ASTM_D_4570_-_02_2021.pdf

Designation:D457002(Reapproved 2021)Standard Test Method forRubber ChemicalsDetermination of Particle Size of Sulfurby Sieving(Dry)1This standard is issued under the fixed designation D4570;the number immediately following the designation indicates the year oforiginal adoption or,in the 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 particle size measurement ofthe coarse fraction of ground sulfurs.It is limited to measure-ment of particles greater than 45 m(No.325 sieve).If thesulfur is very fine and the screens become plugged by thecaking of the sulfur,it may be necessary to use a wet sieveprocedure instead.1.2 The values stated in SI units are to be regarded as thestandard.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,health,and environmental practices and deter-mine the applicability 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-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2E11 Specification for Woven Wire Test Sieve Cloth and TestSievesE145 Specification for Gravity-Convection and Forced-Ventilation Ovens3.Significance and Use3.1 This test method is used to evaluate sulfur for suitabilityas a rubber vulcanizing agent.Sulfur particles must be smallenough to dissolve in rubber during cure to produce a uniformnetwork of cross-links.This test method is used as a qualitycontrol method to ensure that large particles are not present(and to determine if the sulfur follows a typical pattern for sizedistribution).4.Apparatus4.1 Standard Sieves,stainless steel,203 mm in diameterconforming to Specification E11.The stainless steel cloth shallrange in mesh size from 45 to 250 m.The sieve set shouldinclude a lid and a bottom pan.4.2 Mechanical Sieve Shakers,such as a Tyler Ro-Tap3orequivalent unit.4.3 Balance,with a minimum capacity of 500 g sensitive to0.1 g.4.4 Balance,with a minimum capacity of 150 g sensitive to0.001 g.4.5 Oven,circulating air type,controlled to 70 6 2C.5.Reagent5.1 Tri-calcium Phosphate,screened to a fineness of lessthan 45 m.6.Procedure6.1 Weigh each sieve to the nearest 0.1 g and assemble inorder of increasing mesh size from bottom to top.Add a bottompan.Choice of sieves depends on the information desired.6.2 Into a beaker or suitable container,weigh precisely100.0 g of sulfur to the nearest 0.1 g.When the sulfur is veryfine,add 2.0 g of tri-calcium phosphate(see 5.1)and blendthoroughly using a spatula.6.3 Transfer all the sulfur to the top sieve and add the lid.Fix the sieve vest firmly in the mechanical sieve shaker.Runthe unit for 10 min,stop,remove the sieves,and weigh eachsieve to the nearest 0.1 g.Return the sieves to the unit and runan additional 3 min.Reweigh each sieve again to the nearest0.1 g.Repeat until the sieves reach constant mass.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.20on Compounding Materials and Procedures.Current edition approved Nov.1,2021.Published December 2021.Originallyapproved in 1986.Last previous edition approved in 2017 as D4570 02(2017).DOI:10.1520/D4570-02R21.2For 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 to the standards Document Summary page onthe ASTM website.3This unit may be purchased from the Fisher Scientific Co.,585 Alpha Dr.,Pittsburgh,PA 15238.Copyright 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 established 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.1?7.Calculation7.1 Determine the residue remaining on each sieve by massdifference.For higher precision,transfer the small residue fromthe coarser screen to a weighing dish and weigh to the nearest0.01 g.7.2 The percent residue on each screen is equal to theamount in grams on each screen.7.3 The percent residue passing through each screen isdetermined by accumulating the total percent material col-lected on that screen and the coarser screens used andsubtracting the total from 100.%residue through(for any screen)=100 sumation of%sulfu