ASTM_D_3184-11.pdf

Designation:D3184-11INTERNATIONALStandard Practice forRubber-Evaluation 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(s)indicates an editorial change since the last revision or reapproval.1.Scopealso be used in research and development work and for1.1 This practice covers the standard materials,test formu-comparison of different rubber samples in a standard formula.las,mixing procedures,and test methods for the evaluation andproduction control of natural rubber(NR).4.Standard Test Formulas1.2 The values stated in SI units are to be regarded as the4.1 Standard Formulas:standard.The values given in parentheses are for informationQuantity,Parts by Mass,and Formula Noonly.Industry1A Gum2A Black3AAGumMaterialReferenceFilled1.3 This standard does not purport to address all of theMaterial No.100.00safety concerns,if any,associated with its use.It is theNatural rubber100.00100.00Zinc oxide0916.005.006.00responsibility of the user of this standard to establish appro-Sulfur0313.502.253.50priate safety and health practices and determine the applica-Stearic acid0210.502.000.50Oil furnaceIRB#735.00bility of regulatory limitations prior to use.blackeMercaptobenzothiazole0020.502.Referenced DocumentsTBBSC0030.700.70Total110.50144.95110.702.1 ASTM Standards:2Batch factor:D412 Test Methods for Vulcanized Rubber and Thermoplas-Mill3.03.03.0tic Elastomers-TensionMiniature internalmixer:ED1485 Practice for Rubber from Natural Sources-Cam Head0.570.480.57Sampling and Sample PreparationBanbury Head0.500.420.50D1646 Test Methods for Rubber-Viscosity,Stress Relax-ation,and Pre-Vulcanization Characteristics(Mooney Vis-Recommended formula for Test Method D2084 vulcanization characteristicsusing oscillating disk cure eter)The current Industry Reference Black may be used in place of NIST 378,D2084 Test Method for Rubber Property-Vulcanizationalthough slightly different results may be obtained.Using Oscillating Disk Cure Meter N-tert-butyl-2-benzothiazole sulfenamide.For mill mixes,weigh the rubber and carbon black to the nearest 1.0 g,the sulfurD3182 Practice for Rubber-Materials,Equipment,and Pro-and accelerators to the nearest 0.02 g,and all other compounding materials to thecedures for Mixing Standard Compounds and Preparingnearest 0.1 g.Standard Vulcanized SheetsEFor MIM batches weigh the rubber carbon black to the nearest 0.1 g,thecompounding material blend to the nearest 0.01 g,and individual compoundingD4483 Practice for Evaluating Precision for Test Methodmaterials,if used,to the nearest 0.001 g.For the MIM procedure,it is recom-Standards in the Rubber and Carbon Black Manufacturingmended that a blend of compounding materials,including black,be prepared toimprove accuracy in the weighing of these materials.This material blend is pre-Industriespared 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 blending3.Significance and Usesmall quantities.3.1 This practice is mainly intended for referee purposes but5.Sample Preparationmay be used for quality control of rubber production.It may5.1 For tests intended for referee purposes obtain andprepare the samples in accordance with Test Methods D1485.This practice is under the jurisdiction of ASTM Committee D11 on Rubber andare the direct responsibility of Subcommittee D11.22 on Natural Rubber.6.Mixing ProceduresCurrent edition approved May 1,2011.Published July 2011.Originally approvedin 1973.Last previous edition approved in 2007 as D3184-07.DOI:10.1520/6.1 The following three mixing procedures are offered asD3184-11.follows:2 For referenced ASTM standards,visit the ASTM website,www.astm.org,or6.1.1 Mill Method A-For gum formulas 1A and 3A.contact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page on6.1.2 Mill Method B-For black formula 2A.the ASTM website.6.1.3 MIM Method C-For formula 1A.2A,and 3A.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1D3184-11NorE 1-It is not implied that comparable results will be obtained byNorE 1-Do not cut any stock while free carbon black is evident in thethese test methods.bank or on the milling surface.Be certain to run any pigments that drop6.2 Mill Method A:through the mill to the milling stock.6.2.1 For general mixing procedures,refer to PracticeDura-Accumu-tion,lative,D3182.minmin6.2.2 Mixing shall be done with the mill roll temperatureSet the mill opening at 1.70 mm(0.067 in.).Add zinc25oxide.Make one cut from each side.maintained at 70 5C(158+9F).The indicated millAdd the carbon black evenly across the mill at a uniform1419openings are desired and should be maintained insofar asrate.When about half the black is incorporated,add thepossible to provide a standard for uniform breakdown of thestearic acid and open the mill to 1.90 mm(0.075 in.).Make one 3 cut from each side then add the remainderrubber due to milling.of the carbon black.6.2.3 Mixing Cycle-Gum Compound:Add the accelerator,taking care to avoid any loss.21Sweep the mill pan and add until all the pigment is in theDura-Accumu-batch.Make three y cuts from each side.tion,lative,Add the sulfur and that which falls into the mill pan.24minminMake one cut from each side.Set the mill opening at 0.20 mm(0.008 in.)and pass the11Cut the stock from the mill.Set the opening at 0.80 mm226rubber through the rolls twice without banding.(0.032 in.)and pass the rolled stock endwise through theBand with the mill opening at 1.40 mm(0.055 in.)andmill six times.break down,opening the mill to 1.90 mm(0.075 in.)asOpen the mill to give a minimum stock thickness of 6329the band becomes smooth.mm(0.25 in.)and pass the stock through the rolls fourAdd the stearic acid.27times,folding it back on itself each time.Add the zinc oxide,sulfur,and accelerator.Make three cuts from each side.13Total Time 29Cut the stock from the mill.Set the opening at 0.80 mm215(0.032 in.)and pass the rolled stock endwise through the6.3.3.1 Check the batch mass and record.If it differs frommill six times.the theoretical value by more than 0.5 reject the batch.Open the mill to give a minimum stock thickness of 6318mm(0.25 in.)and pass the stock through the rolls four6.3.3.2 From this stock,cut enough sample to allow testingtimes,folding it back on itself each time.of compounded viscosity in accordance with Test MethodsD1646,or curing characteristics in accordance with TestTotal Time18Method D2084,or both,if these are desired.Sheet off the stock6.2.3.1 Check the batch mass and record.If it differs fromfrom the mill at a setting to give an approximate finish gage ofthe theoretical value by more than 0.5%reject the batch.2.20 mm(0.085 in.).Cool on a flat,dry metal surface.6.2.3.2 From this stock,cut enough sample to allow testing6.3.3.3 For routine laboratory testing,condition the sheetedof compounded viscosity in accordance with Test Methodscompound for1to24hat232C(73.43.6F)andaD1646 or curing characteristics in accordance with Testrelative humidity not greater than 55%For maximum preci-Method D2084.or both,if these are desired.Sheet off the stocksion,condition for I to 24 h in a closed container to preventfrom the mill at a setting to give an approximate finish gage ofabsorption of moisture from the air or in an area controlled at2.2 mm(0.085 in.).Cool on a flat,dry metal surface.35+5 relative humidity.6.2.3.3 For routine laboratory testing,condition the sheetedcompound for1to24hat232C(73.43.6F)anda6.4 Method C-Miniature Internal Mixer Mix:6.4.1 For general mixing procedure,refer to Practicerelative humidity not greater than 55%For maximum preci-D3182.Mix with the head temperature of the miniaturesion,condition for I to 24 h in a closed container to preventinternal mixer maintained at 60+3C(140 5F)and theabsorption of moisture from the air or in an area controlled atunloaded rotor speed at 6.3 to 6.6 rad/s(60 to 63 rpm).35+5%relative humidity.6.4.2 Prepare the rubber by passing it through a mill one6.3 Mill Method B:time with the temperature set at 50+5C(122+9F)and an6.3.1 For general mixing procedures,refer to Practiceopening of 0.5 mm(0.02 in.)thick.Cut the sheet into strips thatD3182are approximately 25 mm(1 in.)wide if desired.6.3.2 Mixing shall be done with the mill roll temperature6.4.3 Mixing Cycle:maintained at 70+5C(158+9F).The indicated millDura-Accumu-openings are desired and should be maintained insofar astion,lative,minminpossible to provide a standard for uniform breakdown of theCharge the mixing chamber with the rubber strips and the00rubber due to millingblended materials,lower the ram,and start the timer.6.3.3 Mixing Cycle-Black-Filled Compound:Allow to mix.1Raise the ram,add carbon black,sweep the orifice,and2Dura-Accumu-lower the ram.tion.lative.Allow the batch to mix,raising the ram momentarily to0minminsweep down the materials,if necessary.Set the mill opening at 0.20 mm(0.008 in.)and pass therubber through the rolls twice without banding.6.4.3.1 Turn off the motor,raise the ram,remove the headBand the rubber on the front roll with the mill opening at23and discharge the batch.Measure and record the maximum1.40 mm(0.055 in.).Make two cuts from each side.batch temperature if desired.2D3184-116.4.3.2 Immediately pass the batch twice through a labora-7.Preparation and Testing of Vulcanizatestory mill maintained at 50 5(122 9F)and with the roll7.1 For stress-strain testing,prepare test slabs and vulcanizeseparation of 3 mm(0.125 in.).them in accordance with Practice D3182.6.4.3.3 Check the batch mass and record.If it differs from7.1.1 The recommended standard cure times are 10,20,40,the theoretical value by more than 0.5%,discard the batch.and 80 min at 140C(284F).6.4.3.4 Cut a specimen for testing vulcanization character-7.1.2 Condition the cure sheets for 16 to 96 h at a tempera-istics in accordance with Test Method D2084,if required.ture of 23 2(73.43.6F).Condition the specimen for 1 to 24 h at 23 3C(73.45.4F)before testing.NorE 2-Quality control of production may require testing within 1 to6.4.3.5 If either compound viscosity or stress-strain testing6 h,to provide close surveillance of the plant operations;however,slightlydifferent results may be obtained.is required,pass the rolled compound end-wise through themill six times with the mill rolls set at 50 5C(122 9F)7.1.3 Prepare test specimens in accordance with Practiceand 0.8 mm(0.032 in.).D3182 and obtain modulus,tensile,and elongation parameters6.4.3.6 Cut a specimen to allow testing for compoundin accordance with Test Methods D412.viscosity in accordance with Test Methods D1646,if required.7.2 An alternative to measuring stress-strain properties of6.4.3.7 If tensile stress is required,sheet off the compoundvulcanizates is the cure meter measurement of vulcanizationfrom the mill at a setting to give a finished gage of approxi-parameters in accordance with Test Method D2084.mately 2.2 mm(0.085 in.)by passing the folded stock between7.2.1 The recommended standard test conditions are 1.7 Hzthe rolls set at 50 5(122 9F)four times always in the(100 cpm)oscillation frequency,1 0.03 amplitude ofsame direction to obtain the effects of mill direction.Cool onoscillation,and 160 0.3(320 0.5F)die temperature.a flat,dry metal surface.7.2.2 The recommended standard test parameters are ML,6.4.3.8 For routine laboratory testing,condition the sheetedMH,ts1,t(50),and t(90).For formula 3A,use MHr insteadcompound for 1 to 24 h at 23 3C(73.4 5.4F)and aof MHrelative humidity not greater than 55%.For maximum preci-sion,condition for 1 to 24 h in a closed container to prevent8.Keywordsabsorption of moisture from the air or in an area controlled at8.1 mill method;miniature mixer;mixing procedures;natu-35 5%relative humidity.ral rubber;sample preparation;test methodsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.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 reviewed 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 theresponsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you shouldmake 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