1、Designation:D122903(Reapproved 2015)Standard Test Method forRubber PropertyCompression Set at Low Temperatures1This standard is issued under the fixed designation D1229;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last
2、 revision.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 evaluation of the
3、ability ofvulcanized rubbers that have been compressed at room tem-perature and then subjected to low temperature(air or carbondioxide atmosphere),to recover from deformation when takenfrom the clamping device while still at the low temperature.1.2 The values stated in SI units are to be regarded as
4、 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 app
5、lica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D395 Test Methods for Rubber PropertyCompression SetD832 Practice for Rubber Conditioning For Low Tempera-ture TestingD3767 Practice for RubberMeasurement of DimensionsD4483 Practice for Evaluating Precision
6、 for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries3.Summary of Test Method3.1 At room temperature,a test specimen is compressed to25%of its original thickness and exposed for a specified timeat a specified low temperature.3.2 Upon release from compression,the specimen i
7、s al-lowed to recover while remaining at the test temperature.3.3 The residual deformation of the specimen is measured10 s and 30 min after removal from the compressive device.3.4 Compression set of the specimen is calculated accordingto the equations in 9.1.4.Significance and Use4.1 Rubber products
8、,such as hydraulic seals on aircraft,submarine hatch gaskets,and hydraulic brake cups,may beexposed to varying temperature extremes.This test methodprovides a means of determining the extent to which recoveryfrom compression at normal ambient temperatures is inhibitedupon release of the compressive
9、force during subsequentexposure at low temperatures.5.Compression Set5.1 For the purpose of this test method,compression set ofvulcanizates shall be the loss in thickness of the specimenexpressed as a percentage of the original deflection.This set,unlike conventional compression set at elevated temp
10、eratures,is temporary since the specimen will regain its originaldimensions when brought back to room temperature or slightlyabove.6.Apparatus6.1 Compression Set Jigs,with suitable steel spacer bars inaccordance with Method B of Test Methods D395.6.2 Dial Micrometer,as described in Practice D3767.6.
11、3 Cold Box,cooled by solid carbon dioxide(Dry Ice),liquid carbon dioxide,liquid nitrogen,or mechanicallyrefrigerated,preferably by the top-opening type,and capable oftemperature control within 61C(1.8F)of the specifiedtesting temperature as prescribed in Practice D832.The testchamber shall be equipp
12、ed with a vise,“C”clamp,or othersuitable device for holding the compression set jig.7.Test Specimen7.1 The standard test specimen shall be a cylindrical disk29.0 6 0.5 mm(1.14 6 0.02 in.)in diameter and 12.5 6 0.5mm(0.49 6 0.02 in.)in thickness,as specified in Test MethodsD395.8.Procedure8.1 Origina
13、l Thickness MeasurementMeasure the originalthickness,to,at the center of the specimen to the nearest 0.02mm(0.001 in.).1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.10 on Physical Testing.Current edition approved June
14、15,2015.Published September 2015.Originallyapproved in 1952.Last previous edition approved in 2008 as D1229 03(2008).DOI:10.1520/D1229-03R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume i
15、nformation,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 8.2 Application of LoadPlace a test specimen betweenclean,unlubricated plates of the compression device with thespa
16、cers on each side of it.Use only one specimen with eachpair of steel plates,and place in the center between the plates.Tighten the bolts so as to draw the plates together uniformlyuntil they are in contact with the spacers.The compressionemployed shall be 25%for all hardnesses.8.3 Within 30 min after the jigs are loaded,place them in thelow-temperature cabinet,and maintain at the service tempera-ture for which the vulcanizates are being evaluated.In theevent the service temperature is unknown,th