1、Designation: F 2703 08Standard Test Method forUnsteady-State Heat Transfer Evaluation of Flame ResistantMaterials for Clothing with Burn Injury Prediction1This standard is issued under the fixed designation F 2703; the number immediately following the designation indicates the year oforiginal adopti
2、on 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. Scope1.1 This test method measures the non-steady state heattransfer through flame
3、resistant materials for clothing subjectedto a combined convective and radiant heat exposure.1.1.1 This test method is not applicable to materials that arenot flame resistant.NOTE 1The determination of a materials flame resistance shall bemade prior to testing and done in accordance with the applica
4、bleperformance and/or specification standard for the materials end-use.1.1.2 This test method accounts for the thermal energycontained in an exposed test specimen after the standardizedcombined convective and radiant heat exposure has ceased andis used to estimate performance to a predicted second-d
5、egreeskin burn injury.1.2 This test method is used to measure and describe theresponse of materials, products, or assemblies to heat undercontrolled conditions, but does not by itself incorporate allfactors required for fire hazard or fire risk assessment of thematerials, products, or assemblies und
6、er actual fire conditions.1.3 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-pound or other units that are commonlyused for thermal testing.1.4 This standard does not purport to address the safetyconcerns, if any, asso
7、ciated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1776 Practice for Con
8、ditioning and Testing TextilesD 1777 Test Method for Thickness of Textile MaterialsD 3776 Test Methods for Mass Per Unit Area (Weight) ofFabricE 457 Test Method for Measuring Heat-Transfer Rate Usinga Thermal Capacitance (Slug) CalorimeterF 1494 Terminology Relating to Protective Clothing3. Terminol
9、ogy3.1 Definitions:3.1.1 breakopen, nin testing thermal protective materials,a material response evidenced by the formation of a hole in thetest specimen during the thermal exposure that may result inthe exposure energy in direct contact with the heat sensor.3.1.1.1 DiscussionThe specimen is conside
10、red to exhibitbreakopen when a hole is produced as a result of the thermalexposure that is at least 3.2 cm2(0.5 in.2) in area or at least 2.5cm (1.0 in.) in any dimension. Single threads across theopening or hole do not reduce the size of the hole for thepurposes of this test method.3.1.2 charring,
11、nthe formation of a carbonaceous residueas the result of pyrolysis or incomplete combustion.3.1.3 dripping, na material response evidenced by flow-ing of the polymer.3.1.4 embrittlement, nthe formation of a brittle residue asa result of pyrolysis or incomplete combustion.3.1.5 heat flux, nthe therma
12、l intensity indicated by theamount of energy transmitted divided by area and time;kW/m2(cal/cm2s).3.1.6 ignition, nthe initiation of combustion.3.1.7 melting, na material response evidenced by soften-ing of the polymer.3.1.8 unsteady state heat transfer value, nin testing ofthermal protective materi
13、als, a quantity expressed as thetime-dependent difference between the incident and exitingthermal energy values normal to and across two definedparallel surfaces of an exposed thermal insulative material.3.1.9 thermal performance estimate (TPE), nin testing ofthermal protective materials, the cumula
14、tive amount of energyidentified by the intersection of a measured time-dependent1This test method is under the jurisdiction ofASTM Committee F23 on PersonalProtective Clothing and Equipment and is the direct responsibility of SubcommitteeF23.80 on Flame and Thermal.Current edition approved July 1, 2
15、008. Published August 2008.2For 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.1Copyright ASTM International, 100
16、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.heat transfer response through a subject material to a time-dependent, empirical predicted second-degree skin burn injuryperformance curve3, expressed as a rating or value; J/cm2(cal/cm2).3.1.10 response to heat exposur
17、e, nin testing the resis-tance to heat transfer of thermal protective materials, theobservable response of the material to the energy exposure asindicated by break-open, melting, dripping, charring, em-brittlement, shrinkage, sticking, and ignition.3.1.11 second-degree burn injury, nin testing of th
18、ermalprotective materials, reversible burn damage at the epidermis/dermis interface in human tissue.3.1.12 shrinkage, na decrease in one or more dimensionsof an object or material.3.1.13 sticking, na material response evidenced by soft-ening and adherence of the material to the surface of itself ora
19、nother material.3.1.14 sample test suite, nany number of test specimensused to derive a single thermal performance estimate value.3.1.14.1 Discussionthe determination of a single thermalperformance estimate value requires exposing a number ofspecimens under varying exposure conditions so that thethe
20、rmal energy stored in the sample after the heat source isremoved is considered and accounted for when determiningperformance against a burn injury prediction.3.1.15 For the definitions of protective clothing terms usedin this method, refer to Terminology F 1494, and for othertextile terms used in th
21、is method, refer to Terminology D 123.4. Summary of Test Method4.1 A horizontally positioned test specimen is exposed to acombined convective and radiant heat source with an exposureheat flux of 84 6 2kW/m2(2 6 0.05 cal/cm2s).NOTE 2Other exposure heat flux values are allowed, however differ-ent expo
22、sure conditions have the potential to produce different results. Thetest facility shall verify the stability of other exposure levels over thematerials exposure time interval (used to determine the thermal perfor-mance estimate value) and include this in the test results report.4.2 The unsteady-stat
23、e transfer of heat through the testspecimen is measured using a copper slug calorimeter. Thechange in temperature versus time is used, along with theknown thermo-physical properties of copper, to determine therespective thermal energy passed through the test specimen.4.3 A Thermal Performance Estima
24、te value of the testspecimen is determined iteratively as the intersection of thetime-dependent cumulative heat response as measured by thecalorimeter to a time-dependent, empirical predicted second-degree skin burn injury performance curve identified in10.4.1.5,Eq1).4.4 Observations of the thermal
25、response of the specimenresulting from the exposure are optionally reported.5. Significance and Use5.1 This test method is intended for the determination of athermal performance estimate value of a material, a combina-tion of materials, or a comparison of different materials used inflame resistant c
26、lothing for workers exposed to combinedconvective and radiant thermal hazards.5.2 This test method evaluates a materials heat transferproperties when exposed to a heat exposure at a constant valueand specific duration. Air movement at the face of thespecimen and around the calorimeter can affect the
27、 measuredheat transferred due to forced convective heat losses. Minimiz-ing air movement around the specimen and test apparatus willaid in the repeatability of the results.5.3 This test method accounts for the thermal energy storedin the exposed test specimen after the heat exposure hasceased. Highe
28、r values of Thermal Performance Estimate rat-ings determined in this test associate to higher values ofthermal (convective and radiative) energy protection against apredicted skin burn injury.5.4 This test method maintains the specimen in a static,horizontal position and does not involve movement ex
29、cept thatresulting from the exposure.5.5 This test method specifies a standardized 84 6 2kW/m2(2 6 0.05 cal/cm2s) exposure condition. Differentexposure conditions have the potential to produce differentresults. Other exposure conditions representative of the ex-pected hazard are allowed but shall be
30、 reported with the resultsalong with a determination of the exposure energy levelstability.5.6 This test method contains optional provisions for con-ducting certification testing against a prescribed ThermalPerformance Estimate value.6. Apparatus and Materials6.1 General ArrangementThe measurement a
31、pparatusconfiguration consists of a combined convective and radiantenergy heat source, a water cooled shutter for exposure control,a specimen and sensor support structure, a specimen holderassembly, a copper calorimeter sensor assembly, and a dataacquisition/analysis system. Automation of the appara
32、tus forexecution of the measurement procedure is allowed. Thegeneral arrangement of the test apparatus configuration isshown in Fig. 1.6.2 Gas SupplyPropane (commercial grade or better) orMethane (technical grade or better).6.3 Gas FlowmeterAny gas flowmeter or rotometer withrange to give a flow equ
33、ivalent of at least 6 L (0.21 ft3)/min airat standard conditions.6.4 Thermal Energy Source6.4.1 Two each, Meker or Fisher burners jetted for theselected fuel gas (propane or methane) with a 38 mm (1.5 in.)diameter top arranged so that the bodies (top section) do not3Derived from: Stoll, A.M. and Chi
34、anta, M.A., “Method and Rating System forEvaluations of Thermal Protection”, Aerospace Medicine, Vol 40, 1969, pp.1232-1238 and Stoll, A.M. and Chianta, M.A., “Heat Transfer through Fabrics asRelated to Thermal Injury”, Transactions New York Academy of Sciences, Vol 33(7), Nov. 1971, pp. 649-670.F27
35、03082obstruct the quartz lamps and their flame profiles overlap.Dimension tolerances are 65%.6.4.2 Nine 500W T3 translucent quartz infrared lamps4,connected to a variable electrical power controller, arranged asa linear array with 13 6 0.5 mm center-to-center spacing set125 6 10 mm from the specimen
36、 surface.6.4.2.1 Use of a water-cooled housing for the quartz infra-red lamp bank is recommended. This helps to avoid heatingadjacent mechanical components and to shield the operatorfrom the radiant energy.6.5 Thermal Sensor6.5.1 The transmitted heat sensor is a 4 6 0.05 cm diametercircular copper s
37、lug calorimeter5constructed from electricalgrade copper with a mass of 18 6 0.05 g (prior to drilling) witha singleANSI type J (Fe/Cu-Ni) orANSI type K (Ni-Cr/Ni-Al)thermocouple wire bead (0.254 mm wire diameter or finerequivalent to 30 AWG) installed as identified in 6.5.2 andshown in Fig. 2. The s
38、ensor holder shall be constructed fromnon-conductive heat resistant material with a thermal conduc-tivity value of # 0.15 W/mK, high temperature stability, andresistance to thermal shock. The board shall be nominally 1.3cm (0.5 in.) or greater in thickness. The sensor is held into therecess of the b
39、oard using three straight pins, trimmed to anominal length of 5 mm, by placing them equidistant aroundthe edge of the sensor so that the heads of the pins hold thesensor flush to the surface.6.5.1.1 Paint the exposed surface of the copper slug calo-rimeter with a thin coating of a flat black high te
40、mperaturespray paint with an absorptivity of 0.9 or greater6. The paintedsensor must be dried and cured, in accordance with themanufacturers instructions, before use and present a uniformlyapplied coating (no visual thick spots or surface irregularities).In the absence of manufacturers instructions,
41、 an external heatsource, for example, an external heat lamp, shall be used tocompletely drive off any remaining organic carriers in a freshlypainted surface before use.NOTE 3Emissivity of painted calorimeters is discussed in the ASTMReport, “ASTM Research Program on Electric Arc Test Method Devel-op
42、ment to Evaluate Protective Clothing Fabric; ASTM F18.65.01 TestingGroup Report on Arc Testing Analysis of the F 1959 Standard TestMethodPhase 1”76.5.2 The thermocouple wire bead is installed in the calo-rimeter as shown in Fig. 2.6.5.2.1 The thermocouple wire bead shall be bonded to thecopper disk
43、either mechanically or by using high melting point(HMP) solder.(1) A mechanical bond shall be produced by mechanicallydeforming the copper disk material (utilizing a copper fillingslug as shown in Fig. 2) around the thermocouple bead.(2) A solder bond shall be produced by using a suitableHMP solder
44、with a melting temperature 280C.NOTE 4HMP solders consisting of 5 %Sb-95 %Pb (307C meltingpoint) and 5 %Sb-93.5 %Pb-1.5 %Ag (;300C melting point) have beenfound to be suitable. The 280 C temperature minimum identified abovecorresponds to the point where melting of the solder bond would beexperienced
45、 with an 17 second exposure of an 84 kW/m2heat flux to aprepared copper calorimeter with a surface area of 12.57 cm2and a massof 18.0 g. A careful soldering technique is required to avoid “cold” solderjoints (where the solder has not formed a suitable bond of the thermo-couple to the copper disk).6.
46、5.3 Weight the sensor board assembly so that the totalmass is 1.0 6 0.01 kg and the downward force exhibited by thecopper slug sensor surface is uniform.NOTE 5Any system of weighting that provides a uniformly weightedsensor is allowed. An auxiliary stainless steel plate affixed to and/orindividual w
47、eights placed at the top of the sensor assembly have beenfound to be effective.4A 500 Watt T3 120VAC quartz infrared heat lamp, product number 21651-1from Philips Lighting Company has been used successfully in this application.5See Test Method E 457 for information regarding slug calorimeters.6Zynol
48、yte #635 from Aervoe Industries has been found suitable. Zynolyte is aregistered trademark of the Glidden Company.7Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: F181001.NOTE 1Note the exposure heat source incorporates two Meke
49、r burners and nine quartz infrared lampsFIG. 1 Apparatus used to Measure Heat Transfer Performance of Textile MaterialsF27030836.6 Data Acquisition/Analysis SystemA data acquisition/analysis system is required that is capable of recording thecalorimeter temperature response, calculating the resultingthermal energy, and determining the test endpoint by compar-ing the time-dependent thermal energy transfer reading to anempirical performance curve.6.6.1 The data acquisition component shall have a minimumsampling rate of four samples per second f
