EN ISO norms for ceramic tiles 2 EN ISO norms for ceramic ...

1 205 APPENDIXEN ISO norms for ceramic tiles - Testing methodsEN ISO norms for ceramic tiles - RequirementsUNI-designationCategories of selectionThe Centro Ceramico in BolognaCeramic Arbitration BoardConstitution and Rules of Procedure123456206 APPENDIX 1EN ISO norms for ceramic tiles - Testing methodsEN ISO 10545 - Part 1 ceramic tilesSampling and basis for acceptance This standard applies to uninstalledceramic tiles . It establishes the rules for thecomposition of a sample lot. The lot must consist of tiles producedunder conditions and with properties thatare assumed to be uniform. Thus everyconsignment, that is every quantity of tilesdelivered within two days, must bedivided into sub-consignments that areassumed to be homogeneous and can thusconstitute inspection lots.

2 The number of lots to be inspected andthe choice of properties to be consideredfor inspection will be subject to agreementbetween supplier and consumer, as will bethe choice of location where the samplingwill be performed. The sampling will be performed byrandomly taking samples from theinspection lot. Usually two samples aretaken. Every sample must be packed,sealed and labelled. Every property will be assigned a sample size , or a minimum number oftiles to be inspected as noted in a table,together with the basis of acceptance orrejection. Tests on the sample tiles must beperformed according to the methodsspecified in the corresponding regard to the preceding EuropeanStandards (EN163), the table setting forththe standards of acceptance and rejectionhas been modified to take into account: new added testing methods, and aneliminated method; modifications in product requirements:for all requirements which are notobligatory but which must be declared bythe manufacturer, the table specifies thatthe basis for acceptance or rejectiondepends on the conformity (or lack thereof)with the manufacturer s ISO 10545 - Part 2 Determination of dimensions andsurface quality Method applicable to all ceramic tiles .

3 For all measurements, 10 whole tiles arerequired. Instruments include vernier calipers,micrometer, screw gauges or other suitableapparatus. tiles with surfaces of less than4 cm2 are excluded from all measurementsother than ( ) Measurement of length and width. Eachside of the tile must be measured 5 mmaway from the corners. The averagedimension of a square tile consists in theaverage of 4 measurements and theaverage size of the sample consists in theaverage of 40 average length and width of an oblongtile consists in the average of themeasurements of two opposite sides, sothat the average length and width of thesample consist in the average of twentymeasurements of each dimension. Measurement of thickness. Thickness ismeasured by first tracing the twodiagonals, then measuring the thickestpoint along each of the four segmentsobtained.

4 In the case of extruded tiles , fourlines perpendicular to the direction ofextrusion are traced, and the thickness ismeasured at the thickest point on each line. Measurement of straightness of deviation from straightness of a sideis measured at the center of that side, andthe measurement must be taken for everyside of every single tile. Measurement of rectangularity. Thisconsists in the deviation of the outercorner of the side of the tile (5 mm fromthe corner) from the inner side of thecalibrating plate. Deviation fromrectangularity is expressed, in percentageterms, by the formula: /L . 100 where L isthe length of the adjacent side of the tile. Measurements of surface flatness is defined by the 3measurements described below which, fortiles smaller than 40 x 40 mm, are takenwith metal straight edges and thicknessfeeler gauges.

5 Center curvature: the departure of thecenter of the tile from the plane in which 3of the 4 corners lie. For every tile, 4measurements are taken. The maximumcenter curvature is expressed in mm or asa percentage relative to the diagonalcalculated from the work size. Edge curvature: the departure of the centerof a tile from the plane in which 3 of the 4corners lie. The maximum edge curvatureis expressed in mm or as a percentage ofthe relative work size. Warpage: the departure of the fourthcorner of tile from the plane in which theother three angles maximum warpage is expressed in mmor as a percentage of the diagonalcalculated on the basis of the work size. Surface quality. This assessment requiresa surface of at least 1 square meter and aminimum of 25 tiles must be placed under a lightsource of 300 lux and observed withthe naked eye from a distance of quality of the surface is expressed as apercentage of tiles without surface effects must notbe considered defects (see correspondingparagraph under product standards).

6 Cracks, nipped edges and nipped corn-ers can not be considered 1 LRectangularityStraightness of sidesDeviation from rectangularity: /LDeviation from straightness: c/LWork sizeLDCenter curvature+ - +c-c+ c- cCenter curvature: c/DEdge curvatureWarpage+ b- b+ s- sEdge curvature: /LWarpage: /DEN ISO 10545 - Part 3 Determination of water absorption,apparent porosity, apparent relativedensity and bulk density Method applicable to all ceramic tiles . The test must be performed on 10 wholetiles in cases where the surface of each tileis less than m2; if greater than m2,5 tiles will suffice. In any case, every testsample must weigh a minimum of 50 g. After tiles are brought to a constantweight through drying, they are weighedwith a precision which depends on theweight of the tile.

7 tiles are then placed tobe boiled in a container of distilled or de-ionized water, in such a way that they donot touch the bottom and are completelyimmersed. Container should be kept atboiling point for two hours. Then tilesshould be left cooling for four hoursimmersed in water. Once the tiles havebeen removed from the container, excesswater is removed with a chamois leatherand tiles are then weighed, again asprecisely as for dry weight. The absorption of water, expressed as apercentage of the weight of the drymaterial, is expressed in the formula:[(m2- m1)x100]/m1where:m1 = the mass of the dry tilem2 = the mass of the wet average absorption of water of thesample is determined by the arithmeticaverage of the individual results, andresults must be rounded off to a singledecimal determination of water absorption,which is required for a product sassignment to a group, remains the sameas that stipulated by the EuropeanStandards (EN 99).

8 Other properties havealso been added for which no requirementexists (that is, these properties are notconsidered in the sections on productrequirements) but which may be useful intypifying the structure of the tile s ceramicmass: for theses properties, waterabsorption is measured through waterimpregnation at a residual pressure of100 1 kPa for 30 ISO 10545 - Part 4 Determination of modulus of ruptureand breaking strength Method applicable to all ceramic tiles . The test must be performed on wholetiles whose number depends on the size ofthe tiles (Table 1). Only exceptionally largetiles, or tiles whose shapes make itimpossible to insert them in the apparatus,may be cut. The tile is placed on two supporting rodswith the proper surface uppermost ( ) sothat it protrudes by the length 1 beyond eachsupporting rod.

9 The load is applied evenlyat a constant rate of increase of stress(1 N/mm2 s) by means of a third rod incontact with the proper surface, equidistantbetween the supporting rods. Extruded tilesmust be so positioned that the direction ofextrusion is perpendicular to the rods. ForFig. 1 Scheme tiles , the longer side must beperpendicular to the support rods. The resistance to bending , expressedas N/mm2, is given by the formulawhere :F = breaking load (in N)L = span between the supporting rods (inmm)b = width of the tile at the broken edge (inmm)h = minimum thickness of the tile (in mm)measured along the broken average resistance to bending of thesample is the arithmetic average of theindividual test method is the same as thatdescribed in the preceding EuropeanStandards (EN 100: the so-called three-APPENDIX 1 Dimension of tile(mm) 95< 95 48< 48 18 Diameter of rods, d(mm)20105 Thickness of rubber, t(mm) of tile beyond the edgesupport, l(mm)1052 Minimum numberof tiles for test7710 Table 1 Instrumentalparameters for themeasurement ofmodules ofruptures, accordingto the format of method ).

10 An importantmodification has been introduced: the testreport must note not only the load Frequired to break the sample and themodulus of rupture from bending, but alsothe breaking strength calculated S . Themodulus of rupture is undoubtedly animportant parameter, but it refers to anintrinsic property of ceramic material: inphysical terms, it represents work per unitof volume, a value that may be useful forthe specifier but that gives no informationon the maximum load that a tile can last parameter depends on thedimensions of the sample: in fact, given thesame level of water absorption (and thusthe same intrinsic properties of thematerial), the value of the modulus ofrupture from bending is the same, butthe force F required to break the samplevaries depending on the dimensions of thesample itself.