ASTM_D_5461_-_06_2012.pdf

Designation:D546106(Reapproved 2012)Standard Test Method forRubber Compounding MaterialsWet Sieve Analysis ofPowdered Rubber Compounding Materials1This standard is issued under the fixed designation D5461;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 a procedure for the qualitativeevaluation of aggregate size and aggregate size distribution ofpowdered rubber accelerators and other compounding materi-als which are insoluble in water.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Terminology2.1 Definitions:2.1.1 aggregatea cluster of individual particles making upthe mass of the material.2.1.2 aggregate size distributionthe distribution of aggre-gates obtained by passing wetted rubber chemicals throughstacked sieves of known mesh which are arranged in order ofdecreasing size.3.Summary of Test Method3.1 A sample of powdered rubber chemical is wetted with adilute aqueous solution of soap and defoamer.The sample istransported by water flow through stacked sieves arranged inorder of decreasing mesh size.The material retained on theface of each sieve is dried in an oven.The dry mass of retainedmaterial is obtained for each sieve.The percent retainedmaterial is calculated on the basis of original sample mass.Individual masses and percentages are summed to evaluate theaggregate size distribution for the sample.4.Significance and Use4.1 This test method is used to evaluate the suitability ofpowdered rubber chemicals,particularly accelerators,for usein rubber compounds that require very small particle clusters toachieve a uniform cross-linked network.This test method isintended to be used to ensure that no excessively large particlesare present that would result in network“flaws”and todetermine that the powdered product follows a typical patternof size distribution.4.2 In view of the inherent variability in this type of method,it is recommended that the results be used only in a semi-quantitative sense;that is,comparisons within a laboratory orrelative comparisons of samples against reference samples,orboth.5.Apparatus5.1 Standard Sieves,stainless steel,200 mm(approximately8 in.)diameter containing selected stainless steel wire clothswith openings in the range of 45 to 250 m.(This correspondsto 325 to 60 mesh sieves.)NOTE1If the 200 mm diameter sieves are not available,the smaller76 mm diameter sieves can be used.In this case,the sample mass shouldbe reduced from 50 to 10 g.5.2 Analytical Balance,150 g capacity,1.0 mg sensitivity.5.3 Convection Oven,controlled at 70 6 2C.For lowmelting materials,the oven temperature should be set 10Cbelow the melting point.5.4 Aluminum Weighing Dishes,disposable,55 to 60 mmdiameter,approximately 1 g mass.5.5 No.6 Stiff Bristle Artist Brush,having 10 to 45 mm longbristles.6.Reagents and Materials6.1 Detergent,sodium alkylbenzenesulfonate(SABS),40%active or equivalent.6.2 Silicone Defoamer,2water soluble.6.3 Soap Solution,prepared by adding 100 g of SABS and200 cm3silicone defoamer to 20 dm3water.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.11 on Chemical Analysis.Current edition approved May 1,2012.Published July 2012.Originally approvedin 1993.Last previous edition approved in 2006 as D5461 06.DOI:10.1520/D5461-06R12.2The sole source of supply of the apparatus(Dow-Corning FG-10)known to thecommittee at this time is Dow-Corning,Midland,MI.If you are aware of alternativesuppliers,please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical committee,1which you may attend.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.Procedure7.1 Place the soap solution in a suitable carboy on a shelf orstand over a sink and discharge the solution from the bottom ofthe container through 6 mm(0.25 in.)rubber tubing connectedto a bottom outlet.A pinch-clamp serves as a control valve.7.2 Assemble pre-cleaned sieves(200 or 76 mm)into astack,with the largest sieve opening on top.For example:Sieve SizeSieve Opening,mTop602501001502007527053Bottom325457.3 Place the sieve stack in the sink under the discharge linefor the soap solution and under a sink tap equipped with anaerator.7.4 Wet the surface of each screen with water and soapsolution.