1、BS EN ISO845:2009ICS 83.100,NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDCellular plasticsand rubbers Determination ofapparent density (ISO845:2006)This British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 July 2
2、009 BSI 2009ISBN 978 0 580 66946 0Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 845:2009National forewordThis British Standard is the UK implementation of EN ISO 845:2009. Itis identical to ISO 845:2006. It supersedes BS EN ISO 845:1995 which iswithdrawn.The UK participation i
3、n its preparation was entrusted to TechnicalCommittee PRI/24, Testing of rigid and flexible cellular materials.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. User
4、s are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 845June 2009ICS 83.100 Supersedes EN ISO 845:1995 English VersionCellular plastics and rubbers - Determination of appare
5、nt density(ISO 845:2006)Caoutchoucs et plastiques alvolaires - Dtermination de lamasse volumique apparente (ISO 845:2006)Schaumstoffe aus Kautschuk und Kunststoffen -Bestimmung der Rohdichte (ISO 845:2006)This European Standard was approved by CEN on 30 May 2009.CEN members are bound to comply with
6、the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre
7、 or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial ver
8、sions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spa
9、in, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Member
10、s.Ref. No. EN ISO 845:2009: EBS EN ISO 845:2009EN ISO 845:2009 (E) 3 Foreword The text of ISO 845:2006 has been prepared by Technical Committee ISO/TC 61 “Plastics” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 845:2009 by Technical Committee CEN/TC 24
11、9 “Plastics” the secretariat of which is held by NBN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2009, and conflicting national standards shall be withdrawn at the latest by December
12、 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 845:1995. According to the CEN/CENELEC Internal
13、 Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
14、 Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 845:2006 has been approved by CEN as a EN ISO 845:2009 without any modification. BS EN ISO 845:2009ISO 845:2006(E) ISO 2006 All rights reserved i
15、iiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Apparatus 1 5 Test specimens . 2 5.1 Dimensions 2 5.2 Number of test specimens. 2 5.3 Conditioning 2 6 Procedure 2 7 Expression of results . 3 8 Accuracy 3 9 Test report . 4 BS EN ISO 845:2009ISO 845:2006
16、(E) iv ISO 2006 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body in
17、terested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechni
18、cal Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the
19、 technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights.
20、 ISO shall not be held responsible for identifying any or all such patent rights. ISO 845 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 10, Cellular plastics. This third edition cancels and replaces the second edition (ISO 845:1988), which has been technically revised. BS
21、EN ISO 845:2009INTERNATIONAL STANDARD ISO 845:2006(E) ISO 2006 All rights reserved 1Cellular plastics and rubbers Determination of apparent density 1 Scope This International Standard specifies a method for determining the apparent overall density and the apparent core density of cellular plastics a
22、nd rubbers. If the material to be tested includes skins formed during a moulding/extrusion, the apparent overall density or the apparent core density, or both, can be determined. If the material does not have skins formed during moulding, the term “overall density“ is not applicable. For shaped mate
23、rials, a different method such as buoyancy method may be used. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document
24、 (including any amendments) applies. ISO 291, Plastics Standard atmospheres for conditioning and testing ISO 1923, Cellular plastics and rubbers Determination of linear dimensions 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 apparent overa
25、ll density cellular material mass per unit volume of a sample, including all skins formed during moulding 3.2 apparent core density cellular material mass per unit sample after all skins formed during moulding have been removed 4 Apparatus Ordinary laboratory apparatus and the following. 4.1 Balance
26、, capable of determining the mass of a test specimen to an accuracy of 0,1 %. 4.2 Measuring instruments, in accordance with ISO 1923. BS EN ISO 845:2009ISO 845:2006(E) 2 ISO 2006 All rights reserved5 Test specimens 5.1 Dimensions Each specimen shall be of a shape such that its volume can be easily c
27、alculated. It shall be cut without deforming the original cell structure of the material. The size of a specimen should preferably be as large as possible, commensurate with the apparatus available and with the shape of the original material. The total volume of a specimen shall be at least 100 cm3.
28、 For rigid materials, when the apparent overall density is being determined using a specimen cut from a larger sample, the ratio of the area of skin formed during moulding to the total volume shall be the same for the specimen as for the sample. 5.2 Number of test specimens A minimum of five specime
29、ns shall be tested. The sample may be a manufactured object whose mass and volume can be measured accurately. Its total mass and total volume may be used to determine the sample density. 5.3 Conditioning 5.3.1 For measurement purposes, wait at least 72 h after manufacture before cutting the specimen
30、s from product samples. If required, this period may be reduced to 48 h or 16 h if experience shows that, 48 h or 16 h after manufacture, the difference in density compared with the density 72 h after manufacture is less than 10 %. 5.3.2 The specimen shall be kept for at least 16 h at standard atmos
31、pheres or in a desiccator (dry conditions) as defined below. This conditioning period may be part of the 72 h period following manufacture. Standard atmospheres in accordance with ISO 291 are a) (23 2) C, (50 10) % relative humidity, b) (23 5) C, (50 2010+) % relative humidity, or c) (27 5) C, (65 2
32、010+) % relative humidity. Dry conditions are (23 2) C, or (27 2) C. 6 Procedure 6.1 Measure the dimensions, in millimetres, of the specimen in accordance with ISO 1923. Make a minimum of three separate measurements of each dimension. For rigid materials in board form, make at least five measurement
33、s of the central area. Calculate the mean values for each dimension and from these measurements calculate the volume of the specimen. 6.2 Weigh each specimen to an accuracy of 0,5 % and record its mass in grams. BS EN ISO 845:2009ISO 845:2006(E) ISO 2006 All rights reserved 37 Expression of results
34、7.1 The density (apparent overall density or apparent core density) of a test specimen, in kilograms per cubic metre, is given by the formula: 610mV = where m is the mass, in grams, of the test specimen; V is the volume, in cubic millimetres, of the test specimen. Calculate the mean value of the den
35、sity from the result for all test specimens and round it to the nearest 0,1 kg/m3. NOTE With certain low-density closed-cell materials, for example those with densities less than 15 kg/m3, buoyancy may be a cause of error. Allowance for this factor may be made as follows: 6aa10mmV+= where mais the m
36、ass of displaced air, in grams, calculated by multiplying the volume, in cubic millimetres, of the test specimen by the density, in grams per cubic millimetres, of air at atmospheric temperature and pressure. The density of air at a temperature of 23 C and a pressure of 101 325 Pa (760 mmHg) is 1,22
37、0 106g/mm3; the density of air at 27 C and 101 325 Pa is 1,195 5 106g/mm3. 7.2 Calculate the standard deviation s (estimated) as follows and report it to two significant figures: 221xnxsn=where x is the value of a single measurement; x is the arithmetic mean of the set of measurements; n is the numb
38、er of measurements made. 8 Accuracy 8.1 The values given in this clause were developed from data obtained using rigid materials only and with test specimens conditioned for 72 h. Their validity for other materials and conditioning periods has yet to be determined. 8.2 The inter- and intra-laboratory
39、 accuracy of this test method can be expected to vary for different materials. Results of a five-laboratory collaborative test programme showed that, for certain materials, measured absolute density differences can be limited to 1,7 % (at 95 % confidence) within a single laboratory. Measured absolut
40、e density differences between laboratories can be limited to 2,6 % (at 95 % confidence) for the same material. BS EN ISO 845:2009ISO 845:2006(E) 4 ISO 2006 All rights reserved9 Test report The test report shall include the following information: a) a reference to this International Standard; b) a co
41、mplete identification of the material tested; c) the temperature and humidity at which the test specimens were conditioned; d) the presence or absence of surface skins and whether skins were removed for testing; e) the presence of densification, striations or other defects of the test specimens; f)
42、the individual test results, stating details of the test specimen shape, test specimen dimensions and the location from which they were taken; g) the mean value of the density (apparent overall density or apparent core density) and the standard deviation; h) whether any allowance was made for buoyan
43、cy and, if so, the size of the correction and details of the temperature, pressure and relative humidity of the ambient air during the test; i) any deviation from the procedure specified in this International Standard. BS EN ISO 845:2009BS EN ISO845:2009BSI GroupHeadquarters 389Chiswick High Road,Lo
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