1、Designation: D4400 99 (Reapproved 2012)1Standard Test Method forSag Resistance of Paints Using a Multinotch Applicator1This standard is issued under the fixed designation D4400; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1NOTESole source of supply footnote was re
3、moved editorially and new footnote placed in Precision section in Novem-ber 2012.INTRODUCTIONThe multinotch applicator used in this test method is a drawdown blade with a series of notches ofsuccessively higher clearance, referred to as the Anti-Sag Meter. See Fig. 1 and Fig. 2 for arepresentative d
4、iagram and photograph. The numerical value for sag resistance obtained with thisinstrument is referred to as the Anti-Sag Index.Anti-Sag Meters are made with several clearance ranges for different types of coatings (see 5.1 andTable 1). In developing this standard the task group used an instrument w
5、ith a range from 4 to 24 mils,but the method is applicable to any clearance range, and results using instruments with overlappingranges correlate and have equal validity.The basic method was developed in 19622and is referenced in U.S. Federal specificationsTT-E-508, TT-E-506, and TT-P-1511.Apreshear
6、 program is essential for a drawdown sag test to duplicate the breakdown in structure thatoccurs when thixotropic paints are applied by brushout or other practical application methods. Theprocedures therefore include the preshearing of paints just prior to making test applications.1. Scope1.1 This t
7、est method covers the laboratory determination ofthe sag resistance of aqueous and nonaqueous liquid coatings atany level of sag resistance.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport
8、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. Referenced Documents2.1 ASTM Standards:3D2196 T
9、est Methods for Rheological Properties of Non-Newtonian Materials by Rotational (Brookfield type)Viscometer2.2 U.S. Federal Specifications:4Fed. Spec. TT-E-508 Alkyd semi-gloss enamelFed. Spec. TT-E-506 Alkyd gloss enamelFed. Spec. TT-P-1511 Interior latex gloss and semi-glossfinishes3. Summary of T
10、est Method3.1 After preshearing, the coating is applied to a test chartwith a multinotch applicator. The charts are immediately hungvertically with the drawdown stripes horizontal, similar torungs of a ladder, with the thinnest stripe at the top. After1This test method is under the jurisdiction of A
11、STM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.42 on Architectural Coatings.Current edition approved May 15, 2012. Published May 2012. Originallyapproved in 1984. Last previous edition approved in 2007 as D4400 99 (2007
12、).DOI: 10.1520/D4400-99R12E01.2“Design of an Improved Sag Tester,” Offcial Digest, Vol 34, No. 453, October1962.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the
13、standards Document Summary page onthe ASTM website.4Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
14、959. United States1drying in this position, the drawdown is examined and rated forsagging. A typical sag pattern obtained by this procedure isshown in Fig. 3.4. Significance and Use4.1 Evaluation of sag resistance is essential in qualitycontrol for both producers and purchasers of coatings. Practica
15、lapplication tests are poor in reproducibility, while viscometricmethods, for example Test Methods D2196, are time-consuming and lack the convincing aspect of actual sagging.This method provides simple and rapid tests, whereby sagresistance is demonstrated by a visible sag pattern, and is ratedobjec
16、tively in terms of numerical values that correlate withbrushout test observations.5. Apparatus5.1 Multinotch Applicator, Anti-Sag Meter, a drawdownblade with a series of notches of successively higher clearance.Select a clearance range suitable for the type of coating undertest in accordance with Ta
17、ble 1.5.2 Test Surfaces, sealed, smooth-surfaced paper test charts,with sizes and designs as follows:5.2.1 Black and White Charts, about 193 by 288 mm (758by 1138 in.), the black area comprising about 140 mm (512 in.)centered on the drawdown path.Achart of this design is shownin Figs. 3 and 4.5.2.2
18、Plain White Charts, about 193 by 285 mm (758 by1114 in.).5.3 Glass Drawdown Plate, plus straightedge guide forattachment thereto.5.4 Catch-papers, thin sheets of sealed paper, for catchingsurplus paint at the completion of a drawdown.5.5 Equipment for the Preshearing of Aqueous Coatings:5.5.1 Syring
19、e, 10-mL, disposable plastic type.5.5.2 Syringe Needle, 15gby40mm(112 in.) to fit syringe.5.5.3 Syringe Extension Tubing, clear vinyl, inside diameter3.2 mm (18 in.), outside diameter 5 mm (36 in.).5.6 Equipment for the Preshearing of Nonaqueous Coat-ings:5.6.1 Rotary Mechanical Stirrer, variable sp
20、eed.5.6.2 Circular Mixing Paddle, diameter approximately 48mm (178 in.).5.6.3 Mixing Container, cylindrical jar or can with capacityof up to 500 mL (1 pt).6. Procedure6.1 Preparation of Sample:6.1.1 Stir thoroughly with a spatula in the original container.6.1.2 Strain if necessary to remove large pa
21、rticles or skins.6.1.3 Adjust the temperature of the coating to 23 6 2C(73.5 6 3.5F).6.2 Preshearing with Syringe and Needle (Aqueous Coat-ings):6.2.1 Prepare the paint as described in 6.1.6.2.2 Cut a 60-mm (212-in.) length of syringe extensiontubing and attach it to the syringe.6.2.3 Press the syri
22、nge barrel firmly to expel air, dip the endof the syringe into the coating, pump slightly to expel remain-ing air, then withdraw 8 mL of coating.FIG. 1 Diagram of the Medium Range Anti-Sag MeterFIG. 2 Medium Range Anti-Sag MeterD4400 99 (2012)126.2.4 Remove and discard the extension tubing and thena
23、ttach a syringe needle.6.2.5 Eject the contents of the syringe in front of theapplicator as rapidly as possible, with firm, steady pressure.6.3 Preshearing with a Rotary Mechanical Mixer (Non-aqueous Coatings):6.3.1 Prepare the paint as described in 6.1 and fill themixing container slightly more tha
24、n half. Set the containerunder the stirrer so that the paddle is about 5 mm (14 in.) fromthe bottom.6.3.2 Mix vigorously for 1 min at a speed sufficient to forma moderate vortex, with the entire contents of the can in rapidcircular motion. Rotor speeds of 1300 to 3600 r/min have beenfound satisfacto
25、ry, the optimum speed depending on therelative diameters of the mixing paddle and container. Forreferee tests the operators should agree upon the specificcontainer, paddle, and mixing speed.6.3.3 Immediately after mixing place about 8 mL of paint infront of the applicator and draw down in accordance
26、 with 6.4.6.4 Application of the Test Coating:6.4.1 Affix a suitable test chart onto the drawdown plate.Use black and white charts in accordance with 5.2.1 for light ormoderately dark colored coatings and white charts in accor-dance with 5.2.2 for very dark coatings.6.4.2 Fasten the straightedge ont
27、o the drawdown plate in asuitable position.6.4.3 Place the Anti-Sag Meter at the far end of the chart,the open side toward the operator and shoulder against thestraightedge guide.6.4.4 If desired, position a catch-paper just underneath thelower edge of the chart.6.4.5 Preshear in accordance with 6.2
28、 or 6.3 and immedi-ately draw down the coating at a uniform speed of about 150mm (6 in.)/s, with the applicator pressed against the straight-edge to maintain a straight path. See Fig. 4 for illustration ofthis step.6.4.6 Immediately hang the chart with the drawdown stripesin a horizontal position li
29、ke rungs in a standing ladder, thethinnest stripe at the top, and allow to dry in that position. Atypical test pattern derived using this procedure is shown inFig. 3.6.5 Rating the Drawdown:6.5.1 When the film is dry, note the notch numbers markedon the Anti-Sag Meter and identify the corresponding
30、stripesaccordingly.6.5.2 Observe the sag pattern, ignoring the bottom stripe,which serves only as a position reference for the stripe aboveit, and the leading and trailing edges of the drawdown,considering only the central 140 mm (512 in.) of the blade path.This corresponds to the black area of the
31、black and white chartdescribed in 5.2.1. (See Fig. 3 for a typical sag pattern of thistype.)6.5.3 Select the lowest (thickest) stripe that has resistedcrossing the gap to touch the next lower stripe. This is referredto as the index stripe.TABLE 1 Anti-Sag MetersAvailable RangesRange For Coating Type
32、: Notch ClearancesAASM-1 Standard Solvent-borne architectural Mils 345678910112m 75 100 125 150 175 200 225 250 275 300ASM-2 Low Industrial O.E.M. coatings Mils 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6m 25 38 50 63 75 88 100 113 125 138 150ASM-3 High High build coatings Mils 14 16 18 20 25 30 35 40 45 50 60m
33、 350 400 450 500 625 750 875 1000 1125 1250 1500ASM-4 Medium Water borne architectural Mils 4 6 8 10 12 14 16 18 20 22 24m 100 150 200 250 300 350 400 450 500 550 600AMils are exact. Wet film thickness is about half of clearance.FIG. 3 Typical Sag PatternNOTE 1Note use of straightedge guide.FIG. 4 D
34、rawing Down with the Anti-Sag MeterD4400 99 (2012)136.5.4 Estimate the degree to which the next lower stripe (thepost-index stripe) has merged with the one below it, anddetermine the corresponding addendum fraction, as specified inTable 2.6.5.5 Multiply the fraction from 6.5.4 by the differencebetwe
35、en the index and post-index stripe number to obtain theindex addendum.6.5.6 Add the index addendum to the index stripe number toobtain the Anti-Sag Index and record same.7. Report7.1 Report the Anti-Sag Index of the coating as recorded in6.5.6.8. Precision5,68.1 CorrelationIn an interlaboratory stud
36、y in which op-erators in seven laboratories tested six water-reducible paintscovering a wide range of sag resistance and in five laboratoriestested four solvent-reducible paints covering a wide range ofsag resistance, the Spearman Rank Correlation Coefficient was0.92 versus brushouts (a coefficient
37、of 1.0 indicates perfectagreement in ranking).8.2 SensitivityIn the interlaboratory study described in8.1, the sensitivity criterion values have been computed to be4 for brushouts versus 11 for this procedure. The latter is thusapproximately three times more sensitive to differences in sagresistance
38、 than brushouts.8.3 Precision:8.3.1 Two interlaboratory tests were conducted to establishthe precision of this test method. The first test was thatdescribed in 8.1. The second test consisted of operators in fivelaboratories performing three tests on each of three paints. Onthe basis of the second in
39、terlaboratory test, the within-laboratory pooled coefficients of variations for both water- andsolvent-reducible paints were 4.4 %. On the basis of the firstinterlaboratory test, the between-laboratory pooled coefficientof variation was found to be 12.4 % for water-reducible paintsand 8.8 % for solv
40、ent-reducible paints. Based on these coeffi-cients of variation, the following criteria should be used forjudging the acceptability of results at the 95 % confidencelevel:8.3.1.1 RepeatabilityTwo results obtained by the sameoperator for either water-reducible or solvent-reducible paintsshould be con
41、sidered suspect if they differ by more than10.7 %.8.3.1.2 ReproducibilityTwo results obtained by operatorsin different laboratories should be suspect if they differ by morethan 34.4 % for water-reducible paints and 23.4 % for solvent-reducible paints.9. Keywords9.1 Anti-Sag Index; rheological proper
42、ties; sag-resistanceASTM 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 determination of the validity of any such patent rights, and the riskof infringement
43、 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 withdrawn. Your comments are invited either for revision of this standard or fo
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45、 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 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM
46、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).5The Leneta Anit-Sag Meter was used in the inter
47、laboratory study.6Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1040.TABLE 2 Intermediate RatingsDegree of Merger ofPost-Index StripeAddendumFractionComplete 0.0Almost complete 0.2Somewhat more than half 0.4Half 0.5Somewhat less than half 0.6Slight (just touching) 0.8D4400 99 (2012)14
