BS 2782-1 Method 140A-1992 Methods of testing plastics - Thermal properties - Determination of the burning behaviour of horizontal and vertical specimens in contact with a small-fl.pdf

1、BRITISH STANDARD BS 2782-1: Method 140A: 1992 ISO 1210:1992 Methods of testing Plastics Part 1: Thermal properties Method 140A: Determination of the burning behaviour of horizontal and vertical specimens in contact with a small-flame ignition source IMPORTANT NOTE. Before reading this method it is e

2、ssential to read BS2782-0, Introduction, issued separately. UDC (678.5/.8).01:620.1:536.46BS2782-1:Method 140A:1992 This British Standard, having been prepared under the directionof the Plastics and Rubber Standards Policy Committee, was published underthe authority of the Standards Board and comes

3、into effect on 15 December1992 BSI 03-1999 The following BSI references relate to the work on this standard: Committee reference PRM/21 Draft for comment 86/45274 DC ISBN 0 580 21439 7 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Plas

4、tics and Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/21, upon which the following bodies were represented: British Plastics Federation British Textile Confederation Department of the Environment (Building Research Establishment) Department of Trade and Industry (National Phy

5、sical Laboratory) EEA (the Association of Electronics, Telecommunications and Business Equipment Industries) Electrical and Electronic Insulation Association (BEAMA Ltd.) GAMBICA (BEAMA Ltd.) Ministry of Defence Packaging and Industrial Films Association Plastics and Rubber Institute Pira Internatio

6、nal RAPRA Technology Ltd. Yarsley Technical Centre Ltd. Amendments issued since publication Amd. No. Date CommentsBS2782-1:Method 140A:1992 BSI 03-1999 i Contents Page Committees responsible Inside front cover National foreword ii 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Principle 1 5 Si

7、gnificance of test 1 6 Apparatus 2 7 Specimens 2 8 Method A Determination of linear burning rate of horizontal specimens 3 9 Method B Determination of afterflame and/or afterglow times on vertical specimens 5 Annex A (informative) Classification system for determining the burning behaviour of horizo

8、ntal and vertical specimens in contact with a small-flame ignition source 9 National annex NA (informative) Details of laboratory burner (ignition source P/PF2) 10 Figure 1 Horizontal burning test apparatus (Method A) 4 Figure 2 Flexible-specimen support fixture (Method A) 4 Figure 3 Vertical-burnin

9、g test apparatus (Method B) 7 Figure 4 Optional indicator rod attachment (Method B) 7 Table 1 Rate of burning 5 Table 2 Afterflame and afterflame plus afterglow times 8 List of references Inside back coverBS2782-1:Method 140A:1992 ii BSI 03-1999 National foreword This British Standard has been prepa

10、red under the direction of the Plastics and Rubber Standards Policy Committee and is identical with ISO1210:1992 PlasticsDetermination of the burning behaviour of horizontal and vertical specimens in contact with a small-flame ignition source, published by the International Organization for Standard

11、ization (ISO). The Technical Committee has reviewed the provisions of the draft of ISO10093 to which reference is made in the text and has decided to include the relevant part of the specification as National annex NA. WARNING NOTE. This British Standard, which is identical with ISO1210, does not ne

12、cessarily detail all the precautions necessary to meet the requirements of the Health and Safety at Work etc. Act1974. Attention should be paid to any appropriate safety precautions and the method should be operated only by trained personnel. A British Standard does not purport to include all the ne

13、cessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International standard Corresponding British Standard ISO291:1977 BS2782Methods o

14、f testing plastics Part0:1992Introduction (Appendix A is identical) ISO293:1986 Method901A:1988Compression moulding test specimens of thermoplastic materials (Identical) ISO294:1975 Method910A:1977Injection moulding test specimens of thermoplastic materials (Identical) ISO295:1991 Method902A:1992Com

15、pression moulding of test specimens of thermosetting materials (Identical) ISO845:1988 BS4370Methods of test for rigid cellular materials Part1:1988Methods1 to5 (Method2 is technically equivalent) ISO1043-1:1987 BS3502Symbols for plastics and rubber materials Part1:1991Schedule for symbols for plast

16、ics (Identical) ISO5725:1986 BS5497Precision of test methods Part1:1987Guide for the determination of repeatability and reproducibility for a standard test method by interlaboratory tests (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1

17、to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on theinside front cover.ISO1210:1992(E) BSI 03-1999 1 1 Scope 1.1 This International Standard specifies a small-sc

18、ale laboratory screening procedure for comparing the relative burning behaviour of vertically or horizontally oriented plastic specimens exposed to a small-flame ignition source. 1.2 This method of test determines the afterflame/afterglow times and damaged length of specimens. It is applicable to so

19、lid and cellular materials having an apparent density of not less than250kg/m 3 , determined in accordance with ISO845. This method is not applicable to materials that shrink away from the applied flame without igniting. 1.3 The classification system described inAnnex Ais intended for quality assura

20、nce and the preselection of component materials for products. This system is not intended for assessment of the fire behaviour of building materials or furnishings. The method of test described may be used for the preselection acceptance of a material, providing positive results are obtained at the

21、thickness equal to the smallest thickness used in the application. NOTE 1Test results are influenced by material components, e.g.pigments, fillers and fire-retardants, and properties such as the direction of anisotropy and molecular mass. 2 Normative references The following standards contain provis

22、ions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the pos

23、sibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO291:1977, PlasticsStandard atmospheres for conditioning and testing. ISO293:1986, PlasticsCompression moulding test specimens of th

24、ermoplastic materials. ISO294:1975, PlasticsInjection moulding test specimens of thermoplastic materials. ISO295:1991, PlasticsCompression moulding of test specimens of thermosetting materials. ISO845:1988, Cellular plastics and rubbers Determination of apparent (bulk) density. ISO1043-1:1987, Plast

25、icsSymbols Part1:Basic polymers and their special characteristics. ISO5725:1986, Precision of test methods Determination of repeatability and reproducibility for a standard test method by inter-laboratory tests. ISO10093: 1) , PlasticsFire testsStandard ignition sources. 3 Definitions For the purpos

26、es of this International Standard, the following definitions apply. 3.1 afterflame persistence of flaming of a material, under specified test conditions, after the ignition source has been removed 3.2 afterflame time the length of time for which a material continues to flame, under specified test co

27、nditions, after the ignition source has been removed 3.3 afterglow persistence of glowing of a material, under specified test conditions, after cessation of flaming or, if no flaming occurs, after removal of the ignition source 3.4 afterglow time the time during which a material continues to glow, u

28、nder specified test conditions, after cessation of flaming or after the ignition source has been removed 4 Principle A test specimen bar is supported horizontally or vertically by one end and the free end is exposed to a specified gas flame. The burning behaviour of the bar is assessed by measuring

29、the linear burning rate (method A) or the afterflame/afterglow times (method B). 5 Significance of test 5.1 Tests made on a material under the conditions specifed can be of considerable value in comparing the relative burning behaviour of different materials, in controlling manufacturing processes,

30、or in assessing any change in burning characteristics prior to, or during use. The results obtained from this method are dependent on the shape, orientation and environment surrounding the specimen and on the conditions of ignition. Correlation with performance under actual service conditions is not

31、 implied. 1) To be published.ISO1210:1992(E) 2 BSI 03-1999 5.2 Results obtained in accordance with this International Standard shall not be used to describe or appraise the fire hazard presented by a particular material or shape under actual fire conditions. Assessment for fire hazard requires consi

32、deration of such factors as: fuel contribution, intensity of burning (rate of heat release), products of combustion and environmental factors such as the intensity of source, orientation of exposed material and ventilation conditions. 5.3 Burning behaviour as measured by this test method is affected

33、 by such factors as density, any anisotropy of the material and the thickness of the specimen. 5.4 Certain materials may shrink from the applied flame without igniting. In this event, test results are not valid and additional test specimens will be required to obtain valid tests. If the test specime

34、ns continue to shrink from the applied flame without igniting, these materials are not suitable for evaluation by this method of test. 5.5 The burning behaviour of some plastic materials may change with time. It is accordingly advisable to make tests before and after ageing by an appropriate procedu

35、re. The preferred oven conditioning shall be7 days at70 C. However, other ageing times and temperatures may be used by agreement between the interested parties and shall be noted in the test report. 5.6 The effect on the burning behaviour of additives, deterioration, and possible loss of volatile co

36、mponents are measurable using this method. Results obtained using this method may serve for comparing the relative performance of materials and can be helpful in material assessment. 6 Apparatus 6.1 Laboratory fume hood/cupboard, having an inside volume of at least0,5m 3 . The chamber shall permit o

37、bservation and shall be draught-free, while permitting normal thermal circulation of air past the specimen during burning. For safety and convenience, it is desirable that this enclosure (which can be completely closed) be fitted with an evacuation device, such as an exhaust fan, to remove products

38、of combustion, which may be toxic. However, it is important to be able to turn the device off during the actual test and start it again immediately after the test to remove the products of combustion. NOTE 2The amount of oxygen available to support combustion is naturally important for the conduct o

39、f these flame tests. For tests conducted by this method when burning times are protracted, chamber sizes less than1m 3 may not provide accurate results. 6.2 Laboratory burner, as specified in ISO10093, (ignition source P/PF2), having a barrel length of100mm 10mm and an internal diameter of9,5mm 0,3m

40、m. Do not equip the barrel with an end attachment such as a stabilizer. 6.3 Ring stand, with clamps or the equivalent, adjustable for positioning of the specimen. 6.4 Timing device, accurate to1s. 6.5 Measuring scale, graduated in millimetres. 6.6 Supply of technical-grade methane gas, with regulato

41、r and meter for uniform gas flow. NOTE 3Other gas mixtures having a heat content of approximately37MJ/m 3 have been found to provide similar results. 6.7 Desiccator, containing anhydrous calcium chloride or other drying agent. 6.8 Conditioning room or chamber, capable of being maintained at23 C 2 C

42、and a relative humidity of(50 5)%. 6.9 Micrometer, capable of being read to0,01mm. 6.10 Air-circulating oven, capable of being maintained at70 C 1 C while providing not less than five air changes per hour. 7 Specimens 7.1 All specimens shall be cut from a representative sample of the material (sheet

43、s or end-products), or shall be cast or injection- (see ISO294), compression- (see ISO293 or ISO295) or transfer-moulded to the necessary shape. After any cutting operation, care shall be taken to remove all dust and any particles from the surface; cut edges shall have a smooth finish. 7.2 Bar speci

44、mens should preferably be125mm5mm long,13,0mm 0,3mm wide and3,0mm 0,2mm thick. Other thicknesses may be used by agreement between the interested parties and, if so, shall be noted in the test report. However, the maximum thickness shall not exceed13mm. NOTE 4Tests made on specimens of different thic

45、knesses, densities, molecular masses, directions of anisotropy and types or levels of colour(s) or filler(s) and flame-retardant(s) may not be comparable. 7.3 A minimum of26 bar specimens shall be prepared. NOTE 5It is advisable to prepare additional specimens in the event that the situation describ

46、ed in5.4 is encountered.ISO1210:1992(E) BSI 03-1999 3 8 Method ADetermination of linear burning rate of horizontal specimens 8.1 Complementary apparatus (see Figure 1) 8.1.1 Wire gauze, 20 mesh (approximately20 openings per25mm), made with0,40mm to0,45mm diameter steel wire and cut into125-mm square

47、s. 8.1.2 Support fixture, for testing specimens that are not self-supporting (see Figure 2). 8.2 Specimens Three specimens shall be tested. Each specimen shall be marked with two lines perpendicular to the longitudinal axis of the bar,25mm and100 mm from the end that is to be ignited. 8.3 Conditioni

48、ng Unless otherwise required by the specification for the material being tested, two sets of three specimens shall be preconditioned in accordance with ISO291, at23 C 2 C and (50 5)% relative humidity for48h. Testing shall be conducted at ambient room conditions within one hour of being conditioned.

49、 8.4 Procedure 8.4.1 Clamp the specimen at the end farthest from the25mm mark, with its longitudinal axis horizontal and its transverse axis inclined at45 . Clamp the wire gauze(8.1.1) horizontally beneath the specimen, with a distance of10mm between the lower edge of the specimen and the gauze, and with the free end of the specimen even with the edge of the gauze (see Figure 1). 8.4.2 With the central axis of the burner tube vertical, set the burner(6.2) to produce a blue flame20mm 2mm high by adjusting the gas supply(6.6)