1、Designation: D 4009 92 (Reapproved 2006)Standard Guide forFoam Stability of Hand Dishwashing Detergents1This standard is issued under the fixed designation D 4009; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last re
2、vision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide provides guidelines for several techniques ofmeasuring the foam stability of light-duty hand dishwashingdetergent
3、 products in the presence of artificially applied test-food soils. It is intended as a laboratory screening test to aid inthe formulation of products, for quality control and as a basisbetween the formulator and supplier in standardizing specificproducts performance.1.2 This standard does not purpor
4、t to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Summary of Guide2.1 Soiled dinner plates are
5、washed by hand in solutions ofhand dishwashing detergents under standardized conditionsuntil an end point of near-disappearance of the foam is reached,after which the number of plates washed is compared to thenumber of plates washed using a standard product.3. Significance and Use3.1 The guide, as n
6、ow constituted, is not suitable for rankingof hand dishwashing products, since no basis is available at thistime for correlation of the foam stability of these productsusing any particular food soil or combination of soils withconsumers ranking of performance.3.2 The relative foam stability ranking
7、of hand dishwashingdetergent products will vary greatly depending on the type offood soils used in the test. Therefore, selection of the standardfood soil to be used in a test shall be made by agreementbetween the interested parties on the basis of experience.3.3 This laboratory screening guide incl
8、udes flexibility inseveral areas so as to allow its use by the maximum number oflaboratories, without purchase of significant additional equip-ment. It should be recognized, therefore, that differences inspecific equipment may result in a reduced level of interlabo-ratory and interoperator precision
9、, and such results must beevaluated with caution.4. Recommended Conditions4.1 Water HardnessIf only one test is to be made, hardwater (150 ppm, about 9 grains per gallon (gpg) is suggested.To produce a more complete picture of product performance,test at two or three additional hardness levels: soft
10、 water (35ppm, 2 gpg); moderately hard water (100 ppm, 6 gpg); or veryhard water (260 ppm, 15 gpg).4.1.1 Calcium/Magnesium Ratio (as CaCo3)It is sug-gested that this ratio be adjusted for different water hardness asfollows:Water Hardness Range,ppm (gpg)Calcium/MagnesiumRatio0to60(0to3.5) 4:161 to 12
11、0 (3.6 to 7.0) 3:1121 and over (7.1 and over) 2:14.2 Water TemperatureThe water temperature at the startof the test should be adjusted to 47C (117F).5. Materials5.1 Plain White Glazed Dinner Plates in Sound Condition200 to 230 mm (8 to 9 in.) in diameter, with 160 to 165 mm (614 to 612 in.) indented
12、 bottom.5.2 Dishpan (conventional)Bottom diameter = 280 mm(11 in.), top diameter = 370 mm (1412 in.), depth = 140 mm (512 in.). Sheet metal or plastic are suitable materials.5.3 Dishcloth (any conventional brand), Dish Mop, or Dis-posable DishclothsEnough clean dish cloths (or dish mops)should be av
13、ailable to ensure the use of a fresh cloth (or dishmop) for each test run in one day. A new disposable clothshould be used for each wash.5.4 Any suitable reservoir of 4-L capacity, that can bereadily loaded with test water and that can deliver its contentsthrough a 9.5-mm (38-in.) (inside diameter)
14、drainage tip.Preferably, this drainage tube is an open-shut style to permitfull flow immediately upon opening.6. Standard Soils6.1 Four soils, representative of those commonly used forhand dishwashing tests, are described below. Other soil com-positions may be used.6.1.1 Soil A:1This guide is under
15、the jurisdiction of ASTM Committee D12 on Soaps andOther Detergents and is the direct responsibility of Subcommittee D12.16 on HardSurface Cleaning.Current edition approved Feb. 1, 2006. Published March 2006. Originallyapproved in 1981. Last previous edition approved in 1997 as D 4009 92 (1997).1Cop
16、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.wt %Lard (not hydrogenated) 18.3Wesson oil 9.2Corn oil 9.2Oleic acid (USP) 4.2Salt 0.4Gelatin 0.4Flour 41.6Water 16.7100.06.1.1.1 Prepare this mixture on the day prior to use. Discardany so
17、il more than one day old. Prepare as follows: Weigh thelard, vegetable oil, corn oil, and oleic acid into a beaker andwarm to 38C (100F). Add the salt, gelatin, and flour whilemixing with a spatula. Store at 3 to 6C (38 to 42F) overnight.The following day, just prior to use and without heating, blen
18、din the water with a large 200-mm (8-in.) spatula. Apply soil atroom temperature. A bright dye may be added to aid visualinspection.6.1.2 Soil B:Flour 50 %Shortening 48 %Oleic acid (USP) 2 %6.1.2.1 Warm the shortening with oleic acid to 38C(100F). Slowly add flour while mixing with a spatula andwarm
19、ing to 49C (120F). Hold soil temperature at 49 6 1.5C(120 6 3F) while soiling dishes.NOTE 1In order to prevent soil from melting off plates, do not exceedthe proper wash water temperature of 47C (117F).6.1.3 Soil CShortening.6.1.3.1 Warm the shortening to 42 6 1.5C (108F 6 3F)and maintain at this te
20、mperature during soiling. A smallamount of an oil-soluble dye, can be added to the warmshortening before soiling to provide visual evidence of soilresidue.6.1.4 Soil D:wt %Shortening 42.85Spray-dried egg powder 14.3Tap water 42.856.1.4.1 Prepare as follows: Weigh into the bowl of anelectric househol
21、d mixer, the required amount of shortening.Weigh in egg powder and then blend at low speed with themixer to form a thick paste. Add tap water, heated to about40C (104F), over a period of about 1 min, while mixing, andthen blend for approximately 4 to 5 min until the mixtureattains a homogeneous crea
22、my consistency. The quantityprepared should be sufficient for one days work only, soilbeing made up fresh daily. Approximately 450 g of shorteningand 150 g of egg powder make sufficient soil for about 500plates.7. Preparation of Soiled Plates7.1 Wash the plates thoroughly, by usual hand methods or i
23、nan automatic dishwasher, before starting the test and betweentest soilings/washings to provide clean dry plates.7.2 Place on a balance, the beaker containing the selectedsoil, A, B, or C. Set to weigh 6.0 6 0.1 g light. Use a spatulaor spoon to remove 6.0 g soil for application to a plate.Alternati
24、vely, weigh each plate, tare, and then add soil to 6.0 60.1 g.7.3 Transfer Soil A or B most readily, with a small spatula.Scrape all soil from the spatula on the edge of the plate. Soil C,a liquid at 42C (108F), can be added from a small spoon orby using an automatic pipet syringe by Manostat set to
25、 deliver6.0 g.7.4 For Soil D use a press-down cream dispenser withadjustable plunger to deliver 2 6 0.03 g of soil to each plate.7.5 Use ones finger to spread the soil over the surface of theplate. Disposable gloves are recommended for this procedure.Soiled plates are then stacked in convenient size
26、d piles (20 to25 plates). The top plate of each pile may be inverted to preventdrying out of soil. After soiling the last plate of each stack, theresidual soil on the finger is removed by wiping on the sides ofthe stacked, soiled plates.7.6 Wash Soils A, B or D the same day as soiling. Test washSoil
27、 C the day after soiling.7.7 Keep soil well mixed by frequent stirring and keep soilcovered. Do not use excess soil or soiled dishes beyond thetime schedule, as noted.8. Preparation of Dishwash Solution8.1 The standard concentration is 0.10 % product. Thestandard temperature is 47C (117F). Other “as
28、 is” or solidsconcentrations can be used in comparison testing.8.1.1 Prepare 4 L of test water at desired hardness andtemperature and place in reservoir.8.1.2 Draw 100 mL of test water from the reservoir.8.1.3 Divide this into four equal portions of 25 mL each.8.1.4 Swirl4gofproduct in a flask conta
29、ining 25 mL of testwater and pour into the wash pan.8.1.5 Rinse this flask with 25 mL of test water three times,pouring each rinse into the wash pan.8.1.6 Add the 3.9 L of test water remaining in the reservoirto the wash pan. The reservoir delivery tip is situated 610 mm(24 in.) above the bottom of
30、the dish pan so that it delivers intothe center of the pan.9. Washing Procedure9.1 Two alternative methods for washing the soiled platesare explained in the following:9.1.1 Method APlace the dishcloth in the wash water andthe first dish is washed beginning at 20 s after the wateraddition is complete
31、. Wash one dish at a time, both front andback, using a rotating motion with the dishcloth while keepingthe dish half submerged in an angular position with the bottomof the dishpan. Use a soiled dish every 30 s and continuewashing to reach an end point where just half the surface of thewash solution
32、shows a thin layer of foam. Dishes washed canbe rated at whole or half dishes, depending on the operatorsmeasurement of residual foam.9.1.2 Method BIn an alternative method, slide two soiledplates edgewise into the wash bowl. Hold one of these at 45to the horizontal, so that about half of its area i
33、s above the washliquor surface, and most of the foam is to the front of the plate.D 4009 92 (2006)2Remove the soil from the plate by four circular strokes of adishmop or cloth. Pass the mop or cloth through the liquorsurface on each stroke. Foam is thus stirred into the washliquor, and the soil is s
34、imultaneously emulsified. Then turn theplate and similarly clean its reverse side, but with three circularstrokes. Brush back any foam adhering to the plate into thebowl with the mop or cloth, and then transfer the plate to a sinkor container of hot water or detergent. Then take a third soiledplate
35、from the pile, and slide underneath the plate already in thebowl. Wash the second plate as described above, and repeat thecycle. Foam height is gradually reduced, and eventually freeliquor surface, that is liquor not covered by foam, becomesvisible. Note the number of plates washed, and continue the
36、washing operation. In general, one more plate will reduce thearea of foam to about half (or less than half) of the total liquorsurface. Note the number of plates washed to this half-foamend point and wash further plates until almost completedestruction of the foam occurs. This normally takes only on
37、emore plate. The result of the test is taken as the number ofplates washed at the half-foam end point. Experience hasshown that this end point is the one least subject to errors injudgement by operators.10. Cleaning Procedure10.1 After each test, the dishcloth or dishmop should beboiled in detergent
38、 solution, thoroughly rinsed out with hot tapwater, and as much liquid as possible removed by squeezing.The plates that have been washed during the test should bethoroughly washed and rinsed, placed in racks and allowed todry. Alternatively, an automatic dishwasher may be used. Thewash bowl must be
39、well cleaned after each test.11. Reference Blend11.1 Periodically, and specifically when using any newcomponents in the preparation of a soil or when evaluating anew set of samples, it is prudent to test a known pair ofdishwash blends to permit some comparison with previousdata. This reference mix s
40、hould wash the same number ofdishes within the normal variation limits.12. Arrangement of Tests12.1 Since the absolute level of results, that is, number ofplates washed to the foam end point, may be different fordifferent operators and on different days, these possible effectsshould be allowed for b
41、y:12.1.1 Testing each product the same number of times byeach operator,12.1.2 Testing products on a comparative basis, and12.1.3 Conducting at least four replicate tests.12.2 The products should be tested until a suitable andspecified statistically determined confidence interval is reachedbetween th
42、e appropriate comparisons.13. Data Evaluation13.1 The test conditions, such as, water hardness, productconcentration, temperature, test method, and method of dataanalysis, should be specified.13.2 Calculate the average number of plates washed by eachproduct, including that of a reference product, ov
43、er the severalreplicate tests. Express the performance of a product as apercentage of the performance of a reference product. Differ-ences in performance may also be expressed as relative platecount averages, as long as a suitable statistical method can beadopted that will allow one to determine pro
44、duct differences atspecified, statistically determined confidence intervals.14. Precision and Bias14.1 When experienced operators are employed, the 95 %confidence level of a result, average of four tests, should beapproximately6 5%.14.2 Plate count averages and standard deviations for agiven product
45、 have little, if any, direct value in assessingproduct differences. Product differences can be evaluated onlythrough sufficient testing to determine the performance differ-ence it is necessary to establish to ascertain whether twoproducts are different with a specified degree of confidence.14.3 Whil
46、e appropriate statistical treatments for analyzingdata and evaluating confidence intervals can be found in anumber of texts and papers, the following references can berecommended.14.3.1 Mandel, J., and Lashof, T. W. “The InterlaboratoryEvaluation of Testing Methods,” ASTM Bulletin, No. 239, July1959
47、.14.3.2 Snedecor, G. W., Statistical Methods, 5th Ed., IowaState College Press, Ames, Iowa, 1956.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determi
48、nation of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or wi
49、thdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
