1、Designation: D2863 13D2863 17Standard Test Method forMeasuring the Minimum Oxygen Concentration to SupportCandle-Like Combustion of Plastics (Oxygen Index)1This standard is issued under the fixed designation D2863; 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.This standard has been approved for use by agencies of the U.S. Department of Defense.
3、1. Scope*1.1 This fire-test-response standard describes a procedure for measuring the minimum concentration of oxygen, expressed aspercent volume, that will just support flaming combustion in a flowing mixture of oxygen and nitrogen.1.2 This test method provides three testing procedures. Procedure A
4、 involves top surface ignition, Procedure B involvespropagating ignition, and Procedure C is a short procedure involving the comparison with a specified minimum value of the oxygenindex.1.3 Test specimens used for this test method are prepared into one of six types of specimens (see Table 1).1.4 Thi
5、s test method provides for testing materials that are structurally self-supporting in the form of vertical bars or sheet upto 10.5-mm thick. Such materials are solid, laminated or cellular materials characterized by an apparent density greater than 15kg/m3.1.5 This test method also provides for test
6、ing flexible sheet or film materials, while supported vertically.1.6 This test method is also suitable, in some cases, for cellular materials having an apparent density of less than 15 kg/m3.NOTE 1Although this test method has been found applicable for testing some other materials, the precision of
7、the test method has not been determinedfor these materials, or for specimen geometries and test conditions outside those recommended herein.1.7 This test method measures and describes the response of materials, products, or assemblies to heat and flame undercontrolled conditions, but does not by its
8、elf incorporate all factors required for fire hazard or fire risk assessment of the materials,products, or assemblies under actual fire conditions.1.8 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.9 This standard does not
9、purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use. Specific hazard
10、s statement are given in Section 10.1.10 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conductingthese tests.NOTE 2This test method and ISO 4589-2 are technically equivalent when using the gas measurement and control device described in 6.3
11、.1, with directoxygen concentration measurement.1.11 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the
12、World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD1071 Test Methods for Volumetric Measurement of Gaseous Fuel SamplesD1622 Test Method for Apparent Density of Rigid Cellular Plastics1 T
13、his test method is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.30 on Thermal Properties.Current edition approved Sept. 1, 2013Aug. 15, 2017. Published September 2013August 2017. Originally approved in 1970. Last previous edition appro
14、ved in 20122013as D2863 - 12D2863 - 13.1. DOI: 10.1520/D2863-13.10.1520/D2863-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page
15、on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that use
16、rs consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
17、hocken, PA 19428-2959. United States1D4802 Specification for Poly(Methyl Methacrylate) Acrylic Plastic SheetE176 Terminology of Fire StandardsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method2.2 ISO Standards:3ISO 4589-2 PlasticsDetermination of Flamma
18、bility by Oxygen IndexPart 2, Ambient TemperaturesISO 7823-1 Poly(Methylmethacrylate) SheetsTypes, Dimensions and CharacteristicsPart 1Cast SheetsISO 13943 Fire SafetyVocabulary3. Terminology3.1 Definitions3.1.1 For definitions of terms used in this test method refer to the terminology contained in
19、Terminology E176 and ISO 13943.In case of conflict, the definitions given in Terminology E176 shall prevail.3.2 Definitions of Terms Specific to This Standard:3.2.1 ignitionthe initiation of combustion.3.2.2 oxygen index (OI)the minimum concentration of oxygen determined by the method in 12.1, expre
20、ssed as volumepercent, in a mixture of oxygen and nitrogen that will just support flaming combustion of a material initially at 23 6 2C underthe conditions of this test method.3.3 Symbols Specific To This Test Method:3.3.1 Cooxygen concentration in percent volume.3.3.2 CFfinal value of oxygen concen
21、tration in percent volume.3.3.3 Cieach of the oxygen concentration percentages used during measurement of the last six responses in the NT series.3.3.4 Oneither the period or extent of burning exceeds the relevant limit specified in Table 2.3.3.5 Xthe period or extent of burning exceeds the relevant
22、 limit specified in Table 2.3.3.6 NLseries of “X” or “O” results.3.3.7 NTseries of “X” or “O” results plus five (NT = NL + 5).3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.TABLE 1 Test Specimen DimensionsTestSpecimenT
23、ypeADimensionsMaterial FormLength,mmWidth,mmThickness,mmI 80 to 150 10 0.5 4 0.25 for molding materialsII 80 to 150 10 0.5 10 0.5 for cellular materialsIIIB 80 to 150 10 0.5 # 10.5 for sheet materialsIVC 70 to 150 6.5 0.5 3 0.25 alternative size forself-supporting moldingor sheet materialsIV 70 to 1
24、50 6.5 0.5 3 0.25 alternative size forself-supporting moldingor sheet materialsVB 140 5 52 0.5 #10.5 for flexible film or sheetVIBD 140 to 200 20 0.02 to0.10for thin film; limited to filmthat can be rolled by thewire specified in 6.7VIB, C 140 to 200 20 0.02 to0.10for thin film; limited to filmthat
25、can be rolled by thewire specified in 6.7A Test specimens of Types I, II, III, and IV are suitable for materials that areself-supporting at these dimensions. Test specimens of Form V and VI are suitablefor materials that require support during testing. Test specimens of Form VI aresuitable for film
26、materials that can be rolled into a self-supporting specimen by theprocedure in 7.4.B Compare results obtained using Type III, V, and VI test specimens only to thoseobtained using specimens of the same form and thickness. It is assumed that theamount of variation in thickness for such materials will
27、 be controlled by otherstandards.C The Type IV (ASTM) specimen will eventually be discontinued in favor of theType 1 (ISO) specimen.C The test specimen of Type VI is suitable for thin film that is self-supporting whenit is rolled (see 7.4). Dimensions in the table are of the specimen size from which
28、the rolled form is made. If the film is very thin, it is possible that proper results willonly be obtained if two or more layers are combined in the preparation of the rollto obtain proper results.D2863 1723.3.8 *standard deviation of the oxygen concentration.3.3.9 dinterval between oxygen concentra
29、tion levels in percent volume.3.3.10 ka factor to be determined from Table 3.3.3.11 nnumber of measurements of oxygen concentration.4. Summary of Test Method4.1 A small test specimen is supported vertically in a mixture of oxygen and nitrogen flowing upwards through a transparentchimney. The upper e
30、nd of the specimen is ignited and the subsequent burning behavior of the specimen is observed to comparethe period for which burning continues, or the length of specimen burnt, with specified limits for each burning. By testing a seriesof specimens in different oxygen concentrations, the minimum oxy
31、gen concentration is determined.4.2 Three procedures are included in this test method. In ProcedureA, a complete assessment of the oxygen index is conductedusing top surface ignition. In Procedure B, a complete assessment of the oxygen index is conducted using propagating ignition.Procedure C provid
32、es a comparison with a specified minimum value of oxygen index and can be conducted using top surfaceignition or propagating ignition.5. Significance and Use5.1 This test method provides for the measuring of the minimum concentration of oxygen in a flowing mixture of oxygen andnitrogen that will jus
33、t support flaming combustion of plastics. Correlation with burning characteristics under actual use conditionsis not implied.TABLE 2 Criteria for Oxygen Index MeasurementsATest SpecimenType (See Table 1) Ignition ProcedureAlternative CriteriaPeriod ofBurningAfterIgnition(s)Extent of BurningBI, II, I
34、II, IV, and VI A(top surface ignition)180 50 mm below the topof the specimenI, II, III, IV, and VI B(propagating ignition)180 50 mm below theupper referencemarkV propagating ignition 180 80 mm below theupper referencemark (on the frame)A These criteria do not necessarily produce equivalent oxygen in
35、dex results forspecimens of differing shape or tested using different ignition conditions orprocedures.B The extent of burning is exceeded when any part of the visibly burning portion ofa specimen, including burning drips descending the vertical faces, passes the levelindicated in the column.TABLE 3
36、 Determination of k1 2 3 4 5 6Responses for the Last FiveMeasurementsValues of k for which the first NL determinations are: Responses for the Last FiveMeasurementsA(a) O OO OOO OOOOXOOOO 0.55 0.55 0.55 0.55 OXXXXXOOOX 1.25 1.25 1.25 1.25 OXXXOXOOXO 0.37 0.38 0.38 0.38 OXXOXXOOXX 0.17 0.14 0.14 0.14
37、OXXOOXOXOO 0.02 0.04 0.04 0.04 OXOXXXOXOX 0.50 0.46 0.45 0.45 OXOXOXOXXO 1.17 1.24 1.25 1.25 OXOOXXOXXX 0.61 0.73 0.76 0.76 OXOOOXXOOO 0.30 0.27 0.26 0.26 OOXXXXXOOX 0.83 0.76 0.75 0.75 OOXXOXXOXO 0.83 0.94 0.95 0.95 OOXOXXXOXX 0.30 0.46 0.50 0.50 OOXOOXXXOO 0.50 0.65 0.68 0.68 OOOXXXXXOX 0.04 0.19
38、0.24 0.25 OOOXOXXXXO 1.60 1.92 2.00 2.01 OOOOXXXXXX 0.89 1.33 1.47 1.50 OOOOOA Values of k for which the first NL determinations are (b) X, XX, XXX, and XXXX are as given in Table 3 opposite he appropriate response in Column 6, but with the signof k reversed, that is: OI = CF kd (see 12.1).D2863 173
39、5.2 In this test method, the specimens are subjected to one or more specific sets of laboratory test conditions. If different testconditions are substituted or the end-use conditions are changed, it is not always possible by or from this test to predict changesin the fire-test-response characteristi
40、cs measured. Therefore, the results are valid only for the fire-test-exposure conditionsdescribed in this test method.6. Apparatus6.1 Test Chimney. The test chimney consists of a heat-resistant glass tube of 75 to 100-mm inside diameter and 450 to 500-mmheight. The opening at the top of the chimney
41、shall be restricted to provide an outlet of 40 6 2-mm diameter, either by providingan overhead cap or by designing the glass chimney appropriately. The bottom of the chimney, or the base to which the tube isattached, shall contain noncombustible material to evenly mix and distribute the gas mixture
42、entering at this base. Glass beads 3to 5 mm in diameter in a bed 80 to 100-mm deep have been found suitable. The chimney shall be mounted securely on the baseto prevent air leaks. One example of a design is shown in Fig. 1.NOTE 3It is helpful to place a wire screen above the noncombustible material
43、to catch falling fragments and to aid in keeping the base of the columnclean.1. Burning Specimen 6. Glass Beads in a Bed 11. Pressure Gauge2. Clamp with Rod Support 7. Brass Base 12. Precision Pressure Regulator3. Igniter 8. Tee 13. Filter4. Wire Screen 9. Cut-Off Valve 14. Needle Valve5. Ring Stand
44、 10. Orifice in Holder 15. RotameterFIG. 1 Typical Equipment LayoutD2863 1746.2 Specimen Holders6.2.1 Specimen Holder for Self-Supporting SpecimensAny small holding device that will support the specimen at its base andhold it vertically in the center of the chimney is an acceptable specimen holder.
45、A typical arrangement (see Fig. 1) consists of alaboratory thermometer clamp inserted into the end of a glass tube held in place by glass beads or otherwise firmly supported.6.2.2 Specimen Holder for Specimens of Flexible Sheet or Film Materials that Require SupportAspecimen holder for flexiblefilm
46、or sheet materials that require support shall be able to support the specimen by both vertical edges in a frame equivalent tothat illustrated by Fig. 2, with reference marks at 20 and 100 mm below the top of the frame. The profile of the holder and itssupport shall be smooth to minimize induction of
47、 turbulence in the rising flow of gas.6.2.3 Thin Film Rolling ToolIn order to prepare self-supporting specimens from thin films (see 7.4), use a 2 6 0.1-mmstainless steel rod with a 0.3 6 0.05-mm slit at one end, equivalent to that illustrated in Fig. 3. The actual specimen holder shallbe the one in
48、 6.2.1.6.3 Gas Measurement and Control Devices. Gas measurement and control devices shall be suitable for measuring theconcentration of oxygen in the gas mixture entering the chimney with an accuracy of 60.5 %, by volume, of the gas mixture andfor adjusting the concentration of oxygen in the mixture
49、 with a precision of 60.1 %, by volume, of the gas mixture, when the gasvelocity through the chimney is 40 6 2 mm/s at 23 6 2C.6.3.1 The system for gas measurement and control involves needle valves on individual and mixed gas supply lines, aparamagnetic oxygen analyzer that continuously samples the mixed gas, and a flow meter to indicate when the gas flow throughthe chimney is within the required limits. See Annex A4 for an alternate system for gas measurement.6.3.2 The system used for gas measuremen
