SIST EN 321:2004

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Wood-based panels - Determination of moisture resistance under cyclic test conditionsSRJRMLKPanneaux a base de bois - Détermination de la résistance a l'humidité selon essais cycliquesHolzwerkstoffe - Bestimmung der Feuchtebeständigkeit durch Zyklustest79.060.01Wood-based panels in generalICS:SIST EN 321:2004enTa slovenski standard je istoveten z:EN 321:200101-januar-2004SIST EN 321:2004SLOVENSKI
STANDARDSIST EN 321:1996/AC:1998SIST EN 321:19961DGRPHãþD

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 321November 2001ICS 79.060.01Supersedes EN 321:1993English versionWood-based panels - Determination of moisture resistanceunder cyclic test conditionsPanneaux à base de bois - Détermination de la résistanceà l'humidité selon essais cycliquesHolzwerkstoffe - Bestimmung der Feuchtebeständigkeitdurch ZyklustestThis European Standard was approved by CEN on 30 September 2001.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 standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Management Centre 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 Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2001 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 321:2001 E

ScopeThis European Standard specifies a test method for the determination of the moisture resistance of wood-basedpanels under cyclic test conditions.2
Normative referencesThis European Standard incorporates, by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text, and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references, the latest edition of thepublication referred to applies (including amendments).EN 310,
Wood based panels — Determination of modulus of elasticity in bending and of bending strength.EN 317,
Particleboards and fibreboards — Determination of swelling in thickness after immersion in water.EN 319,
Particleboards and fibreboards — Determination of tensile strength perpendicular to the plane of the board.EN 325,
Wood based panels — Determination of dimensions of test pieces.EN 326-1,
Wood based panels — Sampling, cutting and inspection — Part 1: Sampling and cutting of test piecesand expression of test results.3
PrincipleTest pieces are exposed to three cycles, each comprising immersion in water, freezing, and drying at elevatedtemperature. After cyclic treatment, the test pieces are then reconditioned and their swelling in thickness andresidual strength determined.4
Apparatus4.1
Water bathA water bath which shall maintain water at a temperature of (20 ± 1) °C.4.2 Freezing cabinetA freezing cabinet which shall be capable of maintaining a temperature of between - 12 °C and - 25 °C. It shall alsobe capable of regaining this temperature within 1 h after inserting the test pieces.4.3
Drying cabinetA laboratory drying cabinet with forced, evenly distributed air ventilation, which shall maintain a temperature of(70 ± 2) °C and have (25 ± 5) air exchanges per hour. It shall be capable of reaching a temperature of (70 ± 2) °Cwithin 2 h after inserting the test pieces.4

Test pieces5.1 SamplingSampling and cutting of the test pieces shall be carried out according to EN 326-1 and the relevant materialspecification standard.5.2 Dimensions of test piecesDimensions shall be in accordance with EN 310, EN 317 and EN 319 as appropriate.5.3
ConditioningThe test pieces shall be conditioned to constant mass in an atmosphere with a relative humidity of (65 ± 5) % anda temperature of (20 ± 2) °C. Constant mass is considered to be reached when the results of two successiveweighing operations, carried out at an interval of 24 h, do not differ by more than 0,1 % of the mass of each testpiece.6 Procedure6.1 Treatment of the test piecesThe following sequence of operations shall be carri
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