1、BS EN 927-5:2006ICS 87.040NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPaints and varnishes Coating materialsand coating systems forexterior woodPart 5: Assessment of the liquid waterpermeabilityLicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/200
2、9 07:57, Uncontrolled Copy, (c) BSIThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 October2008 BSI 2008ISBN 978 0 580 56079 8Amendments/corrigenda issued since publicationDate CommentsBS EN 927-5:2006National forewordThis British Standard is t
3、he UK implementation of . It supersedes BSEN 927-5:2000 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee STI/28, Paint systems for non-metallic substrates.A list of organizations represented on this committee can be obtained onrequest to its secretary.Th
4、is publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolle
5、d Copy, (c) BSIBS EN 927-5:2006EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 927-5 December 2006 ICS 87.040 Supersedes EN 927-5:2000 English Version Paints and varnishes - Coating materials and coating systems for exterior wood - Part 5: Assessment of the liquid water permeability Peintures e
6、t vernis - Produits de peinture et systmes de peinture pour le bois en extrieur - Partie 5 : Dtermination de la permabilit leau liquide Beschichtungsstoffe - Beschichtungsstoffe und Beschichtungssysteme fr Holz im Auenbereich - Teil 5: Beurteilung der Wasserdurchlssigkeit This European Standard was
7、approved by CEN on 4 May 2006. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
8、 standards 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 other language made by translation under the responsibility of a CEN member into its own language and noti
9、fied to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Nethe
10、rlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitatio
11、n in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 927-5:2006: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 2 Contents Page Foreword3 Introduction .4 1 Scope 5 2 Normative re
12、ferences 5 3 Terms and definitions .5 4 Principle5 5 Test panels .5 6 Apparatus .9 7 Procedure .9 8 Calculation and expression of results.10 9 Precision.10 10 Test report 11 Annex A (informative) Interpretation of test results and further calculations 12 Annex B (informative) Suggested form for spec
13、ifying application parameters.13 Bibliography 18 Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 3 Foreword This document (EN 927-5:2006) has been prepared by Technical Committee CEN/TC 139 “Paints and varnishes”, t
14、he secretariat of which is held by DIN. 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 June 2007, and conflicting national standards shall be withdrawn at the latest by June 2007. This document s
15、upersedes EN 927-5:2000. EN 927 consists of the following parts under the general title: Paints and varnishes Coating materials and coating systems for exterior wood Part 1: Classification and selection Part 2: Performance specification Part 3: Natural weathering test Part 5: Assessment of the liqui
16、d water permeability Part 6: Exposure of wood coatings to artificial weathering using fluorescent UV lamps and water According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyp
17、rus, 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 United Kingdom. Licensed Copy: Wang Bin, ISO/EXCHANGE CH
18、INA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 4 Introduction The treatment of exterior wood surfaces has both aesthetic and protective functions. A vital purpose of a coating system is to protect the wood against aesthetic deterioration (e.g. blue stain
19、 attack) and dimensional changes. Because such attacks are mainly caused by high moisture contents in the wood, a knowledge of the relative water permeability properties of coating materials applied to exterior wood is helpful in selecting products for particular end-use applications, as described i
20、n EN 927-1. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 5 1 Scope This part of EN 927 specifies a test method for assessing the liquid water permeability of coating systems for exterior wood. 2 Normative referen
21、ces 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) applies. prEN ISO 2808:2004, Paints and varnishes Dete
22、rmination of film thickness (ISO/DIS 2808:2004) ISO 554, Standard atmospheres for conditioning and/or testing Specifications 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 water absorption ability of a coated or uncoated wood panel to absorb
23、 water from liquid or vapour 3.2 water permeability ability of a coating system to allow the transmission of water as liquid or vapour EN 927-1 3.3 stable mass mass achieved when the difference between two subsequent weighings within 24 h does not exceed 0,2 % 4 Principle Water permeability is asses
24、sed by measuring the water uptake over a 72 h period of a coated test panel exposed to liquid water. The coating under test is applied to the face of a defined test panel where the remaining face and sides are carefully sealed using a sealer of a defined mandatory low permeability. Results are expre
25、ssed as water absorption of coated wood panels in grams per square metre test surface per 72h. 5 Test panels 5.1 Wood The wood shall be spruce (Picea abies) that has been selected to be free from knots and cracks, to be straight-grained and of normal growth rate (i.e. between 3 and 8 annual rings pe
26、r 10 mm). The inclination of the growth rings to the test face shall be (45 10). See Figure 1. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 6 The wood shall be free from blue stain and evidence of surface or bulk
27、 infection. Abnormal porosity (caused by bacterial attack) shall be avoided. Abnormally porous wood can be detected qualitatively by the rapid absorption of a drop of propan-2-ol (isopropanol) applied to the surface; the drop should not be absorbed in less than 30 s by normal wood. The test should b
28、e carried out at not less than six places, widely separated on the rear face of the test panel. The density of the wood shall be between 0,4 g/cm and 0,5 g/cm when measured at an equilibrium moisture content of approximately 12 %. The measured density shall be recorded. Condition the wood prior to c
29、onversion into test panels in accordance with ISO 554 at (20 2) C and a relative humidity of (65 5) %. Dimensions in millimetres Key 1 Front of panel (test face) a Min. 3, max. 8 growth rings/10 mm. Angle of growth rings to test face min. 35, max. 55. Figure 1 Selection of wood 5.2 Preparation and s
30、election of test panels Convert the conditioned wood into panels (340 2) mm (70 2) mm (20 2) mm in size. It is intended that after coating one panel 150 mm in length will be cut from each end of this 340 mm long panel. This will leave an off-cut Ccapproximately 40 mm in length from the middle of the
31、 panel, to be used in due course for the determination of film thickness (see 5.3.5 and Figure 2). The panels shall be planed all round to a smooth and uniform finish. Any panels showing surface splitting shall be rejected. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Unc
32、ontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 7 5.3 Preparation of coated and uncoated panels 5.3.1 Wood conditioning Prior to coating, condition the panels to constant mass in accordance with ISO 554 at (20 2) C and a relative humidity of (65 5) %. Panels shall be weighed at intervals of
33、 not less than one day until they have reached a stable mass (see 3.3). 5.3.2 Panel selection Select three panels for each of the coatings to be tested. Select also three panels for testing the sealer product; this set of panels will serve as sealed controls (see Figure 2). Mark each panel to identi
34、fy the test face as that convex to the annual rings. Dimensions in millimetres Figure 2 Cutting of test panels Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 8 5.3.3 Coating application Coating systems shall be app
35、lied according to the manufacturers specifications. Apply each test coating system to the test face only (convex side of the panels). Each coating system under test requires 3 test panels (340 mm 70 mm 20 mm). When the coating systems have dried, cut a test panel 150 mm in length from both ends of e
36、ach long panel (see Figure 2). The three small coated off-cuts Ccare used for the determination of film thickness. Three additional panels are required to check the test face with the selected sealer. This sealer and the number of layers should be identical with the later on used sealer for sealing
37、the test panels (150 mm 70 mm 20 mm). The liquid water permeability of the sealer shall not exceed 30 g/m in 72 h (see Figure 2). Additional information is given in Annex B. 5.3.4 Sealing and conditioning Panels shall be sealed in the same way whether they are applied for test coatings or control of
38、 sealer. Seal the sides, end-grains and reverse faces of the panels against water entry using at least two coats of a flexible moisture-impermeable coating, for example a solvent-free epoxy or polyurethane paint. The sealer shall cover the edges completely and overlap the test face by 2 mm (see Figu
39、re 3). Apply the sealer to the end grain so many times that a closed and uniform film is obtained. Dimensions in millimetres Key 1 Test face. 2 2 mm l Length of the test face w Width of the test face Figure 3 Sealing of panels After sealing, condition the panels in the controlled environment (see 5.
40、3.1) until constant mass is achieved (for typically 7 to 28 days). After drying of the sealer measure and record the actual test area of each panel (see Figure 3). Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 9 5
41、.3.5 Dry film thickness Determine the dry film thickness of the coating on the off-cuts (see Figure 2) of the test panels. Remove one small chip of coated wood from each of the off-cuts and examine by microscopy in accordance with prEN ISO 2808:2004, method 6A. Make 5 measurements on each chip and c
42、alculate and record the mean value in micrometres. The dry film thickness is defined as the thickness of the layer on (above) the wood surface. Systems may penetrate the wood material to some extent, but this part is not included in the determination. 6 Apparatus 6.1 Microscope for measurement of dr
43、y film thickness in accordance with prEN ISO 2808:2004, method 6A. 6.2 Conditioning room, of appropriate size, controlled at a temperature of (20 2) C and a relative humidity of (65 5) %, in accordance with ISO 554. 6.3 Container for deionized water, of size sufficient to hold the all the panels und
44、er test. 6.4 Balance, capable of weighing to the nearest 0,01 g. 7 Procedure 7.1 Pre-conditioning It is known that the water permeability of some types of coating can change markedly during a relatively short period of exposure to water. For such coatings the values of water permeability obtained du
45、ring a short period of contact with water might not be representative of those obtained during long-term service. For this reason all panels shall be subjected to a leaching procedure before commencement of the absorption cycle. This procedure shall be carried out twice as follows: 24 h floating fac
46、e down in deionized water, such that the test face is fully submerged; 3 h drying at (20 2) C and a relative humidity of (65 5) % in accordance with ISO 554; 3 h drying at 50 C; 18 h drying at (20 2) C and a relative humidity of (65 5) % in accordance with ISO 554. All panels shall be handled togeth
47、er. After preconditioning, the test panels shall be conditioned by returning them to the controlled environment (see 6.2) in accordance with ISO 554 at (20 2) C and a relative humidity of (65 5) %, until a stable mass is achieved once more. 7.2 Absorption cycle Weigh the test panels to the nearest 0
48、,01 g and record the initial mass (m0). Fill the container (6.3) with deionized water and place it in the conditioning room (6.2). The water shall have reached stable temperature in the conditioned room, i.e. (20 2) C. Float the test panels face down on the surface of the water ensuring that the who
49、le of the test face is fully wetted. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 13/01/2009 07:57, Uncontrolled Copy, (c) BSIBS EN 927-5:2006EN 927-5:2006 (E) 10 After 72 h remove the test panels from the water, blot lightly to remove any water droplets and weigh. Record the elapsed time and mass (m1). All handling of the panels shall be carried out in the conditioning room (6.2). 7.3 Optional testing of weathered panels If required, coatings may be subjected to a weath
