHOD OF PREPARING SECONDARY FIBER IN PRODUCTION OF CELLULOSE-CONTAINING FIBROUS MATERIAL | 2005 |
|
RU2298059C1 |
| METHOD FOR PREPARING OF SECONDARY FILAMENT FROM CORRUGATED CARDBOARD IN THE COURSE OF MANUFACTURE OF FIBROUS MATERIALS | 2004 |
|
RU2244775C1 |
| METHOD OF REMOVING PRINTING INK FROM WASTE PAPER | 2020 |
|
RU2744563C1 |
| METHOD FOR ALKALI TREATMENT OF PRINTED PAPER | 2010 |
|
RU2435892C1 |
| WASTE PAPER MASS PROCESSING METHOD | 2001 |
|
RU2200215C1 |
| WASTE PAPER MASS PROCESSING METHOD | 2006 |
|
RU2305146C1 |
| REMOVAL OF PRINKING INK FROM WASTE PAPER | 2009 |
|
RU2513386C2 |
| METHOD OF PREPARING PULP FROM WASTE PAPER FOR MANUFACTURING PAPER AND CARDBOARD | 2000 |
|
RU2154703C1 |
| METHOD OF PREPARING WASTE PAPER MASS FOR MAKING TISSUE PAPER | 0 |
|
SU988941A1 |
