ASTM_D_4572_-_89_2012.pdf

Designation:D457289(Reapproved 2012)Standard Test Method forRubber ChemicalsWet Sieve Analysis of Sulfur1This standard is issued under the fixed designation D4572;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 evaluation of the particlesize distribution of the coarse fraction of sulfur.It is limited tothe measurement of those particles greater than 45 m(No.325sieve).1.2 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.Referenced Documents2.1 ASTM Standards:2D4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3.Significance and Use3.1 This test method is used to evaluate sulfur for suitabilityas a rubber vulcanizing agent.Sulfur particles must be signifi-cantly small enough to dissolve in rubber during cure andproduce a uniform network of cross-links.This test method isused as a quality control method to ensure that no excessivelylarge sulfur particles are present and to see if the productfollows a typical pattern of size distribution.3.2 This procedure is necessary when problems of the sulfurcaking occur with the use of the dry sieving procedure forparticle size.4.Apparatus4.1 Standard Sieves,stainless steel,76 mm diameter con-taining selected stainless steel wire cloth in the range of 45 to250 m mesh count.4.2 No.6 Stiff Bristle Artist Brush,having 10 to 15 mm longbristles.4.3 Balance,with a minimum capacity of 150 g sensitive to0.001 g.4.4 Oven,circulating air type,controlled to 70 6 2C.5.Materials5.1 Liquid Detergent.6.Procedure6.1 Weigh 10.0 g of the sulfur sample into a 250-cm3beaker.Wet the sulfur with 25 mL of water.Mix thoroughly with aglass stirring rod to guarantee wetting all the sulfur.NOTE1A1%solution of a liquid detergent may be used if the sulfursample does not wet out properly.6.2 Weigh each cleaned and dried sieve to the nearest 0.001g.Assemble preweighed stainless steel sieves in order ofdescending fineness with the coarsest screen on top.Carefullytransfer the wetted sulfur to top screen using additional waterto wash all of the sulfur out of the beaker.Wash the sulfurthrough the top sieve with a gentle stream of water from anozzle and detergent(see 5.1)as needed.Tap or vibrate thescreen while washing.Finally,break up all agglomerated sulfurparticles using the brush.Clean sulfur from the bristles of thebrush using wash water.Be careful that the wash water doesnot back up on the finer sieves causing the sulfur slurry tooverflow the sieve sides.6.3 Remove the top sieve.Wash off any residual sulfurslurry on the underside of the sieve.Repeat the washingprocedure described in 6.2 ensuring total transport of the finesulfur particles through each successive sieve.6.4 Carefully dry the sides of the sieves with a lint freetowel,and place each sieve separately in a drying oven at 70Cfor 1 h or until the sulfur is dry.Remove the sieves and cool atleast12h in a dessicator.6.5 Weigh each sieve to the nearest 0.001 g.When theamount of sulfur on the coarser sieves is very small(a fewparticles),it may be appropriate to brush the particles on to apreweighed glassine weighing paper and weigh the sulfurdirectly.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.20 on Compounding Materialsand Procedures.Current edition approved May 1,2012.Published June 2012.Originallyapproved in 1986.Last previous edition approved in 2005 as D4572 89(2005).DOI:10.1520/D4572-89R12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.Calculation7.1 Calculate the percent retained on each sieve,P,asfollows:P 5M1M23100(1)where:M1=mass residue,g,andM2=mass sample,g.7.1.1 In order to determine how much would be retained ona finer sieve,it is necessary to accumulate the mass of materialcollected on all the sieves and add it to the mass of materialfrom the selected sieve.7.2 The amount of material passing through each sieve isdetermined by subtracting the percent of the material collectedon the sieve from 100.8.Report8.1 Report the following information:8.1.1 Proper identification of samples,8.1.2 Identification of each sieve used,8.1.3 Percent retained on each sieve,and8.1.4 Percent material passing