1、Designation: D1921 061Standard Test Methods forParticle Size (Sieve Analysis) of Plastic Materials1This standard is issued under the fixed designation D1921; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision
2、. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1NOTEAdded research report information to Section 17 editorial
3、ly in September 2010.1. Scope*1.1 These test methods cover the measurement of theparticle size of plastic materials in the powdered, granular, orpelleted forms in which they are commonly supplied. As thesetest methods utilize dry sieving, the lower limit of measure-ment is considered to be about 38
4、m (No. 400 sieve). Forsmaller particle sizes, sedimentation test methods are recom-mended.1.2 Two test methods are described:1.2.1 Test Method AThis test method uses multiple sievesselected to span the particle size of the material. This methodis used to determine the mean particle diameter and part
5、iclesize distribution.1.2.2 Test Method BThis test method is an abbreviatedversion of Test Method A conducted with a few specific sieves.This test method determines “percent passing” or “percentretained” on a given sieve. Test Method B is applicable tomaterials which do not have a normal particle si
6、ze distributionsuch as pellets and cubes.1.3 The values stated in SI units shall be consideredstandard for dimensions of the wire cloth openings and thediameter of the wires used in the wire cloth. The values statedin inch-pound units shall be considered standard with regard tothe sieve frames.1.4 T
7、his 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.NOTE 1There is no te
8、chnically equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2E11 Specification for Woven Wire Test Sieve Cloth and TestSievesE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3. Summary of Test Methods3.1 A dry mass of plastic material is
9、 placed on a series ofsieves arranged in order of increasing fineness and the mass isdivided into fractions corresponding to the sieve opening.4. Significance and Use4.1 These test methods can be used to determine particlesize distribution and therefore are useful for determininglot-to-lot uniformit
10、y.4.2 The particle sizes of plastic materials affect the handlingcharacteristics and sometimes will affect the processing char-acteristics of some polymers.5. Interferences5.1 Some materials develop a static charge during sieving.This charge interferes with the sieving process and results in acoarse
11、 bias. Use of an antistat is necessary to obtain meaning-ful results.5.2 The choice of antistat (or slip agent) has been known toaffect the coarse bias. Some materials are more effective inaiding the fines to separate from the mass.5.3 Too much material on a sieve causes mass blinding andresults in
12、a coarse bias. The sieve selection and charge weightmust be chosen to avoid overloading any sieve.1These test methods are under the jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.70 on AnalyticalMethods (Section D20.70.01).Current edition approved
13、 April 1, 2006. Published June 2006. Originallyapproved in 1961. Last previous edition approved in 2001 as D1921 - 01. DOI:10.1520/D1921-06E01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vo
14、lume information, refer to the standards Document Summary page onthe ASTM website.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.5.4 Wavy, improperly stretched wire-c
15、loth may allow wiresto separate without being visually damaged. Sieves with wavyor torn wires shall not be used, as they no longer conform toSpecification E11.6. Apparatus6.1 Balance, 500-g minimum capacity with the capability ofreading to the nearest 0.1 g.6.2 Mechanical Sieving Device and Time Swi
16、tchA me-chanical sieve-shaking device equipped with an automatic timeswitch. This device shall be capable of imparting uniformrotary motion and a tapping action at a rate of 150 6 10taps/min.6.3 Wire Cloth Sieves, woven wire cloth conforming toSpecification E11, as shown in Table 1, mounted in 8-in.
17、203-mm frames. The number of sieves and the choice of sizesshall be selected for the material being tested. A cover and abottom pan are also required.6.4 Accessories for Cleaning the Screens:6.4.1 Brush3,6.4.2 Vacuum Cleaner, and6.4.3 Air Hose.7. Reagents and Materials7.1 Antistat (or slip) agent su
18、itable to the material beingtested.8. Hazards8.1 The sieving operation and cleaning of the sieves some-times introduce fine plastic particles and antistat agent into theatmosphere. Take precautions to avoid breathing these par-ticles.9. Sampling9.1 Homogenize the lot where possible before removing t
19、hetest sample to avoid segregation of particles during handling.10. Preparation of Apparatus10.1 Thorough cleaning and inspection of the sieve arerequired prior to initiating a test. Carefully clean the sieveswith a brush and vacuum cleaner or compressed air, or both.Periodic washing with soap and w
20、ater or suitable solvent isrecommended with some materials.10.2 Tare each sieve and the pan. Record tare weights to thenearest 0.1 g.10.3 Assemble sieves so that the sieve openings decrease insize in sequence from the top of the stack. Place the pan at thebottom.10.4 Use full- or half-size screens t
21、o accommodate theholder in the shaker.11. Conditioning11.1 The plastic material must be in a free-flowing condi-tion.11.2 If possible, condition the material to the laboratorytemperature and humidity.TEST METHOD A12. Procedure12.1 Select sieves in sufficient number to cover the expectedrange of part
22、icle sizes, and nest them together in order ofdiminishing opening with the coarsest sieve on top and the panon the bottom.12.2 Select sieves in sufficient number to have significantmeasurable quantities on four or more sieves. Weigh the sieveson a balance reading to the nearest 0.1 g. Record these s
23、ievemasses as their tare masses, respectively.12.3 Weigh 50 g of sample to the nearest 0.1 g and transferit to the top of the stack. Record the sample weight used. Largesample size causes screen blinding and will skew the results tothe coarse particle size. A screen is considered blinded if it ishol
24、ding 20 or more g. For repeatable results, use a smallersample size.NOTE 2For some materials an antistat (or slip agent) is needed. Add1 % of the antistat (or slip agent) to the sample and mix in with a spatula.With polyvinyl chloride resins, it has been found that the distribution willskew to eithe
25、r the fine or the coarse particle size depending on the antistatused. Record the antistat (or slip agent) used.12.4 Cover the stack and place it in the mechanical sieveshaker. Start the shaker and run for 10 min. Run the shaker fora longer time if it is required by the material and the efficiencyof
26、the shaker.12.5 After shaking, carefully separate the stack of sieves,beginning at the top, and weigh each sieve with powder to thenearest 0.1 g. Determine the net weight of the powderremaining in each sieve by subtracting the sieve tare massesfrom the total weight of the sieve and the powder in tha
27、t sieve.12.6 If the cumulative total of actual weight is less than98 %, carefully check the weights and operations and repeatthe work if necessary.13. Analysis of Particle Distribution13.1 Calculation of Particle Distribution:13.1.1 Obtain net weight of material retained on each sieve.Calculate perc
28、entage by dividing net weight by total sampleweight 3 100.13.1.2 Repeat for each sieve.13.2 Calculation of Mean Particle Size:13.2.1 Obtain net weight of material retained on each sieve.13.2.2 Determine an average particle size for each sieve.The average particle size is defined as the nominal openi
29、ng sizeof that sieve plus the nominal opening size of the next largersieve in the stack divided by two.NOTE 3Options are recommended to determine the average mesh sizeof the top sieve and the pan. On the coarse end, if the particles havealready been through a coarser screen, the screen size of the “
30、throughscreen” can be used as the upper limit of the top screen (first screen). Acommonly used method is to place a set of sieves with openings greaterthan the desired top sieve. Select the lowest sieve where there is noparticle on or the amount of particles on the sieve is insignificant. Use theope
31、ning size of this sieve for calculation. Similar analog can be used to thepan by using smaller opening sieves. A more practical way is to divide the3The sole source of supply of the Type 8577 (W. S. Tyler) Brush known to thecommittee at this time is W. S. Tyler, Inc., 8750 Tyler Blvd., Mentor, OH 44
32、060. Ifyou are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.D1921 0612TABLE 1 Nominal Dimensions, Permissible Variations for
33、 Wire Cloth of Standard Test Sieves (U.S.A.) Standard SeriesSieve DesignationNominal SieveOpening, in.APermissibleVariation ofAverage Openingfrom the StandardSieve DesignationOpening DimensionExceeded By NotMore Than 5 % ofthe OpeningsMaximumIndividual OpeningNominal WireDiameter, mmBStandardCAltern
34、ative(1) (2) (3) (4) (5) (6) (7)125 mm 5 in. 5 63.70 mm 130.0 mm 130.9 mm 8.00106 mm 4.24 in. 4.24 63.20 mm 110.2 mm 111.1 mm 6.30100 mmD4in.D4 63.00 mm 104.0 mm 104.8 mm 6.3090 mm 312 in. 3.5 62.70 mm 93.6 mm 94.4 mm 6.3075 mm 3 in. 3 62.20 mm 78.1 mm 78.7 mm 6.3063 mm 212 in. 2.5 61.90 mm 65.6 mm
35、66.2 mm 5.8053 mm 2.12 in. 2.12 61.60 mm 55.2 mm 55.7 mm 5.0050 mmD2in.D2 61.50 mm 52.1 mm 52.6 mm 5.0045 mm 134 in. 1.75 61.40 mm 46.9 mm 47.4 mm 4.5037.5 mm 112 in. 1.5 61.10 mm 39.1 mm 39.5 mm 4.5031.5 mm 114 in. 1.25 61.00 mm 32.9 mm 33.2 mm 4.0026.5 mm 1.06 in. 1.06 6800 mm 27.7 mm 28.0 mm 3.55
36、25.0 mmD1.00 in.D1 6800 mm 26.1 mm 26.4 mm 3.5522.4 mm78 in. 0.875 6700 mm 23.4 mm 23.7 mm 3.5619.0 mm34 in. 0.750 6600 mm 19.9 mm 20.1 mm 3.1516.0 mm58 in. 0.625 6500 mm 16.7 mm 17.0 mm 3.1513.2 mm 0.530 in. 0.530 6410 mm 13.83 mm 14.05 mm 2.8012.5 mmD 12 in.D0.500 6390 mm 13.10 mm 13.31 mm 2.5011.
37、2 mm716 in. 0.438 6350 mm 11.75 mm 11.94 mm 2.509.5 mm38 in. 0.375 6300 mm 9.97 mm 10.16 mm 2.248.0 mm516 in. 0.312 6250 mm 8.41 mm 8.58 mm 2.006.7 mm 0.265 in. 0.265 6210 mm 7.05 mm 7.20 mm 1.806.3 mmD 14 in.D0.250 6200 mm 6.64 mm 6.78 mm 1.805.6 mm No. 312E0.223 6180 mm 5.90 mm 6.04 mm 1.604.75 mm
38、 No. 4 0.187 6.150 mm 5.02 mm 5.14 mm 1.604.00 mm No. 5 0.157 6.130 mm 4.23 mm 4.35 mm 1.403.35 mm No. 6 0.132 6.110 mm 3.55 mm 3.66 mm 1.252.80 mm No. 7 0.110 6.095 mm 2.975 mm 3.070 mm 1.122.36 mm No. 8 0.0937 6.080 mm 2.515 mm 2.800 mm 1.002.00 mm No. 10 0.0787 6.070 mm 2.135 mm 2.215 mm 0.9001.7
39、 mm No. 12 0.0661 6.060 mm 1.820 mm 1.890 mm 0.8001.4 mm No. 14 0.0556 6.050 mm 1.505 mm 1.565 mm 0.7101.18 mm No. 16 0.0469 6.045 mm 1.270 mm 1.330 mm 0.8301.00 mm No. 18 0.0394 6.040 mm 1.080 mm 1.135 mm 0.560850 mFNo. 20 0.0331 635 m 925 m 970 m 0.500710 m No. 25 0.0278 630 m 775 m 815 m 0.450600
40、 m No. 30 0.0234 625 m 660 m 695 m 0.400500 m No. 35 0.0197 620 m 550 m 585 m 0.315425 m No. 40 0.0165 619 m 471 m 502 m 0.280355 m No. 45 0.0139 616 m 396 m 426 m 0.224300 m No. 50 0.0117 614 m 337 m 363 m 0.200250 m No. 60 0.0098 612 m 283 m 306 m 0.160212 m No. 70 0.0083 610 m 242 m 263 m 0.14018
41、0 m No. 80 0.0070 69 m 207 m 227 m 0.125150 m No. 100 0.0059 68 m 174 m 192 m 0.100125 m No. 120 0.0049 67 m 147 m 163 m 0.090106 m No. 140 0.0041 66 m 126 m 141 m 0.07190 m No. 170 0.0035 65 m 108 m 122 m 0.06375 m No. 200 0.0029 65 m 91 m 103 m 0.05063 m No. 230 0.0025 64m 77m 89m 0.04553 m No. 27
42、0 0.0021 64m 66m 76m 0.03645 m No. 325 0.0017 63m 57m 66m 0.03238 m No. 400 0.0015 63m 48m 57m 0.03032 m No. 450 0.0012 63m 42m 50m 0.02825 mDNo. 500 0.0010 63m 34m 41m 0.02520 mDNo. 635 0.0008 63m 29m 35m 0.020AOnly approximately equivalent to the metric values in Column 1.BThe average diameter of
43、the wires in the x and y direction, measured separately, of any wire cloth shall not deviate from the nominal values by more than 615 %.CThese standard designations correspond to the values for test sieve openings recommended by the International Standards Organization, Geneva, Switzerland, exceptwh
44、ere noted.DThese sieves are not in the standard series, but they have been included because they are in common usage.EThese numbers (312 to 635) are the approximate number of openings per linear inch, but it is preferred that the sieve be identified by the standard designation inmillimetres or micro
45、metres.F1000 m1 mm.D1921 0613opening size of the sieve above the pan by two and use it as the averageparticle size of the pan.13.2.3 For materials that have a normal distribution, calcu-late the mean particle size asDm5 (Pi3 Di!where:Dm= mean particle diameter, m,Pi= material retained on sieve (or p
46、an), %, andDi= average particle size of material on sieve, m.14. Report14.1 Report the following information:14.1.1 Percentage of material retained on each sieve, withits corresponding sieve size,14.1.2 Sample weight,14.1.3 Antistat (or slip agent) used, and14.1.4 Mean particle size and method used
47、for calculation.TEST METHOD B15. Procedure15.1 Choose the sieve(s) to be used and weigh each of themto the nearest 0.1 g. Record these sieve masses as their taremasses, respectively. If a single sieve is being used, stack it onthe pan and transfer a sample weighing 100 6 0.1 g to thatsieve. If two s
48、ieves are to be used in the analysis of the sample,stack the coarse sieve over the fine sieve and transfer theweighed sample to the coarse sieve. For those finely dividedpowders which tend to clog the sieves, add 1.0 % of an antistat(see Note 2).15.2 Cover the stack and place it in the mechanical si
49、eveshaker. Start the shaker and run for 10 min 6 15 s.15.3 After shaking, carefully separate the stack of sieves,beginning at the top, and weigh each sieve with powder to thenearest one tenth of a gram.16. Report16.1 Report the following information:16.1.1 Percentage of material retained on each sieve, withits corresponding sieve size,16.1.2 Sample weight, and16.1.3 Antistat (or slip agent) used.17. Precision and Bias417.1 PrecisionTable 2 and Table 3 are based
