1、Designation:D 2433 93(Reapproved 2002)Standard Test Methods forRubber Thread1This standard is issued under the fixed designation D 2433;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses
2、 indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the testing of both roundextruded latex and rectangular cut rubber thread products inwhich the base material used in manufacture may b
3、e naturalrubber or synthetic rubber,alone or in combination.These testsare to be made only on the bare uncovered rubber thread.1.2 Owing to the comparatively small cross section of thematerial and also because of the unusual conditions of serviceof this material,certain special test methods have bee
4、n devel-oped and take the place of the tests for other rubber products.1.3 Comparisons may only be made on new rubber threadsor those of identical processing histories.In the interpretationof results from threads which have been subjected to spooling,fabrication,or other process,the previous history
5、 is important,and what is known of this and any relaxation treatments usedshould be stated.1.4 The test methods appear in the following sections:SectionsDensity7-11Count12-16Metric Yield(Length per Unit Weight)17-19Tensile Strength20-22Elongation at Break23 and 24Stress at Predetermined Elongation25
6、-27Elongation Under Fixed Force(Method A)28-30Elongation Under Fixed Force(Method B)31-34Stress Retention35-391.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety a
7、nd health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 1566 Terminology Relating to Rubber2D 4483 Practice for Determining Precision for Test MethodStandards in the Rubber and Carbon Black Industries2E 171 Specification
8、for Standard Atmospheres for Condi-tioning and Testing Flexible Barrier Materials33.Significance and Use3.1 For adequate service performance,rubber threads mustbe tested by appropriate test methods.This standard gives anumber of test methods that are known to be important inrubber thread technology.
9、4.Interferences4.1 Samples or test specimens shall not be allowed to comeinto contact with copper,manganese,or their compoundsduring sample preparation or testing.5.Sample Preparation5.1 The samples and test specimens derived therefrom shallbe kept in a relaxed state and conditioned for not less tha
10、n 16h before testing.The test specimen selected should be clean,dry,and free from any visual defects.6.Test Conditions6.1 The test shall be performed in a standard atmospherehaving a temperature of 23 6 1C(73.4 6 1.8F)and a relativehumidity of 50 6 2%,as defined in Specification E 171.DENSITY7.Termi
11、nology7.1 Definitions of Terms Specific to This Standard:7.1.1 density of a rubber threadthe mass of a unit volumeof thread measured at a temperature of 23 6 1C(73.461.8F)expressed as megagrams per cubic metre.8.Summary of Test Method8.1 The density of a rubber thread is determined by employ-ing two
12、 liquids of known density.These liquids are mixedtogether in such a proportion that,during immersion,a testspecimen of the thread under examination remains suspended,that is,neither floats nor sinks.The density of this mixture ismeasured and this value taken as the density of the specimen.9.Apparatu
13、s9.1 Glass Cylinder,having a capacity of about 1000 cm3.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.37 on Coated Fabricsand Rubber Thread.Current edition approved Dec.10,2002.Published February 2003.Originallyapp
14、roved in 1965.Last previous edition approved in 1998 as D 2433 93(1998).2Annual Book of ASTM Standards,Vol 09.01.3Annual Book of ASTM Standards,Vol 15.09.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.9.2 Hydrometer or Hydrostatic Balanc
15、e(0.001 m3),tomeasure the density of the liquids to an accuracy of not lessthan 0.005 Mg/m3.10.Suitable Mixtures10.1 Most of the rubber threads on the market have adensity in the range from 0.90 to 1.11 Mg/m3.It is necessary,therefore,to have a series of liquids having densities withinthis range.Mix
16、tures of ethanol(0.79 Mg/m3)and distilledwater are suitable.A saturated solution of zinc chloride indistilled water is suitable for densities greater than 1.00 Mg/m3.10.1.1 Before the mixtures are used they shall be homoge-neous and free from air bubbles.They shall be kept in closedcontainers so as to avoid evaporation.They should be used ata temperature of 23 6 2C.11.Procedure11.1 Take four test specimens approximately 10 mm longfrom the thread.Dip each specimen in ethanol and rub betweenthe fi
