ASTM_D_3800_-_99.pdf

Designation:D 3800 99Standard Test Method forDensity of High-Modulus Fibers1This standard is issued under the fixed designation D 3800;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 indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the determination of the densityof high-modulus fibers and is applicable to both continuous anddiscontinuous fibers.1.2 This standard may involve hazardous materials,opera-tions,and equipment.This standard does not purport toaddress all of the safety concerns,if any,associated with itsuse.It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.See Section 9 for additional information.1.3 The values stated in SI units are to be regarded asstandard.2.Referenced Documents2.1 ASTM Standards:D 891 Test Methods for Specific Gravity,Apparent,ofLiquid Industrial Chemicals2D 1505 Test Method for Density of Plastics by the Density-Gradient Technique3D 3878 Terminology of High-Modulus Reinforcing Fibersand Their Composites4D 5229/D 5229M Test Method for Moisture AbsorptionProperties and Equilibrium Conditioning of Polymer Ma-trix Composite Materials4D 6308 Guide for Identification of Composite Materials inComputerized Material Property Databases4E 12 Terminology Relating to Density and Specific Gravityof Solids,Liquids,and Gases5E 177 Practice for Use of the Terms Precision and Bias inASTM Test Methods6E 1471 Guide for Identification of Fibers,Fillers,and CoreMaterials in Computerized Material Property Databases43.Terminology3.1 DefinitionsTerminology D 3878 defines terms relatingto composite materials.Terminology E 12 defines terms relat-ing to density.Practice E 177 defines terms relating to statis-tics.In the event of a conflict between terms,TerminologyD 3878 shall have precedence over other standards.3.2 Symbols:rs5 density of standardrl5 density of liquidrf5 density of fiberrmf5 density of the measured fiber containing sizingrml5 density of the measured liquid containing sur-factantrsur5 density of surfactantrsz5 density of sizingrw5 density of waters5 standard deviationM15 weight of suspension wire in airM25 weight of suspension wire in liquid(to immer-sion point)M35 weight of suspension wire plus item whosedensity is to be determined(in air)M45 weight of suspension wire plus item whosedensity is to be determined(in liquid)M3 M15 weight of item for density to be determined inairM4 M25 weight of item for density to be determined inliquid4.Summary of Test Method4.1 GeneralUsing random selection techniques,a suitablesize sample of high-modulus fiber can be tested by any of thethree procedures described in this test method.Procedure Ausing water with a surfactant as the liquid medium is preferreddue to environmental and safety considerations.The othermethods shall not be used if Procedure A is adequate.Interimuse of Procedures B or C is allowed while a comparison ismade to results using Procedure A.4.2 Procedure ABuoyancy(Archimedes)Method:4.2.1 The sample is weighed in air and weighed in a liquidthat will thoroughly wet the sample and is of a lower density.4.2.2 The difference in weight of the sample in the twomedia is the buoyancy force.This force is converted to sample1This test method is under the jurisdiction of ASTM Committee D-30 onComposite Materials and is the direct responsibility of Subcommittee D30.03 onConstituent/Precursor Properties.Current edition approved Oct.10,1999.Published February 2000.Originallypublished as D 3000 79.Last previous edition D 3800 79(1990)e1.2Annual Book of ASTM Standards,Vol 15.05.3Annual Book of ASTM Standards,Vol 08.01.4Annual Book of ASTM Standards,Vol 15.03.5Discontinued;see 1995 Annual Book of ASTM Standards,Vol 15.05.Replacedby Terminology E 1547.6Annual Book of ASTM Standards,Vol 14.02.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.volume by dividing it by the liquid density.The sample weightin air divided by the sample volume equals the sample density.4.3 Procedure BSink-Float Technique:4.3.1 The sample is placed in a container containing a liquidthat will thoroughly wet the sample and is of a lower density.A liquid of higher density than the sample and miscible withthe first liquid is then added slowly to the container underconstant gentle mixing until the sample is suspended in themixture.4.3.2 The density of the resulting mixed liquid is deter-mined using either a hydrometer or a pycnometer.The densityof the sample is equal to the density of the liquid in which thesample is suspended.4.4 Procedure CFor an alternative method,which may beused,see Test Method D 1505.5.Significance and Use5.1 Fiber density is useful in the evaluation of new materialsat the re