1、Designation:D145686(Reapproved 2014)Standard Test Method forRubber PropertyElongation at Specific Stress1This standard is issued under the fixed designation D1456;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revis
2、ion.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers determination of the elo
3、ngationof soft vulcanized rubber compounds under a specified stress.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 appl
4、ica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D1349 Practice for RubberStandard Conditions for Test-ingD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3183 Practice for Ru
5、bberPreparation of Pieces for TestPurposes from Products3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 piecethe portion of the sample that is prepared fortesting.3.1.2 specific stressforce divided by the cross-sectionalarea of the original specimen.4.Summary of Test Method4.1
6、The test method starts with a piece taken from thesample and includes:(1)the preparation of the specimen and(2)measurement of the elongation of the specimen subjected toa prescribed stress for a specified period of time.The stress isapplied by suspension of a known mass which,under gravity,gives the
7、 desired stress.5.Significance and Use5.1 This test method is useful for determining the variabilityin material and the influence of parameters affecting thestress-strain properties of rubber vulcanizates,for example,temperature,relative humidity,preconditioning of rubber,andso forth.This test metho
8、d is particularly useful for theevaluation of compounding materials used for reference pur-poses.6.Apparatus6.1 Testing MachineTests shall be made on a power-driven machine complying with the following requirements:The machine shall be capable of extending the specimen at auniform speed of between 7
9、5 and 90 mm/s(15 and 18 ft/min)until the mass is freely suspended.It shall be equipped with atiming device that automatically starts the instant the mass isfreely suspended by the specimen and signals the operatorwhen the elongation is to be measured.The machine shall havea millimetre scale and an i
10、ndicating device so that elongationmeasurements to the nearest millimetre can be made withoutparallax.A holder shall be attached to the lower grip so thatmasses may be added,preferably by an automatic device,toobtain the desired stress.The masses shall correspond tomultiples of the force required fo
11、r 0.01-mm thickness of thespecimen and shall be accurate within the force required for0.002-mm thickness of the specimen.The grips that hold thespecimen in the tester shall be of a type that tightens automati-cally as the applied tension increases and exerts a uniformpressure across the gripping sur
12、faces.A satisfactory tester,including die and thickness gage,is shown in Fig.1.6.2 DieThe die shall be capable of cutting straight speci-mens with parallel sides,approximately 150 mm(6 in.)longand within 60.02 mm(60.001 in.)of the specified width forthe specimens(see 7.1)at any point along their len
13、gth.Asuitable die is shown in Fig.2.This die consists of six strips ofrazor-blade steel,sharpened on one edge,and clamped in arigid mounting.The blades are approximately 150 mm(6 in.)long,19 mm(0.75 in.)wide,and 0.25 mm(0.010 in.)thick;they are clamped rigidly between metal spacers to produce thedes
14、ired width of specimen and project approximately 3 mm(0.12 in.)above the spacers.The blades can easily be replacedwhen they become dull or nicked.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.10 on Physical Testing.Cur
15、rent edition approved Nov.1,2014.Published December 2014.Originallyapproved in 1957.Last previous edition approved in 2010 as D1456 86(2010).DOI:10.1520/D1456-86R14.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book o
16、f 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 6.3 Bench MarkerThe bench marker shall have two par-allel knife edges that are ground smooth and true,and that arebetween 0.05 and 0.08 mm(0.002 and 0.003 in.)in width at theedge and beveled at an angle of not more than 15.Thedistances between the centers of the knife edges shall be 100 60.
