1、April 2013 Translation by DIN-Sprachendienst.English price group 8No part of this translation 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 8
2、3.180!$L0“1974113www.din.deDDIN EN 828Adhesives Wettability Determination by measurement of contact angle and surface free energyof solid surface;English version EN 828:2013,English translation of DIN EN 828:2013-04Klebstoffe Benetzbarkeit Bestimmung durch Messung des Kontaktwinkels und der freien O
3、berflchenenergie festerOberflchen;Englische Fassung EN 828:2013,Englische bersetzung von DIN EN 828:2013-04Adhsifs Mouillabilit Dtermination par mesurage de langle de contact et de lnergie superficielle libre de lasurface solide;Version anglaise EN 828:2013,Traduction anglaise de DIN EN 828:2013-04S
4、upersedesDIN EN 828:1998-01www.beuth.deDocument comprises 13 pagesIn case of doubt, the German-language original shall be considered authoritative.02.13 DIN EN 828:2013-04 2 A comma is used as the decimal marker. National foreword This document (EN 828:2013) has been prepared by Technical Committee
5、CEN/TC 193 “Adhesives” (Secretariat: AENOR, Spain). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Working Committee NA 062-04-55 AA Prfung von Konstruktions-klebstoffen, -klebverbindungen und Kernverbunden. Ame
6、ndments This standard differs from DIN EN 828:1998-01 as follows: a) in the title, “critical surface tension” has been replaced by “surface free energy”; b) “Safety Statement” and “Environmental Statement” have been added; c) Clause 3 “Terms and definitions” has been extended to include “3.1 triple
7、point”, “3.2 baseline”, “3.5 contour analysis” and “3.6 surface free energy of a solid”; d) the recommended test liquids have been changed; e) the number of drops to be measured has been changed; f) the measurement method has been rendered more precise and brought in line with the state of the art;
8、g) the former Annex A “Critical surface measurement” has been deleted. Previous editions DIN EN 828: 1998-01 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 828 January 2013 ICS 83.180 Supersedes EN 828:1997English Version Adhesives - Wettability - Determination by measurement of contact angle
9、and surface free energy of solid surface Adhsifs - Mouillabilit - Dtermination par mesurage de langle de contact et de lnergie superficielle libre de la surface solide Klebstoffe - Benetzbarkeit - Bestimmung durch Messung des Kontaktwinkels und der freien Oberflchenenergie fester Oberflchen This Eur
10、opean Standard was approved by CEN on 24 November 2012. 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
11、 concerning such national standards may be obtained on application to the CEN-CENELEC 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 memb
12、er into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, Fra
13、nce, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES K
14、OMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 828:2013: EEN 828:2013 (E) 2 Contents Page Foreword . 3 1 Scope 4 2 Normative references . 4 3 Terms and de
15、finitions 4 4 Principle 6 5 Test equipment . 6 6 Measuring conditions 7 7 Procedure . 8 8 Expression of results . 9 9 Test report 9 Bibliography 11 DIN EN 828:2013-04 EN 828:2013 (E) 3 Foreword This document (EN 828:2013) has been prepared by Technical Committee CEN/TC 193 “Adhesives”, the secretari
16、at of which is held by AENOR. 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 July 2013, and conflicting national standards shall be withdrawn at the latest by July 2013. Attention is drawn to the
17、 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 828:1997. Safety Statement People applying this document, the user shall be familia
18、r with normal laboratory practice. This standard does not purport to address all the safety problems, if any, associated with its use. It is the responsibility of the user to establish safety and health practices and to ensure their compliance with the provisions of any regulatory conditions. Enviro
19、nmental Statement It is understood that some of the material permitted in this standard may have a negative environmental impact. As technological advantages lead to acceptable alternatives for these materials, they will be eliminated from this standard as far as possible. At the end of the test, th
20、e user of the standard should take care to carry out appropriate disposal of waste, according to local regulations. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulg
21、aria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Tu
22、rkey and the United Kingdom. DIN EN 828:2013-04 EN 828:2013 (E) 4 1 Scope This European Standard specifies a method for the determination of the surface free energy of a solid surface by measuring the contact angle of a liquid wetting the solid surface. It allows the prediction of the ability of a p
23、articular adhesive to wet a particular adherend. It can be used to characterise surfaces intended for pre-treatment, coating or bonding. NOTE 1 In order to determine the surface free energy, the method of measuring the static contact angle is used in combination with a statistical interpretation. NO
24、TE 2 The measurement results are influenced by mechanical surface roughness and chemical homogeneity. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cit
25、ed applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 923:2005+A1:2008, Adhesives Terms and definitions 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 923:2005+A1:2008 and the followi
26、ng apply. 3.1 triple point point where the solid, the liquid and the gas phases coincide with each other Note 1 to entry: The triple point can be identified in the silhouette of a liquid drop situated on a test piece, at the intersection of the drops contour line with the test piece surface. 3.2 bas
27、eline in the case of plane test pieces, a straight line going through the two triple points 3.3 contact angle angle to the baseline, formed by a tangent to the drop contour going through one of the triple points (see Figure 1) DIN EN 828:2013-04 EN 828:2013 (E) 5 Key 1 solid body surface 2 liquid dr
28、op Lsurface tension (= surface energy) of the liquid in equilibrium with the gas phase Ssurface free energy of the solid body surface SLinterfacial energy of the solid body surface in contact with the liquid contact angle Figure 1 Wettability 3.4 wettability a liquid coming into contact with a solid
29、 surface exhibits a typical drop shape. The characteristic of the drop is the angle formed by the tangent to the contour at the triple point (wetting point) (Figure 1). A contact angle = 0 indicates a surface that is completely wetted 3.5 contour analysis image analysis procedure consisting in captu
30、ring the silhouette of a liquid drop on a surface by optical methods and calculating the contour profile of that silhouette 3.6 surface free energy of a solid Senergy measure (expressed in mN/m) which characterises the wettability of a solid material by a liquid that is based on the adsorption theor
31、y. The forces present in the state of equilibrium are described by Youngs formula: S= SL+ L cos (1) The Young-Dupr formula defines the work of adhesion obtained during wetting: Wad= L+ L cos = L (1 + cos ) (2) The position of the thermodynamic equilibrium resulting in the formation of the static con
32、tact angle depends on both the pressure and the temperature conditions. When carrying out the measurement, standard conditions should be maintained. Since the interfacial energy and the surface energy are based on interactive forces between atoms or molecules, it is necessary to take polarity into c
33、onsideration when assessing the wettability. Examples for polar interactions are as follows: dipole-dipole interactions; hydrogen bridge bonds; acid-base interactions. DIN EN 828:2013-04 EN 828:2013 (E) 6 The non-polar (disperse) interactions are commonly described as London interactions. In accorda
34、nce with 1 and 2, the interfacial energy SLbetween a solid body (S for “solid“) and a liquid (L for “liquid“) is the sum of the surface tensions of the two phases (S+ L), reduced by the disperse and the polar interactions at the phase border. These interactions are described as the doubled sum of th
35、e geometric mean values of the disperse (DLDS ) and the polar (PLPS ) tension components of the individual phases: SL= S+ L 2 ( DDSL+ PPsL) (3) Substitution SLfrom the Youngs formula (1) and rearrangement of formula (3) to the general form of a straight line y = mx + b (4) leads to the following for
36、mula: ( )1 cos2mbxy+= + PLL PDSSDDLL(5) The square of the slope is the polar proportion of the solid body surface energyPS , the square of the ordinate intercept b is the disperse proportionDS . The sum of the two proportions is the total surface free energy of the solid body S. 4 Principle Ten drop
37、s each of at least three and up to eight known, different liquids are dosed onto a plane test piece surface. For each drop, the left and the right contact angles are measured. From the averaged contact angles of each liquid combined with its surface tension and its polar and disperse proportions, th
38、e surface free energy of the solid body is calculated, subdivided into the polar and the disperse proportions. Preferably, the liquids used should exhibit different polar and disperse proportions of the interfacial tension. Recommended liquids and their characteristic interfacial tensions are listed
39、 in Table 1. The drop volumes suitable for the measurement depend on the type of the liquid and should be adjusted such that the negative influence of gravity on the contact angle is kept to a minimum. 5 Test equipment 5.1 Solid surface to be assessed, substrate with pre-treated or untreated surface
40、. 5.2 Contact-angle measuring system, any contact-angle measuring device, preferably systems comprising digital image acquisition and image analysis to comply with the current state of the art. Figure 2 gives an example of a schematic representation of a contact-angle measuring system. DIN EN 828:20
41、13-04 EN 828:2013 (E) 7 Table 1 Recommended test liquids Designation of the test liquid Surface tension mN/m Disperse proportion mN/m Polar proportion mN/m Literature (Author) Water 72,80 21,80 51,00 See 3 Diiodomethane 50,80 50,80 0,00 See 3 Ethylene glycol 47,70 30,90 16,80 See 3 Glycerol 63,40 37
42、,00 26,40 See 3 Hexadecane 27,60 27,60 0,00 See 3 -Bromine naphthalene 44,60 44,60 0,00 See 3 Benzyl alcohol 38,90 29,00 9,90 See 4 Decalin 30,60 30,60 0,00 See 3 Key 1 lighting 2 sample carrier 3 dosage 4 optical system 5 screen Figure 2 Contact-angle measuring system 5.3 Reagents, at least three a
43、nd up to eight of the test liquids recommended in Table 1. WARNING These reagents are chemicals carefully follow the safety advice on the labels and in the safety data sheets. 5.4 Micropipette (or suitable syringes for micro-dosing) which can be fastened above the sample carrier or the surface to be
44、 tested, respectively, by means of an appropriate holder. 6 Measuring conditions Constant measuring conditions in accordance with the thermodynamic state function (temperature and pressure) shall be maintained. DIN EN 828:2013-04 EN 828:2013 (E) 8 7 Procedure 7.1 The contact-angle measuring device s
45、hall be adjusted horizontally by means of the level. 7.2 The contact-angle measuring device, the lighting and the image acquisition and analysis system are switched on. The image display is adjusted to be sufficient with regard to brightness and contrast (the manufacturers information should be take
46、n into consideration). The light source of the contact-angle measuring device shall be calibrated to obtain optimum contrast and grey scale value in the image of a drop and of a surface. The dosing needle is moved to the upper edge of the image and the zoom of the contact-angle measuring device is s
47、et in a way that the contour width of the located drop covers two thirds of the width of the image. Afterwards the drop image shall be focussed. 7.3 The dosing system is filled with one of the selected liquids. It shall be ensured that any contaminations during filling are avoided. 7.4 A plane sampl
48、e of the surface to be measured is placed on the sample carrier. The sample carrier shall be adjusted such that the sample surface is located in the lower half of the image and in a horizontal position. 7.5 The dosing needle is positioned approximately 1 mm above the sample surface. The drop shall be dosed such that its volume is between 2 l and 6 l, depending on the liquid selected. Recommended drop volumes are given in Tab
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