EN 323-1993 en Wood-Based Panels - Determination of Density《木基板 密度测定》.pdf

1、CEN ENt323 93 = 3404589 0043820 704 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 323 February 1993 UDC 674.815: 620.1: 531.754 Descriptors: Wood-based panel, fibreboard, particleboard, plywood, OSB, cement-bonded particleboard, test method, density (mass/volume) English version Wood-based pa

2、nels - Determination of density Panneaux base de bois - Dtermination de la masse volumique Holzwerkstoffe - Bestimmung der Rohdichte This European Standard was approved by CEN on 1992-12-15. CEN members are bound to comply with the CENICENELEC Internal Regulations which stipulate the conditions for

3、giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official v

4、ersions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgiu

5、m, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassa

6、rt 36, B-1050 Brussels O 1993 Copyright reserved to CEN members Ref. No. EN 323 : 1993 E CEN ENS323 93 = Page 2 EN 323: 1993 Foreword This European Standard was prepared by Working Group 4 Common test methods (Secretariat: United Kingdom) of Technical Committee CEN/TC 112 Wood-based panels (Secretar

7、iat: Germany). The text is based on IS0 9427 : 1989 which has been elaborated with European participation. This Standard is one of a series of standards specifying methods of test for determining dimensions and properties of wood-based panels. No existing European Standard is superseded. This Europe

8、an Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 1993, and conflicting national standards shall be withdrawn at the latest by December 1994. In accordance with the Common CENXENELEC Rules the following

9、 countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. 3404589 004l182L 640 Contents 1 Scope 2 Normative references 3 Pri

10、nciple 4 Apparatus 5 Test pieces 6 Procedure 7 Expression of results 8 Testreport Annex A (informative) Bibliography page 3 3 3 3 3 4 4 4 5 1 Scope This European Standard specifies a method for determining the density of test pieces of wood-based panelS.Such result may be used to estimate the densit

11、y of wood-based panels according to EN 326-1. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated

12、references, subsequent amendments to or revisions of any of these publications apply to this European Standard, only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 325 Wood- based panels - Determination of dimens

13、iorts of test pieces EN 326- 1 Wood- based panels - Sampling, cutting and inspection Part 1: Sampling and cutting of test pieces and expression of test results1) 3 Principle Density is determined as the ratio of the mass of each test piece, to its volume, both measured at the same moisture content,

14、and the use of these results to estimate the density of whole boards. 4 Apparatus 4.1 Instrument for thickness measurement Micrometer or similar measuring instrument, having flat and parallel circular measuring surfaces of (16 I i) mm diameter and an operation force of (4 I 1) N. The graduation of t

15、he apparatus shall allow reading to 0,Ol mm. Page 3 EN 323 : 1993 4.2 Instrument for length and width measurement Sliding caliper, or any other instrument with measuring surfaces of at least 5 mm width, graduated to allow reading to 0,l mm. 4.3 Balance Balance, allowing measurement to 0,Ol g. 5 Test

16、 pieces 5.1 Sampling and cutting Sampling and cutting of the test pieces shall be carried out in accordance with EN 326-1. 5.2 Dimensions The test pieces shall be square in shape, with sides of a nominal length of 50 mm. In the case of extruded panels, cellular panels, or panels of similar structure

17、 with cavities parallel to the length or width of the test piece, the total length or width of the test piece shall be at least twice the length or width of any individual core element (i.e. two tube diameters plus two web thicknesses) and the test pieces shall have a symmetrical cross-sectional are

18、a as shown in figure I. 5.3 Conditioning If necessary, the test pieces shall be conditioned to constant mass in an atmosphere with a relative humidity of (65 f 5) % and a temperature of (20 f 2) OC. Constant mass is considered to be reached when the results of two successive weighing operations, car

19、ried out at an interval of 24 h, do not differ by more than 0,l % of the mass of the test piece. Figure 1. Cross-section of a tubular board )At present at the draft stage (EN ENL323 93 m 3404589 0043823 413 m Page 4 EN 323: 1993 6 Procedure 6.1 Weighing Wpiah Pnrh twt nipce to an accuracy of 0,Ol g.

20、 7 Expression of results 7.1 The density p of each test piece (in kg/m3) shall be calculated from the formula: Df dimensions n q. m . ric a) Measure the thickness, t, at a point of the intersection of the diagonals as shown in figure 2 where (unless this coincides &th a surface irregu&ity which may

21、influence the measurement) to an accuracv of 0.05 mm. m is the mass of the test pieces in g b1, b2 and t are in mm, as defined in 6.2. pass through the centres of opposite edges as shown in figure 2, to an accuracy of 0,l mm. 8 lkst report As described in EN 326-1. - -. “-“ 6.2 Measurement 4 Measure

22、 the dimensions 01 ror np in accordance with EN 325, a! c bl Dimensions in millimetres. Figure 2. Point of measurement Annex A (informative) Bibliography EN 309 Particleboards - Definition EN 313-1 and classgication Plywood - ClassZification and minology Part 1: CMfication EN 316 Fibreboards - Definition, ckrssi,fication and symbols EN 633 Cement- bonded particleboards - Definition2 IS0 9427 : 1989 Wood-based panels - Demination of density :)At present at the draft stage