1、Designation: F 2700 08Standard Test Method forUnsteady-State Heat Transfer Evaluation of Flame ResistantMaterials for Clothing with Continuous Heating1This standard is issued under the fixed designation F 2700; the number immediately following the designation indicates the year oforiginal adoption o
2、r, 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 resi
3、stant materials for clothing subjectedto a continuous, combined convective and radiant heat expo-sure.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 according to the appl
4、icable performanceand/or specification standard for the materials end-use.1.1.2 This test method does not predict a materials skinburn injury performance from the specified thermal energyexposure. It does not account for the thermal energy containedin the test specimen after the exposure has ceased.
5、NOTE 2See Appendix X4 for additional information regarding thistest method and predicted skin 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
6、for fire hazard or fire risk assessment of thematerials, products, or assemblies under 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 te
7、sting.1.4 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 appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Docume
8、nts2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1776 Practice for Conditioning 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 Capacit
9、ance (Slug) CalorimeterF 1494 Terminology Relating to Protective ClothingF 2703 Test Method for Unsteady-State Heat TransferEvaluation of Flame Resistant Materials for Clothing withBurn Injury Prediction3. Terminology3.1 Definitions:3.1.1 breakopen, nin testing thermal protective materials,a materia
10、l 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 considered to exhibitbreakopen when a hole is produced as a result of the thermalexposure tha
11、t 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, nthe formation of a carbonaceous residueas the result of pyrolysis or incomplete combu
12、stion.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 thermal intensity indicated by theamount of energy transmitted divided by area and time;kW/m
13、2(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 materials, a quantity expressed as thetime-dependent difference between the incident and exi
14、tingthermal energy values normal to and across two definedparallel surfaces of an exposed thermal insulative material.1This 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 Ther
15、mal.Current edition approved July 1, 2008. 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 webs
16、ite.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.9 heat transfer performance value (HTP), nin testingof thermal protective materials, the cumulative amount ofenergy identified by the intersection of the measured time-dependent
17、 heat transfer response through the subject materialto a time-dependent, empirical performance curve, expressedas a rating or value; J/cm2(cal/cm2).3.1.10 response to heat exposure, nin testing the thermalresistance of thermal protective materials, the observableresponse of the material to the energ
18、y exposure as indicated bybreak-open, melting, dripping, charring, embrittlement, shrink-age, sticking, and ignition.3.1.11 shrinkage, na decrease in one or more dimensionsof an object or material.3.1.12 sticking, na material response evidenced by soft-ening and adherence of the material to the surf
19、ace of itself oranother material.3.1.13 For the definitions of protective clothing terms usedin this method, refer to Terminology F 1494, and for othertextile terms used in this method, refer to Terminology D 123.4. Summary of Test Method4.1 A horizontally positioned test specimen is exposed to acom
20、bined convective and radiant heat source with an exposureheat flux of 84 6 2kW/m2(2 6 0.05 cal/cm2s).NOTE 3Other exposure heat flux values are allowed, however differ-ent exposure conditions have the potential to produce different results. Thetest facility shall verify the stability of other exposur
21、e levels over thematerials exposure time interval (used to determine the heat transferperformance value) and include this in the test results report.4.2 The unsteady-state transfer of heat through the testspecimen is measured using a copper slug calorimeter. Thechange in temperature versus time is u
22、sed, along with theknown thermo-physical properties of copper, to determine therespective thermal energy passed through the test specimen.4.3 Aheat transfer performance value of the test specimen isdetermined as the intersection of the time-dependent cumula-tive heat response as measured by the calo
23、rimeter to atime-dependent, empirical performance curve identified in10.9.4.4 Observations of the thermal response of the specimenresulting from the exposure are optionally noted.5. Significance and Use5.1 This test method is intended for the determination of theheat transfer performance value of a
24、material, a combination ofmaterials, or a comparison of different materials used in flameresistant clothing for workers exposed to combined convectiveand radiant thermal hazards.5.2 This test method evaluates a materials unsteady-stateheat transfer properties when exposed to a continuous andconstant
25、 heat source.Air movement at the face of the specimenand around the calorimeter can affect the measured heattransferred due to forced convective heat losses. Minimizingair movement around the specimen and test apparatus will aidin the repeatability of the results.5.3 This test method maintains the s
26、pecimen in a static,horizontal position and does not involve movement except thatresulting from the exposure.5.4 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. Use of other expo
27、sure conditions that are representativeof the expected hazard are allowed but shall be reported withthe results along with a determination of the exposure energylevel stability.5.5 This test method does not predict skin burn injury fromthe heat exposure.NOTE 4See Appendix X4 for additional informati
28、on regarding thistest method and predicted skin burn injury.6. Apparatus and Materials6.1 General ArrangementThe measurement apparatusconfiguration consists of a combined convective and radiantenergy heat source, a water cooled shutter for exposure control,a specimen and sensor support structure, a
29、specimen holderassembly, a copper calorimeter sensor assembly, and a dataacquisition/analysis system. Automation of the apparatus forexecution of the measurement procedure is allowed. Thegeneral arrangement of the test apparatus configuration isshown in Fig. 1.6.2 Gas SupplyPropane (commercial grade
30、 or better) orMethane (technical grade or better).6.3 Gas FlowmeterAny gas flowmeter or rotometer withrange to give a flow equivalent of at least 6 L (0.21 ft3)/min airat standard conditions.6.4 Thermal Energy Sources6.4.1 Two each, Meker or Fisher burners jetted for theselected fuel gas (propane or
31、 methane) with a 38 mm (1.5 in.)diameter top and an orifice size of 1.2 mm (364 in.) arranged sothat the bodies (top section) do not obstruct the quartz lampsand their flame profiles overlap. Dimension tolerances are65%.6.4.2 Nine 500W T3 translucent quartz infrared lamps3,connected to a variable el
32、ectrical power controller, arranged asa linear array with 13 6 0.5 mm center-to-center spacing set125 6 10 mm from the specimen 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
33、 operatorfrom the radiant energy.6.5 Thermal Sensor6.5.1 The transmitted heat sensor is a 4 6 0.05 cm diametercircular copper slug calorimeter constructed from electricalgrade copper with a mass of 18 6 0.05 grams (prior to drilling)with a single ANSI type J (Fe / Cu-Ni) or ANSI type K (Ni-Cr/ Ni-Al
34、) thermocouple wire bead (0.254 mm wire diameter orfiner equivalent to 30 AWG) installed as identified in 6.5.2and shown in Fig. 2 (see Test Method E 457 for informationregarding slug calorimeters). The sensor holder shall be con-structed from non-conductive heat resistant material with athermal con
35、ductivity value of # 0.15 W/mK, high tempera-ture stability, and resistance to thermal shock. The board shallbe nominally 1.3 cm (0.5 in.) or greater in thickness. The3A 500 Watt T3 120VAC quartz infrared heat lamp, product number 21651-1from Philips Lighting Company has been used successfully in th
36、is application.F2700082sensor is held into the recess of the board using three straightpins, trimmed to a nominal length of 5 mm, by placing themequidistant around the edge of the sensor so that the heads ofthe pins hold the sensor flush to the surface.6.5.1.1 Paint the exposed surface of the copper
37、 slug calo-rimeter with a thin coating of a flat black high temperaturespray paint with an absorptivity of 0.9 or greater4. The paintedsensor must be dried and cured, according to the manufacturersinstructions, before use and present a uniformly applied coat-ing (no visual thick spots or surface irr
38、egularities). In theabsence of manufacturers instructions, an external heat source,for example, an external heat lamp, shall be used to completelydrive off any remaining organic carriers in a freshly paintedsurface before use.NOTE 5Absorptivity of painted calorimeters is discussed in theASTM Researc
39、h Report, “ASTM Research Program on Electric Arc TestMethod Development to Evaluate Protective Clothing Fabric; ASTMF18.65.01 Testing Group Report on Arc Testing Analysis of the F 1959Standard Test MethodPhase 1.”56.5.2 The thermocouple wire bead is installed in the calo-rimeter as shown in Fig. 2.6
40、.5.2.1 The thermocouple wire bead shall be bonded to thecopper disk 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 bea
41、d.(2) A solder bond shall be produced by using a suitableHMP solder with a melting temperature 280C.NOTE 6HMP solders consisting of 5 %Sb-95 %Pb (307 C meltingpoint) and 5 %Sb-93.5%Pb-1.5 %Ag (300 C melting point) have beenfound to be suitable. The 280 C temperature minimum identified abovecorrespon
42、ds to the point where melting of the solder bond would beexperienced 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 no
43、t formed a suitable bond of the thermo-couple to the copper disk).6.5.3 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 7Any system of weighting that provides a uniformly weightedsensor is allow
44、ed. An auxiliary stainless steel plate affixed to and/orindividual weights placed at the top of the sensor assembly have beenfound to be effective.6.6 Data Acquisition/Analysis SystemA data acquisition/analysis system is required that is capable of recording thecalorimeter temperature response, calc
45、ulating 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 for temperatures to250C with a mi
46、nimum resolution of 0.1C and an accuracy of60.75C. It must be capable of making cold junction correc-tions and converting the millivolt signals from either the typeJ or K thermocouple to temperature (see NIST Monograph 175or ASTM MNL 126Manual on the Use of Thermocouples inTemperature Measurement).6
47、.7 Solvents, alcohol or petroleum solvent for cleaning thecopper slug calorimeter.6.8 Paint, flat-black, spray type with an absorptivity value0.90.6.9 Specimen Holder Assembly(See Fig. 3.) Three com-plete assemblies are desirable for testing efficiency. Alterationis allowed to provide for mechanical
48、ly restraining a specimenin the holder (see 10.3.2.1).NOTE 8The upper specimen mounting plate is designed so that the4Zynolyte #635 from Aervoe Industries has been found suitable. Zynolyte is aregistered trademark of the Glidden Company.5Supporting data have been filed at ASTM International Headquar
49、ters and maybe obtained by requesting Research Report RR: F181001.6Available from ASTM Headquarters.NOTE 1Note the exposure heat source incorporates two Meker burners and nine quartz infrared lampsFIG. 1 Apparatus used to Measure Heat Transfer Performance of Textile MaterialsF2700083copper calorimeter assembly fits into the center cutout.An optional spacercomponent is also designed to fit into the center cutout with the coppercalorimeter positioned on top of it. Tolerances for all dimensions are61 % to accommodate these arrangement req
