ASTM D1929-2012 Standard Test Method for Determining Ignition Temperature of Plastics《塑料燃点测定的标准试验方法》.pdf

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1、Designation: D1929 12Standard Test Method forDetermining Ignition Temperature of Plastics1This standard is issued under the fixed designation D1929; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numbe

2、r in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This fire test response test method2covers a laboratorydet

3、ermination of the flash ignition temperature and spontane-ous ignition temperature of plastics using a hot-air furnace.1.2 CautionDuring the course of combustion, gases orvapors, or both, are evolved that have the potential to behazardous to personnel.1.3 This standard is used to measure and describ

4、e theresponse of materials, products, or assemblies to heat andflame under controlled conditions, but does not by itselfincorporate all factors required for fire-hazard or fire-riskassessment of the materials, products, or assemblies underactual fire conditions.1.4 Fire testing is inherently hazardo

5、us. Adequate safe-guards for personnel and property shall be employed inconducting these tests.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 health pr

6、actices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in 1.2 and 1.3.NOTE 1This test method and ISO 871-1996 are identical in alltechnical details.2. Referenced Documents2.1 ASTM Standards:3D618 Practice for Conditioning Plastic

7、s for TestingE176 Terminology of Fire Standards2.2 International Standards:4ISO 871-1996 PlasticsDetermination of Ignition Tem-perature Using a Hot-Air FurnaceISO 5725 Precision of Test MethodsDetermination ofRepeatability and Reproducibility for Standard Test Meth-ods by Interlaboratory TestsIEC 58

8、4-2 ThermocouplesPart 2: Tolerances3. Terminology3.1 For definitions of terms relating to fire, see TerminologyE176.3.2 Definitions of Terms Specific to This Standard:3.2.1 flash ignition temperature (FIT)the minimum tem-perature at which, under specified test conditions, sufficientflammable gases a

9、re emitted to ignite momentarily uponapplication of a small external pilot flame.3.2.2 glowing combustioncombustion of a material in thesolid phase without flame but with emission of light from thecombustion zone, caused by slow decomposition and carbon-ization at various points in the specimen, wit

10、hout generalignition occurring.3.2.3 spontaneous ignition temperature or self-ignition tem-perature (SIT)the minimum temperature at which the self-heating properties of the specimen lead to ignition or ignitionoccurs of itself, under specified test conditions, in the absenceof any additional flame i

11、gnition source.4. Significance and Use4.1 Tests made under conditions herein prescribed can be ofconsiderable value in comparing the relative ignition charac-teristics of different materials. Values obtained represent thelowest ambient air temperature that will cause ignition of thematerial under th

12、e conditions of this test. Test values areexpected to rank materials according to ignition susceptibilityunder actual use conditions.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.30 on Thermal Proper-ties.30.03).Curr

13、ent edition approved April 15, 2012. Published June 2012. Originallyapproved in 1962. Last previous edition approved in 2011 as D1929 11.DOI:10.1520/D1929-12.In 1996, this test method was totally revised to be technically equal toISO 871-1996, and a specific air velocity is specified, which eliminat

14、es the need forapproximations.2The following reference may be of interest in connection with this test method:Stetchkin, N. P., “A Method and Apparatus for Determining the Ignition Charac-teristics of Plastics,” Journal of Research, National Institute of Standards andTechnology, Vol 43, No. 6, Decem

15、ber 1949 (RP 2052), p. 591.3For 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.4Available from American National

16、Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.2 This test is not inten

17、ded to be the sole criterion for firehazard. In addition to ignition temperatures, fire hazardsinclude other factors such as burning rate or flame spread,intensity of burning, fuel contribution, products of combustion,and others.5. Apparatus5.1 Hot-Air Ignition FurnaceA furnace similar to thatshown

18、in Fig. 1, consisting primarily of an electrical heatingunit and specimen holder.5.2 Furnace TubeA vertical tube with an inside diameterof 100 6 5 mm and a length of 230 6 20 mm, made of aceramic that will withstand at least 750C. The vertical tubestands on the furnace floor, fitted with a plug for

19、the removal ofaccumulated residue.5.3 Inner Ceramic TubeA ceramic tube that will with-stand at least 750C, with an inside diameter of 75 6 5 mm,length of 2306 20 mm, and thickness of approximately 3 mm,placed inside the furnace tube and positioned 20 6 2mmabove the furnace floor on three small space

20、r blocks. The topis covered by a disk of heat-resistant material with a 25 62-mm diameter opening in the center that is used for observa-tion and passage of smoke and gases. The pilot flame is locatedimmediately above the opening.NOTE 2Fire resistant materials such as silica glass and stainless stee

21、lhave also been found suitable for this application.5.4 Air SourceAn outside air source to supply clean airnear the top of the annular space between the ceramic tubes,through a copper tube at a steady and controllable rate. AirFIG. 1 Cross Section of Hot-Air Ignition FurnaceD1929 122shall be heated

22、and circulated in the space between the twotubes and enter the inner furnace tube at the bottom. Air shallbe metered by a rotameter or other suitable device.5.5 Electrical Heating Unit, contained within the mineralfiber sleeve and constructed of 50 turns of 1.3 6 0.1 mmNichrome V alloy wire, wound a

23、round the furnace tube andembedded in heat-resistant cement.NOTE 3Other constructions such as finely coiled wire embedded inmolded ceramic fiber have also been found to be acceptable.5.6 Insulation, consisting of a layer of mineral fiber, ap-proximately 60-mm thick, and covered by a metal jacket.5.7

24、 Pilot Igniter, consisting of a nominal 1.8 6 0.3-mminside diameter (ID) copper tubing attached to a gas supply of94 % minimum purity propane and placed horizontally 5 6 1mm above the top surface of the disk cover. The pilot flameshall be adjusted to 20 6 2 mm in length and centered abovethe opening

25、 in the disk cover.5.8 Specimen Support and HolderThe specimen pan con-sists of a metal container of approximately 0.5-mm thick steelmeasuring 406 2 mm in diameter by 15 6 2 mm in depth. Itis held in a ring of approximately 2.0-mm diameter stainlesssteel welding rod. The ring is welded to a length o

26、f the sametype of rod extending through the cover of the furnace, asshown in Fig. 1. The bottom of the specimen pan shall belocated 185 6 5 mm down from the top of the inner furnacetube.5.9 Thermocouples, 0.5-mm diameter, Chromel-Alumel(Type K) or Iron-Constantan (Type J), for temperature mea-sureme

27、nt connected to a calibrated recording instrument with atolerance not exceeding 62C. The thermocouple toleranceshall be in accordance with IEC 584-2, Table 1, Class 2 orbetter.5.10 Heating ControlA suitable variable transformer oran automatic controller connected in series with the heatingcoils.5.11

28、 Timing Device, having an accuracy of at least 1 s.6. Location of Thermocouples6.1 Thermocouple TC1measures the temperature, T1,ofthespecimen. It is located as close as possible to the center of theupper surface of the specimen when the specimen is in placewithin the furnace. The thermocouple wire i

29、s attached to thespecimen support rod.6.2 Thermocouple TC2gives some indication of the tem-perature, T2, of the air traveling past the specimen. It is located10 6 2 mm below the center of the specimen pan. Thethermocouple wire is attached to the specimen support rod.NOTE 4Thermocouple TC2may be inst

30、alled through a hole drilledadjacent to the inspection plug below the specimen pan.6.3 Thermocouple TC3measures the temperature, T3,oftheheating coil. It is located adjacent to the furnace heating coiland is used as a reference for temperature adjustment purposesbecause of its faster response.NOTE 5

31、Thermocouple TC3may be a 1.6 6 0.1-mm diameter metallicsheathed thermocouple.7. Test Specimens7.1 It is acceptable to use as test specimens materials, orproducts, supplied in any form, with some examples beingpellets, powders and films. It is also acceptable to use com-posites as test specimens. The

32、 test report shall include fulldetails of the form in which the test specimens have beentested.NOTE 6Specimens containing high levels of inorganic fillers aredifficult to evaluate.NOTE 7In some cases the same material will give different results iftested in different forms.7.2 A specimen mass of 3.0

33、 6 0.2 g shall be used formaterials having a density greater than 100 kg/m3.7.2.1 Instructions for Specific Types of Test Specimens:7.2.1.1 For sheet materials, cut the sheet into squares of 206 2by206 2 mm maximum size, and stack these to a heightthat gives the required specimen mass.7.2.1.2 For fi

34、lm materials, roll a strip 20 6 2 mm wide andof length sufficient to give the required specimen mass.7.2.1.3 For cellular materials having a density less than100kg/m3, remove any outer skin and cut the specimens in theform of a block measuring 20 6 2by206 2by506 5 mm.7.3 Sufficient material is requi

35、red for at least two determi-nations.7.4 The test specimens shall be conditioned at 23 6 2C and50 6 10 % relative humidity for not less than 40 h prior to test,in accordance with Practice D618.8. Procedure8.1 Flash Ignition Temperature (FIT):8.1.1 Set the air velocity to 25 mm/s by adjusting the act

36、ualair flow rate through the full section of the inner tube at thefurnace temperature, using the following formula:Qv5 6.62 3293Twhere:Qv= air flow rate, L/min, andT = temperature, K, at T2.Ensure that the air flow rate is maintained at 610 % of thecalculated value.8.1.2 Adjust the electric current

37、supplied to the heating coilby means of the variable transformer or automatic controller,by reference to temperature T3until the air temperature, T2,remains constant at the desired initial test temperature.NOTE 8The temperature of 400C is used when no prior knowledgeof the probable flash ignition te

38、mperature range is available. Other startingtemperatures may be selected if information on the material indicates abetter choice.8.1.3 Raise the specimen pan to the cover opening, andplace the specimen on the pan. Lower the pan into the furnace,ensuring that thermocouples TC1and TC2are in their corr

39、ectposition (see 6.1 and 6.2). Start the timer, ignite the pilot flame,and watch for evidence of a flash or mild explosion ofcombustible gases that may be followed by continuous burningof the specimen. Flaming or glowing combustion can also beobserved by a rapid rise in temperature T1, as compared w

40、ithtemperature T2.D1929 1238.1.4 At the end of 10 min, depending on whether ignitionhas or has not occurred, lower or raise the temperature T2by50C accordingly, and repeat the test with a fresh specimen.8.1.5 When the range within which the flash ignition tem-perature lies has been determined, begin

41、 the test 10C belowthe highest temperature within this range, and continue bydropping the temperature in 10C steps until the temperature isreached at which there is no ignition during a 10 min period.8.1.6 Record the lowest air temperature, T2, at which a flashis observed, during the 10 min period,

42、as the flash ignitiontemperature.8.2 Spontaneous Ignition Temperature (SIT):8.2.1 Follow the same procedure as described in 8.1, butwithout the pilot flame.8.2.2 Ignition will be evidenced by flaming or glowingcombustion of the specimen. It may be difficult, with somematerials, to detect spontaneous

43、 ignition visually when burningis by glowing combustion rather than flaming. In such cases, arapid rise in temperature T1above that of T2accompanied by avisual observation is the more reliable reference.8.2.3 Record the lowest air temperature, T2, at which thespecimen burns, during the 10 min period

44、, as the spontaneousignition temperature.9. Test Report9.1 Report the following information:9.1.1 Reference to this test method;9.1.2 Designation of the material, including the name of themanufacturer and composition;9.1.3 Form of the material (granules, sheet, etc.);9.1.4 Mass of the test specimen,

45、 g;9.1.5 Density of the cellular test specimens, kg/m3;9.1.6 Flash ignition temperature (FIT), C;9.1.7 Spontaneous ignition temperature (SIT), C;9.1.8 Whether the combustion observed was flaming orglowing;9.1.9 Observations regarding the behavior of the specimenduring the test (how ignition occurred

46、, the formation of soot orsmoke, excessive foaming, melting, bubbling, smoking, etc.);and9.1.10 The following statement:“These test results relate only to the behavior of testspecimens under the particular conditions of the test. They arenot intended to be used, and shall not be used, to assess thep

47、otential fire hazards of a material in use.”10. Precision and Bias10.1 The precision and bias of this test method is beingdeveloped internationally through ISO/TC61/Sc4. Relativeprecision data based on a preliminary interlaboratory studyconducted in 1994, using ISO/DIS 871 as protocol, is indicatedi

48、n Appendix X1. Findings from this interlaboratory studyresulted in changes to the procedure; therefore, another inter-laboratory study was considered necessary and will be startedin 1996.11. Keywords11.1 flash ignition temperature; ignition temperature; spon-taneous ignition temperatureAPPENDIX(Nonm

49、andatory Information)X1. RESULTS OBTAINED BY INTERLABORATORY TRIALSX1.1 An interlaboratory study was conducted in 1994 usingISO/DIS 871.1 protocol for the testing criteria.X1.2 These precision data were determined from interlabo-ratory tests involving seven laboratories, on six polymericmaterials, with three replicates of each material. The resultingdata were analyzed in accordance with ISO 5725 and aresummarized in Table X1.1 and Table X1.2.X1.3 Repeatability, in the normal and correct operation ofthe test method, is the difference between two aver