1、October 2009DEUTSCHE NORM English price group 6No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 83.100!$ZCe“1553266www.
2、din.deDDIN EN ISO 845Cellular plastics and rubbers Determination of apparent density (ISO 845:2006)English version of DIN EN ISO 845:2009-10Schaumstoffe aus Kautschuk und Kunststoffen Bestimmung der Rohdichte (ISO 845:2006)Englische Fassung DIN EN ISO 845:2009-10SupersedesDIN EN ISO 845:1995-06www.b
3、euth.deDocument comprises 9 pagesDIN EN ISO 845-2009-10 2 National foreword This standard has been prepared by Technical Committee ISO/TC 61 “Plastics” in collaboration with Technical Committee CEN/TC 249 “Plastics”, (Secretariat: NBN, Belgium). At present a DIN committee does not exist for this sta
4、ndard since the parties concerned have not shown any interest in work on the subject. The Normenausschuss Kunststoffe (Plastics Standards Committee), is obliged to publish the standard, however, as the subject falls in its domain. The DIN Standards corresponding to the International Standards referr
5、ed to in this document are as follows: ISO 291 DIN EN ISO 291 ISO 1923 DIN EN ISO 1923 Amendments This standard differs from DIN EN ISO 845:1995-06 as follows: a) The accuracy of the balance has been changed to 0,1 % (4.1). b) Standard atmospheres have been updated in accordance with ISO 291. c) Sub
6、clause 8.3 has been deleted. Previous editions DIN 53420: 1958-01, 1978-12 DIN EN ISO 845: 1995-06 National Annex NA (informative) Bibliography DIN EN ISO 291, Plastics Standard atmospheres for conditioning and testing DIN EN ISO 1923, Cellular plastics and rubbers Determination of linear dimensions
7、 EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 845June 2009ICS 83.100 Supersedes EN ISO 845:1995 English VersionCellular plastics and rubbers - Determination of apparent density(ISO 845:2006)Caoutchoucs et plastiques alvolaires - Dtermination de lamasse volumique apparente (ISO 845:2006)Scha
8、umstoffe 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 the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national
9、 standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any ot
10、her 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 versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia,
11、Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KO
12、MITEE 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 Members.Ref. No. EN ISO 845:2009: EEN ISO 845:2009 (E) 2 Contents Page Foreword .3 1 Scope4 2 Normative references4 3 Terms and def
13、initions .4 4 Apparatus.4 5 Test specimens5 5.1 Dimensions 5 5.2 Number of test specimens .5 5.3 Conditioning 5 6 Procedure.5 7 Expression of results6 8 Accuracy 6 9 Test report7 DIN EN ISO 845-2009-10 EN ISO 845:2009 (E) 3 Foreword The text of ISO 845:2006 has been prepared by Technical Committee I
14、SO/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 249 “Plastics” the secretariat of which is held by NBN. This European Standard shall be given the status of a national standard, either by publicat
15、ion 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 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 s
16、hall 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 Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bu
17、lgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The te
18、xt of ISO 845:2006 has been approved by CEN as a EN ISO 845:2009 without any modification. DIN EN ISO 845-2009-10 1 Scope This International Standard specifies a method for determining the apparent overall density and the apparent core density of cellular plastics and rubbers. If the material to be
19、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 materials, a different method such as
20、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 (including any amendments) applie
21、s. 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 overall density cellular material mass
22、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, capable of determining the mass
23、of a test specimen to an accuracy of 0,1 %. 4.2 Measuring instruments, in accordance with ISO 1923. EN ISO 845:2009 (E) DIN EN ISO 845-2009-10 45 Test specimens 5.1 Dimensions Each specimen shall be of a shape such that its volume can be easily calculated. It shall be cut without deforming the origi
24、nal 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. For rigid materials, when the apparent overall densit
25、y 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 specimens shall be tested. The sample may be a manufactured o
26、bject 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 specimens from product samples. If required, this period may b
27、e 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 atmospheres or in a desiccator (dry conditions) as defined
28、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 2010+) % relative humidity. Dry conditions are (23 2) C
29、, 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 measurements of the central area. Calculate the mean values for e
30、ach 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. EN ISO 845:2009 (E) DIN EN ISO 845-2009-10 57 Expression of results 7.1 The density (apparent overall density or apparent core density) of a t
31、est 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 density from the result for all test specimens and round it to the nearest 0,
32、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 mass of displaced air, in grams, calculated by multiplying the volume, in c
33、ubic 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 1,220 106g/mm3; the density of air at 27 C and 101 325 Pa is 1,195 5 106g/mm3.
34、 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 number of measurements made. 8 Accuracy 8.1 The values given in this clause we
35、re 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 accuracy of this test method can be expected to vary for different materi
36、als. 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 absolute density differences between laboratories can be limited to 2,6 % (at 95
37、% confidence) for the same material. EN ISO 845:2009 (E) DIN EN ISO 845-2009-10 69 Test report The test report shall include the following information: a) a reference to this International Standard; b) a complete identification of the material tested; c) the temperature and humidity at which the tes
38、t 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) the individual test results, stating details of the test specimen shape, test specimen dimensi
39、ons 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 buoyancy 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. EN ISO 845:2009 (E) DIN EN ISO 845-2009-10 7
