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[April 2007]
Dyson Thermal Technologies Meets Challenges With Revolutionary Kiln Furniture
As energy prices soar and with instability in supply meaning that a high tariff structure is more than likely to prove the reality – in the short-term at least – ceramic manufacturers will be paying even more attention than they usually do to any element of production that can be characterised as an energy sink. Obviously, the area in and around the kiln will come under close scrutiny.
Dyson Thermal Technologies, the company within Dyson Group responsible for developing, manufacturing and marketing world class ceramic kiln furniture, saw the early signs which have led to these concerns in the industry and straight away began to address the technical hurdles that needed to be straddled.
One major result of Dyson TT's developmental approach has been the introduction of the Dylite range of kiln furniture products, well received by major sector customers in the industry and fast becoming an automatic choice for certain key areas of ceramic firing.
In all, group technologists worked for a period of five years to achieve this revolutionary cordierite material, succeeding when it was launched on to the market to present the industry with something that is around only half the weight of standard cordierite. Aside from any other advantages then, this immediately delivered to users main refractory systems at just above 50% of their previous weight – leading to substantially reduced energy consumption, massive fuel savings and increased ability to play a part in faster firing cycles, with attendant increase in kiln speed and throughput.
These facts alone would make Dylite a natural choice for some of the major ceramic sectors. There is, however, more. With Dylite kiln furniture systems, thermal shock resistance is improved over standard cordierite, leading to longer refractory life, while its lower specific heat capacity allows for quicker heating and cooling. This gives manufacturers a golden triangle of reduced cost, high effectiveness and enhanced flexibility.
The Dylite material also exhibits very high apparent porosity, around 45%, which means that when batt wash is being used it is much more easily absorbed, achieves good adherence and results in a much improved protective coating. As with all of Dyson TT kiln furniture, Dylite is suitable for use up to 1300°C under compression or in non load-bearing applications. It is better used in situations where bending strength is not critical and it is not recommended for load-bearing batts where they are intended for use above 1000°C. Dylite's MoR at 1250°C is 7, as opposed to an MoR of 10 for the more general purpose Dycor material.
Dylite is an alumina/silica/magnesia system and the thermal expansion from 20°C to 1000°C is just 0.25%. The company's special manufacturing process for this kiln furniture range is what makes the difference and gives the product its lightweight, low density character. It is being successfully used in the UK and abroad in both primary and secondary kiln furniture applications.
Some users have made the decision to switch to Dylite in a big way and the company was pleased to be asked to design and install a complete flexible system at Roy Kirkham & Co Ltd in Stoke-on-Trent, one of the leading manufacturers of quality English fine bone china products.
All the components being used at the Tunstall tableware plant have been manufactured in Dylite. Roy Kirkham's ware is manufactured to the highest standards, using unleaded glaze and a blend of fine china clays and feldspars to give a bright, classical, translucent finish. Consistent high quality is the watchword for all of the company's individually designed patterns and the decorating kiln – firing up to around 850°C – has been performing well with the new, adjustable placing system over a number years.
Director Steve Kirkham commented: “Using Dylite has substantially reduced our energy costs as the material is half the weight of normal kiln furniture and has also benefitted us because we can fire our kilns faster than with normal cordierite materials”.
The experience that Dyson TT has gained from manufacturing Dylite has enabled the company to run further development programmes and it now also offers another technically superior product in the same family of materials. Hybrid Dylite, which can readily be used at temperatures up to 1300°C, is often seen as a compromise between the very low density of Dylite and the performance of Dycor.
Porosity is still high, at 35%, but this range of kiln furniture is around 50% more dense than Dylite and exhibits a better bending resistance at elevated temperatures. It has very low rates of thermal expansion and offers products with excellent thermal shock resistance. It is still fully 20% lighter than standard cordierite kiln furniture products and so while strong, still provides fuel cost savings and can be used in rapid firing cycles.
Website: www.dysontt.com
ENDS