1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW3232 Test Method for Determining the Flammability of Interior Trim Materials Copyright 2011 General Motors Company All Rights Reserved August 2011 Originating Department: North American Engineering Standards Page 1 of 15 1 Scope Note: Nothing in thi
2、s standard supercedes applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. This test method shall be used to determine the horizontal burn rate of automotive materials. Burn rate is determi
3、ned immediately following an exposure for a short duration to a small flame. The small flame is placed in contact with one edge of the material. 1.2 Foreword. Not applicable. 1.3 Applicability. The method permits testing of materials and parts of the vehicle interior, individually or in combination
4、up to a thickness of 13 mm. It is normally only applicable to materials and parts within a 13 mm range to the passenger compartment air space. 1.3.1 Testing Frequency. All sources supplying parts or materials to this requirement must perform routine quality control testing to confirm compliance of e
5、ach lot of material or parts produced. 1.3.2 Lot Identification. Each lot of material shall remain readily available and identifiable, until the tests are complete so it may be retrieved in the event of inspection and/or test failure. Each lot of material shall have a unique identification. 1.3.3 Us
6、e of Incoming Material Test Data. When a source location can demonstrate that their process does not adversely affect flammability, the source location may use test data from each lot of incoming material. 2 References Note: Only the latest approved standards are applicable unless otherwise specifie
7、d. 2.1 External Standards/Specifications. CONTRAN Resolution 675/86 GB8410 FMVSS 302 KMVSS Article 95 2.2 GM Standards/Specifications. GMW3221 2.3 Additional References. None 3 Resources 3.1 Facilities. 3.1.1 Test Cabinet. One configuration satisfying these requirements is shown in Figures A1 thru A
8、3. The test cabinet consists of a rectangular steel cabinet of approximately internal dimensions 381 mm long, 203 mm deep and 356 mm high. It shall have a heat resisting glass observation window, a closable opening to permit insertion of the test specimen mounting fixture and a hole to accommodate t
9、ubing for a gas burner. A 13 mm clearance space around the top of the cabinet, ten 19 mm diameter holes in the base of the cabinet and legs to elevate the bottom of the cabinet by 10 mm are to be provided for ventilation. 3.1.2 Apparatus for conditioning as required and to the appropriate requiremen
10、ts as described in GMW3221 (Code A), unless otherwise specified in the relevant material specification. 3.1.3 Drying oven capable of maintaining the specified temperature within the specified tolerances. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot fo
11、r Resale-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3232 Copyright 2011 General Motors Company All Rights Reserved August 2011 Page 2 of 15 3.1.4 Chemical Fume Cupboard. Chemical fume cupboard suitable for mounting the test cabinet to avoid the diffusion of combustion products to the laboratory durin
12、g test. A natural venting hood is permissible, provided adequate ventilation is assured. Any forced air ventilation shall be the minimum required for venting. 3.2 Equipment. 3.2.1 Test Specimen Mounting Fixture. One configuration satisfying these requirements is shown in Figures A4 and A5. This shal
13、l consist of two matching U-shaped frames of metal (e.g., aluminum) stock 25 mm wide and 10 mm thick. The interior dimensions of the U-shaped frames shall be 51 mm wide by 330 mm long. Gauge lines shall be marked (e.g., by slots) on the upper frame 38 and 292 mm respectively from its open end. In or
14、der to support sub size test specimens and those that soften and bend during test, the lower frame shall have the means to accommodate thin heat resistance wires that span the width of the U-shaped frame at 25 mm intervals. (Grooves cut into the lower frame to accommodate 0.2 mm, nickel-chrome, ther
15、mo wire are recommended.) 3.2.1.1. Specific Korean Legal Requirements (KMVSS Article 95). In order to support sub size specimens where the maximum available width is 50 mm or less, the lower frame shall have the means to accommodate thin heat resistant wires that span the width of the U-shaped frame
16、 at 25 mm intervals. Wires shall not be used for other reasons than above for certification to KMVSS Article 95. (Grooves cut into the lower frame to accommodate 0.2 mm, nickel-chrome, thermo wire are recommended.) 3.2.2 Support Stand. One configuration satisfying these requirements is shown in Figu
17、re A6. A metal stand to locate and support the test specimen mounting fixture (3.2.1) in the center of the cabinet during test is required. 3.2.3 In order to detect when the flame front has progressed to each of the gauge lines, it is recommended to use lightweight cotton thread counterbalanced with
18、 approximately 14 g weights spanning the full width of the lower frame at the gauge lines (Figure A4). 3.2.4 A stopwatch calibrated to an accuracy of 0.5 s. 3.2.5 Bunsen burner with a tube of (10.0 0.5) mm inside diameter and provided with a gas adjusting valve to give a flame (38 1) mm high when th
19、e tube is vertical and the air inlet to the burner is closed. 3.2.6 Gas to provide a flame temperature equivalent to that of natural gas. 3.2.7 Metal comb with seven to eight smooth rounded teeth per 25 mm. 3.2.8 Cutting dies or shears for preparation of test specimens. 3.2.9 Specific Chinese Legal
20、Requirements (GB8410) Ventilating Cabinet. The combustion box shall be placed in a ventilating cabinet. The inner volume of the cabinet shall be 20 to 110 times that of the combustion box, and none of the length, width or height may be more than 2.5 times greater than either of the other two dimensi
21、ons. At points 100 mm from the front and back of the final position of the combustion box, measure the speed of air passing the ventilating cabinet. The speed must be 0.10 to 0.30 m/s. 3.3 Test Vehicle/Test Piece. 3.3.1 Wherever possible, from the available material or component, rectangular test sp
22、ecimens (355 2) mm long and (100 2) mm wide, shall be taken. The thickness of the test specimens shall be that of the single or composite material used in the vehicle, except when the materials or composites thickness exceeds 13 mm. Then the test specimens shall be cut down to 13 mm, measured from t
23、he surface of the specimen closest to the passenger compartment air space. 3.3.2 Where it is not possible to obtain flat test specimens due to surface curvature, the test specimens shall be cut to not more than 13 mm in thickness at any point. As far as possible the test specimens shall be of unifor
24、m thickness. 3.3.2.1 Specific Chinese Legal Requirements (GB8410). If the part is bent so that it is impossible to take a flat sample, then take the part that is most flat and make the arch rise of the sample not more than 13 mm. If the arch rise of the sample exceeds 13 mm, then make a standard sam
25、ple with the same material, same technique and same structure as the part (356 mm 100 mm), and let the thickness be the minimum width but not greater than 13 mm. 3.3.3 Testing of Smaller Sized Samples. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for
26、Resale-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3232 Copyright 2011 General Motors Company All Rights Reserved August 2011 Page 3 of 15 3.3.3.1 General Requirements. The maximum available length or width of test specimens shall be used where either dimension is less than (355 2) mm and (100 2) mm r
27、espectively. 3.3.3.2 Specific Japanese Legal Requirements. The minimum acceptable sample size shall be 25 mm in width and 293 mm in length. 3.3.3.3 Specific Brazilian Legal Requirements (CONTRAN Resolution 675/86). The minimum acceptable sample size shall be 3 mm in width, but samples (3 to 60) mm w
28、ide shall be (355 2) mm long, and samples (60 to 100) mm wide shall be at least 138 mm long. 3.3.3.4 Specific Chinese Legal Requirements (GB8410). Where the shape and size of the part are insufficient to be made into a standard sample of the specified size, then make a sample of the following minimu
29、m size, and keep records. a. If the part is 3 to 60 mm wide, it shall be at least 356 mm long. In this case, make the width of the sample as close to that of the part as possible. b. If the part is wider than 60 mm, it shall be at least 138 mm long. In this case, the possible burnt distance is equiv
30、alent to the distance from the first gauge mark to the place where the flame goes out or from the first gauge mark to the end of the sample as shown in Figure 2. c. If the part is 3 to 60 mm wide but shorter than 356 mm or if it is wider than 60 mm but shorter than 138 mm, it shall not be tested acc
31、ording to GB8410. Samples narrower than 3 mm shall also not be tested. 3.3.4 Where sample sizes or shapes restrict the ability to test, molded samples of raw material shall be made 100 mm in width and 355 mm in length with a thickness no greater than the thinnest component cross section from the act
32、ual part for which the sample is being substituted. In sampling the test panels it shall be ensured that they are fully representative of the material or composite under test. 3.3.5 In the case of materials made of superimposed layers of different materials which are not composite materials, all the
33、 layers of the materials included within a depth of 13 mm from the surface facing towards the passenger compartment air space shall be tested individually. 3.3.6 Test specimens shall be cut from materials or composites both in production direction and perpendicular to this (e.g., warp and weft direc
34、tion, longitudinal and lateral direction, etc.) if possible. The material direction of the longitudinal and lateral test specimens must be clearly marked in a manner to identify their original orientation within the roll as shown in Figure 1. There shall be no ink markings within the test area of th
35、e specimen. 3.3.7 The requirement concerning transmission of a flame front shall not apply to a surface created by the cutting of a test specimen for purposes of testing. 3.3.8 Materials or composites with napped or tufted surface shall be placed on a flat surface and combed twice against the nap wi
36、th a comb having seven to eight smooth rounded teeth per 25 mm. 3.3.9 For painted or molded in color plastic parts the data of the initial tested color can be used for other colors, if the burn rate (Bmax and Bstat) is 50 mm/minute for the tested color and if all of the following criteria are fulfil
37、led: 3.3.9.1 Criteria. x Material is natural or integrally colored plastic x Material is made of one layer (no laminate, no composite, no cellular structure) x Same filler/additive package is used x Part has wall thickness of 2 mm Copyright General Motors Company Provided by IHS under license with G
38、eneral Motors CompanyNot for Resale-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3232 Copyright 2011 General Motors Company All Rights Reserved August 2011 Page 4 of 15 Figure 1: Example of Sampling The following apply to Figure 1: 1. E.g., Material Roll 2. Material Direction 3. Longitudinal Test Speci
39、mens 4. Lateral Test Specimens NOTE: For specimens cut from direction 3, mark in alternating directions so that the material may be burned with the flame traveling into the roll (nearest to furthest) or out from the roll (furthest to nearest). For specimens cut from direction 4, mark in alternating
40、directions so that the material may be burned from left to right or from right to left. See 4.3.1.1. 3.4 Test Time. Not applicable. 3.5 Test Required Information. Material component information such as vendor name, raw material, production date and pretreatment shall be reported to the test engineer
41、. 3.6 Personnel/Skills. Not applicable. 4 Procedure 4.1 Preparation. 4.1.1 Conditioning. Immediately prior to tests all test specimens shall be conditioned for a minimum of 24 h according to GMW3221 (Code A). 4.1.2 Ageing. In addition to tests conducted in the as received condition, all materials wh
42、ich do not meet criteria to 3.3.9.1, shall additionally be tested for flammability after the following artificial condition. The test cycle shall commence with: x (48 1) h at (+40 3) C and (93 5)% relative humidity, followed by x (168 1) h at (+90 3) C x And completed without interruption. 4.1.3 Qua
43、ntity of Test Specimens. 4.1.3.1 Initial Approval and Arbitration. For initial sample approval and arbitration purposes, at least 20 specimens shall be tested except when any individual specimen burn rate exceeds 100 mm/minute. If any individual specimen has a burn rate that exceeds 100 mm/minute th
44、e material does not meet the flammability requirement and all additional testing shall be terminated. If all burn rates are less than 100 mm/minute, test at least 10 specimens each from the longitudinal and lateral directions with at least 5 specimens tested as received and at least 5 specimens test
45、ed after having been aged. For each direction and condition, see 5.2.1.2 to determine if additional specimens must be tested. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for Resale-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3232 Copyright 2011 General
46、 Motors Company All Rights Reserved August 2011 Page 5 of 15 4.1.3.2 Routine Quality Control. For quality control purposes, at least two specimens from both the lateral and longitudinal direction in the as received condition shall be tested from each production lot. For the samples from any one dire
47、ction, half of the samples shall have the burn direction 180 from the burn direction of the other half of the samples. The test shall be performed and the material must comply with the requirements of 5.2.2 and 5.2.2.1 of this specification prior to the release of the lot from the manufacturing faci
48、lity. 4.1.3.2.1 Inherently Flame Resistant Materials. Materials which contain no added flame retardant additives and exhibit no burn rates in excess of 75 mm/minute during approval testing and after quality control testing of twenty successive production lots, shall be considered Inherently Flame Re
49、sistance. No further production quality control testing shall be required. 4.2 Conditions. 4.2.1 Environmental Conditions. Test shall be conducted at ambient conditions according to GMW3221 (Code A). 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.3 Instructions. 4.3.1 Mount the
