1、BRITISH STANDARD BS EN 1748-2-1:2004 Glass in building Special basic products Glass ceramics Part 2-1: Definitions and general physical and mechanical properties The European Standard EN 1748-2-1:2004 has the status of a British Standard ICS 01.040.81; 81.040.20 BS EN 1748-2-1:2004 This British Stan
2、dard, was published under the authority of the Standards Policy and Strategy Committee on 27 September 2004 BSI 27 September 2004 ISBN 0 580 44457 0 National foreword This British Standard is the official English language version of EN 1748-2-1:2004. It supersedes BS EN 1748-2:1998 which is withdraw
3、n. The UK participation in its preparation was entrusted by Technical Committee B/520, Glass and glazing in building, to Subcommittee B/520/1, Glass and glazing in building Basic and transformed glass products, which has the responsibility to: A list of organizations represented on this subcommittee
4、 can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Searc
5、h” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obl
6、igations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary
7、 of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 15 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORME
8、EUROPENNE EUROPISCHENORM EN174821 September2004 ICS01.040.81;81.040.20 SupersedesEN17482:1997 Englishversion GlassinbuildingSpecialbasicproductsGlassceramics Part21Definitionsandgeneralphysicalandmechanical properties VerredanslaconstructionProduitsdebasespciaux Partie21VitrocramiquesDfinitionetdesc
9、ription GlasimBauwesenSpezielleBasiserzeugnisse GlaskeramikTeil21:Definitionenundallgemeine physikalischeundmechanischeEigenschaften ThisEuropeanStandardwasapprovedbyCENon21June2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Stan
10、dardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebyt
11、ra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia
12、,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinany
13、formandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN174821:2004:EEN 1748-2-1:2004 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Chemical composition 6 4.1 Principal Constituents.6 4.2 Tint 6 5 Physical and mechanical characteristics6 5.1
14、 General characteristics .6 5.2 Definition of clear glass ceramics7 5.3 Stability of physical and chemical characteristics.8 6 Dimensional requirements8 6.1 Manufacturing dimensions .8 6.1.1 Stock sizes .8 6.1.2 Final cut sizes 8 6.2 Thickness .8 6.2.1 Tolerances 8 6.3 Length, width, squareness and
15、tolerances.9 7 Quality requirements.10 7.1 Methods of observation and measurement 10 7.1.1 Optical faults 10 7.1.2 Visual faults10 7.2 Acceptance levels11 7.2.1 Optical faults, spot faults, linear/extended faults.11 7.2.2 Edge defects for final cut sizes12 8 Designation 14 Bibliography 15 EN 1748-2-
16、1:2004 (E) 3 Foreword This document (EN 1748-2-1:2004) has been prepared by Technical Committee CEN /TC 129 “Glass in Building“, the secretariat of which is held by BIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsem
17、ent, at the latest by March 2005, and conflicting national standards shall be withdrawn at the latest by March 2005. This document supersedes EN 1748-2:1997. This document consists of the following parts: EN 1748-2-1 Glass in building - Special basic products - Glass ceramics Part 2 1: Definitions a
18、nd general physical and mechanical properties EN 1748-2-2 Glass in building - Special basic products - Glass ceramics Part 2-2: Evaluation of conformity/Product standard According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to im
19、plement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingd
20、om. EN 1748-2-1:2004 (E) 4 1 Scope This document defines, specifies and classifies glass ceramics for use in building. It indicates their chemical composition, main physical and mechanical properties, dimensional and minimum quality requirements (in respect of optical and visual faults). This docume
21、nt applies to glass ceramics supplied in stock sizes or in cut sizes for final end use. This document does not apply to final cut sizes having a dimension less than 100 mm or a surface area less than 0,05 m. 2 Normative references The following referenced documents are indispensable for the applicat
22、ion 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. EN 410, Glass in building - Determination of luminous and solar characteristics of glazing 3 Terms and definitions For
23、 the purposes of this document, the following terms and definitions apply. 3.1 glass ceramics type of glass consisting of a crystalline and a residual glass phase. The glass is obtained by normal glass manufacturing methods, e.g. casting, floating, drawing, rolling and is subsequently subjected to a
24、 heat treatment which transforms, in a controlled manner, part of the glass into a fine grained crystalline phase. The glass ceramics has properties which deviate from those of the glass from which it was transformed. 3.2 floated glass ceramics flat, transparent or translucent, clear or tinted glass
25、 ceramics having parallel and polished faces obtained by continuous casting and flotation on a metal bath. 3.3 drawn sheet glass ceramics flat, transparent or translucent, clear or tinted glass ceramics obtained by continuous drawing, initially vertically, of a regular thickness and with the two sur
26、faces fire polished. 3.4 rolled glass ceramics flat, transparent or translucent, clear or tinted glass ceramics obtained by rolling. 3.5 cast glass ceramics flat, transparent or translucent, clear or tinted glass ceramics obtained by casting. 3.6 nominal length, H and nominal width, B pane length or
27、 pane width defined with reference to the direction of draw of the glass ceramics ribbon as shown in Figure 1. EN 1748-2-1:2004 (E) 5 Key Direction of draw Figure 1 Relationship of length, width and direction of draw 3.7 stock sizes glass ceramics delivered in manufacturers standard stock sizes. 3.8
28、 final cut size pane of glass ceramics that has been cut down to the dimensions being required either for installation or processing into a final product e.g. insulating glass units. 3.9 optical faults faults, which lead to distortions on the appearance of objects observed through the glass ceramics
29、. 3.10 visual faults faults, which alter the visual quality of the glass ceramics. They are spot faults and linear / extend faults. 3.11 spot faults spot fault is a nucleus, which is sometimes accompanied by a halo of distorted glass ceramics. The dimension of a spot fault comprising a nucleus with
30、a halo is obtained by multiplying the dimension of the nucleus by a factor of approximately 3. 3.12 linear / extended faults these faults can be on or in the glass ceramics, in the form of deposits, marks or scratches that occupy an extended length or area. 3.13 edge defects these defects can occur
31、on the edge of a cut size piece in the form of entrant and emergent faults and / or bevels. 3.14 concentration, c the sum of the lengths of gaseous inclusions greater than 1,0 mm in any circle of 400 mm diameter. EN 1748-2-1:2004 (E) 6 4 Chemical composition 4.1 Principal Constituents The magnitude
32、of the proportions by mass of the principal constituents of all the glass ceramics products covered by this standard is as follows: Silicon dioxide SiO 250 % to 80 % Aluminium oxide Al 2 O 315 % to 27 % Lithium oxide Li 2 O 0 % to 5 % Zinc oxide ZnO 0 % to 5 % Titanium dioxide TiO 20 % to 5 % Zircon
33、ium dioxide ZrO 20 % to 5 % Magnesium oxide MgO 0 % to 8 % Calcium oxide CaO 0 % to 8 % Barium oxide BaO 0 % to 8 % Sodium oxide Na 2 O 0 % to 2 % Potassium oxide K 2 O 0 % to 2 % Others 0 % to 5 % 4.2 Tint Body tinted glass ceramics is obtained by the addition of suitable materials. 5 Physical and
34、mechanical characteristics 5.1 General characteristics Conventional numerical values for the physical and mechanical characteristics of the glass ceramics used to manufacture basic product are given in Table 1. These values, for normal annealed glass ceramics (without any further toughening), are no
35、t precise requirements with which the glass ceramics shall strictly comply, but are the generally accepted figures for use in calculations where a high degree of accuracy is not required. EN 1748-2-1:2004 (E) 7 Table 1 Physical and mechanical characteristics of glass ceramics Characteristic Symbol V
36、alue and unit Density (at 18 o C) 2500 kg/m 3to 2600 kg/m 3Hardness (Knoop) HK 0,1/20 6 to 7,5 GPa Youngs modulus (modulus of elasticity) E 9 x 10 10Pa Poissons ratio 0,2 Characteristic bending strength f g,k 45 x 10 6 Pa 1Specific heat capacity c p 0,8 x 10 3J/(kg * K) to 0,9 x 10 3J/(kg * K) Nomin
37、al value of average coefficient of linear expansion between 20 o C and 300 o C zero Resistance against temperature differential and sudden temperature change 650 K 2Thermal conductivity 1,5 W/(m * K) Mean refractive index to visible radiation (380 nm to 780 nm) n 1,5 Emissivity (corrected) 0,837 1A
38、design method will be made available from TC 129 WG8 (prEN 13473) 2Generally accepted value that is influenced by edge quality and glass type 5.2 Definition of clear glass ceramics A glass ceramics product is defined as clear glass ceramics when it is not tinted and when the light transmittance of t
39、he glass ceramics material, unmodified by the possible presence of a coating or surface roughness, after any necessary pre-treatment measured according to EN 410 rounded to the nearest 0,01 is greater than or equal to the value given in Table 2 for the nominal thickness of the glass ceramics product
40、. In order to measure the light transmittance characteristics of glass ceramics, to determine whether it can be classified as clear, it is necessary, in some cases, to carry out a pre-treatment: coatings on smooth surfaces have to be eliminated, without modifying the thickness of the glass ceramics
41、substrate. rough surfaces, with or without coatings, have to be eliminated by smoothing and polishing. The thickness of the glass ceramics will be modified by this process. The light transmittance of a glass ceramics substrate has to be measured with its surfaces in a polished condition. EN 1748-2-1
42、:2004 (E) 8 Table 2 Minimum values for determining if a transparent or translucent glass ceramics product is clear Nominal thickness in mm Minimum value (1,2)3 4 5 6 7 8 0,86 0,84 0,82 0,80 0,78 0,76 1)The limiting values given are applicable provided that the measured thickness of the glass ceramic
43、s product is within the allowable tolerances for the nominal thickness of that product. 2)The values given are not suitable for design. They are values used only for the definition of clear glass ceramics and exclude the effects of coatings and of surface patterns. The values of light transmittance
44、used for design should be obtained from the glass manufacturer, measured according to EN 410. 5.3 Stability of physical and chemical characteristics For glass ceramics products, the physical and chemical characteristics can be considered as remaining constant over time. a) Since glass ceramics is in
45、sensitive to photochemical effects, the spectral properties (transmission of light and solar energy) of the glass ceramics products are not modified by direct or indirect solar radiation. b) The surface of glass ceramics used in building is virtually insensitive to attack from the environment. 6 Dim
46、ensional requirements 6.1 Manufacturing dimensions 6.1.1 Stock sizes Glass ceramics delivered in the following size range: Nominal length H: 500 mm to 3300 mm Nominal width B: 500 mm to 2300 mm 6.1.2 Final cut sizes Glass ceramics delivered in any dimension less than those covered by the stock sizes
47、. The minimum cut size shall have dimensions H and B not less than 100 mm and a minimum surface area of not less 0,05 m. 6.2 Thickness The actual thickness shall be the average of four measurements, taken to the nearest 0,01 mm, one taken at the centre of each side. Measurement shall be made by mean
48、s of an instrument of the calliper micrometer type. 6.2.1 Tolerances The actual thickness, rounded to the nearest 0,1 mm shall not vary from the nominal thickness by more than the tolerances shown in Table 3. EN 1748-2-1:2004 (E) 9 Table 3 Nominal thicknesses and thickness tolerances Nominal thickness in mm thickness tolerances in mm 3 4 5 6 7 8 0,5 0,5 0,5 0,5 0,5 0,5 6.3 Length, width, squareness and tolerances The nominal dimensions for the length, H, an
