ASTM F955-2015 Standard Test Method for Evaluating Heat Transfer through Materials for Protective Clothing Upon Contact with Molten Substances《通过接触带熔态物质的防护衣材料评估热传递的标准试验方法》.pdf

《ASTM F955-2015 Standard Test Method for Evaluating Heat Transfer through Materials for Protective Clothing Upon Contact with Molten Substances《通过接触带熔态物质的防护衣材料评估热传递的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM F955-2015 Standard Test Method for Evaluating Heat Transfer through Materials for Protective Clothing Upon Contact with Molten Substances《通过接触带熔态物质的防护衣材料评估热传递的标准试验方法》.pdf（8页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: F955 15Standard Test Method forEvaluating Heat Transfer through Materials for ProtectiveClothing Upon Contact with Molten Substances1This standard is issued under the fixed designation F955; the number immediately following the designation indicates the year of originaladoption or, in t

2、he case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the evaluation of materialsthermal resistance to heat transfe

3、r when exposed to a moltensubstance pour.1.1.1 This test method was validated using molten sub-stances of aluminum, brass, and iron. The test shall bepermitted to be adapted for use with other substances.1.2 This test method is applicable to materials from whichfinished primary protective apparel ar

4、ticles are made.1.3 This test method does not measure the flammability ofmaterials, nor is it intended for use in evaluating materialsexposed to any other thermal exposure.1.4 Use this test method to measure and describe theproperties of materials, products, or assemblies in response tomolten substa

5、nce pour under controlled laboratory conditionsand shall not be used to describe or appraise the thermal hazardor fire risk of materials, products, or assemblies under actualconditions. However, it is acceptable to use results of this testas elements of a thermal risk assessment which takes intoacco

6、unt all the factors that are pertinent to an assessment of thethermal hazard of a particular end use.1.5 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 and hea

7、lth practices and determine the applica-bility of regulatory limitations prior to use. Specific hazardstatements are given in Section 8.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesE457 Test Method for Measuring Heat-Transfer Rate Usinga Thermal Capacitance (Slug)

8、CalorimeterF1002 Performance Specification for Protective Clothingand Materials for Use by Workers Exposed to SpecificMolten Substances and Related Thermal HazardsF1494 Terminology Relating to Protective Clothing3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 break-openin test

9、ing thermal protective material, aresponse evidenced by the formation of a hole in the materialwhich allows the molten substance to pass through the mate-rial.3.1.2 charringthe formation of carbonaceous residue asthe result of pyrolysis or incomplete combustion.3.1.3 drippinga material response evid

10、enced by flowingof the polymer.3.1.4 embrittlementthe formation of a brittle residue asthe result of pyrolysis or incomplete combustion.3.1.5 heat fluxthe thermal intensity indicated by theamount of energy transmitted divided by area and time, W/m2(cal/cm2s).3.1.6 human tissue burn tolerance (heat t

11、olerance)in thetesting of thermal protective materials, the amount of thermalenergy predicted to cause a second-degree burn injury inhuman tissue.3.1.7 ignitionthe initiation of combustion.3.1.8 meltinga material response evidenced by softeningof the polymer.3.1.9 primary protective clothingprotecti

12、ve clothing de-signed to be worn for work activities during which significantexposure to molten substance splash, radiant heat, and flame islikely to occur.3.1.9.1 DiscussionPrimary protective clothing is used inwork activities that include charging, tapping, and pouring,during which work is carried

13、 out in close proximity to moltensubstances and hot surfaces where contact with either is likely.3.1.10 response to molten substance pourin testing ther-mal protective material, the observed effect of molten sub-stance contact on textile properties or deterioration of thematerial.1This test method i

14、s 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, 2015. Published July 2015. Originally approvedin 1985. Last previous edition approved in 2007 as F95

15、5 07. DOI: 10.1520/F0955-15.2For 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.Copyright ASTM International, 100

16、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.11 shrinkagea decrease in one or more dimensions ofan object or material.3.1.12 thermal end pointin the testing of thermal protec-tive materials, the point where the copper slug calorimetersensor response (heat ener

17、gy measured) intersects with apredicted skin burn injury model.3.2 For definitions of other textile terms used in this testmethod, refer to Terminology D123.4. Summary of Test Method4.1 Amaterial specimen is mounted on a vertical incline andis exposed to a molten substance pour of prescribed minimum

18、temperature, volume, pour rate, and vertical height.4.2 The amount of heat energy that is transmitted throughthe test specimen during and after the molten substanceexposure is measured using two copper slug calorimeters. Theheat transport response is assessed versus the Stoll curve, anapproximate hu

19、man tissue tolerance predictive model thatprojects the onset of a second-degree skin burn injury asmanifested by a blister (See 12.2).4.3 A specific set of subjective evaluations is performed onthe test specimen response to the molten substance exposureusing a standardized rating scale for appraisal

20、 (found in AnnexA1).5. Significance and Use5.1 Workers who have the potential to be exposed to moltenmetal contact shall be permitted to wear protective clothingusing materials that have been evaluated for heat transfer usingthis test method.5.2 This test method rates materials, that are intended fo

21、rprimary protective clothing against potential molten substancecontact, for their thermal insulating properties and their reac-tion to the test exposure.5.3 The protective performance, as determined by this testmethod, will relate to the actual end-use performance only tothe degree that the end-use

22、exposure is identical to theexposure used in the test method.5.4 Visual inspection of the specimen subjectively notes thematerials resistance to molten substance contact.6. Apparatus6.1 The test apparatus consists of four major components asfollows:6.1.1 An inclined specimen mounting and exposure bo

23、ardwith two copper slug calorimeter thermal sensors and supports,6.1.2 A pouring crucible and pouring mechanism,6.1.3 A furnace for melting the test metal, and6.1.4 Instruments for measuring test conditions and testresults.6.2 Sensor Construction6.2.1 Each copper slug calorimeter shall be 18 6 1g,40

24、mm diameter and 1.6 mm thick and shall be constructed fromelectrical grade copper with a single 30 gage, iron/constantanthermocouple wire and shall be installed as identified in Fig. 1.6.2.2 The exposed surface of each copper slug calorimetershall be painted with a thin coating of a flat black hight

25、emperature spray paint with an emissivity of 0.9. The paintedsensor shall be dried before use and present a uniformlyapplied coating (no visual thick spots or surface irregularities).Note that an external heat source, for example, an external heatlamp, has been used to completely drive off any remai

26、ningorganic carriers on a freshly painted surface.6.3 Specimen/Sensor BoardNOTE 1Sensor ConstructionPlace a straight, bare tip thermocouplewire into the hole located in the center of the copper disk. Place a short“copper plug” into the center hole with the thermocouple junction byclipping a section

27、of bare copper wire of appropriate diameter that, whencombined with the thermocouple wire, will just fit into the center hole.Use a center punch to mechanically wedge the wire bundle into place.Peen around the hole to further secure the thermocouple into the copperdisk. Take care not to cut the ther

28、mocouple wire during this assemblyprocess. Check the electrical continuity and thermal response prior tousing the completed copper slug calorimeter.FIG. 1 Sensor ConstructionF955 1526.3.1 The specimen/sensor board shall be nominally 250mm by 406 mm 10 in. by 16 in. and fabricated of a flame andheat

29、resistant material with a thermal conductivity value of 0.15 W/mK, high temperature stability, and resistance tothermal shock. The board shall be nominally 13 mm 0.5 in. orgreater in thickness.6.3.2 The copper slug calorimeters shall be located in thecenterline of the sensor board and mounted as sho

30、wn in Fig. 1.The calorimeters shall be located 101 mm and 203 mm 4 in.and 8 in. respectively, from the top of the board to thecalorimeter centers as indicated in Fig. 2.6.3.3 An attachment method shall be provided that affixesthe test specimen to the board such that it covers both sensorsand extends

31、 at least 25 mm 1 in. beyond all edges.6.3.4 The sensor board shall be inclined at an angle of 70from horizontal.6.3.5 The sensor board shall be located so that it meets thepour geometry illustrated in Fig. 2, where the molten substanceis introduced at the centerline of the board.6.4 Pouring Crucibl

32、eThe pouring crucible shall be suit-able for the substance being poured and for handling tempera-tures up to at least 56C 100F above the pouring tempera-ture. Crucible sizes appropriate for specific substances areshown in Table 1. The crucible shall be attached to a tiltingmechanism capable of turni

33、ng the ladle at the rate of onerevolution per 4.7 6 0.2 s. The crucible shall be pivoted at apoint 25 mm 1 in. below the top of the crucible on thevertical. When tilted, the tilted action shall be stopped me-chanically after a rotation of 10 6 5 from the vertical (Fig. 2).See also Annex A2.6.5 Furna

34、ceAsuitable furnace for melting and heating thetest substance is needed. The furnace and lining must be of atype that the chemistry of the substance is not changed duringcontact with the furnace nor throughout the term of the testseries.6.6 Pouring height shall be 305 mm 12 in. (See Fig. 2).6.7 Data

35、 Acquisition SystemThe system shall be capableof recording the calorimeter outputs as required by the test.6.7.1 The temperature data (calorimeter outputs) shall beacquired at a minimum sampling rate of four samples persecond per calorimeter. The acquisition system shall be able torecord temperature

36、s to 150C 300F, have at least a resolu-tion of 0.1C 0.2F, and measuring accuracy of 60.75C61.4F.7. Materials7.1 Description of standard substances for test purposes isincluded in Table 1.8. Hazards8.1 Perform the test in a ventilated area to carry awaycombustion products, smoke, and fumes. Care shal

37、l be exer-cised in handling the hot substance. A full fire extinguisher,preferably of the carbon dioxide type, shall be readily avail-able. Use normal safety practices for the handling of the moltensubstance and potentially flammable materials. Place a catchpan filled with dry sand under the assembl

38、y. Extreme care shallbe taken to prevent contact between the molten substance andwater because explosive quantities of steam can result.8.2 The sensor board and calorimeter assembly becomeheated during prolonged testing. Use protective gloves whenhandling these hot objects and during the pour.9. Sam

39、pling and Specimen Preparation9.1 Lot SizeFor acceptance sampling purposes, a lot isdefined as 4572 m 5000 yd or a single shipment of a singlestyle of material, whichever is smaller. A lot shall be permittedto constitute all or part of a single customer order.9.2 Lot SampleAs a lot sample, takea2m2.

40、2 ydfull-width piece of material from both the beginning and end ofthe lot.9.3 Test SpecimensCut and identify three test specimensfrom each sample. Make each test specimen at least 305 6 2mm by 460 6 2 mm 12 6116 by 18 6116 in. Do not cutsamples closer than 10 % of the material width from the edgean

41、d arrange the specimens across the sample swatch so as toget as representative a sampling as possible.9.4 Sensor Care:9.4.1 Initial TemperatureCool the sensor after a pourexposure with a jet of air to approximately 21C 70F justprior to positioning the test specimen.9.4.2 Surface ReconditioningWipe t

42、he sensor face with anonabrasive material immediately after each run, while it ishot, to remove any decomposition products which condense,since these could be a source of error. If there is a deposit onthe surface of the sensor that appears to be thicker than a thinlayer of paint, or is irregular, t

43、he sensor surface requiresreconditioning. Carefully clean the cooled sensor with acetoneor petroleum solvent, making certain there is no ignition sourcenearby. Repaint the surface, if bare copper is showing, with athin layer of flat black spray paint as identified in 6.2.2 above.FIG. 2 Schematic of

44、Test ApparatusF955 15310. Procedure10.1 Specimen MountingA piece of the test material,prepared in accordance with 9.3, against the sensor board withthe sample material hung over the sensor board, centeredhorizontally over the calorimeters with the top of the materialabout 130 mm 5 in. above the top

45、of the upper sensor. Attachthe test material to the sensor board by an appropriate means.10.1.1 Multiple Layer SamplesFor the standard tests tomeasure the protective property of multiple layer samples,place the surface of the material to be used as the outside of thegarment facing out. Place the sub

46、sequent layer(s) underneath inthe order used in wearing with the surface to be worn towardthe skin facing the calorimeters.10.2 Pour MethodMolten substance of sufficient quantityfor the test series is first heated in a furnace. When the sampleis mounted and all is in readiness, the test substance sh

47、all bebrought to about 56C 100F above the pour temperature.Make molten substance temperature measurements with anappropriate device such as an optical pyrometer or other heatmeasuring device with an accuracy of at least 614C 625F.Use a preheated crucible appropriate to the substance beingused, as sh

48、own in Table 1. Put a quantity of substance, 610 %of the weight shown in Table 1 in the test crucible, and thentransfer it into the pouring rig. Align the assembly holding thepouring crucible so that the main part of the molten substancestream impacts on the material specimen directly above thecente

49、r of the top calorimeter.10.2.1 The data acquisition system is started several sec-onds before the actual molten material pour is initiated. Thisestablishes the average starting copper slug calorimeter tem-peratures for the heat energy determination.10.2.2 When the temperature of the molten substance dropsto the appropriate pour temperature, tilt the crucible and pourthe substance onto the material specimen set on the inclinedsensor panel board for the test. (Take extreme care to avoidbeing splashed