ASTM_D_5930_-_09.pdf

Designation:D593009Standard Test Method forThermal Conductivity of Plastics by Means of a TransientLine-Source Technique1This standard is issued under the fixed designation D5930;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()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This test method covers the determination of the thermalconductivity of plastics over a temperature range from 40 to400C.The thermal conductivity of materials in the range from0.08 to 2.0 W/m.K can be measured covering thermoplastics,thermosets,and rubbers,filled and reinforced.1.2 The values stated in SI units shall be regarded asstandard.1.3 This standard does not purport to address the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish proper safety andhealth practices and determine the applicability of regulatorylimitations prior to use.NOTE1There is no known ISO equivalent to this test method.2.Referenced Documents2.1 ASTM Standards:2C177 Test Method for Steady-State Heat Flux Measure-ments and Thermal Transmission Properties by Means ofthe Guarded-Hot-Plate ApparatusC518 Test Method for Steady-State Thermal TransmissionProperties by Means of the Heat Flow Meter ApparatusC1113 Test Method for Thermal Conductivity of Refracto-ries by Hot Wire(Platinum Resistance ThermometerTechnique)D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD2717 Test Method for Thermal Conductivity of LiquidsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE1225 Test Method for Thermal Conductivity of SolidsUsing the Guarded-Comparative-Longitudinal Heat FlowTechnique3.Terminology3.1 DefinitionsTerminology used in this standard is inaccordance with Terminology D883.3.2 Definitions of Terms Specific to This Standard:3.2.1 temperature transient,nthe temperature rise associ-ated with the perturbation of a system,initially at a uniformtemperature.The system does not attain thermal equilibriumduring the transient.3.2.2 thermal conductivity,nthe time rate of steady heatflow/unit area through unit thickness of a homogeneous mate-rial in a direction perpendicular to the surface induced by a unittemperature difference.3.2.2.1 DiscussionWhere other modes of heat transfer arepresent in addition to conduction,such as convection andradiation,this property often is referred to as the apparentthermal conductivity,app.3.2.2.2 DiscussionThermal conductivity must be associ-ated with the conditions under which it is measured,such astemperature and pressure,as well as the compositional varia-tion of the material.Thermal conductivity may vary withdirection and orientation of the specimen since some materialsare not isotropic with respect to thermal conductivity.In thecase of thermoset polymers,thermal conductivity may varywith the extent of cure.3.2.3 thermal diffusivitya heat-transport property given bythe thermal conductivity divided by the thermal mass,which isa product of the density and the heat capacity.3.3 Symbols:3.3.1 CProbe constant.3.3.2 Thermal conductivity,W/m.K.3.3.3 QHeat output per unit length,W/m.3.3.4 T2The temperature(K)recorded at time t2.3.3.5 T1The temperature(K)recorded at time t1.3.4 Subscript:3.4.1 avaverage.3.4.2 appapparent.3.4.3 refreference.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Properties.Current edition approved Aug.15,2009.Published September 2009.Originallyapproved in 1997.Last previous edition approved in 2001 as D5930-01.DOI:10.1520/D5930-09.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Test Method4.1 Line-Source TechniqueThis is a transient method fordetermining thermal conductivity(1,2).3A line source of heatis located at the center of the specimen being tested.Theapparatus is at a constant initial temperature.During the courseof the measurement,a known amount of heat produced by theline-source results in a heat wave propagating radially into thespecimen.The rate of heat propagation is related to the thermaldiffusivity of the polymer.The temperature rise of the line-source varies linearly with the logarithm of time(3).Thisrelationship can be used directly to calculate the thermalconductivity of the sample.The line-source of heat can beachieved in a number of ways.In this test method,it is in theform of a probe as described in 7.2.5.Significance