ASTM D2449-1988(2011) Standard Specification for Rubber Bales From Natural SourcesLimit on Coating 《天然橡胶包上橡胶覆层的极限值的标准规格》.pdf

1、Designation: D2449 88 (Reapproved 2011)Standard Specification forRubber Bales From Natural SourcesLimit on Coating1This standard is issued under the fixed designation D2449; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year

2、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 bale coating on bales of naturalrubber (that have rubber wrapper sheets on the bales) and

3、includes test method description. It specifies the maximumpermissible amount of such coating.1.2 This specification is not applicable to natural rubber thatis packaged with plastic wrappers, as no bale coating is used.1.3 The following safety hazards caveat pertains only to thetest method portion, S

4、ection 5, of this specification: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions pr

5、ior to use.2. Referenced Documents2.1 ASTM Standards:2D1278 Test Methods for Rubber from Natural SourcesChemical AnalysisD1485 Practice for Rubber from Natural SourcesSampling and Sample Preparation3. Requirements3.1 The average amount of bale coating on the bales in thesample should not exceed 4 6

6、0.1 g/kg of rubber. Lots may berejected if the bale coating exceeds this amount.NOTE 1Four grams per kilogram of rubber is equivalent to amaximum of 1 lb/250 lb-bale.4. Sampling4.1 Carefully remove portions at random from the outsidewrapper sheets from any three sides of the bale so as to lose amini

7、mum of bale coating. Handle and store the sampledportions so as to lose a minimum of bale coating. The numberof bales sampled from a lot shall be in accordance with PracticeD1485, or as agreed upon between the purchaser and the seller.5. Test Methods5.1 Summary of Methods:5.1.1 Method AThe amount of

8、 mineral filler from balecoating present on the outside wrapper sheets of the bales isdetermined using an ashing procedure.5.1.2 Method BThe amount of bale coating on the outsidewrapper sheets of all grades of smoked sheet rubbers only isdetermined by a brushing or scraping procedure.5.1.3 The brush

9、ing or scraping procedure, while muchfaster, is not suitable for use on crepe sheet rubbers because ofpenetration through holes in the outside wrapper sheet anddifficulties of removal from between wrapper sheets. Thisnecessitates the use of the ash procedure on crepe sheetrubbers.5.2 Significance an

10、d UseThe rubber bale coating is usefulfor eliminating the adhesion or sticking together of bales whenin contact with each other during transportation and/or storage.Excessive coating may result in reduced compounded physicalproperties.5.3 Procedure:5.3.1 Method A (Ash Method)Die out or cut two 50 by

11、50-mm test specimens, within a tolerance of 61 mm, fromeach of three portions removed from the bale, taking care notto lose the bale coating. Test each specimen separately. Anybale coating falling from the test specimen should be added tothe ash crucible together with the test specimen. Ash inaccord

12、ance with Test Methods D1278, with the exception ofthe weight of the 50-mm square specimen to the nearest 0.01 grather thana5to6-gspecimen of homogenized rubber.5.3.2 Method B (Brushing or Scraping Method)Die outor cut out a test specimen 150 by 150-mm, within a toleranceof 61 mm, from each of the t

13、hree portions removed from thebale, following the precautions given in 4.1. Weigh the testspecimen to the nearest 0.01 g before and after removal of balecoating. Remove the bale coating, using a stiff wire brush or byscraping, taking care not to abrade rubber from the wrappersheet while thoroughly r

14、emoving as much of the bale coatingas possible.5.4 Calculations:5.4.1 Method A (Ash Method)Calculate the amount ofbale coating per bale as follows:1This specification is under the jurisdiction ofASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.22 on Natural Rubber.Cur

15、rent edition approved Nov. 1, 2011. Published January 2012. Originallyapproved in 1965. Last previous edition approved in 2007 as D2449 88 (2007).DOI: 10.1520/D2449-88R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Ann

16、ual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.A 5 BC/SW (1)where:A = amount of bale coating, g/kg rubber,B = nominal surf

17、ace area of bale, mm2,C = average amount of ash for the six test specimens, g,S = surface area of test specimen, mm2, andW = nominal weight of bale, kg.5.4.2 Method B (Brushing or Scraping Method)Calculatethe amount of bale coating per bale as follows:A 5 BC/SW (2)where:A = amount of bale coating, g

18、/kg rubber,B = nominal surface area of bale, mm2,C = average amount of bale coating, g, for the three testspecimens determined from the difference in weightsbefore and after removal of bale coating,S = surface area of test specimen, mm2, andW = nominal weight of bale, kg.5.5 Precision and BiasNo sta

19、tement is made about eitherthe precision or the bias of the test method in SpecificationD2449, because there is no way to obtain uniform samples thatcan be shipped without changing the coating adhering to thesamples.6. Keywords6.1 ash method; bale coating; bareback bales; brushingmethod; mineral fil

20、ler; natural rubber balesASTM 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 infring

21、ement 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 either for revision of this standard

22、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 hearing you shouldmake your views

23、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 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/).D2449 88 (2011)2