1、Designation: F2894 11Standard Test Method forEvaluation of Materials, Protective Clothing and Equipmentfor Heat Resistance Using a Hot Air Circulating Oven1This standard is issued under the fixed designation F2894; 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 covers quantitative measurements andsubjective observatio
3、ns that characterize the performance forevaluating the heat resistance of materials, protective clothingand equipment when exposed in a hot air circulating oven.1.2 This test method is intended to evaluate physicalchanges in materials, protective clothing and equipment at aspecified heat exposure.1.
4、2.1 The specified heat exposure in the hot air circulatingoven is a combination of convective heat and radiant heat.1.3 Materials, protective clothing and equipment are evalu-ated for visible changes or subjected to a material propertymeasurement following a specified heat exposure.1.4 This test met
5、hod enables the quantitative measurementof shrinkage that occurs as a result of a specified heat exposurein a hot air circulating oven.1.5 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to other units that are commonly used fo
6、r thermaltesting.1.6 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 practices and determine the applica-bility of regulatory limitations prior to us
7、e.NOTE 1Flame resistant and heat resistant materials are described in arange of different standards and meet a range of different requirements.For materials tested in accordance with this test method, the applicablestandard shall be used to establish preconditioning, conditioning andtesting conditio
8、ns and requirements.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesE145 Specification for Gravity-Convection and Forced-Ventilation OvensF1494 Terminology Relating to Protective Clothing2.2 AATCC Standard:Test Metho
9、d 135 Dimensional Changes in Automatic HomeLaundering of Woven and Knit Fabrics32.3 NFPA Standards:NFPA 1975 Standard on Station/Work Uniforms for Fireand Emergency Services43. Terminology3.1 Definitions of Terms3.2 For definitions of terms used in this test method, use thefollowing documents: If th
10、e terms are related to textiles refer toTerminology D123; if the terms are related to protectiveclothing refer to Terminology F1494.3.2.1 convective heat, nheat transferred by the motion ofa fluid.3.2.2 degradation, na deleterious change in one or moreproperties of a material.3.2.2.1 DiscussionIn th
11、ermal testing of materials, protec-tive clothing and equipment, degradation is a material responseevidenced by a change in either or both the visual propertiesand the performance properties of the test specimen.3.2.2.2 DiscussionDegradation generally is associatedwith a chemical composition change t
12、hat can result in a changein a visual property, for example, color, or it can result in achange in a performance property including but not limited tostrength, hand, flammability, penetration resistance, waterrepellency and air permeability.Atest specimen that changes inone property does not necessa
13、rily change in other properties.Evidence of degradation in performance properties usuallyrequires additional measurements related to properties ofspecific interest. Discoloration is a visible material responserelated to degradation. When discoloration is observed, it shallbe reported.3.2.3 ignition,
14、 nthe initiation of combustion.1This is under the jurisdiction of ASTM Committee F23 on Personal ProtectiveClothing and Equipment and is the direct responsibility of Subcommittee F23.80 onFlame and Thermal.Current edition approved July 1, 2011. Published July 2011. DOI:10.1520/F2894-11.2For referenc
15、ed 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.3Available from American Association of Textile Chemists and Colorists(AAT
16、CC), P.O. Box 12215, Research Triangle Park, NC 27709, http:/www.aatcc.org.4Available from National Fire Protection Association (NFPA), 1 BatterymarchPark, Quincy, MA 02169-7471, http:/www.nfpa.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, U
17、nited States.3.2.4 melting, nin thermal testing of materials, protectiveclothing and equipment, the liquefaction of material under theinfluence of heat.3.2.5 protective clothing, nan item of clothing that isspecifically designed and constructed for the intended purposeof isolating all or part of the
18、 body from a potential hazard; or,isolating the external environment from contamination by thewearer of the clothing.3.2.6 protective equipment, na non-clothing item ofequipment that is specifically designed and constructed for theintended purpose of isolating all or part of the body from apotential
19、 hazard; or, isolating the external environment fromcontamination by the user of the equipment.3.2.7 radiant heat, nheat communicated by energy propa-gated through space and transmitted by electromagnetic waves.3.2.8 shrinkage, na decrease in one or more dimensionsof an object or material.3.3 Defini
20、tions of Terms Related to Thermal Testing ofMaterials, Protective Clothing and Equipment:3.3.1 deformation, nin thermal testing of materials, pro-tective clothing and equipment, a material response evidencedby a change in shape of the test specimen that is irreversible atroom temperature.3.3.1.1 Dis
21、cussionAchange in shape caused by the speci-fied heat exposure such as distortion of woven or non wovenfabrics or curling of knit fabrics shall not be identified asdeformation as long as these changes are reversible at roomtemperature.3.3.2 delamination, nin thermal testing of materials, pro-tective
22、 clothing and equipment, a material response evidencedby the separation of two of more layers of the test specimen inwhole or in part.3.3.3 dripping, nin thermal testing of materials, protec-tive clothing and equipment, a response evidenced by flowingof the polymer and by the formation of droplets f
23、rom theflowing material.3.3.4 flaking, nin thermal testing of materials, protectiveclothing and equipment, a material response evidenced by theunassisted loss of visible particles of material from the testspecimen when the test specimen is removed from the oven forinspection.3.3.4.1 DiscussionThe sp
24、ecimen shall not be abraded,flexed or impacted to generate flaking.3.3.5 hole formation, nin thermal testing of materials,protective clothing and equipment, the appearance of a visibleaperture during the test exposure.3.3.5.1 DiscussionThe specimen is considered to exhibithole formation when a visib
25、le hole is produced as a result ofthe thermal exposure that is approximately 3 mm (0.12 in.) indiameter or greater, or if the hole is rectangular in shapeapproximately 3 mm (0.12 in.) in width and length or greater.Single threads across the hole do not reduce the size of the holefor the purposes of
26、this test method.3.3.6 melting, nin thermal testing of materials, protectiveclothing and equipment, the liquefaction of material under theinfluence of heat.3.3.7 separation, nin thermal testing of materials, protec-tive clothing and equipment, a material response evidenced bysplitting or delaminatin
27、g.3.3.8 splitting, nin thermal testing of materials, protectiveclothing and equipment, a material response evidenced by thetest specimen breaking into two or more pieces in whole or inpart.3.3.9 sticking, nin thermal testing of materials, protectiveclothing and equipment, a material response evidenc
28、ed by thetest specimen adhering to itself or to other surfaces.3.3.9.1 DiscussionThis test method is conducted in amanner that avoids the contact of test specimens with ovensurfaces or with adjacent test specimens. However, it is stillpossible for test specimens to stick to the mounting hooks orclam
29、ps and this observation shall be reported. Another evalu-ation of sticking specific to fabrics is described in 7.2.1 and 8.3of NFPA 1975.4. Summary of Test Method4.1 The test method evaluates the heat resistance of mate-rials, protective clothing and equipment using a hot air circu-lating oven.4.2 S
30、pecimens shall be exposed in the test oven at aspecified temperature for a specified oven exposure time asrequired by the applicable material or product specification.4.2.1 If no material or end product specification require-ments for the oven temperature and oven exposure time areprovided, the oven
31、 temperature shall be 260 +8/-0C (500+14/-0F) and the oven exposure time shall be 5 minutes+15/-0 seconds.4.3 Following heat exposure, the test specimen is removedand examined for evidence of one or more of the followingphenomena: ignition, melting, dripping, separation, etc., see11.5.4.4 If specifi
32、ed, test specimens are evaluated for shrinkageas a result of the convective heat exposure.5. Significance and Use5.1 This test method is used to evaluate the heat resistanceof materials, clothing and equipment when exposed to combi-nation of convective heat and radiant heat in a hot aircirculating o
33、ven.5.2 If specified, this test method is used for the measurementof material shrinkage following a convective heat exposure ina hot air circulating oven.5.3 This test method is not intended to simulate the actualexposure of material, clothing or equipment in high heatconditions such as a fire envir
34、onment.6. Apparatus6.1 Test OvenThe test oven shall be a horizontal-flowcirculating oven with minimum interior dimensions of 610 mmby 610 mm by 610 mm such that a specimen can be suspendedand be positioned at least 50 mm (2 in.) from any interior ovensurface or other specimen.6.1.1 The test oven sha
35、ll have an air velocity of 0.5 m/s to1.5 m/s at the standard temperature and pressure of 21C atlocal atmospheric pressure, measured at the geometric centerpoint of the oven.F2894 1126.1.2 The test oven shall be equipped with an oven sensingthermocouple which is used as part of the oven temperatureco
36、ntrol mechanism.6.1.2.1 The oven sensing thermocouple shall be positionedso that it is level with the horizontal centerline of a mountedsample specimen, and the oven sensing thermocouple shall beequidistant between the vertical centerline of a mountedspecimen positioned in the middle of the oven and
37、 the ovenwall where the airflow enters the oven test chamber.6.1.2.2 The oven sensing thermocouple shall be an exposedbead, Type J or Type K, No. 30 AWG thermocouple.6.2 Specimen MountingMetal hooks or clamps shall beused to suspend the specimens in the oven.6.2.1 If the specimens are too large to b
38、e suspended, asuitable insulating form shall be placed in the center of theoven and the specimen shall rest on the insulating form.Ceramic has been found to be an effective material for thisform.6.3 Optional Stretching FrameThe optional stretchingframe consists of a board with uniformly spaced pins
39、along theperimeter at intervals of 25 mm (1 in.) to secure knit materials.Construct the stretching frame to accommodate the test speci-men size specified in 9.1.1 and 9.1.2 so that the pins are locatedapproximately 50 mm (2 in.) inward from the edges of the testspecimen.6.3.1 The optional stretching
40、 frame is permitted to be usedbefore the knit specimen is placed in the oven for marking thespecimen for shrinkage determination. The stretching frame isnot used while the knit specimen is exposed in the oven. Theoptional stretching frame is also permitted to be used for aspecified period of time af
41、ter heat exposure in the oven toreturn knit specimens to their original dimensions. See 9.3.1and 11.6.1.7. Hazards7.1 Normal precautions shall be taken for working aroundhot surfaces and flaming, melting or dripping test specimens.7.2 The oven shall be properly vented to ensure that harmfulvapors an
42、d gases are evacuated from the laboratory.8. Preconditioning of Test Samples8.1 Material samples not obtained from garments for pre-conditioning shall be at least 1 m2(1.2 yd2) to ensure sufficientmaterial for the test specimen size requirements in 9.1.1 and9.1.2. The material sample shall be repres
43、entative of thematerial utilized in the construction of the protective clothingend product.8.1.1 If the material width is less than 1 m (1.1 yd), thesample shall be the full width of the material and the length ofthe sample shall be sufficient to meet the test specimen sizerequirements of 9.1.1 or 9
44、.1.2.8.1.2 Precondition samples of protective clothing as com-plete items.8.1.3 Precondition samples of protective equipment as com-plete items.8.2 Precondition samples as required by the applicablematerial or end product specification.8.2.1 If no material or end product specification require-ments
45、for preconditioning are provided, precondition samplesaccording to the temperature, relative humidity and condition-ing time required by Practice D1776.8.2.2 If the test specimen form is not included in PracticeD1776, condition the test specimen at 21 6 1C (70 6 2F)and 65 6 2 % RH for eight hours.9.
46、 Preparation of Test Specimens9.1 After preconditioning cut test specimens to the specifiedsize for testing.9.1.1 Cut each material test specimen from the materialsample or from the protective clothing complete item to a sizeof 380 6 13 mm by 380 6 13 mm (15 6 0.5 in. by 15 6 0.5in.).9.1.2 Smaller s
47、ize material test specimens of 150 6 6mmby 150 6 6mm(66 0.25 in. by 6 6 0.25 in.) shall beacceptable for materials that are not to be subjected toshrinkage measurement.9.1.3 For specimens (such as straps) narrower than 150 mmin one dimension, use specimens at their normal width and cutto 150 mm in l
48、ength. Suspend these specimens with their longaxis in a vertical direction.9.1.4 Protective clothing test specimens are permitted to betested in the form and size of the complete items.9.1.5 Test protective equipment specimens in the form andsize of the complete items.9.2 Test a minimum of three tes
49、t specimens from eachpreconditioned sample. Testing a greater number of specimensis permitted to improve precision of test results.9.3 Mark test specimens to be evaluated for shrinkage inaccordance with AATCC Test Method 135.9.3.1 The optional stretching frame shall be permitted to beused to mark knit fabric specimens for shrinkage determina-tions.9.4 Room Temperature ConditioningCondition test speci-mens, including nonwoven specimens, at a temperature of 216 1C (70 6 2F) and 65 6 2 % relative humidity, untilequilibrium is reached, as determined in
