THE SUITABILITY OF AMERICAN WOODS FOR PAPER PULP 65 
Roble Pellix {Nothofagus obliqua) 
Range. — From 33° south latitude to Llanquihue, Chile. 
Description. — The bark is reddish brown with light-gray particles. It is one- 
half inch thiek, not ridged, and readily separated into thin, broad, flat scales. 
The wood closely resembles coigue. 
Oven-dry weight -per cubic foot, green volume. — 
Fiber lengths. — Average, 1.45 mm.; maximum, 1.76 mm.; minimum, 1.12 mm. 
Soda Pulp 
Roble pellin is readily reduced by the soda process, but the pulp is very difficult 
to bleach. Yields of 30 to 35 per cent are obtained, requiring 35 to 40 per cent 
of standard bleaching powder. 
There is little likelihood of this species being considered for pulp, on account 
of its great durability and consequently higher value for railroad ties and struc- 
tural timber. 
Quillai (Chilean cane) (Quillaja saponaria) 
Description. — Resembles cane, except that it is solid and much stronger. 
Oven-dry weight per cubic foot, green volume. — 
Fiber lengths. — Average, 2.2 mm.; maximum, 2.66 mm.; minimum, 1.34 mm. 
Soda Pulp 
Quillai reduces readily by the soda process, yielding 40 to 45 per cent of pulp 
of very good fiber length and capable of use in the manufacture of papers of 
moderate strength. 
On account of the light color of . the pulp it might be considered for use 
unbleached in the manufacture of newsprint. 
TABLES OF COOKING AND STRENGTH DATA 
Tables 6 to 18 give for most of the woods included the results of a majority of 
the test cooks made. They cover cooking conditions, yields, and strength of the 
resulting pulps. For reasons already stated, the data are not in all cases repre- 
sentative of what are, according to the final conclusions, the practical pulping 
characteristics of the species. They may be considered, however, as illustrative 
of possible operating conditions, which in some cases are to be avoided rather than 
imitated. 
The column headings in the tables are, in general, self-explanatory. In the 
tables of sulphite cooks the columns showing the composition of the cooking liquor 
give the percentage of S0 2 in the liquor as free, combined, and total, with the 
commonly accepted understanding that the free is the excess over that required 
to combine with the base and form normal sulphite, even though the latter does 
not exist as such. " Duration of cook" is the total time of cooking, from turning 
on steam to blowing. The steam pressures shown refer in all cases to pressures 
above atmospheric. It is to be noted that these are partial pressures as distin- 
guished from total pressures shown on the gauge. The quantity of bleach required 
was found by methods already described in " Experimental procedure." 
In the strength data the strength factor is obtained by dividing the Mullen test 
value by the weight per ream of the paper tested. The average stretch and aver- 
age breaking length are the average of those values in each direction as deter- 
mined on the Schopper tensile strength tester for paper. The number of double 
folds was obtained on the standard Schopper folding tester. In the cases of both 
the folding and the tearing tests due allowance must be made for the weight of 
the sheet, since the values have not been converted to a standard or unit weight 
basis for want of any known conversion factor. Strength tests are shown for 
relatively few of the cooks of hardwoods, since, on account of their short fibers, 
hardwoods are not often used in papers where strength is of major importance. 
Some of the raw cooks listed in the tables were worked into paper by a special 
beater treatment. This would indicate possibilities of combining chemical with 
mechanical disintegration of the chips and of producing paper of moderate 
strength from unbleached pulps at yields between 70 and 80 per cent. Work 
with caustic soda and caustic soda and sulphur has recently demonstrated this to 
be possible. Light-colored sulphite pulps with yields of over 70 per cent have 
been made, but additional work is necessary to perfect the details. The bearing 
of these developments on the utilization of mill waste or of southern woods for 
newsprint is apparent. The exceptional strength of pulp so obtained from the 
hardwoods is also of interest, 
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