ASTM_D_3184_-_11.pdf

Designation:D318411Standard Practice forRubberEvaluation of NR(Natural Rubber)1This standard is issued under the fixed designation D3184;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 practice covers the standard materials,test formu-las,mixing procedures,and test methods for the evaluation andproduction control of natural rubber(NR).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.Referenced Documents2.1 ASTM Standards:2D412 Test Methods for Vulcanized Rubber and Thermoplas-tic ElastomersTensionD1485 Practice for Rubber from Natural SourcesSampling and Sample PreparationD1646 Test Methods for RubberViscosity,Stress Relax-ation,and Pre-Vulcanization Characteristics(Mooney Vis-cometer)D2084 Test Method for Rubber PropertyVulcanizationUsing Oscillating Disk Cure MeterD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3.Significance and Use3.1 This practice is mainly intended for referee purposes butmay be used for quality control of rubber production.It mayalso be used in research and development work and forcomparison of different rubber samples in a standard formula.4.Standard Test Formulas4.1 Standard Formulas:Quantity,Parts by Mass,and Formula No.MaterialIndustryReferenceMaterial No.1A Gum2A BlackFilled3AAGumNatural rubber.100.00100.00100.00Zinc oxide0916.005.006.00Sulfur0313.502.253.50Stearic acid0210.502.000.50Oil furnaceblackBIRB#7.35.00.Mercaptobenzothiazole0020.50.TBBSC003.0.700.70Total110.50144.95110.70Batch factor:DMill3.03.03.0Miniature internalmixer:ECam Head0.570.480.57Banbury Head0.500.420.50ARecommended formula for Test Method D2084 vulcanization characteristicsusing oscillating disk cure meter.BThe current Industry Reference Black may be used in place of NIST 378,although slightly different results may be obtained.CN-tert-butyl-2-benzothiazole sulfenamide.DFor mill mixes,weigh the rubber and carbon black to the nearest 1.0 g,the sulfurand accelerators to the nearest 0.02 g,and all other compounding materials to thenearest 0.1 g.EFor MIM batches weigh the rubber carbon black to the nearest 0.1 g,thecompounding material blend to the nearest 0.01 g,and individual compoundingmaterials,if used,to the nearest 0.001 g.For the MIM procedure,it is recom-mended that a blend of compounding materials,including black,be prepared toimprove accuracy in the weighing of these materials.This material blend is pre-pared by blending a proportional mass of each material in a dry powder such as abiconical blender or vee blender.A mortar and pestle may be used for blendingsmall quantities.5.Sample Preparation5.1 For tests intended for referee purposes obtain andprepare the samples in accordance with Test Methods D1485.6.Mixing Procedures6.1 The following three mixing procedures are offered asfollows:6.1.1 Mill Method AFor gum formulas 1A and 3A.6.1.2 Mill Method BFor black formula 2A.6.1.3 MIM Method CFor formula 1A,2A,and 3A.1This practice is under the jurisdiction ofASTM Committee D11 on Rubber andare the direct responsibility of Subcommittee D11.22 on Natural Rubber.Current edition approved May 1,2011.Published July 2011.Originally approvedin 1973.Last previous edition approved in 2007 as D3184 07.DOI:10.1520/D3184-11.2For 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 NOTE1It is not implied that comparable results will be obtained bythese test methods.6.2 Mill Method A:6.2.1 For general mixing procedures,refer to PracticeD3182.6.2.2 Mixing shall be done with the mill roll temperaturemaintained at 70 6 5C(158 6 9F).The indicated millopenings are desired and should be maintained insofar aspossible to provide a standard for uniform breakdown of therubber due to milling.6.2.3 Mixing CycleGum Compound:Dura-tion,minAccumu-lative,minSet the mill opening at 0.20 mm(0.008 in.)and pass therubber through the rolls twice without banding.11Band with the mill opening at 1.40 mm(0.055 in.)andbreak down,opening the mill to 1.90 mm(0.075