1、Designation: D 2281 68 (Reapproved 2005)Standard Test Method forEvaluation of Wetting Agents by the Skein Test1This standard is issued under the fixed designation D 2281; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. 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 test method2,3covers the determination of theefficiency of ordinary commercial wetting agents as defined inTermi
3、nology D 459. This test method is applicable underlimited and controlled conditions, but does not necessarilyyield information correlating with specific end uses.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the u
4、ser of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:4D 459 Terminology Relating to Soaps and Other Detergents3. Summary of Test Method3.1 A weighted cotton test sk
5、ein is dropped into a tallcylinder containing a water solution of a wetting agent. Thetime required for a string stirrup connecting the weight and theskein to relax is recorded as the sinking time.4. Apparatus4.1 Hook and Anchor:4.1.1 The hook of a standard weight and the attached anchorshall be pre
6、pared as follows: Bend a piece of No. 10 B a 54-in. (1370-mm)skein requires three folds; a 72-in. (1830-mm) skein, fourfolds; and a 90-in. (2290-mm) skein requires five folds.6. Reagents6.1 WaterThe quality of the water used in the testing ofwetting agents must be given careful consideration. The st
7、ocksolution is best prepared with distilled water. When it is notknown under what conditions the wetting agent is to beemployed, distilled water may likewise be used for finalsolution. On the other hand, for the simulation of mill practice,the final solution for test, and even the first stock soluti
8、ons,should be made up with water from the mill and with anyingredients that are necessary to duplicate exactly the chemicalcomposition of the solutions as they will be used in practice. Ifthis is done, the pH will take care of itself automatically,although the careful chemist will want to check the
9、acidity oralkalinity of the final test solutions either colorimetrically orelectrically.6.2 Acid and Base Test SolutionsFor the purpose ofuniformity, use standard concentrations of acid and alkali forroutine tests made in other than neutral solution. It is recom-mended that tests be made at differen
10、t temperatures in thepresence of 5 or 10 g of concentrated sulfuric acid (H2SO4,spgr 1.84), 5 or 10 g of sodium carbonate (Na2CO3) and 5 or 10g of caustic soda (NaOH)/L of final solution, respectively.6.3 Wetting AgentNormally prepare stock solutions of theagents to be tested to contain 50 g of agen
11、t/L unless thesolubility is so poor that less must be employed. First thor-oughly dissolve the wetting agent in about a quarter of thenecessary distilled water at a temperature above 176F (80C)and then dilute to the final volume with cold distilled water.Take aliquot portions of 5, 7, 10, 15, 25, 35
12、, 50, 75 and 100 mLof the 5 % stock solution with delivery bulb pipets, transfer toa 1-L volumetric flask, and dilute to the mark with the suitabletest solution. This corresponds, respectively, to concentrationsof 0.25, 0.35, 0.50, 0.75, 1.25, 1.75, 2.50, 3.75 and 5.00 g ofwetting agent/L. This rang
13、e of concentrations is sufficient forthe study of any commercial product.7. Procedure7.1 Pour the diluted test solution from a 1-Lvolumetric flaskinto a 1.5-L beaker to ensure mixing. Divide the solution in thebeaker equally between two 500-mLgraduated cylinders. If themore dilute solutions are test
14、ed first, the mixing beaker andcylinders need not be rinsed out and dried each time. Wait afterthe cylinders have been filled until all bubbles below thesurface of the solution have risen to the top before making thesinking tests. Remove foam on the surface of the solutioneither with a 100-mL bulb p
15、ipet or with an aspirator. Wherethere is little tendency for exhaustion of the wetting agent onthe test skeins, practically always true for cotton, it is permis-sible to use the same diluted solution over again several timesrather than to make a new diluted solution for each new skein.In this case o
16、nly one 500-mL cylinder may be filled repeatedlyfrom the solutions of a certain concentration.7.2 Since temperature often markedly affects wetting, stan-dard temperatures of 77, 122, 158, and 194F (25, 50, 70, and90C) have been chosen for testing so as to include thecomplete commercially useful rang
17、e. It is most convenient toattain a temperature of 77F merely by using water that hasbeen brought to the correct temperature in a large pail. For testsat higher temperatures, heat the diluted solution for test in themixing beaker to a temperature somewhat above that required,pour the solution into t
18、he cylinder, and then allow it to coolback to the testing temperature.7.3 Fasten the hook with its anchor at one end of the foldedskein, and cut through the skein with shears at the opposite end.Draw the cut skein through the fingers when testing wettingagents in order to make it more compact. Fold
19、into the skeinnear the hook any threads that have been tied around the skeinto correct its weight.7.4 Hold the skein in one hand with the anchor suspended inthe wetting solution contained in the 500-mL graduated cylin-der. With the other hand start a stop watch just as the skein isreleased into the
20、solution, and stop the watch when the buoyantskein definitely starts to sink to the bottom of the cylinder. Theskein before sinking must be entirely covered with solution andyet it must possess enough buoyancy from the air within theyarn to keep the linen thread taut between the anchor and thehook (
21、Fig. 2).5The sole source of supply of the apparatus known to the committee at this timeis Testfabrics, Inc., P.O. Drawer “O”, Middlesex, NJ 08846. If you are aware ofalternative suppliers, please provide this information to ASTM Headquarters. Yourcomments will receive careful consideration at a meet
22、ing of the responsibletechnical committee, which you may attend. FIG. 2 Wetting Out of SkeinD 2281 68 (2005)27.5 Obtain the average of at least four determinations ofsinking time for each concentration of wetting agent. Anaverage deviation of 10 to 12 % in sinking time may beexpected.NOTE 1The sprea
23、d among readings for sinking time is considerablyreduced by placing the cylinder for test on a vibrating surface. The bubblesare then more uniformly liberated; that is, occasional lingering iseliminated, and greater uniformity follows. It is to be observed thatvibration produces lower average sinkin
24、g concentrations for a givenstandard time and standard hook.8. Presentation of Data8.1 The method of handling the data obtained by thetechnique described above is very important. The most usefulplot where a complete curve is desired is one made on log-loggraph paper with logarithmic coordinates alon
25、g both axes butreading directly in antilogarithms. Values of concentrations ofwetting agent are shown on the horizontal scale, or X-axis, andsinking times in seconds are shown on the vertical scale, orY-axis. A smooth curve is drawn through the points. For mostproducts this curve will be a straight
26、line (Fig. 3).8.2 When sinking curves for two products have the sameslopes for a 3.0-g hook, it has been found that they have thesame slopes for any weight of hook by the method of testingdescribed here. They even have quite closely the same slopesfor any other method of testing in which cotton is e
27、mployed.Under such conditions, it is then logical to assume thatsolutions that cause wetting in equal times for the same lot ofcotton under similar conditions are equivalent. Comparisons ofrelative costs of wetting can then be made as illustrated inTable 1, where the cost for 100 gal of wetting agen
28、t iscalculated from the following formula:Cost for 100 gal of solution at wetting concentration 5 0.8353 wetting concentration in g/L 3 cost/lb!8.3 When two products have markedly different slopes forplots representing the relationship between sinking times andconcentrations on log-log graph paper,
29、great care must beexercised in interpreting the wetting data.9. Precision9.1 The standard deviation based on six replicate determi-nations has been calculated at 10 to 12 % of the averagesinking time measured in the range from 18 to 35 s. Thisapplies to tests made within a single laboratory by a sin
30、gleoperator on a day-to-day basis for the same batch of skeins andthe same wetting agent.FIG. 3 Wetting Time Versus ConcentrationD 2281 68 (2005)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
31、 this standard are expressly advised that determination 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
32、 years andif not revised, either reapproved or withdrawn. 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 co
33、mmittee, 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, PA
34、19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 1 Comparison of Wetting Effic
35、iencies of Two Original AgentsCompared Items Standard Product New ProductWeight of hook, g 3.000 3.000Temperature, F 77 77Medium distilled water, neutral distilled water, neutralCost/lb $0.20 $0.1825-S wetting concentration, g/L 1.95 2.44Equivalent parts 100 125Cost for 100 gal of solution at wetting concentrations $0.325 $0.367D 2281 68 (2005)4
