1、Designation:D122903(Reapproved 2019)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,health,and environmental practices and det
5、er-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendat
6、ions issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.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
7、 Practice for Evaluating Precision 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 relea
8、se from compression,the specimen is 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.Signi
9、ficance and Use4.1 Rubber products,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 inhibit
10、edupon release of the compressive 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 conventiona
11、l compression set at elevated temperatures,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
12、,as described in Practice D3767.6.3 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 D8
13、32.The testchamber shall be equipped with a vise,“C”clamp,or othersuitable device for holding the compression set jig.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.10on Physical Testing.Curren
14、t edition approved Nov.1,2019.Published December 2019.Originallyapproved in 1952.Last previous edition approved in 2015 as D1229 03(2015).DOI:10.1520/D1229-03R19.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of A
15、STMStandards 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 StatesThis international standard was developed in accordance with internationally recognized principl
16、es on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 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 Original Thickness MeasurementMeasure the originalthickness,to,at the c
