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Improvement of the mechanical properties of green tile bodies

Objective



The low fracture resistance of the green bodies used in ceramic tile manufacture produces broken corners, cracking and tile failure in the prefiring stages, and represents one of the main sources of flawed tile. Although these defects originate in the green tile body, a part of these remains undetected until the tile has been fired, which is precisely when it reaches its highest added or commercial value. Currently around 3% of unfired glazed tile is scrapped. Although this scrap is reused in the same manufacturing process, it represents a significant cost, as the unfired glaze layer cannot be reused. On the other hand, about 2% of fired tile is scrapped, involving an important production loss and environmental impact owing to the difficulty of reusing this scrap in the tile manufacturing process. The economic losses stemming from this scrap in total EU ceramic tile production can be assessed at over 175 million ECU, generating around 500,000 t of fired tile waste, of which 50% is reused in the tile manufacturing process, while the remainder needs to be disposed of or recycled in other industrial processes. This project is intended to improve the mechanical properties of green bodies with a view to reducing the economic cost and environmental impact caused by the above economic losses and waste. The fracture mechanism of green ceramic bodies will therefore be studied, defining which mechanical properties of these bodies (mechanical strength, modulus of elasticity and toughness) limit the appearance of the above defects in each process stage (pressing, drying, glazing and firing), establishing methods for the industrial measurement and control of these properties. The relationship will also be determined between process variables, pressing powder characteristics, composition of the raw materials mixture, and presence or absence of additives on the foregoing properties, so as to optimise the processes and produce more robust materials. A consortium has been formed to carry out the project, consisting of three R+TD Centres from different European Union Member States (Italy, United Kingdom and Spain), which have been actively engaged for many years as R+TD performers in the ceramic tile manufacturing branch in their respective countries, and nine companies from these same countries, involving manufacturers of different types of ceramic tiles, and clay, spray dried powder, and additives suppliers. Project timing has been set for two years.

Funding Scheme

CRS - Cooperative research contracts

Coordinator

Atomizadora S.A
Address
Avda. Manuel Escobedo 24
12200 Onda
Spain

Participants (10)

BRITISH CERAMIC RESEARCH LTD.
United Kingdom
Address
Penkhull, Queens Road
ST4 7LQ Stoke-on-trent
Centro Ceramico di Bologna
Italy
Address
Via Martelli 26
40138 Bologna
Ceramco SPA
Italy
Address
Via Dei Falegnami 7
41049 Sassuolo
Cerdomus Ceramiche SpA
Italy
Address
Via Emilia Ponente 1000
40138 Castelbolognese
INSTITUTO DE TECNOLOGIA CERAMICA - AICE
Spain
Address
Carretera De Borriol Campus Universitario Riu Sec
12006 Castellon De La Plana
Peris y Cia, S.A.
Spain
Address
Avda. Manuel Escobedo 26
12200 Onda
Pilkington 's Tiles Limited
United Kingdom
Address
Clifton Junction
M27 8LP Manchester
Taulell S.A.
Spain
Address
Partida Benadresa 2
12006 Castellón
Watts Balke Bearne & Company plc
United Kingdom
Address
Park House, Courtenay Park
TQ12 4PS Newton Abbot
Wooliscroft Tiles limited
United Kingdom
Address
Melville Street, Hanley
ST1 3NB Stoke-on-trent