IT-AP-20120420 INFORMATION REGARDING THE CE MARK
MORE INFORMATION REGARDING THE CE MARK Given the difficulty experienced in interpreting some of the results of the different tests conducted in order to apply the CE mark, Cosentino Research and Development, S.L. offers more detailed information to provide those persons requiring this knowledge with a greater understanding. FLEXURAL STRENGTH (EN 14617-2) Flexural strength (resistance to flexion) under concentrated loads is determined by placing a sample over two rollers with a load placed midway over the sample. The load at failure is measured and the flexural strength (bending) is determined. Materials presenting higher values have greater flexural strength, i.e., they are more flexible. The Silestone colour with the highest flexural strength is Blanco Zeus, which supports a load greater than 70 MPa (megapascals). Low flexural strength, evidenced by values lower than 25 MPa, would cause the material to break easily under flexural loads. These values depend on the thickness of the material. The thicker the material, the greater the flexural strength. These values are classified for the CE mark: Characteristic Values Flexural strength, MPa F 1 <12.0 12.0 F 2 <25.0 25.0 F 3 <40.0 F 4 40.0 All Silestone colours are classified as F 3 or higher, with most classified as F 4. SLIP RESISTANCE (EN 14231 and ENV 12633) Slip resistance is determined by the use of a friction pendulum, consisting of a weighted foot with a spring-loaded rubber test slider (see image). As the pendulum swings, the friction exerted between the slider and the test surface is measured by the reduction in the oscillation length, read using a graduated scale.
The measurements are given as slip resistance values (SRV), which are the scale values from the pendulum. The slider arm rises and falls, and the needle marks a value on the pendulum scale, which increases in line with the height differenced reached by the pendulum. In other words, if a material has low slip resistance, the slider will not be stopped by contact with the material surface and will rise to a certain height on the opposing side. This test is conducted on a wet surface, although, optionally, it can also be carried out on a dry one. When the surface is polished, the units are expressed as polished slip resistance values (PSRV). When the test surface has a different finish, the units are expressed as unpolished slip resistance values (USRV). ABRASION RESISTANCE (EN 14617-4) Abrasion resistance is determined by measuring the imprint left be a standard abrasive on the test material surface, as shown in the image. The test device consists of a rotary abrasion wheel, a small hopper that releases a controlled quantity of the abrasive material and a system to support the sample. Corundum was used as the abrasive with a specific size granule.
The test values are determined in millimetres, which coincide with the length of the imprint produced by the abrasive. The larger the mark left by the abrasive, the less abrasion resistant the material. These values are classified for the CE mark: Characteristic Values Abrasion resistance, mm A 1 >36.5 36.5 A 2 >33.0 33.0 A 3 >29.0 A 4 29.0 All Silestone colours are classified as A 3 or higher, with most classified as A 4. WATER ABSORPTION AND APPARENT DENSITY (EN 14617-1) Water absorption is defined as the maximum amount of water absorbed by the material when it is immersed in de-ionised water at ambient temperature, expressed as a percentage of the dry material weight. Apparent density is the quotient of the mass (in kg) and apparent volume (in m 3 ) within the external material surface of the sample. Water absorption values increase with greater the porosity. More porous materials have a greater tendency to stain. These values are classified for the CE mark: Characteristic Values Water absoprtion, % W 1 >2.0 2.0 W 2 >0.5 0.5 W 3 >0.05 W 4 0.05 All Silestone colours are classified as W 3 or higher. IMPACT RESISTANCE (EN 14617-9) Impact resistance is determined by a somewhat simple test: a 1kg steel ball is dropped from differing heights, with the height at which a fracture is produced in the material determining the energy to failure on impact, which is the stated value. The standard requires the result to be reported in joules (J); however, as this value is not easily understood, it is more visually acceptable to give the result as the height at which the fracture, measured in centimetres, is produced. If no cm value is available, the following approximate conversion can be made: Energy (J) Fracture height (cm)/10
The greater the energy at failure, the greater the height at which the ball needs to fall to produce the fracture. As a general rule, reports on the properties of Cosentino brands provide both results. THERMAL CONDUCTIVITY (EN 12524) Thermal conductivity is a physical property that measures the ability of material to conduct heat. The SI units expressing thermal conductivity are (W/(m K). The higher the thermal conductivity value, the greater the ability of the material to conduct heat. The themal conductivity value of Silestone is taken from information provided in the EN 12524 standard in table form, corresponding to λ=1.3 W/(m K). THERMAL SHOCK RESISTANCE (EN 14617-6) Thermal shock resistance is measured by submitting samples to 20 cycles of heating-drying at 80 o C followed by immersion in cold water at 15 o C, when the material is used in panels on walls and floors, while it is heated-dried to 105 o C when it is for use as kitchen worktops. After 20 cycles, an inspection is made to determine whether there is any change in appearance, and any variation in mass and flexural strength is determined. For the CE mark, the variations in percentages to the properties compared to those prior to the 20 cycles are declared. As a general rule, the variation in mass has a negative value close to zero, which means there has been a slight loss of mass. There may be a positive value close to zero, which shows that the material has gained in mass, a behaviour associated with water absorption. Flexural strength testing tends to produce both positive and negative values. A positive value means that the flexural strength has improved and that the material has become more flexible after the 20 test cycles, while a negative value means that the flexural strength has been reduced and that the material has become more rigid. VISUAL APPEARANCE The visual appearance, colour, roughness, etc. of agglomerated stone must be visually indicated. Given that the appearance is imposed by the colour and surface finish of the Silestone product that is acquired, this property accompanying the CE mark includes the option of No Performance Determined (NPD).
ELECTRICAL RESISTIVITY (EN 14617-13) All substances resist an electrical current to a greater or lesser extent. This opposition is known as electrical resistivity. Materials that are good conductors of electricity have very low electrical resistivity value, while insulating materials have very high resistivity. The test can be carried out at different voltages, meaning that the voltage for the test has to be requested. All tests on Silestone were conducted at 1,000 V. The units are expressed in giga-ohm-metres (GΩ m). The Silestone colours with the highest resin content have higher electrical resistivity values, and are consequently more insulating. REACTION TO FIRE (EN 13501-1) The reaction to fire test consists of arranging wall and floor tiles to form a corner and submitting them to a flame for a certain time, after they are inspected to verify how the material contributed to the flame, and whether flaming droplets and smoke were produced. The classification for reaction to flame is made according to the following table: Classification Sub-category A1 - A2 B smoke C particles, droplets D E particles, droplets F Unclassified for which the classes (or Euroclasses) are: A1, A2 and B: Non-combustible or slightly combustible products. More than 20 minutes until bursting into flame. C: moderately combustible products. Between 10 and 20 minutes until bursting into flame. D: moderately combustible products. Between 2 and 10 minutes until bursting into flame. E: moderately combustible products. F: highly combustible products (or unassessed reaction to flame behaviour. The smoke sub-categories are: s1: insignificant smoke release. s2: moderate smoke release.
s3: significant smoke release. The sub-categories for droplets and particles are: d0: no flaming droplets. d1: flaming droplets that burn for less than 10 seconds. d2: burning droplets. The reaction to flame test must be conducted by an authorised technology centre. This test is the only one Cosentino, S.A. is obliged to carry out at an external technology centre that is authorised every three years. Cosentino, S.A. conducted this test using CIDEMCO facilities. Given that the use for which the CE mark is obtained for Silestone is for modular floor tiles, the obtained classification was B fl, s1 (Report No: 23546-1/2, date: 17-11-2009). The fl subscript indicates that the test is for floor tiles. As it the test was for floor tiles, the droplet subcategory was not applicable. LINEAR THERMAL EXPANSION COEFFICIENT (EN 14617-11) The thermal expansion coefficient is obtained by determining the length of a tile during a change in temperature. A special device known as a dilatometer. The measurement units are o C -1 or mm/mm oc (the latter is more easily understood as it means the increase in length in mm per mm of the tile per 1ºC variation in temperature). Higher the coefficient values mean that the tested tiles dilate more. In order to know how much a tile dilates, the following formula is applied: L f =L 0 (1+α L ΔT) where L is the length of the tile, L0 is the initial length, αl is the linear expansion coefficient and ΔT is the variation in temperature. As an example, a 60x60 cm Blanco Zeus tile that undergoes a 60 o C temperature variation (from ambient temperature 25 o C to 85 o C) will dilate in the following way, given a dilation coefficient of 34.9 10-6 mm/mm oc: L f =600 (1+34.9 10-6 60)=601.25 mm The final length will be 601.25mm; i.e., the tile will have expanded by 1.25mm. This information is important for the preparation of joints. Do not hesitate to contact us if you require any further information. Best wishes, Product Certification Area Cosentino Research and Development, S.L.