Full resolution (JPEG) - On this page / på denna sida - Second part - X. Manufacturing Industries. By Å. G. Ekstrand, Ph. D., Chief Engineer, Control Office of the Department of Finance - 5. Timber-ware Industry - Wood-Pulp Manufacture
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timber-ware industry. 821
stones in a horizontal position, the blocks of wood being brought into
contact with them by hydraulic pressure. A variation in this method
of rough grinding consists in first steeping the blocks of wood in water,
whereby some of the incrusting substances are set free; that gives the
pulp a stronger and tougher consistency, but also a darker colour, as
subsequent to steeping it does not admit of bleaching.
Wood-pulp Factory. Drying Cylinders.
Chemical Wood-pnlp was first manufactured on a large scale in
America from 1862 onwards. The first manufactory in Sweden was
probably Delary in the Kronoberg Län, established in 1871. Best suited
for wood-pulp prepared by chemical processes is the wood of the aspen
tree and the spruce; the pine can also be used, but it yields a less
pliable fiber. In general, one of two methods is employed: the soda
process and the sulphite process. The former is the older, and a slight
modification of it is the sulphate process, in which the loss of soda
during the manufacture is compensated for by sodium sulphate as being
cheaper than soda. The sulphite process, first suggested in 1866 by
Tilghmann, an American, in 1874 became a dangerous rival of the soda
process, inasmuch as at that date E. Mitscherlich, a German, and
D. Francke and C. D. Ekman, Swedes, introduced the process in the
wholesale industry almost simultaneously. The two first named used
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