1、Designation: D 1456 86 (Reapproved 2005)Standard Test Method forRubber PropertyElongation at Specific Stress1This standard is issued under the fixed designation D 1456; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method covers determination
3、of the elongationof 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 deter
4、mine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1349 Practice for RubberStandard Temperatures forTestingD 3182 Practice for RubberMaterials, Equipment, andProcedures for Mixing Standard Compounds and Prepar-ing Standard Vulcanized SheetsD 3
5、183 Practice for RubberPreparation 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. Summa
6、ry of Test Method4.1 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 whic
7、h, under gravity,gives the 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 rubb
8、er, andso forth. This test method 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 specim
9、en at auniform speed of between 75 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 s
10、hall havea millimetre scale and an indicating 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 corresp
11、ond tomultiples of the force required for 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
12、a uniformpressure across the gripping surfaces. 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 fort
13、he specimens (see 7.1) at any point along their length. 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.)1This test method is under the jurisdiction of ASTM Committ
14、ee D11 on Rubberand is the direct responsibility of Subcommittee D11.10 on Physical Testing.Current edition approved Dec. 1, 2005. Published February 2006. Originallyapproved in 1957. Last previous edition approved in 2001 as D 1456 86 (2001).2For referenced ASTM standards, visit the ASTM website, w
15、ww.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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.lon
16、g, 19 mm (0.75 in.) wide, and 0.25 mm (0.010 in.) thick;they are clamped rigidly between metal spacers to produce thedesired 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.6.3 Bench MarkerThe bench marker
17、 shall have twoparallel knife edges that are ground smooth and true, and thatare between 0.05 and 0.08 mm (0.002 and 0.003 in.) in widthat the edge and beveled at an angle of not more than 15. Thedistances between the centers of the knife edges shall be 100 60.10 mm (3.937 6 0.004 in.). A suitable b
18、ench marker isshown in Fig. 3.6.4 Stamp PadThe stamp pad shall have a plane unyield-ing surface such as hardwood, plate glass, or plastic coveredwith a pad containing ink of the desired color and quality formarking the specimen. The ink shall have no deterioratingeffect on the specimen and shall be
19、of a contrasting color to thatof the specimen.6.5 Thickness GageThe thickness gage shall measure theaverage thickness of the specimen between bench marksaccurately to 0.01 mm under a pressure of 22 6 5 kPa (3.2 60.7 psi). It shall be equipped with a dial indicator having0.01-mm graduations, where on
20、e revolution of the dial corre-sponds to 1 mm, and the total range is 2.5 mm. The indicatorshall be mounted above a specially constructed base equippedwith a pressure bar 100 mm long and slightly wider than thespecimen. The pressure bar is pressed upon the surface of thespecimen by means of an adjus
21、table spring. The bar is attachedto a ball joint that possesses sufficient freedom of movement topermit the dial gage to indicate the average thickness of thespecimen. A schematic diagram of the gage is shown in Fig. 4.When the knurled disk, D, is turned so that the handle, H, restsagainst the pin,
22、P, the notch, N, in the rod, R, is at the top,allowing the spring to pull the pressure bar against thespecimen.6.6 Cutting SupportThe cutting surface shall be a smooth,slightly yielding surface for supporting a portion of the testpiece from which the specimen is to be cut so that the blade ofthe die
23、 is not damaged during the cutting of the specimen. It isrecommended that the cutting support have three parts: (1)asolid foundation, such as hardwood or plate glass; (2)asemihard pad such as vinyl plastic or Masonite;3and (3)asmooth cutting surface such as rubber belting, leather belting,or light c
24、ardboard.7. Test Specimens7.1 Preparation of SpecimenIf the material is too thick orhas an uneven surface that may interfere with the test, thematerial shall be buffed and prepared as described in PracticesD 3182 and D 3183. The portion of the test piece from whichthe specimen is to be taken shall b
25、e buffed in a strip formbefore cutting with the die. The width of the specimen dependsupon the testing machine used.NOTE 1Example: For machines supplied with masses in incrementsof 0.01 lb for each 0.01-mm thickness of specimen, the width of thespecimen shall be 8.90 6 0.02 mm (0.357 6 0.001 in.) wh
26、en the stress isa multiple of 0.5 kPa and shall be 6.45 6 0.02 mm (0.254 6 0.001 in.)when the stress is a multiple of 100 psi. This dimension permits thefollowing combinations of stresses to be applied with the four sets ofmasses supplied with these machines:Mass Set Stress, MPa Specimen Width, mmA
27、0.25 8.90B 0.50 8.90C 1.00 8.90D 2.00 8.90Similarly, masses in increments of 5 g for each 0.01 mm of specimenthickness give stresses in multiples of 0.5 MPa when the specimen widthis 9.80 6 0.02 mm.7.2 Cutting SpecimensThe specimen shall be cut with asingle stroke of the die, if possible, so as to o
28、btain smooth-cutsurfaces. To facilitate cutting, the edges of the die may belubricated with water containing a wetting agent and a corro-sion inhibitor such as 0.5 % sodium chromate or with siliconemold release emulsion before each specimen is cut. Benchmarks 100.0 6 0.1 mm apart shall be placed on
29、the straightuniform section of the specimen perpendicular to the longitu-dinal axis by means of the bench marker and ink. The specimenshall be free of mechanical damage.7.3 Measuring SpecimensThe average thickness of thespecimen between bench marks shall be determined to the3Masonite is a registered
30、 trademark of the Masonite Corp.FIG. 1 Strain Testing MachineD 1456 86 (2005)2nearest 0.01 mm by means of the thickness gage as describedin 6.5. The width of the specimen shall be taken as the distancebetween the cutting edges of the blades of the die. Thecross-sectional area of the specimen shall b
31、e calculated bymultiplying the width by the thickness of the specimen.8. Procedure8.1 Test TemperatureThe standard temperature (Note 2)for testing shall be 23 6 2C (73.4 6 3.6F). Conditionspecimens for at least 3 h. Where this temperature conditioncannot be adhered to, the report shall include a sta
32、tement of theactual temperature at the time of test. If the material is affectedby moisture, the specimen shall be conditioned at least 24 hbefore testing in an atmosphere in which the relative humidityis maintained at 50 6 5%.NOTE 2This standard temperature is the same as that prescribed inPractice
33、 D 1349.8.2 Determination of Force to Be AppliedThe stressapplied to the specimen shall be as specified in the detailspecifications. Determine the force to be applied by multiply-ing the specified stress by the cross-sectional area. Whenspecimens of the proper width are used in machines equippedwith
34、 an automatic device for adding the masses, measure onlythe thickness of the specimen to apply the proper masses.Apply the masses to the holder attached to the lower grip.8.3 Measurement of ElongationPlace the specimen in thegrips of the testing machine with the bench marks facing theoperator. Exten
35、d the specimen at a uniform speed of between75 and 90 mm/s (15 and 18 ft/min) until the masses on theFIG. 2 Die for Cutting SpecimensFIG. 3 Bench MarkerD 1456 86 (2005)3lower grip are freely suspended. Measure the distance betweenthe bench marks 60 6 3 s after the masses are freelysuspended, and rec
36、ord the value to the nearest 1 mm.9. Calculations9.1 Calculate the elongation on the specimen as follows:Elongation, % 5 E 2 100 (1)where:E = the length in millimetres between bench marks whenthe specimen is under stress.NOTE 3If a millimetre scale is used, with the zero at 100 mm from theindex for
37、the upper bench mark, the elongation is then given directly onthe scale at the index for the lower bench mark.10. Characteristics of Piece Tested10.1 The median of the values for three specimens shall betaken as the characteristics of the piece of rubber tested, exceptthat under the following condit
38、ions the median of the values forfive specimens shall be used:10.1.1 If one or more values do not meet the specifiedrequirements when testing for compliance with specificationsand10.1.2 If referee tests are being made.11. Report11.1 The report shall include the following:11.1.1 The elongation calcul
39、ated in accordance with Section9,11.1.2 Stress applied to the specimen,11.1.3 Width of specimen,11.1.4 Data of vulcanization of the rubber, if known,11.1.5 Date of test,11.1.6 Temperature of the test room if it is other than asprovided for in 5.1, and11.1.7 Type of testing machine used.12. Precision
40、12.1 Because of a lack of laboratories willing to participatein round robin testing, no precision data are available for thisstandard.13. Keywords13.1 elongationFIG. 4 Base for Thickness GageD 1456 86 (2005)4ASTM International takes no position respecting the validity of any patent rights asserted i
41、n 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 r
42、esponsible 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 car
43、eful 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 your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Internation
44、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 1456 86 (2005)5
