Two stage process for sulfonating mechanical pulp fibers

Details Two stage process for sulfonating mechanical pulp fibers Two stage process for sulfonating mechanical pulp fibers

1984-12-31

1987-11-24

Bashore, S. Leon

Paper making and fiber liberation

Processes of chemical liberation, recovery or purification...

Treatment with particular chemical

162 24, 162 71, 162 84, D21C 304, D21C 326

Patent

active

047087714

ABSTRACT:
A two stage sulfonation system includes a mixing tank, a retention tank, a thickening press, a pressurized vessel, and a liquor recovery press in series relation.
The system is designed to receive mechanical pulp, in a slurry form, first introduced into the mixing tank simultaneously with a metered charge of sodium sulfite solution from the holding tank, the sodium sulfite content of which is at a level from about 40 to about 200 g/l. The solution is mixed into the slurry to provide a relatively uniform and intimate contact thereof with its fiber content. This slurry is transferred to the retention tank and there held subject to a sub-boiling temperature between 140 to 210 degrees F., producing a first stage sulfonation of the fiber content. The slurry is then passed to the pressurized vessel, in the course of which it is subjected to a pressing action, extracting liquor which inherently contains a majority of the original sodium sulfite charge directed to the mixing tank. A second stage sulfonation occurs in the pressurized vessel, producing a fiber which after refining is suited for use as reinforcing pulp in newsprint or specialty grade paper, without need for addition of conventional chemical pulp.

REFERENCES:
patent: 179103 (1875-11-01), Furbish
patent: 3607618 (1971-09-01), Uschmann et al.
patent: 3711366 (1973-01-01), Nakona et al.
patent: 4145246 (1979-03-01), Goheen et al.
patent: 4259148 (1981-03-01), Beath et al.
patent: 4486267 (1984-12-01), Prusas
patent: 4502918 (1985-03-01), Mackie et al.
Kvissgaard, H. J., "Postsulfonation", Norsk Skogind 19, 155-62, (1965), (translation).
Lindholm, C. et al., "Modification of Groundwood Pulp Through Chemical Treatment of the Coarse Fiber Fraction", Paperi ja Puu, 60, 653-664 (1978).

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