h it was
bleached with 17 per cent of bleach without the addition of acid. Since
the preceding paper appeared somewhat weak and had a low tearing
quality, it was decided to use a furnish of 15.7 per cent bleached
sulphite and 84.3 per cent bleached hemp-hurd stock. After loading with
13.1 per cent of clay and sizing with 1.1 per cent of resin size, the
furnish was given a medium brush for one hour, tinted, and run on to the
machine at 70 feet per minute. The stock gave no trouble on the machine,
but it was impossible to judge the effect of the Jordan refiner, because
through an oversight the machine chest had not been cleaned since
previous use on an unbleached yucca material. It is believed, however,
that sheet No. 138 shows improvement in the preparation of the hurd
pulp.
Run No. 139 was made from stock of cooks Nos. 304 and 305, in which
still more caustic soda was employed and the time and temperature of
cooking were increased, giving a yield of total fiber of 40.7 per cent
of the sieved or 39.4 per cent of the unsieved hurds. The cooked stock
still seemed to be undertreated, but it must be remembered that in
working with any new raw material it is impossible to know in advance
how the properly treated material should appear. A washing of one hour
was given while the roll was lowered from a light to a medium brush,
after which the stock was bleached with 17.1 per cent of bleach without
the aid of acid. Since sulphite stock improved the previous paper, this
bleached stock was used in a furnish of 16.6 per cent sulphite and 83.4
per cent hurds, loaded with 16.7 per cent clay, sized with 1.4 per cent
resin size, given a medium brush of two hours, tinted, and run on to the
machine at 70 feet per minute. The Jordan refiner seemed to have little
effect in reducing shives and was therefore left "just off." No trouble
was experienced with the stock on the machine, and the sheet is an
improvement over previous samples.
Run No. 140 was made from cooks Nos. 306 and 307, in which more caustic
soda was employed than in any previous cooks and at a higher
concentration, the fiber yields of which averaged 37.3 per cent of the
unsieved hurds. Not much improvement was apparent in the cooked stock,
in spite of the increased severity of cooking. The stock was washed and
given a medium brush for one hour, bleached with 11.9 per cent of
bleach, assisted with one-half pint of oil of vitriol, and made into a
furnish of 14.9 per cent su
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