1、Designation:D222796(Reapproved 2015)Standard Specification forNatural Rubber(NR)Technical Grades1This standard is issued under the fixed designation D2227;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A nu
2、mber 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 specification covers minimum physical and chemi-cal
3、 quality requirements or specifications for five grades of rawnatural rubber.2.Referenced Documents2.1 ASTM Standards:2D1278 Test Methods for Rubber from Natural SourcesChemical AnalysisD1485 Practice for Rubber from Natural SourcesSampling and Sample PreparationD1646 TestMethodsforRubberViscosity,S
4、tressRelaxation,andPre-VulcanizationCharacteristics(Mooney Viscometer)D3157 Test Method for Rubber from Natural SourcesColorD3194 Test Method for Rubber From Natural SourcesPlasticity Retention Index(PRI)D3533 Test Method for RubberNitrogen Content(With-drawn 2006)33.Detailed Requirements for Grades
5、3.1 The rubber shall conform to the requirements in Table 1.3.2 Any rubber not meeting all the requirements for one ofthe five grades in Table 1 cannot be considered a technicallygraded rubber.4.Significance and Use4.1 The general end-use quality of manufactured rubberproducts depends on the physica
6、l and chemical properties ofthe rubber.5.Classification5.1 TypesTable 1 covers the physical and chemical re-quirements for five grades of natural rubber:Grades L,CV,5,10,and 20.6.Sampling6.1 The sampling and sample preparation shall be in accor-dance with Practice D1485.7.Test Methods7.1 Determine t
7、he properties enumerated in this specifica-tion in accordance with Test Methods D1278,D3533,D3194,D3157,and D1646.8.Keywords8.1 natural rubber(NR);technical grade1This specification is under the jurisdiction ofASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.22 on Nat
8、ural Rubber.Current edition approved Sept.1,2015.Published December 2015.Originallyapproved in 1963.Last previous edition approved in 2011 as D2227 96(2011).DOI:10.1520/D2227-96R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.F
9、or Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United
10、 States1 ASTM 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 righ
11、ts,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 sta
12、ndardsand 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 your views known to the ASTM Commit
13、tee on Standards,at the address shown below.This standard is copyrighted by ASTM International,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 6
14、10-832-9585(phone),610-832-9555(fax),or serviceastm.org(e-mail);or through the ASTM website(www.astm.org).Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center,222Rosewood Drive,Danvers,MA 01923,Tel:(978)646-2600;http:/ 1 Specifications For Technically G
15、raded Natural RubberPropertyRubber GradeAGradeLGradeCVBGrade5Grade10Grade20Dirt,retained on 45m sieve,%max0.0500.0500.0500.1000.200Ash,%max0.600.600.600.751.00Volatile matter,%max0.800.800.800.800.80Nitrogen,%max0.600.600.600.600.60Initial plasticity,min30.303030Plasticity retentionindex,min6060605040Color index,max6.0.Mooney viscosity.605.ASkim rubber is not permitted in any grade,and Grades L,CV,and 5 must beproduced from intentionally coagulated latex.BOther Mooney ranges of Grade CV are available,CV-50 5 and CV-70 5.CVwithout suffix is the 60 5 as shown in the table.D2227 96(2015)2
