ents in Army T. H. VAL-GHN, E. F. HILL1, C. E. SXITH, AND L. R. bTcC0Y Pyandotte Chemicals Corp., FVyandotte, Mich. AND
J. E. SLhIPSON2 O f i c of ~ the Quartermaster General, Wushington, D . C . extensive program was undertaken to advance the test methods, to evaluate all detergents that could be made available in quantities necessary for military requirements, and to devise optimum washing procedures for utilizing the most promising ones. The work was done in three phases: (1) laboratory detergency tests, (2) full scale laundry operations with synthetic sea water, and (3) confirmation of pertinent findings under actual use conditions with sea water. As a result, four products were approved as suitable for military needs of sea water laundering, and improved laundry formulas were developed for all the major classifications of military clothing.
Because of the military need of increasing the range and carrying capacity of our ships during World War 11, emergency measures were talcen by the Navy and the Army Surgeon General to do laundering aboard ships with sea water. Toward the end of 1944 the problem became so urgent that the Army Quartermaster General undertook an intensive research program to provide the best available products and to devise processes for this task. This paper describes the work done by and for the Quartermaster to this end. The lack of accepted laboratory methods for measuring detergency was considered a bigger handicap than the critical shortage of detergent products. An
soften the sea water to the extent. that ordinary laundry soap products can function; to use products which function in t,ha presence of huge quaniities of water-hardening chemical$. Thr first possibility was immediately eliminated, as this whole piohlem stemmed from the lack of sufficient distillation facilities and fuel. Estensive inquiries among manufacturers and research organizations discouraged attempts to soften sea water sufficiently for using soap products. Therefore, the problem resolved to thc third category-i.e., to use products that would function in sea water. This appcarcd to narrow the work largely t o investigating the field of synthetic dptergsnts, which have been used extensively in hard waters. The supply problem of detergent materials offered a treinendous complication. It was necessary to consider only products t>Iiat were immediately available in sufficient,quantities to meet a suhstantial portion of the military needs. A number of materials with very promising performance characteristics were not considered for this reason. The project finally established embraced the following objectives:
K THE first year of World
Xa1 I1 the Officc of the Quartrrmaster General recognized the need for a bar-form detergent, for use in all kinds of waters, which vould serve the miscellaneous cleaning requirements of the individual soldier. T o this end, a product composed of tallolT-coconut oil soap stock and synthetic detergents was devloped by the Research and Development Branch of that office. This “all-purpose soap” satisfied the requirements for high grade toilet soap, as it contained no free alkali, abrasives, highly alkaline salts, or other objectionable materials and it could be used in soft, h y d , and sea water, giving performance far beyond that of any commercial product then available. Although it was found that some of the synthetic organic detergents could be utilized in the mobile field laundries with great success, whether soft, hard, or very hard water was used, neither these nor the all-purpose soap solved the Army’s problem of field laundering in power-operated equipment with sea water. In September 1944 the Surgeon General’s Office adopted what it considered the best synthetic detergent available and developed several special laundering formulas which would satisfy the minimum requirements for power-laundering of white linens in sea mater, This action was particularly needed t o increase the carrying capacity of hospital. ships, and the problem was so urgent that time did not permit of extensive research to determine the best detergents and to devise optimum washing methods. In the late fall of the same year, the Quartermaster Corps was forced to seek additional products to alleviate the serious shortage of the detergents being used throughout the Army, and, if possible, to obtain products that were better suited for sea water laundering. The work herein described is the program which was undertaken by the Research and Development Branch, Military Planning Division, Office of the Quartermaster General, to develop more adequate products and procedures for power laundering in sea water. A research contract wa3 entered into with the Research Department of Wyandotte Chrmicals Corporation for its assistance in the program. In general, there appeared t o be three ways of resolving the water problems in sea water laundering: to use distilled water; to
1. To develop new laboratory test procedures,,or to re-evaluate conventional test procedures for their adaptabllity to sea water operations 2. To test the validity of laboratory data in forecasting performance under actual use conditions 3. To find synthetic detergents that would be superior or at least equal to the one synthetic detergent originally adopted 4. To devise new laundry formulas suitnble for these unusual use conditions Because the quantity of data taken during this work m-as so large, it is impossible to include a complete presentation of thc results obtained and t o give a discussion or interpretation of their meaning in a paper of reasonable length. Therefore, only some of the major rrsults and conclusions of the work are given here. SYNTHETIC DETERGENT PRQDUCTS
Present address, Ethyl Corporation, Detroit, Mich. 2 Present address, Chemical Division, Orr and Sembower, Inc., ReadIn& Pa. 1
The commercial synthetic detergents found to be of some importance and for which data are given are: 112
January 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
Detergent A. The sodium salt of a sulfated monoglyceride Detergent B. An oleyl sulfate Detergent C. The sodium salt of a fatty acid sulfonated amide Detergent D. An alkylol amide Detergent E. A polyalkyl ether condensate of fatty acids' Detergent F. An alkyl aryl polyether alcohol Detergent G. A polyethylene oxide derivabive of sorbital mono-oleate Detergent H. Condensation product of coconut fatty acids and monoethanolamine LABORATORY DETERGENCY STUDIEY
in
Preliminary Screening. 411 the 160-odd deter gents considered this program were tested first for compatibility with sea water
All synthetic sea water referred t o in this article has the following materials dissolved in distilled or softened water to make 1 liter of solution ( 1 ) : MgC12.0HzO CaClz'2H20 NazSOa NaCl
11 .O grams 1 . 6 grams 4 . 0 grams 25 . O grams
Sufficient detergent material was added to synthetic sea water to make a 0.1% solution, and the mixture was shaken vigorously, and then examined for evidence of appreciable insolubility or precipitation. The first series of tests, made a t approximately 70" F., eliminated all but 51 detergents. Those products passing this requirement were subjected to the same test a t 120" F., which is a more realistic temperature for laundering operations. This reduced the number of acceptable products to 41. Laboratory Detergency Evaluation. Thc 41 products still under consideration were subjected to laboratory tests designed to measure two major detergency factors: soil removal from fabrics, and prevention of soil redeposition on the fabric after i t has been removed from the fabric in the washing process (whiteness retention). The test techniques outlined below and described in detail by Vaughn and Smith ( 2 ) afforded separate measurement of these phenomena. SOILRXWOVAL TESTS. The standard soiled fabric used in these tests was prepared by treating a desized muslin with an aqueous solution of a soluble oil and a water-dispersed carbon black. In performing the soil removal test, a 0.25% solution of the detergent material was made in synthetic sea water and agitated with the standard soiled cloth under controlled conditions. The light absorption of the solution was then measured photometrically and the value converted t o terms of milligrams of carbon removed per liter of solution. WHITENESS RETENTION TESTS. The same kind of fabric used for making the standard soil swatches was used for the whiteness retention tests. These tests were made by preparing a detergent solution of 0.25% concentration in sea water, adding t o it a quantity of water-dispersed carbon black, and agitating the solution with the swatches of standard cloth. The whiteness retention was calculated from the ratio of the average reflectance of the fabric after treatment to that of the original sample. It was recognized that sea water laundering involves so many factors not related to ordinary commercial laundering that the above laboratory tests could be considered as indicative only until the results could be substantiated by field tests. Therefore, all detergents which appeared to be approximately equivalent to the already adopted sea water detergent were retained for further consideration. Twenty were so selected, in general on the basis of ability to remove a minimum of 4.3 mg. of carbon per liter of detergent solution and a minimum whiteness retention of 19%, but also taking into consideration availability, physical properties, etc. These standards are of, course, much lower than those accepted in commercial laundry practice. The STUDIESOF OTHER FACTORS AFFECTINGDETERGENCY. effects of such factors as concentration of the detergent solutions, pH, and temperature upon detergency were investigated a t length. These studies were limited to four products selected on the basis
113
of the foregoing work and which could be obtained immediately in sufficient quantities to meet military needs. Detergent Concentration. It was found that a 0.5% concentrrttion of detergent gave maximum soil removal in sea water for most of the products, although in a few instances this high concentration appeared deterimental chiefly in increasing the reaction with sea water to form precipitates on the fabric. The 0.5% concentration of detergents appeared sufficiently advantageous, in spite of some shortcomings, to adopt as the most suitable level I n Table I are shown carbon soil removal and whiteness retention data for four selected products. Effect of p H Variation. The synthetic sea water used in these studies had a pH of 7.4. On the basis of commercial laundry experience it was thought desirable to consider the merits of performing a t least some of the washing operations a t higher p H values. Investigations were made t o determine the increase of pH of sea water by the addition of readily available alkaline materials. I t was necessary not only to increase the p H but to do so with the minimum of reaction between the alkaline material and the sea water. Tests were made a t 140" F. The p H values were determined with a lithium glass electrode. A summary of these findings is given in Table 11. On the basis of the results shown in Table 11, a modified soda (a commercial product approximating in composition a sodium carbonate-bicarbonate ratio of 1 to 1.39) was selected as having the most desirable characteristics for use with synthetic detergents in sea water. The effect upon detergency of its addition t o s e i water laundering systems is shown in Figures 1 to 6 , inclusive. Temperature. With the detergent concentration established and the alkaline salt selected for maintaining proper p H values, a series of detergency tests was made to determine the optimum temperature for the four detergents, alone and when combined with two different concentrations of modified soda. Carbon soil removal results are shown in Figures 1, 2, and 3; and whiteness retention results in Figures 4, 5 , and 6. These studies indicate that the best cleaning is done a t temperatures below 160' F., and with the exception of one product under one specific condition, the optimum deterging temperature appears to be between 120' and 140' F. These findings are particularly significant in view of fuel conservation and, still more important, put the deterging operations in the desired temperature range for removal of proteinaceous soilage, a serious problem encountered in military laundering.
TABLE I. EFFECT OF DETERGENT CONCENTFLATION ON CARBON SOILREMOVAL AKD WHITENESSRETENTION IN SYNTHETIC SEA WATERAT 120" F.
Product Product Product Product
C E F G
Detergent Concentration 0.25 0.5 0.25 0.5 Soil Removal, Whiteness retention, Mg./liter % 13.1 18.2 3.5 3.5 5.5 32.7 7.6 37.3 6.4 5.7 45.8 30.3 5.0 24.4 5.6 24.0
TABLE 11. p H VALUESOF SYNTHETIC SEAWATERSOLUTIONS OF VARIOUSALKALINEMATERIALS
1. 2. 3. 4. 5. 6.
7. 8.
pH at 0.170 ConcenAlkaline Material tration Sodium carbonate (anhy9.0 drous) Modified soda 8.4 Sodium metasilicate (5 hy8.2 drate) Sodium orthosilicate 8.6 Sodium sesquisilieate 8.2 Trisodium phosphate (12 hy7.9 drate) Tetrasodium pyrophosphate 7.1 (anhydrous) Sodium hydroxide 8.7
pH at 0.25% Concentration 8.9 8.4
8.0 8.7 8.3 8.1
Appearance of 0.25% Solution Flocculent precipitate Very slight turbidity Light flocculent precipitate Flocculent precipitate Flocculent precipitate Flocculent precipitate
6.9
Flocculent precipitate
8.9
Flocculent precipitate
INDUSTRIAL AND ENGINEERING CHEMISTRY
114
90
TE M PER ATll RE
LOO
110
'E
120
Vol. 41, No. 1
130
Figure P. Relation of Carbon Soil Removal to Temperature for Synthetic Detergents in Sea Water a t 0.5940 Concentration
140
150
160
"E
TEMPE RATLlRE
Figure 2. Relation of Carbon Soil Removal to Temperature for Synthetic Detergents in §ea Water 0.5% concentration with O~l%o modified soda
80
E
L w I-
%
60
m w
v)
E 40
t
5
;
'20
0
100
110
1'20 130 I40 I50 160 E M P ER A? UR E e F. Figure 3. Relation of Carbon Soil Removal to Temperature for Synthetic Detergents in Sea Water
90
0.5% concentration with 0.325 70modified soda
80 I
I
I
I
I
I
'90
Figure 5 . Relation of Whiteness Retention to Temperature for Synthetic Detergents in Sea Water 0.5
concentration with 0.1 70 modified soda
FIELD LAUNDRY TESTS USING SYNTHETIC SEA WATER
In keeping with the Quartermaster Corps' policy of testing products, processes, and equipment under realistic use conditions prior to supplying them t o the armed forces, laundering tests were made a t Camp Lee, Va., t o substantiate and extend the knowledge gained in the foregoing laboratory investigations. Laundering Equipment. A complete mobile laundry unit was used for making the sea water washing tests.
This equipment consisted of a 30 X 30 inch metal reversingtype washer, a 20-inch extractor, two 36 X 20-inch drying tum-
120
140
130
150
160
"F
Figure 4. Relation of Whiteness Retention to Temperature for Synthetic Detergents in Sea Water a t 0.5% Concen tration
I
F:
110
TEMPERATURE
80 TEMPERATURE
100
I
I
100
I10
I
I
120
130
TEMPERATURE
I
I
I
140
150
160
"E
Figure 6 . Relation of Whiteness Retention to Temperature for Synthetic Detergents in Sea Water 0*5%0ooncentration with 0.325 Q modified soda
blers, steam generating equipment, and all controls, vater lines, etc., necessary for continuous operation. Synthetic sea water was prepared and stored in an adjacent 2000-gallon tank. Rapid solution of the chemicals was accomplished by introducing compressed air a t the bottom of the tank and a t the same time recycling the liquid through a pump. The sea water was pumped to an open drum for preheating with direct live steam to the approximate temperature required in the laundering operations ; final temperature adjustment was made similarly in the wash wheel. Equipment arrangement is given diagrammatically in Figure 7 . Figures 8 t o 13, inclusive, depict certain of these equipment details.
INDUSTRIAL A N D E N G I N E E R I N G CHEMISTRY
January 1949
Sea Water Mixing and Storage
h -
Water
Preheater
llna
115
solvents; an iron soil panel of muslin treated first with a solution of ferric ammonium sulfate followed by a dilute solution of ammonium hydroxide; a whiteness retention panel of clean white, desized percale sheeting; and a muslin panel for the determination of any residual chemicals left u on the cloth. The General Dyestuff soil-GD8printed cotton soil cloth No. 26-was a n experimental material soiled with a printing paste containing carbon black in oil base applied by means of a copper printing roll. Each swatch consisted of a piece of cotton, half of which was printed and half of which was in the original clean condition; thus i t was possible to evaluate both soil removal and whiteness retention upon the same panel. The Colgate soil was likewise a n experimental material consisting of swatches of muslin soiled with oil-suspended colloidal carbon diluted with cottonseed oil and carbon tetrachloride. The Teltester was a cumulative test panel. The same panel was used for a series of ten washes, thus measuring the cumulative effect. The other test panels were single-cycle pieces, being removed after each wash and new ones used for the next. SOILREMOVAL.The soil removal values were obtained using the equation:
% S.R. Wheel
I
- 1
~~~
~
U, S. Army Mobile Laundry Unit Figure 7. Diagram of Sea Water Laundering Installation at Camp Lee, Va.
Laundry Loads. The laundering tests were made on white cottons, as such goods are among the most difficult to clean adequately. As nearly as possible, each load consisted of the same kind and number of items, which were carefully selected so that all loads had approximately the same kind and degree of soilage. Each load contained 20 sheets, 10 surgeon’s gowns, 10 hand towels, 10 bath towels, 10 pillow cases, 3 cook’s jackets, 3 cook’s caps, 3 cook’s aprons, and 3 cook’s trousers. The load had a predominance of proteinaceous soilage and medicinal stains, and about 10% of extremely greasy soilage from cook’s galley. The techniques of determining soil removal and whiteness retention utilized in the laboratory studies are not applicable t o regular laundering operations. I n order to compare the results with commercial standards, test bundles and test swatches of the kind used extensively in evaluating commercial laundering were employed. Each laundering test consisted of washing ten different loads of soiled items under identical conditions of temperature, pH, detergent concentr&tions, etc. Two specimens of each of three standard test bundles or swatches were included in each cycle. Only a general description of these test pieces is given here; further information pertaining to the composition and preparation of these soils may be obtained from the companies responsible for their development.
ST x 100 0,- 8,.
= wr ~
where 0, = original luminous apparent reflectance of unsoiled fabric, Wr = luminous apparent reflectance of washed fabric, and S,= luminous apparent reflectance of soiled fabric. The equation assumes change in reflectance and soil removal t o be proportional, which is not strictly true, but is sufficiently correct for comparison where values do not differ greatly from each other. Reflectance evaluations were made using the Hunter Reflectometer and the green filter supplied with that instrument. Measurements were made on each side of single-thickness fabric pieces. WHITENESSRETENTION. Whiteness retention values (W.R.) for the General Dyestuff and Teltester panels were calculated from the following equation:
The reflectance measurements were made in the same manner as in determining carbon soil removal. IRONSOIL REMOVAL. The same procedure and equation as those used in obtaining carbon soil removal values were employed in meaauring the iron soil removal from that panel of the Teltester. TENSILE STRENGTH Loss. The laundered Teltester whiteness retention panels were cut into strips which were raveled t o a width of 1inch. These strips were wetted with distilled water and allowed to condition for 24 hours a t a relative humidity of 65%
Wyandotte Teltester, Research Division, Wyandotte Chemicals Corporation, Wyandotte, Mich. General Dyestuff soil, Chemical Division, General Dyestuff Corporation, New York, N. Y. Colgate-Palmolive-Peet soil, Technical Division, Research and Development Department, Colgate-Palmolive-Peet Co., Jersey City, N. J. The Wyandotte TeItester panel.was a complex swatch consisting of a section of muslin soiled with a suspension of carbon In a mixture of mineral oil, hydrogenated vegetable Oil, and mineFd
~i~~~~ 8.
Improvised
seaWater
Storage and Mixing Tank
Tank is in actuality a fumigation chamber hraoed and made water tight
INDUSTRIAL AND ENGINEERING CHEMISTRY
116
Figure 9. l e f i to K i g h r .
General View of Sea Water Laundering EquipirieriL
Sea water storage
~ a n km , ixing
and a temperature of 70" F. Brenkiug styeiigths were then obtained using a Scott tensilc strength tester. This same procedure was used on representative samples of the unwashed cloths. The tensile strength losses (T.S I,.) were then computed by the following formula:
yo T.S.L.
=
s-o sw x
____I
100
where SO= tensile strength, pounds per inch, of original unwashed cloth, and 8, = tensile strength, pounds per inch, of washad cloth.
TABLE 111.
kfTAThRL%~-SI)EKIXG FORtIU1.h WHITECCTTONS
hTAVY S E A
(60 Ih. l o a d , 30 X 30 inch n a s h %heel) Water Level Time, Temp,, GalType of Operation Min. F. inches lona Water
First
suds
Seoond suds Third suds Rinse Rinse Rinse
Vol. 41, No. 1
FOK
Supplies, Onncnn
6
120
3
28.7
Sea
Detergent
10
140
3
8.9
Sea
Detergent 16.0
140 I4O 120 100
fi
3
8.9 14.0
Sea Sea Fresh Fresh
Detergent None Sone h'one
7.5
and distribution apparatus, and sea w a t w beater
Laundering Formula Development. Because the existiiig sea water laundering formulas used by the S a v y and the Army Surgeon General (Tables 111 arid IV) did not appear adequate, the early part of the Camp Lee tests was devoted to improving the formulas. Experimental lauiidry formulas were devised wit,h the following goals in mind: (1) to simplify the formulas, ( 2 ) to provide more efficient utilization of heat arid fresh water, (3) to maintain the deterging solution a t approximately 0.5% concentration, (4) t,o detcrmine t,he merits of using an alkaline builder (modified soda) in the deterging operations, ( 5 ) to determine the merits of using polyphosphates, ( 6 ) to accomplish bleaching with ininitnuin tensile strength loss, and ( 7 ) t'o determine the effects of a souring operat,ion. These studies resulted in tentativcly adopting the laundry formula for white cott,ons given in Table V. In comparison mit.h t,he earlier formulas the tentat'ive laundry formula was simpler in operation and required fewer expensive chemicals (such as polyphosphat,es), and its superiority f ~ o ma performance standpoint is illustrated by thc data in Table VI. EVALUATION O F D E T E R G E N T S I N SYNTHETIC S E A N'ATEK LAUNDERING
Seven of the detergents, selected as a superior group based on the previous laboratory evaluations, were subjected to 10-cycle 5 6 14.0 laundering tests in the mobile laundry 6 14.0 5 equipment, using synthetic sea water and the tentative laundering formula. I n this and other tables whiteness retention FOR LVHITC TABLE Iv. ARMYSURGElON GEIVERAL S E A b7.4TER L.4VNDERISG FORIIIULA and tensilc strcngth data are not preCOTTONS sented for the single-cycle panels. I t (60-lh. load, 30 X 30 inch wash wheel) was found early in the work that such Time, T e m p , , -Water Type of Operation Min. a F Inches Gallons Water Sugplie3 Ounoes panels failed t o yield as consistent and Modified soda Sea Break 100 33.0 reproducible measurements of those facDetergent Modified soda 1'20 12.2 Rea First euds tors as did the multicycle or cumulative Detergent effect panels. Converjely, although the 1BO Sea Sodium hexainera Second suds 12.2 solution0 26 0 difference is somewhat less striking, the Detergent 6.75 12 2 Sea Bleach solutionb Bleach suds 3 38 0 single-cycle panels appeared superior to Sodium iiexanietaiiliosi~hate the multicycle panels with respect to solution 9.0 Sea Kone Rinse 4 270 8 18 7 5 evaluation of soil removal. The results, Sea Zone Rinse 4 1.55 8 18 75 8 18 75 Sea None 183 as measured by the applicable dclerminaRime ? 130 X 18 75 Fresh Pione Rinse ? tions of the three test panels, are given 120 4 10 00 Frrsh Sour 1.1 Rinse in Table S'II. Although there are a 1.26 lb./gal. of water. oftentimes differences in the absolute b Sodium hypochlorite aotutlon containing 1% available chlorine. values obtained in n w w x i n g 3, specific. IO .5
7.5
INDUSTRIAL AND ENGINEERING CHEMISTRY
January 1949
TABLE V. TENTATIVE SEA WATERLAUNDERING FORMVLA FOR WHITE COTTONS (60-lb. load, 30 X 30 inch wash wheel) Water Temp., Time, Level, Water F. Min Inches Used 22 100 3 5 Sea
Operation
suds Suds
120
a
5
Sea
suds
140
5
3
Sea
Bleachsuds
180
8
5
Sea
Rinse Rinse Rinse Rinse Rinse Sour
Sea Sea Sea Fresh Fresh Fresh
170 140 130 120 120 110
Supplies 05. synthetic detergent 11 08. modifiedsoda 12 oz. synthetic detereent 6 01. modifieasoda 8 OB. synthetic deter ent 6 0 8 . modifiezsoda 4 OB. synthetic deter ent 6 0 8 . modifiei soda 1% 38 oz. bleach available chlorine None None None None None 1 02. sour"
Standard Army sour consisting of SO'% NaHFz and 50% Nad3iFa.
detergent characteristic, it is encouraging that the order of rating these detergents is similar for each of the three test panels. Four of the detergents (E, F , G, and C) were shown to be superior t o the others. Observations made by trained laundry personnel further substantiated these relative evaluations on the basis Df general appearance and odor of the clothing washed. SHIPBOARD LAUNDERING TESTS WITH NATURAL SEA WATER
In order t o confirm the findings of the Camp Lee laundering teats made in synthetic sea water, laundering tests in natural sea
water were made on an Army hospital ship, the U.S.H.S. Seminole, on a voyage from Charleston, S. C., t o Naples, Italy, and return, during the period July 24 t o August 25, 1945. The laundry equipment consisted of two 42 X 54 inch Monel metal wash wheels, regular extractors, and drying tumblers. The work was done under the cooperative direction of personnel from Wyandotte Chemicals Corporation and the Office of the Quartermaster General. It was estimated t h a t the length of the voyage would permit the evaluation of three detergents and the comparison of the proposed laundering formulas with the existing washing procedures on a comparable scale with the Camp Lee tests (10 cycles each) However, a number of contingencies occurred-seas so rough that laundry personnel could not work, breakdown of equipment, and sickness of practically the entire crew-which prevented the conipletion of the original plans. Therefore, some of the test series had only five successive launderings; and as a result the Wyandotte Teltester results are not directly comparable with the 10cycle tests made at Camp Lee. Included in the shipboard tests
TABLE VII.
Carbon Soil Removal, yo
E
F G C
H B D
TABLE VI. COMPARISON OF TENTATIVE LAUNDERING FORMULA WITH
NAVYA N D ARMYSURGEON GENERALFORMULAS AT CAMP LEE
Laundering Formula Proposedformula Navy formula Army Surgeon General formula Proposed formula Navy formula Army Surgeon General formula
ColtateGeneral PalmoliveDyestuff Wyandotte Teltesterb Peet Panela Panela Product Product Product Product Product Product C E C E C E Per Cent Soil Removal 25.4 36.4 37.6 46.0 32.2 34.3 20.2 28.9 33.7 3*5.8 27.0 22 8 19.4 34.3 29.1 38.1 Per Cent Whitness Retention Not applicable Not applicable Not applicable Not applicable
20.0
25.6
85.4 78.0
90.1 84.5
Not applicable Not applicable Per Cent Tensile Strength Loss Not applicable Not applicable Not applicable Not applicable
88 6
90 0
6 .O
6.6
21.6 7 .O
Not applicable
11 0
16 0
Proposed formula Navy formula Army Surgeon General formula Not applicable 5 Single-cycle test panels. b 10-cycle test panels.
were detergents C and E, which previously had been shown to be superior products, and detergent A, which had not been extensively tested but was felt to be possibly acceptable, and especially because of knowledge received a t the time of the shipboard tests of its probable availability. Laundering Formula Development. One purpose of the shipboard tests was to adapt the laundering formula developed a t Camp Lee t o use conditions. It was found desirable t o modify the tentative formula slightly in order to afford a more practicable decrease in the temperature during the rinse operations. The quantities of detergent used were also somewhat changed, in view of the differences in carry-over of solution from a preceding operation, to maintain the concentration a t approximately 0.5% throughout all the deterging operations. Modified soda was not used in the shipboard tests because, although in general i t improved detergency, if an adequate amount OF sour were not used,
EVALUATION OF DETERGENTS AT CAMPLEE USIXG TENTATIVB LAUNDERINQ FORMULA
Cnl vat& - -_oI__
Detergent
117
PalmolivePeet test panel 36.4 29.9 25.8 25.4 20.3 15.6 13.9
General dyestuff test panel 45.0 37.8 38.6 37.6 33.3 37.4 26.'7
Wyandotte Chemicals Corg. Test Panel
% carbon soil removal 34.3 47.1 46.9 32.2 16.5 14.4 36.7
% irk whiteness soil retenremoval tion 37.2 90.1 36.5 91 . o 29.4 92.4 34.1 85.4 10.4 81.6 12.2 86.2 40.3 90 .o
%. tensile strength loss 21.5 6.6 17.9
6.6
18.1 6.6 10.1
Figure 10.
Rear View of Sea Water Heater
Small valve a t r i g h t controls admission of s t e a m . Large valve at l e f t controls admission of sea water. H e a t e d sea w a t e r leaves the heater through l a r g e hose lying o n ground
INDUSTRIAL AND ENGINEERING CHEMISTRY
118
Figure 11.
Fuel Unit Used to Preheat Water
calcium salts deposited in the fabric, stiffening it, The formula finally adopted is given in Table VIII. Evaluation of Detergents in Natural Sea Water. The selected detergents were evaluated in the Army Surgeon General formula (see Table IV) and in the finally adopted formula (see Table VIII). The Navy formula x a s not included in the shipboard test. The Kavy had found it expedient t o keep storage space a t a minimum, obtain maximum production from equipment, and extend fuel as far as possible, and therefore had adopted a very simple formula with minimum rinsing. It was felt, however, that the use of bleach and sour, higher temperatures, and longer processing time were justified to obtain higher witness retention. The same three kinds of test panels used in the Camp Lee work were included in each test made on the Seminole. Careful visual observations were macle also but were severely limited by the presence of extremely heavy stains and spots already set in the fabrics and which could not have been removed by any normal washing process. These discolorations consisted of excessive amounts of iron stains caused by piling soiled linens on bare, wet, metal deck plates; set and aged blood stains left from previous improper laundering; and many mildew stains. There mas an extremely disagreeable odor present in the items. These v ~ g .
unfavorable conditions were partly caused by inadequate laundering facilities which resulted in the acournulation of a backlog of work during each voyage. Shipboard Results. A summary of the results of the shipboard tests of white cottons is given in Table IX. I n spite of the fact that the detergents tested under the Army Surgeon Geriera1 laundering formula were subjected to only 5 cycles (as compared with 10 throughout the other phases of the program), the following results are apparent when the average for the threr detergent values in the same laundering formula is considered. Based upon single-cycle test pieces (Colgate-Palmolive-Peet and Generai Dyestuff Corporation), the finally adopted laundering formulas~issomewhat superior to the Army Surgeon General formula in soil removal.
TABLEIx.
Detergent
TABLEVIII.
FINALLY ADOPTEDSEA WATER LAUNDERING FORXULA FOR WHITECOTTOKS
(200 Ib. load, 42 X Water Temp., Time, Level, Omration ' F. Min. Inches Suds 100 5 5 5 Suds 120 5 Suds 140 5 5
Blench EUdS
Rinse Rinse Rinse Rinse Rinse
Sour
160
8
5
Sea
170 150 135
4
8 8 8
Sea Sea Sea Fresh Fresh Fresh
130 120
110
4 4
5 5 5
4 4 4
A
C E
54 inch wheel) Wawr Used Sea Sea Sea
Supplies 50 0 8 synthetic detergent 30 o a . synthetic detergent 16 on. synthetic detergent
t. bIeach. 1% h e ohlorme None None None None &-one 7os.sour 4
Vol. 41, No. 1
avail-
Ab
C
E
RESVLTSmoll 5.S.H.S. Seminole LACXDERING TESTS
ScXiMARY O F
Carhon Soil Remoral, % , ColgatePalrnolive General Peet dyestuff test test panel panel
Wyandotte Cheniicals Corp. Test Panel
%
carbon soil removal
70
70
Army Surireou General Laundering Formula 10.6 27.3 7,Ba 12.7" 91.9; 20.4 44.4 14.5O 18.2a 89.0 33.8 61.0 23.ga 18.P 91.00
Sea Water 16.9 22.7 29.0
Laundering 41.8 44.2 50.0
yo
iron whiteness tensile soil retenstrength removal tion loss 14.2[' 21.0a 14.6u
Formula Finally ddopted 19.5 23.8 26.3
25.1 19 1 18.7
86.7 85,l
89.7
19.7 11.2 13.8
Commercia,l Laundering Formulac Soap 14.3 87.2 19.6 42.6 96.4 3.5 a Results of only 5 laundry cycles rather than 10 as done throughout project. b 16 os. detergent instead of 22 os. used in first suds t o prevent suds overflowing wash wheel. Product not finally approved a s meeting minimum requirements. 0 Results inserted for comparison, obtained in commercial laundry using soap and softened wat,er.
INDUSTRIAL AND ENGINEERING CHEMISTRY
January 1949
119
This program had already shown that the laboratory methods would distinguish poor products from the better ones. By taking the carbon soil removal results obtained in the laboratory, from which the curves in Figure 3 were constructed, and averaging them for each product over the temperature range 100' to 160 F., there is obtained the series in order of effectiveness, products E, F, G, and C with the associated values of 8.3, 7.0, 5.1, and 4.9 mg. of carbon per liter, respectively. These values show a high degree of correlation with those obtained with the Colgate-PalmolivePeet test panel in the field tests and shown in Table VII. O
CONCLUSIONS
Figure 12.
Sea Water Mixing and Distribution Apparatus
Device equipped with large pulley i n foreground is a Roote positive pressure blower used t o force air through the synthetic sea water during the mixing process. .Pumps transfer water from the storage tank to the *ea water heater, and heated sea water from heater t o wash wheel
Based upon the cumulative test pieces (Wyandotte Teltester) i t is seen that the whiteness retention after 10 cycles of the finally adopted laundering formula is approximately equivalent to that of only 5 cycles of Army Surgeon General formula. It is probable that 10 cycles of the latter formula would show i t to be markedly inferior to the formula finally adopted. Based upon the cumulative effect pieces (Wyandotte Teltester) there is no greater tensile strength loss (average of the three detergents) after 10 cycles of the finally ado ted formula than after only 5 cycles of the Army Surgeon Generay formula. Based upon the cumulative effect pieces (Wyandotte Teltester) 10 cycles of the finally adopted formula produce on the average substantially more carbon soil removal and somewhat more iron soil removal than 5 cycles of the older procedure. Extrapolation of the data indicated that the finally adopted formula is at least as good as the old, and probably better. The visual inspection gave good agreement with the test panels regarding soil removal and whiteness retention. Personal inspection indicated a very substantial improvement of odor of the items by the formula finally adopted. RELATION OF LABORATORY DETERGENCY STUDIES. - .-- - . SYNTHETIC SEA WATER LAUNDERINGS, AND NATURAL .SEA WATER TESTS
The relationship between the Camp Lee tests in synthetic sea water and the shipboard tests in natural sea water is best illustrated by a comparison of the average results obtained (Table X). It is noteworthy that the Colgate-Palmolive-Peet test panels give comparable soil removal results at Camp Lee and on shipboard, and the General Dyestuff Corporation panels and the Wyandotte Teltester rate the detergents in the same order.
TABLE X. SYNTHETICSEA WATERLAUNDERING (CAMPLEE) COMPARED WITH NATURALSEA WATER LAUNDERIKG (SHIPBOARD)USINGFORMULA FINALLY ADOPTED
Detergent
Carbon Soil Removal, % ColgatePalmoliveGeneral Peet Dyestuff test panel test panel
Wyandotte Chemicals Corp. Test Panel
%
carbon soil removal
70
whiteness retention
The following conclusions are based upon tests of the same detergent concentration (0.5%) in the laboratory, at Camp Lee, and on shipboard. The laboratory methods of evaluating soil removal and whiteness retention used in these studies, although capable of distinguishing poor from promising materials, do not appear capable of differentiating consistently between acceptable and superior detergents. The laboratory methods employed for measuring soil removal give comparable results at 120' F. with Camp Lee cleaning as measured by both the General Dyestuff Corporation panel and the Colgate-Palmolive-Peet panel, and also compare favorably a t 140" F. with the results obtained with the latter type of panel. A test panel which measures the soil removal accomplished during the total of several successive launderings (Wyandotte Teltester) appears inferior to those which measure single-cycle results. Of the methods employed in this program to measure soil removal, the Colgate-Palmolive-Peet single-cycle test panel appears to give the most consistent relation to actual laundering results, based upon visual inspection, odor, etc. Whiteness retention results based on a single washing cycle (such as General Dyestuff Corporation panel) do not appear of value in measuring this characteristic, as the experimental errors of the method outweigh any ordinary performance differences. (This is the antithesis of the soil removal findings in which singlecycle measurements appear advantageous.) The Wyandotte Teltester gives excellent agreement with visual inspection for whiteness retention in regular laundry operations. The laboratory methods for studying whiteness retention in this project give good agreement with actual laundering results as measured by both the Wyandotte Teltester and visual inspection. Detergents giving results differing enough to permit visual ranking were ranked in the same order by both Colgate-Palmolive-Peet and General Dyestuff tests. Test panels that measure cumulative effects (Wyandotte Teltester) appear to be a more accurate means of determining tensile strength loss than single-cycle panels. Under the test conditions rmployed synthetic detergents, in general, have an optimum combination of soil removal and whiteness retention a t temperatures between 120" and 140" F. The laundering formula developed by this program is markedly superior to the Navy formula and somewhat superior t o the Army Surgeon General formula. It is simple in operation and required detergent materials less critical in supply a t the time it was developed. As a result of this work four detergents were approved: products C, E, F, and G.
Synthetic Sea Water (Camp Lee)
C E
23.0 32.0
C
22.7 2Q.O
27.00 28.8"
14.8 20.1
E
Original soil retiectancc 16.3%. b Original soil reflectance 24.0%.
0
23.6 26.3
Bureau of)Ships,Ad InterimSpeoifioation51DlO. (1NT)Detergenh Laundry, Salt Water (1943). (2) Vaughn, T.H., and Smith C. E., Am. Oil Chemisls' Soo., 2, 44-51 (1948) (1)
Natural Sea Water (Shipboard)
44.2b 50.0b
LITERATURE CITED
87.3 87.4 85.1 89.8
RECEIVEDApril 23, 1947.
