1、Designation: D8090 17Standard Test Method forParticle Size Distribution and Shape Analysis of Paints andPigments Using Dynamic Imaging Methods1This standard is issued under the fixed designation D8090; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year 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.1. Scope1.1 This test method covers the determination of particlesize distribution and particle sha
3、pe of liquid paints andpigmented liquid coatings by Dynamic Image Analysis. Thismethod includes the reporting of particles 1 m in size and upto 300 m in size.NOTE 1Shape is used to classify particles, droplets and bubbles and isnot a reporting requirement.NOTE 2The term paint(s) as used in this docu
4、ment includes liquidpaint and liquid pigmented coatings.1.1.1 Some paints may be too viscous to flow through theimaging instrument without dilution which may be used to helpthe paint flow as long as significant contamination is notintroduced into the paint.1.2 The values stated in SI units are to be
5、 regarded asstandard. No other units of measurement are included in thisstandard.1.3 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 appro-priate safety and health practices and de
6、termine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mend
7、ations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D16 Terminology for Paint, Related Coatings, Materials, andApplicationsD3925 Practice for Sampling Liquid Paints and RelatedPigmented Coatings2.2 Other Documents:NIST S
8、RM 1982 Thermal Spray Powder Particle SizeDistribution3ISO12103-1 Medium Test Dust3. Terminology3.1 For the definition of terms used in this standard refer toTerminology D16.3.2 Definitions:3.2.1 bubble, na non paint, gaseous formation within thepaint, generally spherical in shape and visible as a t
9、hick walledring with a transparent center.3.2.2 droplet, na non paint, liquid formation within thepaint, generally spherical in shape and visible as a thin walledring with a transparent center.3.2.3 projected equivalent particle diameter, nthe diam-eter calculated from the projected area o fa partic
10、le if that areaformed a circle, and in equation form isProjected Equivalent Particle Diameter D!5SQRTArea/ 4!5=Area/0.785!3.2.4 projected equivalent particle volume (VD), ntheparticle volume based on the projected equivalent particlediameter, and in equation form isProjected Equivalent Particle Volu
11、me VD! 5 D36 (1)3.2.5 volume fraction, nthe fraction of the total volume ofparticles measured which are below a given percent, and aredenoted as follows:3.2.5.1 Dv10the projected equivalent diameter belowwhich 10 % of the total volume of all particles analyzed isrepresented.3.2.5.2 Dv50the projected
12、 equivalent diameter belowwhich 50 % of the total volume of all particles analyzed isrepresented.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.24 on Physical Properties o
13、f Liquid Paints and Paint Materials.Current edition approved June 1, 2017. Published July 2017. DOI: 10.1520/D8090-17.2For 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 t
14、o the standards Document Summary page onthe ASTM website.3Available from National Institute of Standards and Technology (NIST), 100Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http:/www.nist.gov.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
15、. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Ba
16、rriers to Trade (TBT) Committee.13.2.5.3 Dv90the projected equivalent diameter belowwhich 90 % of the total volume of all particles analyzed isrepresented.4. Summary of Test Method4.1 Test specimen are fed through the dynamic imaginginstrument which is comprised of a camera sensor and illumi-nation
17、source opposing each other to form a measurement zonewhere the fluid image is captured and then analyzed for particlesize and distribution. The particle size and size distributionvalues are based on the projected equivalent particle diameter.Shape parameters can be used to identify air bubbles that
18、maybe present and eliminate them from the reported data. Otherappropriate parameters may be used as well. Likewise forundiluted paints (for example clear paints), shape parameterscan be used to eliminate air bubbles and water droplets thatmay be present from the reported data. Shape parameterformula
19、tions may differ from instrument to instrument.5. Significance and Use5.1 By following this test method, the particle size, particlesize distribution and particle shape of particulates in liquidpaint and pigment dispersions can be measured.5.2 Particle size, particle size distribution and particle s
20、hapehave a great effect on the color, opacity and gloss of paints.Reproducing these characteristics is critical to the quality andperformance of the paint produced.5.3 The dynamic imaging instrument is useful during manu-facturing to detect oversize particles as well as the required sizedistribution
21、 of particles in order to provide quality and consis-tency from batch to batch.6. Interferences6.1 Contaminated environmental conditions and poor han-dling techniques can easily contaminate the sample. Care mustbe taken to ensure test results are not biased by introducedparticles.6.2 High concentrat
22、ions of air bubbles, resulting fromviolent agitation, should be avoided. The software is designedto detect and eliminate them from the data, however highconcentrations can mask other particles.6.3 Steps should be taken to prevent the introduction ofwater into the paint. In undiluted paints, water dr
23、oplets can bedetected and counted as particles giving false positive readings.The software is designed to identify free water droplets andeliminate them from the data.6.4 Samples may be diluted with an appropriate diluent perthe instruments manufacturers instructions. This situationmay arise due to
24、high viscosity levels or high concentrations ofparticles, droplets and bubbles present in the view which maycause reporting errors. The software shall provide an alarm orerror message if particle populations are too high for theinstrument to accurately measure particle size, particle sizedistributio
25、n or particle shape.7. Apparatus7.1 Dynamic Imaging Particle Analyzer, a particle counter,shape and size measuring instrument consisting of a flowthrough cell, an image capture device, means of illuminationand software and readout capabilities. Fig. 1 shows a typicalgravity feed system.7.2 Paint Sha
26、kerany device manufactured to agitate andmix paints in their containers.7.3 Instrument Stand.7.4 Reservoirto contain and mix paint in diluted orundiluted state. Holds up to two litres (2 L) of volume.7.5 Agitatorto mix contents of reservoir. Should be ca-pable of mixing paints with viscosities up to
27、 1 kg/m s.7.6 Inlet/Outlet Lines w/full flow shut off valves.7.7 Drain Line.Alternate Configurations7.8 Injection Pumpa dilution fluid supply can be plumbedin at the location of the upstream shut off valve and used as acounter flow to dilute and mix the paint in the reservoir.Controlling the flow of
28、 diluent dictates the degree of dilution ofthe specimen that flows through the instrument.7.9 Syringe Pumpwhere smaller sample volumes can beeffectively analyzed due to transparency of the paint a syringecan be used to sample the paint and a syringe pump can be usedto propel it through the instrumen
29、t.7.10 Luer-Lok Syringea sterile syringe that can be easilyand quickly connected into the feed line to the instrument.7.11 These alternate configurations can be reviewed inAnnex A1.8. Reagents and Materials8.1 Reticle, traceable to NIST or other widely recognizedstandards body. A 19 mm diameter reti
30、cle with 100 m gridsand 10 m subdivisions has been found to work well for use incalibrating instruments, however various size reticles may beused as appropriate for the particular manufacturers instru-ment.FIG. 1 Example Arrangement of a Flow CellD8090 1728.2 Solvent, preferably a fast drying reagen
31、t, filtered to 0.45micron and compatible with the particular paints being tested.For oil based paints mineral spirit has been found to work wellfor dilution and cleaning. For water based paints water hasbeen found to work well for dilution and cleaning. Othercommon solvents may be used.8.3 Mono-Disp
32、erse Bead Standard, vendor certified to be95% spherical and a coefficient of variance 10%. Ten micron(10 m) have been found to work well, however other sizesmay also be used.8.4 NIST SRM 1982, or similar particle size distributionstandard traceable to NIST or similar widely known body.9. Sample Coll
33、ection and Handling9.1 Refer to Practice D3925 for proper sampling of paintand pigmented coatings for analysis.9.2 Sample containers should be clearly marked identifyingtheir contents at a minimum.9.3 Sample volume should be per instrument manufactur-ers instructions. If particle concentration is to
34、o high (see 6.4)the specimen may be diluted using an appropriate diluentfiltered to 0.45 m to remove contaminants.10. Preparing the Instrument10.1 Clean the instrument with a compatible solvent, fil-tered to 0.45 m, by flushing the solvent through the instrumentunder normal operating conditions. As
35、solvent passes throughthe instrument measure it for particle content. Continue to flushwith fresh solvent until the particle count per mLof the solvent,as measured by the instrument, is well below normal particu-late levels for the paint to be tested.11. Calibration and Verification11.1 Calibration1
36、1.1.1 Instruments must be calibrated by use of a reticletraceable to NIST or other similar standard body (see 8.1). If adifference to the nominal size of particle size standard isrecognized the instrument should be recalibrated. Calibrationshall be performed per the instruments manufacturers instruc
37、-tions at least every 12 months.11.2 Verification11.2.1 Instrument calibration for size shall be verified atleast every 12 months using mono-disperse beads to check (see8.3). The standard may be diluted with water, or otherappropriate diluent (see 8.2), filtered to 0.45 m, to create a testspecimen o
38、f the correct volume for the instrument. Flow thespecimen through the instrument analyzing particle size for therecommended number of frames for analysis per the manufac-turers instructions. Result of mean particle size analysis mustbe within 3% of the particle size standards manufacturerscertified
39、mean value plus its standard deviation. Verificationshall be performed at least every 12 months.11.2.2 Verification of the distribution shall be done at leastevery 12 months. To verify wide size distributions of particlesin paints (wider than 1/1.2) a poly-dispersed standard, or socalled “picket fen
40、ce distribution standard,” must be used. It isa mixture of different particle sizes and has several mono-dispersed particle sizes combined. NIST SRM 1982 (Sec. 8.4)or other similar standard traceable to NIST or similar widelyknown body is acceptable. The standard may be diluted withwater, or other a
41、ppropriate diluent, filtered to 0.45 m, to createa test specimen of the correct volume and concentration for theinstrument. Flow the specimen through the instrument analyz-ing particle size for the recommended number of frames foranalysis per the manufacturers instructions. The instrumentmust detect
42、 the standard manufacturers certified percent pass-ing particle size values within 3%, or 3 m, plus the standardmanufacturers stated standard deviations of those size values.If not check the validity of the standard used and try again. Ifverification fails consult the instrument manufacturers instru
43、c-tion manual. Recalibration may be required.12. Procedure12.1 Diluted Sample12.1.1 Ensure the instrument is set up as indicated in themanufacturers instructions.12.1.2 For paints in original containers or other similarshipping containers, agitate them in those containers using apaint shaker (see 7.
44、2). If opening the container to mechanicallymix, use caution not to introduce contamination or air bubblesto the paint. Follow paint manufacturers instructions onmixing.12.1.3 Withdraw two test specimens from the container, onefrom the bottom half and the other from the top half, into two,non-reacti
45、ve specimen syringes of approximately 5 mL vol-ume. Testing has found that 1 mL of paint in 1 L of solvent issufficient dilution for most paints, however other dilution ratiosmay be used. Reference the manufacturers instructions.12.1.3.1 Inject the first specimen into the reservoir filledwith 1 L of
46、 clean solvent, agitate for 30 seconds and then flowthrough the instrument taking two consecutive data sets.Reference manufacturers instruction for appropriate numberof frames per data set. Calculate the mean particle size byvolume, Dv50, and particle size distribution for both. Rinse thereservoir a
47、nd instrument with clean solvent and repeat with thesecond specimen. If the Dv50 values of the data sets for eachspecimen are within 10% or 5 m, whichever is larger, thenaverage the results of the data sets for each specimen tocalculate the average Dv50 values.12.1.3.2 If then the average Dv50 value
48、s between the topand bottom half specimen are within 10% or 5 m, thenaverage them together to obtain the average Dv50 value for thepaint. Also record the Dv10 and Dv90 values for reporting atminimum. If the Dv50 values are not within 10% or 5 m mixthe sample again and repeat the procedure.12.2 Undil
49、uted Sample12.2.1 Undiluted samples may also be analyzed if the paintis transparent enough. Follow the same procedure as in 12.1.13. Report13.1 The report should include the following information:13.1.1 A reference to this test method,13.1.2 Sample identification,D8090 17313.1.3 Particle size distribution by volume reporting atminimum Dv10, Dv50, and Dv90, and13.1.4 Any deviations from this method.14. Precision and Bias14.1 An interlaboratory study has yet to be concluded. Atemporary statement of repeatability is demonstra
