1、Designation: D7481 18Standard Test Methods forDetermining Loose and Tapped Bulk Densities of Powdersusing a Graduated Cylinder1This standard is issued under the fixed designation D7481; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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. Scope*1.1 This test method covers the apparatus and proceduresfor determining the bulk densities of free flowing
3、 and moder-ately cohesive powders and granular materials up to 3.5 mm insize in their loose (Method A) and tapped (Method B) states.1.2 This test method should be performed in a laboratoryunder controlled conditions of temperature and humidity.1.3 This test method is similar to those of Test Methods
4、B212, B329, B417, D29, and D2854.1.4 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.4.1 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as theindustry stan
5、dard. In addition they are representative of thesignificant digits that generally should be retained. The proce-dures used do not consider material variations, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincreas
6、e or reduce significant digits of reported data to becommensurate with these considerations. It is beyond the scopeof this standard to consider significant digits used in analysismethods for engineering design.1.5 The values stated in SI units are to be regarded asstandard. No other units of measure
7、ment are included in thisstandard.1.6 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, health, and environmental practices and deter-mine the applicability of r
8、egulatory limitations prior to use.1.7 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-mendations issued by the World Trad
9、e Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B212 Test Method for Apparent Density of Free-FlowingMetal Powders Using the Hall Flowmeter FunnelB329 Test Method for Apparent Density of Metal Powdersand Compounds Using the Scott VolumeterB417 Tes
10、t Method for Apparent Density of Non-Free-Flowing Metal Powders Using the Carney FunnelB527 Test Method for Tap Density of Metal Powders andCompoundsC29/C29M Test Method for Bulk Density (“Unit Weight”)and Voids in AggregateD29 Test Methods for Sampling and Testing Lac Resins(Withdrawn 2005)3D653 Te
11、rminology Relating to Soil, Rock, and ContainedFluidsD2216 Test Methods for Laboratory Determination of Water(Moisture) Content of Soil and Rock by MassD2854 Test Method for Apparent Density of ActivatedCarbonD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of
12、 Soil and Rock asUsed in Engineering Design and ConstructionD4164 Test Method for Mechanically Tapped Packing Den-sity of Formed Catalyst and Catalyst CarriersD4753 Guide for Evaluating, Selecting, and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD
13、6026 Practice for Using Significant Digits in GeotechnicalDataD6683 Test Method for Measuring Bulk Density Values ofPowders and Other Bulk Solids as Function of Compres-sive Stress1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Sub
14、committee D18.24 on Characterizationand Handling of Powders and Bulk Solids.Current edition approved June 1, 2018. Published July 2018. Last previousedition approved in 2009 as D7481 - 09, which was withdrawn January 2018 andreinstated in June 2018. DOI: 10.1520/D7481-18.2For referenced ASTM standar
15、ds, 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 Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Su
16、mmary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization establish
17、ed in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1E11 Specification for Woven Wire Test Sieve Cloth and TestSieves3. Terminology3.1 Definitions:3.1.1 For commo
18、n definitions of technical terms in thisstandard, refer to Terminology D653.4. Summary of Test Method4.1 Loose bulk density (Method A) is determined by mea-suring the volume of a known mass of powder that has beenpassed through a screen or funnel into a graduated cylinder.4.2 Tapped bulk density (Me
19、thod B) is achieved by me-chanically tapping a measuring cylinder containing a powder.After observing the initial volume, the cylinder is mechanicallytapped, and volume readings are taken until little furthervolume change is observed.5. Significance and Use5.1 The data from the loose bulk density te
20、st can be used toestimate the size of bags, totes, small bins or hoppers for thestorage of a fixed mass of powder in its loose condition. It canalso be used to estimate the mass of powder that will fit insmall size containers such as drums. It cannot be used toestimate powder quantities of large ves
21、sels such as silos.5.2 Values of loose bulk density obtained using this testmethod should be used with caution, since they can varyconsiderably depending on the inital state of dispersion of thetest specimen, height-to-diameter ratio of specimen in gradu-ated cylinder, dryness of powder, and other f
22、actors.5.3 The data from the tapped bulk density test can be usedto estimate the needed volume of small containers holding afixed mass of powder that has been compacted. An examplewould be a packing line where vibration is used to tamppowders into a small container for effective packing purposes.5.4
23、 Bulk density values can vary significantly if the particlesize of the actual material to be handled is different than tested.A bulk solid consisting of large and small particles often hashigher bulk densities than the fine particles by themselves. Forpowders, lower densities are possible if the fin
24、e particles arefluidized or aerated.5.5 The results of this test method are most applicable tocontainers with volumes up to about one cubic meter. Anothermethod (such as D6683) should be used when consideringlarger silos.NOTE 1The quality of the results produced by this standard isdependent on the c
25、ompetence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Pra
26、ctice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors. Practice D3740 wasdeveloped for agencies engaged in the testing or inspection (or both) ofsoil and rock. As such it is not totally appli
27、cable to agencies performingthis standard. However, users of this standard should recognize that theframework of Practice D3740 is appropriate for evaluating the quality ofan agency performing this standard. Currently there is no known quali-fying national authority that inspects agencies that perfo
28、rm this standard.6. Apparatus6.1 Balance having a minimum capacity of 400 g andmeeting the requirements of Guide D4753 for a balance of 0.1g readability.6.2 250 mL or 100 mL standard glass graduated cylinder.See 7.3.6.3 Two screens: 1.7 mm (No. 12 U.S. sieve), 4.00 mm (No.5 U.S. sieve). Each screen
29、should be full height and 200 mm (8in.) diameter (see Specification E11).6.4 Suitable mechanical tapped density tester that provides afixed drop of 14 6 2 mm at a nominal rate of 300 drops perminute or a fixed drop of 3 mm 6 0.2 mm at a nominal rate of250 drops per minute. A typical tester is shown
30、in Fig. 1.7. Preparation of Apparatus7.1 Check that the balance is set on a sturdy table or bench,leveled and zeroed.7.2 Make sure that the graduated cylinder is clean of anyand all foreign material (including water or other liquids) priorto starting each test.7.3 Depending on the untapped apparent
31、volume of the testspecimen and its particle size gradation, choose either a 250mLor 100 mLstandard glass graduated cylinder using the tablebelow.Graduatedcylindersize, mLUntapped apparent volumeof test specimen, mLUpper limit onparticle size, mmMin. Max. d50Absolutemax.100 50 100 1.3 2.5250 150 250
32、1.7 3.58. Procedure8.1 Loose Bulk Density (Method A):8.1.1 Determine and record the mass of the graduatedcylinder to the nearest 0.1 g.8.1.2 Choose an appropriate dispersion method to ensurethat the material hasnt agglomerated from transit. If this test isbeing conducted on a fine powder with partic
33、les much smallerthan 1 mm, pass a sufficient quantity though a 1.00 mm (18mesh) screen to break up agglomerates that may have formedduring storage. Oversized particles should not be excludedfrom the test. Should any particles not pass through the screen,an alternate dispersion method is required, su
34、ch as selecting ascreen slightly larger than the largest particle to pass thematerial through, or stirring the material in a mixing bowl witha spatula. Maximum limits on particle size for this test areprovided in 7.3. Avoid agglomeration and segregation ofmaterial. Describe method used on Test Data
35、Sheet.8.1.3 If necessary, carefully level the powder withoutcompacting, and read the unsettled apparent volume to thenearest graduated unit. Determine and record the volume of thepowder in the cylinder to the nearest graduated unit; that is, 1mL for the 100-mL cylinder and 2 mL for the 250-mL cylind
36、er,noting that 1 mL is equal to 1 cm3.D7481 1828.1.4 An alternate method would be to fill a 250-mL or100-mL cylinder to a measured volume line.8.1.5 Determine and record the mass of the specimen plusgraduated cylinder to the nearest 0.1 g.8.2 Tapped Bulk Density (Method B):8.2.1 Repeat steps 8.1.1 t
37、hrough 8.1.5.8.2.2 Mechanically tap the cylinder containing the powderspecimen by raising the cylinder and allowing it to drop underits own mass using a suitable mechanical tapped density testerthat provides a fixed drop of 14 6 2 mm at a nominal rate of300 drops per minute. This is Method B1.8.2.3
38、An alternate method (Method B2) is to use a fixeddrop of 3 mm 6 0.2 mm at a nominal rate of 250 drops perminute. This may yield lower values of tapped bulk density.8.2.4 Unless otherwise specified, tap the cylinder 500 timesinitially and measure the tapped volume to the nearest gradu-ated unit. Dete
39、rmine and record the volume of the powder inthe cylinder to the nearest graduated unit; that is, 1 mL for the100-mL cylinder and 2 mL for the 250-mL cylinder, noting that1 mL is equal to 1 cm3.8.2.5 If necessary, carefully level the powder withoutcompacting, and read the settled apparent volume to t
40、he nearestgraduated unit.8.2.6 Repeat the tapping an additional 750 times and mea-sure the tapped volume to the nearest graduated unit.NOTE 2Fewer taps may be appropriate, if validated, for somepowders.8.2.7 If the difference of the two tapped volumes of 8.2.3and 8.2.5 is less than 2 %, use the seco
41、nd measurement for thetapped volume. Otherwise, repeat in increments of 1250 taps,as needed, until the difference between succeeding measure-ments is less than 2 %.9. Calculations9.1 Loose Bulk Density (Method A):9.1.1 Determine the net mass of the specimen by subtractingthe mass of the graduated cy
42、linder from that of the specimenplus graduated cylinder.9.1.2 Divide the net mass of the specimen by the measuredvolume as noted on the graduated cylinder. The calculatedvalue is the loose bulk density in g/cm3. Record value to twosignificant digits if 100-mL cylinder is used, and three signifi-cant
43、 digits if 250-mL cylinder is used.9.2 Tapped Bulk Density (Method B):9.2.1 Divide the net mass of the specimen by the measuredvolume as noted on the graduated cylinder after tapping iscomplete. The calculated value is the tapped bulk density ing/cm3. Record value to two significant digits if 100-mL
44、cylinder is used, and three significant digits if 250-mL cylinderis used.FIG. 1 Typical Mechanical Tapped Density TesterD7481 18310. Report: Test Data Sheet(s)/Form(s)10.1 The methodology used to specify how data are re-corded on the test data sheet(s)/form(s), as given below, iscovered in 1.4.10.2
45、Record as a minimum the following general informa-tion (data):10.2.1 Requesting agency or client and/or identifying num-ber for job or project10.2.2 Technician name or initials, and10.2.3 Date test was run.10.3 Record the following test specimen information (data):10.3.1 Generic name of powder teste
46、d,10.3.2 Chemical name of sample, if known,10.3.3 Specimen moisture (water) content, if determined tonearest 0.1 %. Indicate method used to determine moisture ifnot Test Method D2216,10.3.4 Temperature of specimen, to the nearest 1C,10.3.5 Specimen particle size, if determined. Indicate pro-cedure u
47、sed, which may have been specified by requestingagency or client, and10.3.6 Method used to prepare test specimen in a loose state(Section 8.1.2).10.4 Record as a minimum the following test data:10.4.1 Volume of graduated cylinder,10.4.2 Mass of graduated cylinder empty (tare),10.4.3 Mass of graduate
48、d cylinder filled with material,10.4.4 Volume of loose filled specimen in graduatedcylinder,10.4.5 Mass of specimen plus graduated cylinder,10.4.6 Calculated net mass of specimen,10.4.7 Calculated loose bulk density,10.4.8 Fixed drop during tapped bulk density (Method B1or B2),10.4.9 Rate of drops p
49、er minute during tapped bulk density,10.4.10 Number of taps and corresponding values of cylin-der volume,10.4.11 Calculated tapped bulk density, and10.4.12 Name and model of tapped density tester used.11. Precision and Bias11.1 PrecisionTest data on precision is not presented dueto the nature of the powder and other bulk solids tested by thisstandard. It is not feasible or too costly at this time to have tenor more laboratories participate in a round-robin testing pro-gram. In addition, it is either not feasible or too costly toproduce multiple specimens that have uniform phys
