For sanitary ware and structural ceramics, the ceramic basic masses are traditionally made of naturally occurring raw materials. The individual parts are compiled, prepared and homogenised in special procedures. Afterwards, the basic masses are brought into shape in many different castings or pressing methods. The choice of manufacturing procedure mainly depends on the complexity and number of the parts to be produced. Even though the products differ strongly in many ways, the production process is comparable.

The special properties of the respective basic masses permit - apart from the traditional production - production of many different products in an unprecedented and innovative diversity of forms. At the same time, however, the increasing diversity of forms and complexity of ceramics bring production-technical challenges with them.

One of the decisive production steps is firing of the green parts. The shaped and dried green parts are fired at temperatures of up to 1300°C. These high firing temperatures ensure the corresponding hardness and longevity of the sanitary ware and structural ceramics, such as wall tiles, floor tiles or roof tiles.

Firing takes place in periodic or continuous furnaces. Precise temperature control is highly important for this, since this process step determines the specific properties of the ceramic materials.

The challenge is in keeping the firing profile in the entire furnace homogeneous in order to achieve a homogeneous structure.

In addition to the homogeneous heat distribution in the furnace, production also is to be designed in a sustainably energy-efficient manner and the ecological balance is to be improved. This is best done by optimising the firing process, which has the highest energy consumption throughout the production process.

In order to make the firing process sustainable and energy-efficient, we as an established specialist for high-temperature technology supply the process temperature control rings PTCR as a cost-efficient and simple option for detailed control and optimisation. Essential applications are:

• Process control and optimisation
• Troubleshooting
• Performance increase of the furnace
• Increase of product quality
• Reduction of the QS effort
• Continuous quality assurance
• Sustainable energy savings

If the furnace temperature is recorded via locally attached thermocouples, homogeneity of the temperature field and reproducibility of individual furnace cylces will be ensured at all times. Thermocouples record the temperature in a single position and do not provide any information about the temperature in the position of the workpiece that is finally decisive. This is essentially influenced by the introduced heat energy and cannot be recorded with the thermocouple. Additionally, the heat input at the same nominal furnace temperature will deviate for different loads or different furnace runs.

The PTCR was developed in order to consider the listed framework conditions when measuring the temperature or heat input. All in all, seven different ring types are available for the temperature range from 560°C to 1750°C.

*All ring types are also available in a thinner L version - e.g. ETL 3.5 mm instead of 7 mm high.

The maximum temperature of your firing/sintering process should be roughly in the middle of the temperature range the ring type covers. In the average temperature range, the rings react a lot more sensitively than in the outer temperature range. If the maximum process temperature is in the threshold between two ring types, the selection will be made under consideration of the process conditions, such as the hold time and atmosphere, since both factors also strongly influence ring shrinkage. We recommend contacting us about this.

PTCR can sustainably optimise firing and sintering processes. Deviations in the temperature field of the furnace can be localised and optimised in a targeted manner. This measure permits sustainable reduction of the energy expenditure and the connected operating costs.

The production rejects can be minimised thanks to precise control of the process and the quality standard can be increased. The improved process control permits reduction of the effort in quality assurance. Continuous documentation of the homogeneity of the temperature field by PTCR permits verification of the reproducibility of the individual furnace cycles with little effort.