1、Designation: D 5965 02Standard 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 revision. A number in p
2、arentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope *1.1 These test methods cover three procedures for determin-ing the specific gravity (see definition) of coating powders, asfollows:TEST METHOD AFor
3、 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 expensive methodwith
4、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 results for samp
5、les 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/m3).1.6 This
6、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 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2
7、.1 ASTM Standards:D 3924 Specification for Standard Environment for Condi-tioning and Testing Paint, Varnishes, Lacquers, and Re-lated Materials2D 5382 Guide to Evaluation of Optical Properties of Pow-der Coatings3E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a
8、Test Method43. Terminology3.1 Definitions:3.1.1 Definitions 3.1.1 and 3.1.3 are from Guide D 5382.3.1.2 coating powdersfinely divided particles of resin,either thermoplastic or thermosetting, generally incorporatingpigments, fillers, and additives and remaining finely dividedduring storage under sui
9、table conditions, which, after fusingand possibly curing, give a continuous film.3.1.3 meniscuscurved upper surface of a liquid columnthat is concave when the containing walls are wetted by theliquid.3.1.4 powder coatingscoatings which are protective ordecorative, or both, formed by the application
10、of a coatingpowder to a substrate and fused into continuous films by theapplication of heat or radiant energy.3.1.5 pycnometerinstrument designed to measure the vol-ume of solid materials using Archimedes principle of fluiddisplacement. The displaced fluid is a helium gas.3.1.6 specific gravity(1) s
11、trict 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 grams per millilitre.4. Significance and Use4.1 Test Method A is a less expensive method of determin-ing specific gravity
12、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 metallics, although different models produceddifferent grand averages for each of the three samples tested.4.3 Test Method C is commonl
13、y 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 the raw materials.1These test methods are under the jurisdiction of ASTM Committee D01 onPaint and Related Coatings, Materials, and
14、Applications and are the directresponsibility of Subcommittee D01.51 on Powder Coatings.Current edition approved Jan. 10, 2002. Published March 2002. Originallypublished as D 5965 - 96. Last previous edition D 5965 - 96.2Annual Book of ASTM Standards, Vol 06.01.3Annual Book of ASTM Standards, Vol 06
15、.02.4Annual Book of ASTM Standards, Vol 14.02.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Reagents5.1 PurityWetting vehicles should be of reagent grades.5.2 Hel
16、iumShall be understood to mean high purity ofcommercial grade.6. Conditioning6.1 These tests should be standardized at 73.5 6 3.5F (236 2C) and relative humidity of 50 6 5 % for the two methodsin compliance with Specification D 3924.TEST METHOD AFOR TESTING POWDERCOATINGS, EXCLUDING METALLICS7. Appa
17、ratus and Materials7.1 Volumetric FlaskCalibrated narrow-necked glasstype, having a 50-mL capacity.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-accurac
18、y.7.4 Immersion LiquidHexane was found to be a goodwetting vehicle for the epoxy and polyester 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 Rods For dispersi
19、ngpowder.7.7 Squeeze BottleSuitable for containing and dispensingwetting vehicle.8. Hazards8.1 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. Standardiza
20、tion9.1 Weigh the empty, clean volumetric flask. Record thisweight as WF.9.2 The density of the 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 v
21、ehicle(DL) as follows:DL 5WFL 2 WF!50 mL(1)10. Procedure10.1 Weigh the 50-mL volumetric flask. 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
22、 is completely wet.10.2 The removal of entrapped air has a significant effect onthe accuracy of 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. Wa
23、sh the rod withwetting vehicle, adding the washings to the flask withoutexceeding the 50-mL calibration 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 o
24、f wetting vehicle can be done with a squeeze bottlein a manner to wash any residual powder from 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
25、test to increasethe ease with which this is accomplished. Each flask shall becompletely clean and 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
26、 powder,WF = weight of flask,WFPL = weight of flask, powder, and wetting vehicle,DL = density of 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)whe
27、re:WFP = 50.545 g,WF = 36.581 g,WFPL = 77.200 g,DL = 0.663 g/mL, andDP = unknown.12. 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
28、thewetting vehicle used to determine the specific gravity.13. Precision and Bias513.1 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 Bia
29、sBias has not been determined.5Supporting data are available from ASTM International Headquarters. RequestRR:D01-1100.D 59652TEST METHOD BFOR TESTS REQUIRINGGREATER PRECISION THAN TEST METHOD A,INCLUDING METALLICS, USING HELIUMPYCNOMETRY14. Apparatus and Materials14.1 Commercial Pycnometer Instrumen
30、ts, available fromseveral manufacturers for the measurement 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.
31、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 any sampling takes place.16. Calibration and Standardization16.1 Follow manufacturers instructions for calibration andoperation
32、al 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 Add representative sample to the empty sample holder.The sample quantity should be sufficient to satisfy the mini-mum skeletal v
33、olume 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 pycnometer at the time of analysis.17.3 Place prepared sample holder in outgassing device.17.4 Program outgassing device for in
34、itial outgassing tem-perature. Increase temperature as appropriate 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
35、 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 weight. Record the calculated weight.18. Procedure18.1 Place the filled sample holder in the pycnometer andclose the sample chamber
36、.18.2 Automated Instruments OnlySelect, or input, thedesired 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 enteredafte
37、r the analysis. Determine the skeletal volume a minimum offive times.18.3 Manually Operated Instruments Collect 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. We
38、igh 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 Automated Instruments OnlyInput the final sampleweight. Generate the final sample report.19. Calculations19.1 Automated Instruments
39、OnlyHave software that au-tomatically calculates the results for the chosen reports usingthe final weight input in 16.5.19.2 Manually Operated Instruments Calculate the skel-etal volume using collected data according to the manufactur-ers instructions. Use the final sample weight from 16.4 tocalcula
40、te skeletal densities. Calculate the average and standarddeviation 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 units
41、used 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 THEORETICALCALCULATION BASED ON RAW MATERIALSPECIFIC GRAVITIES21. Calculations21.1 To Calculate the Theoretical Specific Gravity of aCoating Po
42、wder 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 theresulting values for all of the raw materials in the subjectpowder. The product of this calculation shall be the theoreticalspecific grav
43、ity of the coating powder, as follows:Theoretical specific gravity5grand 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 speci
44、fic gravity = RM3 resultingvalueRM4 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 an
45、d Bias522.1 Precision and bias of the procedures in Test Methods AD 59653and 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 tod
46、etermine the specific gravity of two coating powders usingTest Method A and three coating powders using Test Method B.23. Keywords23.1 coating powders; density; metallics; powder coatings;pycnometer; specific gravitySUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to t
47、his standard since the last issue(D 5965 - 96) that may impact the use of this standard.Minor changes to:(1) Reference to hazard statement was deleted from 1.6.(2) Coating powders and powder coating definitions wererevised in Section 3.(3) Helium purity was revised in 5.2(4) Paragraph 14.1 was revis
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