1、Designation:D222796(Reapproved 2020)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.1.2 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
4、Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1278 Test Methods for Rubber from Natural SourcesChemical AnalysisD1485 Practice for Rubber from Natural SourcesSampling and Sample PreparationD1646 TestMethods
5、forRubberViscosity,StressRelaxation,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 Req
6、uirements for Grades3.1 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 de
7、pends on the physical 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 Me
8、thods7.1 Determine the 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 Rubber-like Materials and is the direc
9、t responsibility of Subcommittee D11.22on Natural Rubber.Current edition approved June 1,2020.Published June 2020.Originallyapproved in 1963.Last previous edition approved in 2015 as D2227 96(2015).DOI:10.1520/D2227-96R20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact A
10、STM Customer Service at serviceastm.org.For 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 C7
11、00,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World
12、 Trade Organization Technical Barriers to Trade(TBT)Committee.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 p
13、atent rights,and the riskof infringement of such rights,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 eithe
14、r for revision of this standard or for additional standardsand 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 heari
15、ng you shouldmake your views known to the ASTM Committee 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 ob
16、tained 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).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 Graded Natural RubberPropertyRubber GradeAGradeLGradeCVBGrade5Grade10Grade20Dirt,retained on 45m sieve,%max0.0500.0500.0500.1000.200Ash,%max0.600.60