1、Designation: D5965 02 (Reapproved 2013)Standard Test Methods forSpecific Gravity of Coating Powders1This standard is issued under the fixed designation D5965; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover three procedures for determin-ing the specific gravity (see definition) of coating powders, asfollows:TES
3、T METHOD AFor Testing Coating Powders, Excluding MetallicsTEST METHOD BFor Tests Requiring Greater Precision than Test Method A,Including Metallics, Using Helium PycnometryTEST METHOD CFor Theoretical Calculation Based on Raw Material SpecificGravities1.2 Test Method A can be used as a less expensiv
4、e methodwith reduced accuracy for determining the specific gravity ofcoating powders, excluding metallics.1.3 The ideal gas law forms the basis for all calculationsused in the Test Method B determination of density of coatingpowders.1.4 Test Method B includes procedures that provided ac-ceptable res
5、ults for samples analyzed during round robintesting.1.5 Test Method B uses SI units as standard. State allnumerical values in terms of SI units unless specific instru-mentation software reports surface area using alternate units.Many instruments report density as g/cm3, instead of using SIunits (kg/
6、m3).1.6 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish
7、 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D3924 Specification for Environment for Conditioning andTesting Paint, Varnish, Lacquer, and Related MaterialsD5382 Guide to Evaluation of Opti
8、cal Properties of PowderCoatingsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Terminology3.1 Definitions:3.1.1 Definitions 3.1.1 and 3.1.3 are from Guide D5382.3.1.2 coating powder, nfinely divided particles of resin,either thermoplastic or thermo
9、setting, generally incorporatingpigments, fillers, and additives and remaining finely dividedduring storage under suitable conditions, which, after fusingand possibly curing, give a continuous film.3.1.3 meniscus, ncurved upper surface of a liquid columnthat is concave when the containing walls are
10、wetted by theliquid.3.1.4 powder coating, ncoatings which are protective ordecorative, or both, formed by the application of a coatingpowder to a substrate and fused into continuous films by theapplication of heat or radiant energy.3.1.5 pycnometer, ninstrument designed to measure thevolume of solid
11、 materials using Archimedes principle of fluiddisplacement. The displaced fluid is a helium gas.3.1.6 specific gravity(1) strict definition: the density of asubstance relative to that of water; (2) practical, as used in thistest methodThe numerical value of the density when thelatter is expressed in
12、 grams per millilitre.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and Applications and are the directresponsibility of Subcommittee D01.51 on Powder Coatings.Current edition approved June 1, 2013. Published July 2013. Originally appro
13、vedin 1996. Last previous edition approved in 2007 as D5965 02 (2007). DOI:10.1520/D5965-02R13.2For 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 standards Documen
14、t Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Significance and Use4.1 Test Method A is a less expensive method of determin-ing specific gravity of coating powders, excluding metallics,that produc
15、ed less precise results than Test Method B.4.2 Test Method B provides better precision at higher costand includes metallics, although different models produceddifferent grand averages for each of the three samples tested.4.3 Test Method C is commonly used by the powder coatingindustry to estimate th
16、e coverage of a powder coating at agiven thickness, using the theoretical specific gravity calcu-lated from those of the raw materials.5. Reagents5.1 PurityWetting vehicles should be of reagent grades.5.2 HeliumShall be understood to mean high purity ofcommercial grade.6. Conditioning6.1 These tests
17、 should be standardized at 23 6 2C (73.5 63.5F) and relative humidity of 50 6 5 % for the two methodsin compliance with Specification D3924.TEST METHOD AFOR TESTING POWDERCOATINGS, EXCLUDING METALLICS7. Apparatus and Materials7.1 Volumetric FlaskCalibrated narrow-necked glass type,having a 50-mL cap
18、acity.7.2 BalanceA calibrated laboratory balance having a60.001 g-accuracy. A less accurate balance can be used with arelative effect on the results.7.3 Coating PowderWeighed to 15 g, within a 60.01g-accuracy.7.4 Immersion LiquidHexane was found to be a goodwetting vehicle for the epoxy and polyeste
19、r coatings used in theround robin for the testing of repeatability and reproducibility.7.5 Glass FunnelDesigned to fit within the neck of thevolumetric flask.7.6 Polished Round-Bottom Glass RodsFor dispersingpowder.7.7 Squeeze BottleSuitable for containing and dispensingwetting vehicle.8. Hazards8.1
20、 Exercise care in handling all wetting vehicles. Makesure that personal equipment includes protective gloves,glasses, and clothing. Perform test method using wettingvehicles in a solvent hood.9. Standardization9.1 Weigh the empty, clean volumetric flask. Record thisweight as WF.9.2 The density of th
21、e wetting vehicle, recorded as DL, canbe determined by adding exactly 50 mL of wetting vehicle tothe previously weighed flask and reweighing. Record thisweight as WFL. Calculate the density of the wetting vehicle(DL) as follows:DL 5WFL 2 WF!50 mL(1)10. Procedure10.1 Weigh the 50-mL volumetric flask.
22、 Record this weightas WF.Add 15 g of powder to the clean, dry, weighed flask andaccurately reweigh. Record this weight as WFP. Add enoughwetting vehicle to cover the powder and gently swirl until thepowder is completely wet.10.2 The removal of entrapped air has a significant effect onthe accuracy of
23、 the results. Care should be taken to insurewetting out of the powder is complete. When necessary, stir thepowder with a polished round-bottom glass rod until com-pletely covered by the wetting vehicle. Wash the rod withwetting vehicle, adding the washings to the flask withoutexceeding the 50-mL cal
24、ibration mark.10.3 Add additional wetting vehicle up to the 50-mL mark.Make sure that the bottom of the meniscus is aligned at eyelevel with the line on the front and back of the flask neck. Thisaddition of wetting vehicle can be done with a squeeze bottlein a manner to wash any residual powder from
25、 the neck of theflask. Reweigh and record this weight as WFPL.10.4 Multiple volumetric flasks can be used in rotation toreduce cleaning and complete drying time.10.5 Immediately clean the flask after each test to increasethe ease with which this is accomplished. Each flask shall becompletely clean a
26、nd dry before proceeding to the next test.11. Calculation11.1 Calculate the density of the powder (DP) as follows:DP 5WFP 2 WF50 mL 2WFPL 2 WFPDL5 denominator5 numerator (2)where:WFP = weight of flask and powder,WF = weight of flask,WFPL = weight of flask, powder, and wetting vehicle,DL = density of
27、 wetting vehicle, andDP = specific gravity of powder.11.2 An example, using hexane, would be as follows:DP 550.545 g 2 36.581 g50 mL 277.200 g 2 50.545 g0.663 g/mL513.9649.7965 1.42 specific gravity (3)where:WFP = 50.545 g,WF = 36.581 g,WFPL = 77.200 g,DL = 0.663 g/mL, andDP = unknown.D5965 02 (2013
28、)212. Report12.1 Report the following information:12.1.1 Use duplicate determinations with the average re-ported to two significant figures to the right of the decimal.12.1.2 Report the complete sample identification and thewetting vehicle used to determine the specific gravity.13. Precision and Bia
29、s313.1 PrecisionThe average of duplicate determinations bythis test method should not differ by more than 0.025 using abalance with 0.0001 significant figures or 0.04 using a balancewith 0.001 significant figures.13.2 BiasBias has not been determined.TEST METHOD BFOR TESTS REQUIRINGGREATER PRECISION
30、 THAN TEST METHOD A,INCLUDING METALLICS, USING HELIUMPYCNOMETRY14. Apparatus and Materials14.1 Commercial Pycnometer Instruments, available fromseveral manufacturers for the measurement of skeletal volumeby gas displacement. Some instruments perform calculations ofvolume or density, or both, upon co
31、mpletion of the analysis.Others require manual calculation of skeletal volume anddensity.14.2 Analytical Balance, having a 60.0001-g accuracy.15. Sampling15.1 It is important that the sample being analyzed representthe larger bulk from which it is taken. The bulk sample shouldbe homogeneous before a
32、ny sampling takes place.16. Calibration and Standardization16.1 Follow manufacturers instructions for calibration andoperational verification of the pycnometer and analytical bal-ance.17. Outgassing17.1 Weigh the clean, empty sample holder to the nearest0.1 mg. Record the empty holder weight.17.2 Ad
33、d representative sample to the empty sample holder.The sample quantity should be sufficient to satisfy the mini-mum skeletal volume as required by the manufacturer. Weighand record the weight of the sample and sample holder.NOTE 1Move to the Procedure Section if the sample is to beoutgassed in the p
34、ycnometer at the time of analysis.17.3 Place prepared sample holder in outgassing device.17.4 Program outgassing device for initial outgassing tem-perature. Increase temperature as appropriate for the sample.Allow sample to continue to outgas until prescribed vacuumlevel is achieved or prescribed ou
35、tgassing time, or both.17.5 Reduce the temperature of the outgassing device toambient. Remove the sample holder.17.6 Weigh the sample holder to the nearest milligram toobtain the sample and holder weight. Subtract the emptysample holder weight determined in 16.1 to obtain the out-gassed sample weigh
36、t. Record the calculated weight.18. Procedure18.1 Place the filled sample holder in the pycnometer andclose the sample chamber.18.2 Automated Instruments OnlySelect, or input, thedesired analysis and report parameters. Include the outgassingparameters if the sample preparation is performed as a part
37、 ofthe sample analysis. If necessary, input the outgassing sampleweight. The final weight should be determined and enteredafter the analysis. Determine the skeletal volume a minimum offive times.18.3 Manually Operated InstrumentsCollect three to fivesets of analysis data according to the manufacture
38、rs recom-mended procedure for maximum accuracy and precision.18.4 When the analysis has finished, remove the sampleholder. Weigh the holder to the nearest 0.1 mg. Record the finalholder and sample weight. Subtract the empty holder weightrecorded in 16.1 to obtain the final sample weight.18.5 Automat
39、ed Instruments OnlyInput the final sampleweight. Generate the final sample report.19. Calculations19.1 Automated Instruments OnlyHave software that au-tomatically calculates the results for the chosen reports usingthe final weight input in 18.5.19.2 Manually Operated InstrumentsCalculate the skel-et
40、al volume using collected data according to the manufactur-ers instructions. Use the final sample weight from 16.4 tocalculate skeletal densities. Calculate the average and standarddeviation for skeletal volume and density in accordance withPractice E691.20. Report20.1 Report the following informati
41、on:20.1.1 Complete sample identification and measured skel-etal volumes, statistics, and density determined. Note any unitsused other than standard.20.1.2 Analysis gas type used.20.1.3 Sampling outgassing method, including total timeand outgassing temperature(s).TEST METHOD CFOR THEORETICALCALCULATI
42、ON BASED ON RAW MATERIALSPECIFIC GRAVITIES21. Calculations21.1 To Calculate the Theoretical Specific Gravity of aCoating Powder When the Formula is KnownDivide theamount of each raw material (RM) by its specific gravity. Addthe raw material amounts together and divide by the sum of the3Supporting da
43、ta have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1100.D5965 02 (2013)3resulting values for all of the raw materials in the subjectpowder. The product of this calculation shall be the theoreticalspecific gravity of the coating powder, as fo
44、llows:Theoretical specific gravity 5grand total of amounts RM1 through RM6!sum of resulting values RM1 through RM6!(4)where:RM1 amount divided by specific gravity = RM1 resultingvalueRM2 amount divided by specific gravity = RM2 resultingvalueRM3 amount divided by specific gravity = RM3 resultingvalu
45、eRM4 amount divided by specific gravity = RM4 resultingvalueRM5 amount divided by specific gravity = RM5 resultingvalueRM6 amount divided by specific gravity = RM6 resultingvalueGrand total Sum of resulting values21.2 Report the powder specific gravity.22. Precision and Bias322.1 Precision and bias
46、of the procedures in Test MethodsAand B for measuring the specific gravity of coating powdershas not been determined because the minimum number oflaboratories required by Practice E691 was not met. Aninterlaboratory study was conducted by four laboratories todetermine the specific gravity of two coa
47、ting powders usingTest MethodAand three coating powders using Test Method B.23. Keywords23.1 coating powders; density; metallics; powder coatings;pycnometer; specific gravityASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mention
48、edin this standard. Users of 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
49、 must be reviewed every five 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 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 b
