1、Designation:D107621Standard Specification forRubberConcentrated,Ammonia Stabilized,Creamed,andCentrifuged Natural Latex1This standard is issued under the fixed designation D1076;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the yea
2、r of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers requirements for first gradeconcentrated natural rubber latex(see Table 1)of the followingca
3、tegories:Category 1Centrifuged Hevea natural latex stabilized withammonia only.Category 2Creamed Hevea natural latex stabilized withammonia only.Category 3Centrifuged Hevea natural latex stabilized withlow ammonia.Category 4Centrifuged,or centrifuged and creamed,gu-ayule latex,or other natural rubbe
4、r latex,containing less than200 g total protein per gram dry weight of latex,withammonia or other hydroxide.Category 5Centrifuged Hevea natural latex treated withaluminum hydroxide or by other means,stabilized with am-monia only containing less than 0.5%non-rubber content.1.2 This specification is n
5、ot necessarily applicable to laticesprepared,stabilized,or preserved by other methods,and shallnot be construed as limiting the desirability or usefulness ofother categories of latices.It does apply to natural latex sourcesother than Hevea brasiliensis but does not apply to com-pounded latex concent
6、rates.1.3 The analytical procedures applicable to the specifica-tions are included and appear in the following order:SectionSampling6 and 7Total Solids8Dry Rubber Content9Protein Content10Total Alkalinity11Viscosity12Sludge Content13Coagulum Content14KOH Number15pH16Mechanical Stability17Copper and
7、Manganese18Density19 31Volatile Fatty Acids32 36Boric Acid37Dry Films38Precision for All Test Methods391.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 This international standard was developed in accor-dance with interna
8、tionally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1278 Test
9、Methods for Rubber from Natural SourcesChemical AnalysisD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD5712 Test Method for Analysis of Aqueous ExtractableProtein in Latex,Natural Rubber,and Elastomeric Prod-ucts Using the Modi
10、fied Lowry MethodD6499 Test Method for Immunological Measurement ofAntigenic Protein in Hevea Natural Rubber(HNR)and itsProductsE70 Test Method for pH of Aqueous Solutions With theGlass Electrode3.General Specification Requirements3.1 In manufacturing,the material shall be processed inaccordance wit
11、h the best commercial practice and shall be ofuniform composition.3.2 The material shall conform to the chemical and physicalrequirements prescribed in Table 1.1This specification is under the jurisdiction ofASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Su
12、bcommittee D11.22on Natural Rubber.Current edition approved June 1,2021.Published June 2021.Originallyapproved in 1949.Last previous edition approved in 2020 as D1076 15(2020).DOI:10.1520/D1076-21.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at s
13、erviceastm.org.For Annual Book of ASTMStandards 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
14、internationally recognized principles 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.14.Significance and Use4.1 This specification d
15、enotes limits on the 5 categories oflatex as defined in the scope and defines the test methods to usefor the specified properties.These test methods may be used forproduction control or for referee purposes.5.Inspection5.1 Inspection of the material shall be made as agreed uponbetween the purchaser
16、and the seller as part of the purchasecontract.SAMPLING AND METHODS OF TESTING6.Preparations for Sampling6.1 Drums:6.1.1 Open-Head DrumsThe top shall be removed and thecontents stirred with a high-speed stirrer for 10 min.6.1.2 Closed-Head DrumsIf the drum has at least 2%airspace,which is 20 mm(0.75 in.)on a standard drum,lay it onits side and roll for not less than 10 min.Up end the drum toits original position and allow to stand for 15 min and thenrepeat the rolling operation for at least a fu
