VOL. 30, NO. 3
INDUSTRIAL AND ENGINEERING CHEMISTRY
320
for corrugated container board, but a portion of it will be diverted to bleached products. The relatively low cost of wood and labor in the South give this section a distinct advantage over the producer of sulfite pulp in other sections, except possibly the Pacific Coast, where mills are a t a disadvantage in eastern markets because of transportation costs. Semi-bleached sulfate pulps made in the South can therefore compete with unbleached sulfite from the northern mills, and their manufacture has already begun. Until recently, bleached sulfite has been used almost exclusively in the white grade of paper, such as book and writing papers. The development of processes for bleaching sulfate to a satisfactory color for these grades of paper brings it into direct competition with unbleached sulfite and offers the additional feature of greater strength. The development of these processes for bleaching sulfate pulp will enable the southern mills to extend their operations and permit them to manufacture pulp of high color, a field which has heretofore been denied them.
about 260,000 in 1937. Several large mills for the manufacture of bleached sulfate have either started operations recently or will do so in the near future. One of these is located on the Pacific Coast, one in the Lake States, and three in the Southern States. The three southern mills will have a yearly production of 150,000 tons, or an increase of nearly 50 per cent over the 1936 imports. The South has a definite cost advantage over the foreign mills, and the main incentive in erecting these new mills has been to make the paper industry of the United States independent of the more expensive imported kraft or sulfate pulp. In 1925 the amount of bleached sulfate used in this country was slightly over 5 per cent of the total amount of bleached pulp (sulfite and sulfate). In 1936 this had increased to approximately 15 per cent. This trend is shown by the following tonnage figures: Year 1925 1936
--Bleached Produced 612,576 1,150,000
SulfiteImported 321,413 512,168
--Bleached Produced 31,797 156,800
SulfateImported 19,509 102,375
Production Statistics According to the statistics of the United States Pulp Producers? Association, the production of bleached sulfate pulp in the United States has increased from about 30,000 tons in 1925 to 156,800 in 1936. During the same period the imports of bleached sulfate have increased from 19,509 to 102,375 tons. The consumption of bleached sulfate in the United States a t the end of 1936 was therefore approximately 260,000 tons. A survey of the mill capacity for this grade of pulp estimates an increase from around 170,000 tons in 1935 and 1936 to
The extent to which the southern woods can extend this competition will depend in some measure on further chemical research in improving existing pulping and bleaching methods. Not so many years ago the manufacture of white paper from kraft pulp would have been considered impossible, yet today it is being done. It may not be too optimistic to expect that chemical research will develop improvements that will enable bleached sulfate to replace other types of wood pulp in the manufacture of cellulose products other than paper. RHlCEIVBD November 23, 1937.
Line Coordinate Chart for Vapor Pressures of Organic Solvents D. S. DAVIS Wayne University, Detroit, Mich.
ARDNER and Brewer' presented valuable data on the vapor pressures of eleven commercial high-boiling organic solvents. The samples represented technical products in actual use and were riat specially purified. Their values are in agreement with fragmentary data which exist in the literature, and it appears worth while to present the new data in a compact and readily usable line coordinate chart. As required by the integrated Clausius-Clapeyron equation, the data plot as straight lines on paper ruled log P ws. 1/T so that the equation for each set is of the form log P = A - B/T
G
suggesting the diagram shown in Figure 1 on the opposite Page. Values of constants A and B were determined by the method of averages, discarding occasional pairs of values which appeared to be in error. Table I lists the constants. The line coardinate chart was prepared from these constants, and its use is illustrated as follows: What is the 1 IND.
ENQ.CEBM.,29, 179 (1937).
vapor pressure of benzyl acetate a t 90" C.? Connect 90 on the temperature scale with point 1 and note the intersection with the pressure scale a t 9.2 mm., the desired value. SimiIarIy, what is the boiling point of Hexalin? Connect 760 on the pressure scale with Hexalin point 8 and note the intersection with the temperature scale a t 157" C. TABLEI Organic Solvent Benzyl acetate Benzyl alcohol But 1 carbitol Cargitol Deaalin
A 8.557 9,133 9.684 9.336 8.049
1000 E 2.770 2.965 3.328 3.001 2.389
Organic Solvent Dibutyl phthalate Dimethyl phthalate Hexalin Terpenyl acetate Terpineol Te tralin
A 6.455 9-209 9.337 9.408 9.432 8.235
1000 E 2.662 3.452 2.779 3.224 3.137 2.567
The legend a t the bottom of Figure 1 lists the solvents, their identification numbers? and the limits of the temperature ranges. RECEIVE~D June 1, 1937.
MARCH, 1938
INDUSTRIAL AND ENGINEERING CHEMISTRY
32 1
0 /O
$99
07
L
06
4
De9 C. / 2 4
Benzy/ Acetote Senzy/ A / C O ~ O / Buty/ Csrbifo/ Curb/fo/
5
Decalin
10
6
D i b u t y / Phthalate
7
Dimethy/ Phthdste Hexahn Terpeny/ Acetote
80 to /BO 50 to /SO
3
8
9 /O
N
Terpineo/ Tez?ru/h
2 0 to 230 2 0 to 2 / 0
2
1 0 to im 20 t o 2 / 0
to 200
20 t0
/70
6
/o to /60 0 t 0 /60 /O CO 230
4
2
OOO/
FIQURE 1.
VAPORPRESSURE CHART
