INDUSTRIAL AND EXGINEERING CHE-WISTRY
November, 1931
1276
(15) Travers, Proc. Roy. Soc. ( L o n d o n ) ,TSA, 9 (1906). (16) Trouton and Pool, I h i d . , 17A, 309 (1906). (17) Urquhart and Williams, Shirley I n s l . Mem., 3, 197 (1924);8, 1 (1929): J . Tentilelnsl., 15,4331' (1921); 20,125T (1929). (18) Van Bemmelen. 2 anofg. Chem., 13, 232 (1897). (19) Zsigmondy, Bachman. and Stevenson, Ibid., 15, 189 (1912).
(9) Murphy and Walker, J . Phys. Chem., 32, 176 (1928). (10) Obermiller, Z.physrk. Chem., 109, 145 (1924). (11) Patrick, Colloid Symposium Annual, I , 129 (1929). (12) Pidgeon and Maas, J. A m . Chem. Soc., 62, 1053 (1930). (13) Sheppard, J . Phys. Chem., 34, 1041 (1930). (14) Stamm, IND.ENO.CHEM.,Anal. Ed., 1, 94 (1929).
Turpentine Content of Various Grades of Fire-Still Gum Rosins' Arthur R. Hitch CHEMICAL LABORATORY, GILLICAN-CHIPLEY Co., SAVANNAH, GA.
HE question has often been raised by many of the producers and buyers of pine-gum rosin as to the amount of turpentine present in various grades of gum rosin produced by the ordinary fire-still process. Since it is difficult to completely remove the turpentine from pine gum by the ordinary fire-still method of distillation, and as the various stillers have their own individual methods and habits of stilling, each in some may differing from the other, it is reasonable to expect that there will be a great variation in the percentage of turpentine found in rosins of the same grade, as well as those of different grades. I n order to ascertain, in a preliminary way a t least, the average amount of turpentine present in fire-still rosins of the same grade, as well as those of different grades, three samples of each grade of rosin, from D to X, were selected from the rosin yard of the Downing Company, Brunswick, Ga., for analysis. No two samples of the same grade came from the same producer, and as many producers as could conveniently be secured were included in this investigation. Thirty-six samples of rosin were analyzed, the samples coming from a total of twenty-one producers, all of whom are located in Georgia.
T
Method of Analysis
The following was found to be the quickest and most efficient method for removing turpentine from the rosin under consideration: Two hundred and fifty grams of the rosin sample to be tested were crushed and placed in a 500-cc. distillation flask and heated by direct flame to a temperature of 150" C. (302" F.). The temperature was then raised to 185-190" C. (365-374' F.), and a t the same time the rosin was steamed as rapidly as possible without causing the entrainment of particles of rosin by steam. At this temperature, and with rapid steaming, practically all of the turpentine was driven off in from 20 to 30 minutes. The turpentine and steam were condensed by means of a long condenser and run into a separatory funnel, and the turpentine separated from the water and weighed. Knowing the weight of the original rosin and the weight of the turpentine recovered, the percentage by weight of turpentine present in the original rosin was calculated.
Results
The results of this investigation are given in detail in Table I, showing the variation in the percentage of turpentine present in the individual samples of the same grade as well as the difference in percentage between the various grades. In order not to divulge the source of the samples, the producers are marked by code, each number representing a different producer-for example, Producer 2 may be A. B. Jones and Son, Producer 10 may be Southern Turpentine Co., etc. Table I1 shows the average turpentine content of the samples I
Received June 20, 1931.
of rosin for each of the three groups-light, dark.
medium, and
Table I-Turpentine Content of Various Grades of Rosin GRADEOF CODEN o OF TURPEN- G K A D E OF Cons No. OB TURPENROSIN PRODUCER T I N E ROSIN PRODUCER TlNE
%
X X X
wW
%
1 4 2
3.2 3.0 2.8 Av. 3.00
I I I
3 12 13
0.40 0 32 0.60 Av. 0.44
3
WW
ww
4
5
2.5 0.52 2.8 Av. 1.94
H H H
3 14 15
0.16 0.80 1.04 Av. 0.67
N N
N
3 8 9
0.68 1.40 0.24 Av. 0.77
F F F
3 19 14
0.32 0.40 0.30 Av. 0.34
K K K
8 10 11
0.88 0.48
D D
18 20 21
0.44 0.35
0.60 Av.
Table 11-Averaee
D
Av.
0.65
0.42
0.40
Turpentine Content of Various Grades of Rosin
GRADEOF ROSIN
Av. TURPENTINE CONTENT
X-N Light Medium M-H Dark G-D
% 1.59 0.67 0.36
Summary and Conclusions
A preliminary study has been made of the turpentine content of 36 samples of fire-stili gum rosin of all grades from D to X, inclusive. The results obtained show great variations in t h e turpentine content of rosins of the same grade as well as between rosins of different grades. For different rosin grades the turpentine content varies, on an average, from 3.0 per cent for X to 0.33 per cent for E grade. The greatest variation in turpentine content of samples within the same grade was obtained for the WW rosin and ranged in amount from 0.52 to 2.8 per cent. If the WW rosin containing 2.8 per cent turpentine had been distilled in the same manner as the WW rosin containing only 0.52 per cent turpentine, there would have been a saving in turpentine of 2.28 per cent of the rosin produced, or for each trade barrel of 235 pounds net, a saving of 5.36 pounds or 0.74 gallon, which a t 50 cents per gallon would mean a saving of 37 cents per trade barrel or 64.5 cents per round barrel of rosin or approximately $4.50 for each 10-barrel charge of gum stilled. The results obtained in this work, when averaged, show a marked increase in turpentine content of the rosin from D to X.
