1、Designation: D 5965 02 (Reapproved 2007)Standard Test Methods forSpecific Gravity of Coating Powders1This standard is issued under the fixed designation D 5965; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revis
2、ion. 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 These test methods cover three procedures for determin-ing the specific gravity (see definition) of coating powders, asfollows:
3、TEST 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 expen
4、sive 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
5、results 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 (
6、kg/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 establ
7、ish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 3924 Specification for Environment for Conditioning andTesting Paint, Varnish, Lacquer, and Related MaterialsD 5382 Guide to Evaluation of
8、 Optical Properties of Pow-der CoatingsE 691 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 D 5382.3.1.2 coating powder, nfinely divided particles of resin,either thermoplastic
9、or thermosetting, 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 w
10、alls are 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
11、 of solid 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 exp
12、ressed in grams per millilitre.4. Significance and Use4.1 Test Method A is a less expensive method of determin-ing specific gravity of coating powders, excluding metallics,that produced less precise results than Test Method B.4.2 Test Method B provides better precision at higher costand includes met
13、allics, 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 the coverage of a powder coating at agiven thickness, using the theoretical specific gravity calcu-lated from those of
14、the raw materials.5. Reagents5.1 PurityWetting vehicles should be of reagent grades.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 editio
15、n approved Nov. 1, 2007. Published January 2008. Originallyapproved in 1996. Last previous edition approved in 2002 as D 5965 - 02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informa
16、tion, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2 HeliumShall be understood to mean high purity ofcommercial grade.6. Conditioning6.1 These tests should be stand
17、ardized at 23 6 2C (73.5 63.5F) and relative humidity of 50 6 5 % for the two methodsin compliance with Specification D 3924.TEST METHOD AFOR TESTING POWDERCOATINGS, EXCLUDING METALLICS7. Apparatus and Materials7.1 Volumetric FlaskCalibrated narrow-necked glasstype, having a 50-mL capacity.7.2 Balan
18、ceA 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 polyester coatings used
19、 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 Exercise care
20、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 the wetting vehic
21、le, 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. Record this we
22、ightas 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 the results. C
23、are 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 calibration mark.1
24、0.3 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 the neck of th
25、eflask. 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 and dry before p
26、roceeding 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 wetting vehicl
27、e, 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.12. Report12.1 Report the foll
28、owing 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 Bias313.1 PrecisionThe average of d
29、uplicate 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.3Supporting data have been filed at ASTM International Headquarters and maybe obt
30、ained by requesting Research Report RR:D01-1100.D 5965 02 (2007)2TEST METHOD BFOR TESTS REQUIRINGGREATER PRECISION THAN TEST METHOD A,INCLUDING METALLICS, USING HELIUMPYCNOMETRY14. Apparatus and Materials14.1 Commercial Pycnometer Instruments, available fromseveral manufacturers for the measurement
31、of skeletal volumeby gas displacement. Some instruments perform calculations ofvolume or density, or both, upon completion 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 sa
32、mple being analyzed representthe larger bulk from which it is taken. The bulk sample shouldbe homogeneous before any sampling takes place.16. Calibration and Standardization16.1 Follow manufacturers instructions for calibration andoperational verification of the pycnometer and analytical bal-ance.17
33、. Outgassing17.1 Weigh the clean, empty sample holder to the nearest0.1 mg. Record the empty holder weight.17.2 Add 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 w
34、eight of the sample and sample holder.NOTE 1Move to the Procedure Section if the sample is to beoutgassed in the pycnometer 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 appro
35、priate for the sample.Allow sample to continue to outgas until prescribed vacuumlevel is achieved or prescribed outgassing 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
36、and holder weight. Subtract the emptysample holder weight determined in 16.1 to obtain the out-gassed sample weight. 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
37、 analysis and report parameters. Include the outgassingparameters if the sample preparation is performed as a part 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 offi
38、ve times.18.3 Manually Operated InstrumentsCollect three to fivesets of analysis data according to the manufacturers 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
39、and sample weight. Subtract the empty holder weightrecorded in 16.1 to obtain the final sample weight.18.5 Automated Instruments OnlyInput the final sampleweight. Generate the final sample report.19. Calculations19.1 Automated Instruments OnlyHave software that au-tomatically calculates the results
40、for the chosen reports usingthe final weight input in 18.5.19.2 Manually Operated InstrumentsCalculate the skel-etal 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 standarddevia
41、tion for skeletal volume and density in accordance withPractice E 691.20. Report20.1 Report the following information: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
42、Sampling outgassing method, including total timeand outgassing temperature(s).TEST METHOD CFOR THEORETICALCALCULATION 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 mat
43、erial (RM) by its specific gravity. Addthe raw material amounts together and divide by the sum of theresulting 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 follows:Theoretical specific gra
44、vity5grand 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 resultingvalueRM4 amount divided by specific
45、 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.D 5965 02 (2007)322. Precision and Bias322.1 Precision and bias of the procedu
46、res in Test Methods Aand B for measuring the specific gravity of coating powdershas not been determined because the minimum number oflaboratories required by Practice E 691 was not met. Aninterlaboratory study was conducted by four laboratories todetermine the specific gravity of two coating powders
47、 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 mentionedin this st
48、andard. 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 must be rev
49、iewed 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 by ASTM Internat
