1、Designation: D2227 96 (Reapproved 2011)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 revis
2、ion. 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 Department of Defense.1. Scope1.1 This specification covers minimum physical and
3、chemi-cal 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 Test Methods for Rubb
4、erViscosity, Stress Relax-ation, and Pre-Vulcanization Characteristics (Mooney Vis-cometer)D3157 Test Method for Rubber from Natural SourcesColorD3194 Test Method for Rubber From Natural SourcesPlasticity Retention Index (PRI)D3533 Test Method for RubberNitrogen Content33. Detailed Requirements for
5、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 depends on the
6、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 Methods7
7、.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 is the direct responsibility of Subcom
8、mittee D11.22 on Natural Rubber.Current edition approved Nov. 1, 2011. Published January 2012. Originallyapproved in 1963. Last previous edition approved in 2007 as D2227 96 (2007).DOI: 10.1520/D2227-96R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
9、Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.TABLE 1 Specifications For Technically Graded Natural Rubber
10、PropertyRubber GradeAGradeLGradeCVBGrade5Grade10Grade20Dirt, retained on 45m sieve, % max0.050 0.050 0.050 0.100 0.200Ash, % max 0.60 0.60 0.60 0.75 1.00Volatile matter, % max 0.80 0.80 0.80 0.80 0.80Nitrogen, % max 0.60 0.60 0.60 0.60 0.60Initial plasticity, min 30 . 30 30 30Plasticity retentionind
11、ex, min60 60 60 50 40Color index, max 6.0 . . . .Mooney viscosity . 6065 . . .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 6 5 and CV- 70 65. CV without suffix is the 60
12、6 5 as shown in the table.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this
13、 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 responsible technical committee and must be reviewed every five year
14、s 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 careful consideration at a meeting of theresponsible technical committ
15、ee, 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 International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428
16、-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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).D2227 96 (2011)2
