Vol. 40, No. 12
INDUSTRIAL AND ENGINEERING CHEMISTRY
2370
TABLE IX. PERCEXTSOILREMOVED AT VARIED FORCX LEVELS ASD COKCESTRATIONS OF DETERGEKT 11:20 MINUTES AT 120 O F. Force
Concentration of Detergent, % Active Ingredient 0 . 0 2 0.04 0 . 0 6 0 . 0 8 0.10 0 . 1 2 0.14 0.16
48
Detergent A 37 43 52 61 71 78
58 83
62 86
67 87
69 87
20 30
29 48
Detergent B 36 40 63 72
41 77
47 81
49 81
19
31.5 40 50 58
Detergent C 45.5 55 , 58 66 ., 04 70 .. 70 75 ..
62 73 75 80
.,
, ,
.,
, ,
..
,
4
27
24 4 24 8 12 16 24
s.
.
TABLE P E R CENT SOIL AND CONCENTRATIONS O F Concn., % Active Ingredient 0.04 0.08 0.12
.,
81 64 75 77.5 82
. ..
REVOVED AT V A R I E D F o n c E LEVELS DETERGENT B I N 20 h l I S U T E S A T
The c,oncentratioii of detergent required is inversely proportional to the mechanical force applied \\-hen the degree of soil removal, time, and temperature are kept constant. The time of scouring and t h e detergent concent,ration required are inversely proportional wlicn tho degree of soil removal, force, and temperature are kept const,ant,. The time of scouring and the force are inversely proportional when concentration, temperature, and dcKi.ee of soil removal are kept constant,. An equation relating detergent action with concentration of detergent, mechanical force, and time has been derived for that portion of the detergency curve m-here increased detergent ooncentration is accompanied by increased soil removal. method for calculating the per cent colored-soil renioval from reflcctance data has been developed.
120’F ~~. -. Force F a c t o r 8 12
4
LITERATURE CITED 21
XI. P E R C E N T SOIL REMOVED AT VARIED T I X E S AND CONCEKTRATIONS O F DETERGEXT D hT FORCE 8 AXD 120’ E’.
TABLE
Concn., % Active Ingredient 0.02 0.04 0.08
concentrat’ion is accompanied by iuc shown that:
10
Time, in Minutes 20 40
, 60
range appreciably below the point a t which the concentiationreflectance curve becomes flat. The relative effectiveness for removing soil of two detergents a t different reflectance levels is determined directly by increasing the force or time of scouring for the detergent giving the lower reflectance value until the reflectance values for both detergents are equal a t equal concentrations of t h e product. The ratios of the forces or times required to give the same degree of soil removal with both detergents is a measure of the relative efficiency of the two detergents. This method makes possible compari‘sons of detergents over the entire concentration range used, including concentrations a t which maximum soil removal (below the total available soil on the fabric) has been reached. I n the range of lower concentrations where the reflectance-concentration method is applicable, the results obtained by either method should be the same. However, it does not necessarily follow t h a t the efficiency ratio of detergents a t higher concentrations will be the same as a t these lower concentrations to which comparisons were of necessity limited in the past. Time of washing is the most flexible means of varying the work in comparing detergents, since this variable remains uniform over any desired range. Variations in relative force are not so flexible as variation in time, since force is limited according to the type of machine used. The effect of changing concentration is limited by the inherent properties of the detergent substance. The use of logarithmic graph paper for plotting soil removal against time or relative force minimize8 the number of points required to construct an accurate curve. The products of concentration and force or concentration and time may be used to comparc detergents a t the same degree of soil removal. Inasmuch as these products Rill vary with differences in soiled fabric, a uniform and reproducible standard soiled fabric would be requircd in order to cst,ablish absolute values of C F and CT. SUMMARY
Over the range of Concentration and mechanical work variations studied in a detergent process and where increased detergent
Baeoii, 0 . C., Am. Duestup Reptr., 34, 556 (194.5). Bureau of Ships Ad I n h i m Specification, 51S47(IKTj, “Soap, Salt-Water, Powdered (for Cse in Soft, Nard, or Sea Water) ,” April 1, 1944. C h n d a , A., “Textilhilfsmittel. 1hr.e Cbemie, Kolloid-chcmir i ~ n d Anwendung,” Vienna, Julius Springer., 1939. Crowe, J. B., Am. D y e s t u f R e p t r . , 32, 237-41 (1943). Fall, P. H., J.Phys. Chew., 31,801 (1927). Foote, W. J., Tech. Assoc. Papers, 22, 397 (1939). Gotte, E., KoZZoid-Z., 64, 222, 327, 331 (1933). Kubelka, P., and Munk, F., Z . tech. P h y s i k , 12, ,593 (1931). Laughlin, E. R., A m . Dyestuf Reptr., 34, 280 (1945). MoBain, J. W., Adaances in Colloid Sci., I, 99 (1942). Morgan, 0 . M., Can. J . Research, 6 , 292 (1932). Nolan, P., Paper T r a d e J . , 105,42 (1937). Eric;. CHmi., 21, 80 Rhodes, F. H., and Brainard, S. W., IND. (1929). Robinson, Conmar, Wetting and DeteTyency Sgmposium, Feb. 1920, 1937, Brit. Sect. Intern. Soc. Leather Trades’ Chem., 25-30. Shukow, A. -4., and Bhestakow, P. I. E., Chew.-Ztg., 35, 1027 (1911). Valko, E., “Kolloidchemische Grundlagen der Textilvercdlung,” Berlin, Julius Springer, 1937. Van Zile, B. S.,Oil &. S o a p , 20, 56 (1943). Vaughn, T. H., Vittone, A , , J r . , and Bacon, L. Et., ISD. ENG. CHEM., 33, 1011 (1941). Williams, E. T., Brown, C. B., and Oakley, H. B., Wetting and Detergency Symposium,Feb. 19-20, 1937, Brit. Sect. Intern. Soc. Leather Trades’ Chem., 163-74. t i E r ! F I Y E D April 26, 1947. Presented before the Division of Colloid Cheniist r y a t the 111th Meeting of the .%MERIC.%N CHEMICAI, SOCIETY, .\f,lant,rc City, S . J.
Thermochemistry of S Q ~ ~ U Carbonate IXI and Its Solutions-Addendum In the oiiginal article [ISD ESG.CHs2v 40, 99-102 ( l Y 4 Y ) l Table V, column 4, gives the heat capacity as calories per gram of sodium carbonate decahydiate dissolving during heating. Because the two temperature rangps used, 20 O to 26 and 26 to 32”, are identical these values chcck well. For use over other temperature ranges the heat capacil y should bc expres3cd in calories per centigrade degree per gram of sodrum carbonate derahydrate disqolving Thcw values qhould bc inc1udc.d in Table V.
c./o.
Run 16 18 15 20
Cal./O of Na*COa.lO€I20 Dissolved during Heating 11.3 10.5 10 9 10.7 Av. 10.9
3 4
I ~ E A X E.$, ~ HKOBEAND
THOAI4S
hI. SHEEHY
