1、Designation: E728 91 (Reapproved 2009)Standard Test Method forResistance to Attrition of Granular Carriers and GranularPesticides1This standard is issued under the fixed designation E728; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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 is used to determine the resistance toattrition of granular carriers and granular pe
3、sticides.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if
4、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. For specific hazardstatements see Section 6.2. Referenced Documents2.1 ASTM Standards:2E11
5、 Specification for Woven Wire Test Sieve Cloth and TestSievesE725 Test Method for Sampling Granular Carriers andGranular Pesticides3. Summary of Test Method3.1 Aknown weight of pre-sized granular carrier or granularpesticide is combined with steel balls in a sieve-bottomreceiver pan. After a specifi
6、ed period of mechanical agitation,the steel balls are removed and the weight of the granularmaterial passing through the specified limiting sieve is mea-sured and the resistance to attrition calculated.4. Significance and Use4.1 This procedure was designed principally with granularclay, corncob, nut
7、 shell, or sand carriers and granular pesticideproducts, but need not be limited to these materials. There maybe more appropriate test methods for other types of granularcarriers and pesticide products.5. Apparatus5.1 Brushes, Tyler Model 1778-SB soft brass wire brush, orequivalent, for 100 mesh and
8、 coarser sieves. Tyler nylon bristlebrush, or equivalent, for screens finer than 100 mesh.5.2 Mechanical Sieve Shaker, a Tyler Ro-Tap sieveshaker,or equivalent, or other agreed upon device.5.3 Sieves, U.S. standard sieves, or equivalent conformingto Specification E11. The sieves shall be 2 in. (51 m
9、m) inheight and 8 in. (203 mm) in diameter.5.4 Bottom Receiver Pan and Top Sieve Cover.5.5 Steel Balls, ten58 in. (16 mm) in diameter.5.6 Interval Timer, adjustable, with an accuracy of 610 s.5.7 Balance, sensitivity of 0.1 g.5.8 Beaker, glass, metal, or plastic with 250-mL capacity.6. Hazards6.1 Be
10、fore testing, read the precautionary statements on theproduct label, the material safety data sheet, or both. Takeproper precautions to prevent skin contact and inhalation of thefines and vapors. Take care to prevent contamination of thesurrounding area. Always wear the appropriate safety equip-ment
11、 and, where indicated, wear respiratory devices passed byNIOSH for the product being tested.7. Procedure7.1 For reproducible results on a comparative basis, it isnecessary to use a narrow mesh fraction or cut for this test.Approximately 75 6 5 g of a representative sample as definedin Test Method E7
12、25 is required for each test and duplicationis recommended.1This test method is under the jurisdiction of ASTM Committee E35 onPesticides and Alternative Control Agents and is the direct responsibility ofSubcommittee E35.22 on Pesticide Formulations and Delivery Systems.Current edition approved Oct.
13、 1, 2009. Published November 2009. Originallyapproved in 1980. Last previous edition approved in 2004 as E728 91(2004)1.DOI: 10.1520/E0728-91R09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
14、volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.7.2 Select the limiting screen for the mesh of material to betested. (For 20 to 40 mesh the limiting
15、screen would be 40, for18 to 50 mesh, the limiting screen would be 50, and so forth.)Preclean sieves with brush, then wash and dry the sieves.7.3 Screen out about 75 g of material to be tested using thelimiting screen in the sieve shaker for 10 min or according toproduct specifications (mechanical s
16、ieve shaker; use the ham-mer).7.4 Transfer 50 6 1 g of material to the pan of the sieveassembly. Put the ten58-in. (16-mm) steel balls in the pan withthe sample to be tested and place a clean limiting screen inposition above the bottom receiver pan.7.5 Insert the sieve assembly in the shaker.7.6 Run
17、 the shaker for 10 min or according to productspecifications (mechanical sieve shaker; without the hammer).7.7 Remove the assembly from the shaker. Remove the steelballs from the pan. Transfer the material taken from the pan tothe limiting screen. Reassemble the limiting screen and pan.7.8 Place the
18、 sieve assembly in the shaker and run for 10min or according to product specifications (mechanical sieveshaker; use the hammer).7.9 Remove the screen assembly from the sieve shaker.Transfer the fraction retained on the screen to a tared beakerand weigh the fraction to the nearest 0.1 g.7.10 Determin
19、e the attrition on duplicate samples.8. Calculation8.1 Calculate the percent resistance to attrition to the nearest1.0 % as follows:Percent resistance to attrition 5a 3 100bwhere:a = = weight of fraction retained on limiting screen andb = = total weight of sample as charged.9. Precision and Bias9.1
20、This test method does not yield pass or fail data andshould be used as comparative data only. The pass/fail aspectof the test method should be determined by the supplier or user,or both.10. Disposal of Samples10.1 After testing, store all materials in a safe manner anddispose of used sample material
21、 in accordance with productlabel directions, the material safety data sheets, or both.11. Keywords11.1 attrition; carrier; granule; handling; hardness; pesticideASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this sta
22、ndard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be revi
23、ewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsib
24、le technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).E728 91 (2009)2
