PROJECT DESCRIPTION
BACKGROUND
During the manufacture of ceramic tiles, glaze is traditionally applied in a liquid glaze form. This results in wastage of glaze and generates liquid effluent that requires costly on-site or off-site treatment and disposal. The project aimed to develop a process of applying the glaze to tiles in a dry form using electrostatic charge. This would reduce liquid effluent and improve the efficiency of glaze use.
OBJECTIVES
The project aimed to develop electrostatic techniques for applying glaze to the surface of ceramic tiles prior to firing. In doing so, the project aimed to: - Reduce water usage (inputs into the glaze mix) - Reduce glaze effluent - Promote the recycling of glaze - Reduce the amount of glaze waste going to landfill (designated as a ‘special waste’ because of the presence of heavy metals in glazes) - Reduce clay use because the dry glaze will allow use of a thinner profile tile - Reduce transport because the switch from a liquid to dry glaze will reduce the bulk of glaze for transport - Reduce emissions The production line included spray booths and spray guns, and was located in H&R Johnson’s Tunstall works, Stoke on Trent, UK.
RESULTS
The significant delays in the first year because of difficulties in presenting confidential information on staff costs delayed subsequent stages of the project. This reduced the period available for trials and evaluation. Nevertheless, The project achieved much of what it set out to do in terms of developing a workable technique for dry application of glazes to tiles in a factory situation. The project was successful from a technical point of view, although the early delays prevented completion of some development and testing. The results of the project, if applied, should help companies to meet their environmental responsibilities more cost-effectively. Clear environmental benefits, as detailed in the evaluation section of the final report, include: - Reduced raw material usage - Reduced water usage - Reduced energy requirements - Reduced environmental impact in land usage and construction - Reduced manufacturing losses - Lower transport costs - Reduced emissions. The project produced a detailed analysis of costs and benefits associated with the technique, which indicates that although the immediate economic benefits are not great, the environmental benefits, which are likely to become increasingly important to both government and companies as legislation is progressively tightened, are substantial. For large-volume standard monoporosa glaze application, achieved with zero water content, this process is unique. The technique developed should be of considerable interest to other EU tile manufacturers – especially the bulk producers of more uniform tiles (e.g. plain white / coloured tiles). The project has produced a good example of use of cleaner manufacturing technology that could be used by other EU tile manufacturers. Possible future financial benefits may be achieved through the technique – e.g. reduced costs of raw materials and effluent treatment / disposal costs. Further product development will help to reduce the costs and environmental impacts of the production process in the long term, and to address problems associated with decoration and dry engobe application. The project report states that “there is likely to be no technical reason why further developments of a dry engobe with good adhesion properties and the optimum particle size distribution for spraying should not be successfully developed”. The project provides a good case study of integrated pollution control/cleaner technologies, which should help to encourage other manufacturers in the ceramics industry to adopt comparable changes. In the long term the technique will help to enhance the cost competitiveness of EU tile producers. The significant delays in the first year because of difficulties in presenting confidential information on staff costs delayed subsequent stages of the project. This reduced the period available for trials and evaluation. Nevertheless, The project achieved much of what it set out to do in terms of developing a workable technique for dry application of glazes to tiles in a factory situation. The project was successful from a technical point of view, although the early delays prevented completion of some development and testing. The results of the project, if applied, should help companies to meet their environmental responsibilities more cost-effectively. Clear environmental benefits, as detailed in the evaluation section of the final report, include: - Reduced raw material usage - Reduced water usage - Reduced energy requirements - Reduced environmental impact in land usage and construction - Reduced manufacturing losses - Lower transport costs - Reduced emissions. The project produced a detailed analysis of costs and benefits associated with the technique, which indicates that although the immediate economic benefits are not great, the environmental benefits, which are likely to become increasingly important to both government and companies as legislation is progressively tightened, are substantial. For large-volume standard monoporosa glaze application, achieved with zero water content, this process is unique. The technique developed should be of considerable interest to other EU tile manufacturers – especially the bulk producers of more uniform tiles (e.g. plain white / coloured tiles). The project has produced a good example of use of cleaner manufacturing technology that could be used by other EU tile manufacturers. Possible future financial benefits may be achieved through the technique – e.g. reduced costs of raw materials and effluent treatment / disposal costs. Further product development will help to reduce the costs and environmental impacts of the production process in the long term, and to address problems associated with decoration and dry engobe application. The project report states that “there is likely to be no technical reason why further developments of a dry engobe with good adhesion properties and the optimum particle size distribution for spraying should not be successfully developed”. The project provides a good case study of integrated pollution control/cleaner technologies, which should help to encourage other manufacturers in the ceramics industry to adopt comparable changes. In the long term the technique will help to enhance the cost competitiveness of EU tile producers.
