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1、BRITISH STANDARD BS 2782-0: 1995 Methods of testing Plastics Part 0: Introduction Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:00:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-0:1995 This British Standard, having been prepared under the direction o
2、f the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 May 1995 BSI 12-1998 First published May 1982 Second edition October 1992 Third edition The following BSI references relate to the work on this standard: Committee ref
3、erence PRI/21 Draft announced in BSI News January 1995 ISBN 0 580 23717 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee PRI/21, Testing of plastics, upon which the following bodies were represented: British Plastics Fed
4、eration British Steel Industry British Telecommunications plc British Textile Confederation Department of Trade and Industry (National Physical Laboratory) EEA (the Association of Electronics, Telecommunications and Business Equipment Industries) Electrical and Electronic Insulation Association (BEA
5、MA Ltd.) Electrical Installation Equipment Manufacturers Association (BEAMA Ltd.) GAMBICA (BEAMA Ltd.) Ministry of Defence Packaging and Industrial Films Association PIRA Plastic Industrial Containers Association Plastics and Rubber Institute RAPRA Technology Ltd. Yarsley Technical Centre Ltd. Amend
6、ments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:00:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-0:1995 BSI 12-1998i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Informa
7、tive references1 3Content and usage of BS 27821 4Units1 5Apparatus and reagents1 6Sampling1 7Number of test pieces1 8Preparation of test pieces1 9Direction of testing1 10Test report1 11Standard atmospheres for conditioning and testing2 Annex A (normative) Standard atmospheres for conditioning and te
8、sting plastics3 Annex B (informative) List of methods in BS 2782 published separately and degree of equivalence to international standards5 Annex C (informative) Method 508A: Rate of burning, laboratory method (obsolescent)16 Figure C.1 Specimen under test for rate of burning17 Table 1 Conditioning
9、atmospheres2 Table A.3 Standard atmospheres3 Table A.4 Tolerances4 Table B.1 Methods in BS 2782 and corresponding international standards5 List of referencesInside back cover Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:00:32 GMT+00:00 2006, Uncontrolled C
10、opy, (c) BSI BS 2782-0:1995 ii BSI 12-1998 Foreword This Part of BS 2782 has been prepared by Technical Committee PRI/21 and is a new edition of BS 2782-0:1992, which is withdrawn. BS 2782 describes test methods currently used by the plastics industry for determining the quality of its products. It
11、is intended that the appropriate methods be specified in all British Standards for plastics materials and products. In many methods, the test procedures are identical with those standardized by Technical Committee ISO/TC 61, Plastics, and where this is so, the methods have been published as dual-num
12、bered standards. These international standards are to be considered for adoption as European Standards by CEN/TC 249, Plastics. Annex A is identical with ISO 291:1977, published by the International Organization for Standardization (ISO). Annex B lists the methods in numerical order and also shows t
13、he equivalent ISO standard when appropriate. Warning note. The methods in BS 2782 do not necessarily detail all the precautions necessary to meet the requirements of the Health and Safety at Work etc. Act 1974. Attention should be paid to any appropriate safety precautions, and the methods should be
14、 operated only by trained personnel. This edition introduces technical changes but it does not reflect a full review or revision of the standard, which will be undertaken in due course. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standa
15、rds are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 18, an inside back cover and a back cover. This s
16、tandard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:00:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI B
17、S 2782-0:1995 BSI 12-19981 1 Scope This Part of BS 2782 gives a general introduction to the methods of test for plastics presented in the other Parts. Annex A gives the standard atmospheres for conditioning and testing plastics, annex B lists the individual methods and annex C describes an obsolesce
18、nt method (508A), formerly given in BS 2782:1970 and still referred to by the Building Regulations 1. 2 Informative references This Part of BS 2782 refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are list
19、ed on the inside back cover, but reference should be made to the latest editions. 3 Content and usage of BS 2782 BS 2782 provides a rationalized collection of methods for testing plastics materials and includes tests that are applied to moulding and extrusion compounds, synthetic resins, reinforced
20、plastics, semi-fabricated products such as sheet, film, rod and tube, and finished articles in the form of mouldings and extrusions. Many of the methods are restricted to one set of conditions, and are not necessarily adequate for the production of design data; attention is therefore drawn to BS 461
21、8. The acquisition and presentation of comparable data for basic properties of plastics is given in BS 7008. Many of the methods are not suitable for cellular plastics and attention is drawn to BS 4370 and BS 4443. 4 Units Numerical values in BS 2782 are normally expressed in the units of the Systme
22、 International d Units (SI units), described in BS 5555. 5 Apparatus and reagents Wherever possible, apparatus used should comply with the requirements of the appropriate British Standard. Reagents should be of recognized analytical reagent quality unless otherwise stated, and distilled or demineral
23、ized water should be used wherever water is specified (see BS 3978). 6 Sampling In cases where special precautions are needed to ensure that the test pieces adequately represent the properties of the material in bulk, a sampling procedure is given in the specification for the material. 7 Number of t
24、est pieces It is recognized that specifications for test programmes sometimes require use of different numbers of test pieces from those given in BS 2782. For example, in production, a more informative and accurate result can be obtained if fewer test pieces are taken from one article but more artic
25、les are tested. It should be noted, however, that in general the use of fewer test pieces yields less reliable results. 8 Preparation of test pieces Preparation of test pieces is often one of the most critical stages of the test procedure, and the specified conditions of preparation should be closel
26、y adhered to. In general the procedure adopted enables a test piece representative of the material under test to be obtained with minimal effect on the properties of the material. Test piece preparation is normally referred to in each method described in BS 2782, in some instances by reference to st
27、andards for the materials or products. BS 2782-9 describes general methods of preparation. It should be noted that where no British Standard or other recognized specification exists the procedure should be as agreed between the interested parties. 9 Direction of testing The properties of certain typ
28、es of sheet material may vary with direction in the plane of the sheet. In practice it is usual to cut two groups of test pieces with their major axes respectively parallel and perpendicular to the direction of some feature of the sheet that is either visible or inferred from a knowledge of the meth
29、od of its manufacture. For a particular test the direction of testing is the direction of the long axis of the test pieces, unless otherwise stated. 10 Test report When referring to a test procedure it is necessary to quote the full reference by giving the number of this British Standard, the method
30、 number and the date of publication, e.g. BS 2782:Method 354A:1991. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 09:00:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-0:1995 2 BSI 12-1998 11 Standard atmospheres for conditioning and testing The properti
31、es of plastics can alter considerably with changes in temperature and relative humidity. It is usually necessary to condition test pieces before testing, in addition to controlling the atmosphere during testing, in order to improve the reproducibility of test results. As large a surface as possible
32、of each test piece should be exposed to the conditioning atmosphere. Where appropriate, the test method specifies the conditioning procedure. The standard atmospheres for conditioning and testing given in annex A are to be used whenever possible. For convenience, the relevant parameters of annex A a
33、re given in Table 1. Table 1 Conditioning atmospheres Conditioning procedureTemperatureRelative humidityDuration of conditioning, min. C%h A. For use when control of temperature and humidity is necessary; normal tolerances 23 250 588 B. For use when control of temperature only is necessary; normal t
34、olerance 23 2Ambient humidity4 C. As A, but with close tolerances23 150 288 D. As B, but with close tolerances23 1Ambient humidity4 E. For use when control of temperature or humidity is not necessary Prevailing ambient atmospheric conditions Licensed Copy: London South Bank University, London South
35、Bank University, Tue Dec 12 09:00:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-0:1995 BSI 12-19983 Annex A (normative) Standard atmospheres for conditioning and testing plastics NOTEThis annex is identical, except for the addition of A as a prefix to the clause numbers and A.1 as a prefix t
36、o the annex, with ISO 291:1977 Plastics Standard atmospheres for conditioning and testing published by the International Organization for Standardization (ISO). Wherever the words “international standard” appear, referring to this annex, they should be read as “annex”. There is no corresponding Brit
37、ish Standard to ISO 554 Standard atmospheres for conditioning and/or testing Specifications, referred to in A.1. ISO 554 is referred to for information only, however, so the validity of this annex is not affected. A.1 Scope and field of application This international standard sets out specifications
38、 relating to the conditioning and testing of all plastics and all types of test specimen under approximately normal ambient atmospheric conditions. Special atmospheres applicable to a particular test or material or simulating a particular climatic environment are not included in this international s
39、tandard. NOTEThis international standard has been prepared taking into consideration ISO 554 Standard atmospheres for conditioning and/or testing Specifications. A.2 Definitions A.2.1 conditioning atmosphere the atmosphere in which a sample or test specimen is kept before being subjected to test A.2
40、.2 test atmosphere the atmosphere to which a sample or test specimen is exposed throughout the test NOTEBoth of these atmospheres are defined by specified values for temperature, relative humidity and pressure. A.2.3 conditioning the whole series of operations intended to bring a sample or test spec
41、imen into a state of equilibrium with regard to temperature and humidity the “conditioning procedure” is defined by the “conditioning atmosphere” and the “period of conditioning” A.3 Standard atmospheres These atmospheres are to be used only when the properties of the samples or test specimens are i
42、nfluenced by both temperature and humidity. If humidity has no influence on the properties being examined the relative humidity may be uncontrolled. The two corresponding atmospheres are designated “atmosphere 23” and “atmosphere 27” respectively. Similarly, if neither temperature nor humidity has a
43、ny influence on the properties being examined, the temperature and relative humidity may be uncontrolled. In this case the atmosphere is termed the “ambient atmosphere”. NOTEIn the special case where the plastic material is, or has to be, used at the same time as other materials, an atmosphere of 20
44、 C/65 % relative humidity may be permitted to be used after agreement between the interested parties or if expressly specified. DesignationTemperatureRelative humidityPressureRemarks C%kPa Atmosphere 23/50235086 to 106 Recommended atmosphere Atmosphere 27/652765For tropical countries Licensed Copy:
45、London South Bank University, London South Bank University, Tue Dec 12 09:00:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2782-0:1995 4 BSI 12-1998 A.4 Tolerances NOTE 1Usually, the tolerances are coupled as pairs, i.e. normal tolerance for both temperature and relative humidity or close toleran
46、ce on both. NOTE 2These tolerances apply to the working space of the test enclosure or conditioning enclosure and include both the variation with position in the enclosure and fluctuation with time. A.5 Conditioning The period of conditioning shall be stated in the relevant specifications for the ma
47、terials. NOTE 1When the periods are not stated in the appropriate international standard, the following shall be adopted: a) a minimum of 88 h for atmospheres 23/50 and 27/65; b) a minimum of 4 h for atmospheres 23 and 27. NOTE 2For particular tests and for plastics or test specimens that are known
48、to reach temperature and humidity equilibrium either very rapidly or very slowly, a shorter or longer time for the conditioning period may be specified in the appropriate international standard (see annex A.1). A.6 Testing Unless otherwise specified, the specimens shall be tested in the same atmosph
49、ere in which they have been conditioned. In all cases, the test shall be made immediately after the removal of the test specimens from the conditioning enclosure. Annex A.1 Attainment of equilibrium moisture absorption by plastics in a conditioning atmosphere The amount of moisture absorbed and its rate of absorption by a test specimen conditioned in a humid atmosphere vary significantly according to the nature of the plastic material being examined. The normal conditions for conditioning established in this international standard (see cla