What are common tile terms and terminology? Back to Top

• Bullnose Tiles: Trim tiles featuring one rounded edge used to finish wall installations.
  
• Decorated Tiles: Ceramic tiles that have been embellished by means of hand-painting, silk-screening, decals or other techniques.
  
• Frostproof Tiles: Tiles specifically designed by the manufacturer to withstand freeze/thaw conditions with minimal effect, hence suitable for exterior applications exposed to high humidity and low temperatures.
  
• Frost Resistance: Ability of certain tiles to withstand freeze/thaw conditions with minimal effect.
  
• Grout: Installation material used to fill the joints between tiles
  
• Matte Glaze: Glaze that produces a non-shiny finish.
  
• Moncottura Tiles: Tiles produced by the single-firing method.  Also called Single-fired tiles. Glazed tiles produced by the single-firing method in which the raw tile body and gaze undergo a single pass through the kiln at high temperatures.
  
• Mortar: The setting material used to bond tiles to a given surface.  Different types of mortar are suitable for different backing and conditions.
  
• Mounted Tiles: Tiles assembled into units or sheets by the manufacturer for easier installation.
  
• Porcelain Tiles: Dust-pressed ceramic tiles with water absorption levels of less than 0.5% and high mechanical and chemical characteristics.  The surface of these tiles may be glazed or unglazed, polished or unpolished.

How is slipperiness measured? Back to Top

Concerning the safety of the final user, the slipperiness of a floor, directly linked to the coefficient of friction, is particularly important. The En ISO 10545-17 standard describes various possible methods for measuring the coefficient of friction, each one of which is specific for a different country.

The "ASTM" coefficient (U.S.A.)The ASTM C 1028 standard (Measurement of the static friction coefficient) is used in the U.S.A. for classifying tiles on the basis of their slipperiness. The Ceramic Tile Institute classifies the tiles in three categories: anti-slip (>0,60), not anti-slip (0,50 – 0,60), and questionable friction (< 0,50).

What is meant by water absorption? Back to Top

What is meant by calibre? Back to Top

What is meant by Tone? Back to Top

What is PEI Rating (how is durability measured)? Back to Top

Among the manufacturers of ceramic tile there are certain standards that are universal. ISO Standards have been established by the International Standards Organization to unify product standards and testing methods for ceramic tiles worldwide. One of the most important of these standards is the PEI rating. The P.E.I. (Porcelain Enamel Institute) rating is a measurement of how well a ceramic tile will wear.  Generally, ceramic tile manufacturers classify their products in 5 categories.  They are as follows:

• PEI I   Usually refers to tiles applicable for wall installations only
• PEI II   Suitable for floor applications where there is very light traffic
• PEI III Suitable for most residential applications other than kitchens.
• PEI IV Suitable for all residential applications and some light commercial applications
• PEI V   Suitable for all applications except malls, airports and transportation terminals

In addition, there is a classification, U, which is given to products specifically designed for industrial applications.

How are tiles made? Back to Top

The manufacture of ceramic floor and wall tiles has undergone considerable and continuous changes over the past years. Ceramic wall tiles are normally porous, which favors their adhesion to walls. On the contrary, floor tiles have low porosity, with low-medium water absorption, which gives them better technical characteristics.

Traditionally, tiles were manufactured following different methods and by means of a practically manual process. As from the seventies, the process has gradually been automated and methods have been unified considerably, with dry pressing being the most common and allowing the product to be manufactured in two different ways:

Double firing process

In this process, the pressed body is fired to form a bisque and subsequently a glaze is applied on top of this and the body is once again fired to obtain the final finish.

Single firing process

In the single firing process, the glaze is applied directly on to the pressed and raw body; both are fired simultaneously to obtain the final finish.

For many years there has been a controversy with regard to which of the two methods is better. In fact, having the correct formulation of both the body and the glaze, and keeping strict control of all the manufacturing stages, it is possible to produce good tiles using any of the methods.

Traditionally the double firing process was used more, with firing cycles of forty and twenty hours for the first and second firing respectively (firing of the body and of the glaze). It is currently more convenient to follow the single firing process, with cycles that last only forty-five minutes.

Moreover, in addition to the economy of the single firing process, it is very easy to automate the different manufacturing processes, which in turn results in cost reductions.

Ceramic floor and wall tiles are obtained by preparing a composition of purified raw materials comprising aluminous silicates, with different compositions in the case of floor and wall tiles in red body or in white body.

These compositions undergo dry or wet grinding until a fine grain size is obtained, after which they undergo granulation or drying by subsequent atomization in order to obtain granules with defined characteristics (size, shape, apparent density, fluidity, etc.).

The granulated powder is the base for the obtention of the ceramic product and its homogeneity guarantees the constancy of the physical properties of these materials. The granules feeds a oleodynamic press with a force of 600 to 1400 MT, that forms the tile into the shape and thickness chosen, for which metallic moulds with the exact dimensions are available.

Subsequently, the shaped tiles are dried and glazed with several layers of glazes of different compositions and with optional decorations in accordance with the models available.

Once the tiles have been glazed and decorated, they are placed in an oven for firing in more or less quick cycles and high temperatures, depending on the type of product being manufactured. Maximum temperatures depend on the type of product to be obtained.

The ceramic glaze and decoration embellish the tiles and give them the technical superficial characteristics desired. In the case of ceramic wall tiles, these are impermeability, resistance to detergents, etc, and in the case of floor tiles, they are resistance to abrasion, acids and scratching, etc.

The techniques, process control requirements, careful design that meets the needs of each atmosphere and the care taken in classification, give the product homogeneous characteristics that are in accordance with the requirements of its use.