ASTM_F_577_-_03_2009.pdf

Designation:F57703(Reapproved 2009)Standard Test Method forParticle Size Measurement of Dry Toners1This standard is issued under the fixed designation F577;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers aperture particle size analysisusing an electronic sensing zone apparatus provided with adigital pulse processor.Dry inks,toners,and so forth,arecovered.Particles as small as 1 m and as large as 120 m canbe analyzed.1.2 The values stated in SI units are to be 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 determine the applica-bility of regulatory limitations prior to use.2.Terminology2.1 Definitions of Terms Specific to This Standard:2.1.1 channela size subgroup that has been obtained bydividing the range of the analysis into a certain number of sizecategories.The resolution of the analysis is increased when thenumber of channels is increased.2.1.2 dynamic rangethe ratio between the upper andlower limit of an analysis.2.1.3 number size distributionthe number size distributionis measured and may be represented in a number percent curveas differential,cumulative larger than or cumulative smallerthan.(Figs.1-3).2.1.4 pulse(man height average)by sequencethe maxpulse height average is calculated from the pulses generatedduring the anaylsis(Fig.4).2.1.5 median particle sizethe median size(50%oversizeor undersize)is a convenient value for the central tendency ofa size distribution curve.For a distribution derived by numberof particles,it is called the number median size.2.1.6 volume size distributionthe volume size distributionis calculated by the instruments software and may be repre-sented in a volume percent curve as differential,cumulativelarger than or,cumulative smaller than.(Figs.5-7).3.Summary of Test Method3.1 This technique(1)2determines the number and size ofparticles suspended in an electrolyte by causing them to flowthrough a small orifice on both sides of which are immersedelectrodes.Voltage pulses,whose amplitudes are proportionalto the particle volumes,are generated by changes in resistanceas the particles pass through the orifice.The signal generated isscanned,digitized and integrated in pulses.These pulses areprocessed yielding size and pulse distributions.The pulse datais saved and may be reprocessed at a later time for a differentanalysis range or resolution.3.2 This test method covers the size range from 2%to 60%of the aperture diameter chosen as being appropriate to theexpected particle size range.Aperture Diameter,mParticle Size Range,m501 to 30701.4 to 421002.0 to 601402.8 to 842004 to 200For broader size ranges two aperture tubes may be used andboth results are combined by the instruments software into asingle size distribution.4.Significance and Use4.1 This test is useful in determining particle size charac-teristics of dry toners used in electrostatic imaging devicessuch as copiers and laser printers.It is a practiced method foruse in quality control of toner particle size.5.Apparatus5.1 Electrical Sensing Zone Instrumentation(2),equippedwith a minimum capability of 256 size channels,a digital pulseprocessor and 50,70,100,140,or 200-m aperture tubes.5.2 Software,capable of processing the pulse data to yieldsize distribution graphs and statistics.5.3 Ultrasonic Dispersing Probe,or alternative equipmentsuitable for dispersing the dry toner in an aqueous electrolyte.1This test method is under the jurisdiction ofASTM Committee F05 on BusinessImaging Products and is the direct responsibility of Subcommittee F05.04 onElectrostatic Imaging Products.Current edition approved Feb.1,2009.Published February 2009.Originallyapproved in 1978.Last previous edition approved in 2003 as F577 031.DOI:10.1520/F0577-03R09.2The boldface numbers in parentheses refer to the list of references at the end ofthe test method.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Reagents and Materials6.1 Electrolyte4 weight%aqueous sodium pyrophos-phate or 1 weight%sodium chloride.The electrolyte shall beadequately filtered to remove almost all particle contaminantsgreater than 1 m.Some aqueous electrolytes are commerciallyavailable.6.2 Surfactanta nonionic surface active agent suitable forkeeping toner particles separated while in suspension.6.3 Near monosized spherical particles standardized for thenumber%modal size as calibration standards.37.Sampling7.1 Sample the powder when flowing(1).3The standardized particles are usually available from