New Zealand Tiles Glossary of Techincal Terms

Size and Appearance Characteristics

EN98SIZE & APPEARANCE


A/ Lenght of Sides

The allowed tolerance between side lenght of two different tiles belonging to a material lot of the same profile is + 0.5% of the lenght of the average side

SizeStandard
Tolerance
Max Allowed
Difference

100 x 100+0.5mm1.0mm

150 x 150+0.75mm1.5mm

200 x 200+1.0mm2.0mm

330 x 330+1.65mm2.3mm


B/ Straightness of the edges

This value is expressed by the deviation of the straightness of each edge of tile, measured at the centre of the edge.

The maximum deviation must be + 0.5%


C/ Flatness

The maximum curvature allowed is + 0.5% of either the edge or the diagonal.

SizeStandard Tolerance

100 x 100diagonal+0.70mm


edge+0.50mm

150 x 150diagonal+1.06mm


edge+0.75mm

200 x 200diagonal+1.43mm


edge+1.00mm

330 x 330diagonal+2.33mm


edge+1.65mm

Water Absorption

EN99WATER ABSORPTION


The porosity of the material is inversely proportional to its technical characteristics: the higher the porosity, the lower the level of hardness, bending strength and absorption.

Mohrs Hardness

EN101SURFACE HARDNESS MOHRS


The reference value of glaze hardness indicates the capacity of the glaze to resist abrasion due to continuous foot traffic and rubbing over long periods of time.

Hardness is determined according to Mohrs comparative criteria, that is, a test which makes a direct comparison with increasingly harder minerals.

The hardness is considered to be the value of the Mohrs scale corresponding to the first mineral by which the glaze is scratched.

The minimum level of hardness required by the standards is 5. The most common enemy of ceramic tiles is quartz sand (Mohrs 7) some tiles now have Mohrs values higher than this.


Mohrs hardness scale:

1Soapstone6Feldspar

2Gypsum7Quartz

3Calcite8Topaz

4Fluorite9Corundum

5Apatite10Diamond

PEI

EN154ABRASION RESISTANCE


Steel balls of various sizes, corundum powder, and distilled water comprise the abrasive load which is applied at 300rpm to the sample tiles in order to determine their resistance to wear according to the PEI method.


Level of AbrassionClassUse

Wear visible at 150revsIbathrooms and bedrooms

Wear visible at 600revsIIliving areas excluding entrance halls

Wear visible at 1500revsIIIany living area

Wear not visible at 1500revsIVintensive use premises

Wear not visible at 12000revsVflooring for very heavy traffic

Frost Resistance

EN202FROST RESISTANCE


The frost resistance test reveals any defects which appear on the test samples after being subjected to various cycles of alternative freezing and thawing.

The test tiles are soaked in water, then placed in refrigerated units where each cycle of freezing / thawing goes alternately from +15 degC to -15 degC and the cycle is repeated 50 times. The tiles are then inspected for damage to either the surface or edges.

Monocottura

Monocottura


This production process allows the simultaneous firing of the clay body with the glaze. Tiles produced by this method demonstrate higher mechanical resistance and better glaze-body adhesion than tiles produced by the double-fired method.

Porcelain

POCELAIN


Also known as china tile or fully vitrified stoneware, porcelain tile contains the raw materials similar to those used for manufacturing china. The result is a non porous bisque of high mechanical strenght that can be used for interior or exterior floors. While these tiles used to be nearly all unglazed, these tiles are now made either glazed or unglazed. The unglazed tiles are coloured through mixing mineral oxides throughout the bisque. Special effects can also be created to the unglazed tiles by polishing the surface or by applying a thin layer of glass to the surface.

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