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INCREASING THE AVAILABILITY OF BALL CLAYS
In 2020, Sibelco completed the acquisition of two producers of high quality clay in the Donbass region of Ukraine. The acquisition will enable Sibelco to provide you with additional materials for porcelain ceramic products.
An evolving market
The market for tiles and ceramics is evolving rapidly with growing demand for high-end ceramics products such as slabs and technical porcelain tiles and increasing demand for whiter, wider and more wear-resistant tiles. The best quality raw materials for the tile industry are without question Ukrainian clays, which offer a number of advantages including high mechanical and bonding strength and the ability to guarantee reduced linear shrinkage and consequently superior flatness in the case of large sizes.
How ball clays can help
Sibelco’s ball clays provide benefits such as:
- high fusibility features that reduce the final porosity of the ceramic body and increase the speed of the firing cycle;
- a white-firing colour which improves the colour of fired tiles thereby reducing the usage of engobe in porcelain glazed tiles;
- a low level of organic matter that allows a fast firing cycle.
All of these benefits contribute to superior products and an increased production yield.
A long history in quality clays
Sibelco is a long-standing leader in clays for ceramics and tiles and produces clays in Ukraine, UK, Germany, Russia and Indonesia. Sibelco’s operations are supported by applied technology laboratories in Europe and Asia. The acquisition of Euromineral and Kurdyumovsky Plant adds a further 400,000 tonnes of annual capacity to Sibelco’s product portfolio.
To know more about Sibelco’s ball clays, please contact us at email@example.com
PROFILING THE BENEFITS OF NEPHELINE IN IMPROVING MATT GLAZES
Nepheline syenite plays an important role in matt glaze production. Using high-quality materials such as Nepheline can help to significantly improve the functional and aesthetic properties of the matt glaze and finished tile, as well as reducing your overall production costs.
Creating a perfect matt effect
Matt glazes give tiles a natural look and open up different design possibilities. But creating a matt glaze that is also functional (in terms of ease of cleaning and resistance to scratching and chemicals) can be very challenging. Drawn from Sibelco’s unique deposits in Norway, Nepheline enhances the aesthetic and functional characteristics of matt glazes in a number of ways, as well as helping to reduce your production costs. The benefits include:
• Increased silkiness and whiteness
• Improved ink colour development
• Increased scratch resistance
• Reduced cracking
• Lower melting temperature
The trend towards large format tiles means that manufacturers need to minimise glaze-related pinhole defects in order to reduce costly volumes of fired waste. Nepheline helps to significantly reduce scrap waste after firing due to problems with pinholes. This is even more important when glazing slabs, as a defect on a 1.5m x 3m piece means a lot more wastage than a defective 60cm x 60cm wall.
Improved scratch resistance and lower costs
In comparison to other nepheline products, Nepheline’s higher alumina content improves scratch resistance. It also means that the glaze formula needs less expensive calcined alumina, clay and kaolin, too much of which can adversely affect glaze slip rheology and aesthetic surface appearance. When used in place of feldspar, Nepheline reduces the melting temperature of the glaze (thanks to high levels of sodium and potassium) thereby helping to reduce overall energy consumption.
A higher coefficient of thermal expansion
Nepheline also has a higher coefficient of thermal expansion (CoE) than a standard sodium feldspar, making the glaze CoE more compatible with the CoE of the tile body to improve the body-engobe-glaze fit. In terms of firing temperatures, Nepheline is extremely stable up to 1,070°C whilst sintering and softening points are close to the firing temperature for glazed vitrified tiles (GVT).
Achieving a good balance between ink colour development, matt level and whiteness
Free of magnesia and with a barium oxide content of 0.4, our laboratory tests show that Nepheline enhances digital ink colour development whilst delivering a good level of matt glaze surface. It therefore outperformed other nepheline products in the tests, which either
delivered good colour development but a lower matt, or a higher matt but lower colour development. Our tests also showed that GVT tiles with a glaze made with Nepheline were easier to clean than those made with other nepheline products.
When whiteness matters, Nepheline again outperforms alternative nepheline products, thanks to low levels of iron oxide and titanium dioxide (0.21%). And because of its purity, Nepheline has a higher nepheline content than alternative products and contains no free quartz.
To know more about Sibelco’s Nepheline products, please contact us at firstname.lastname@example.org.