An infrared system from Heraeus Noblelight is helping to ensure improved lamination of tufted carpet tiles, manufactured by Advance Carpet Tiles of Blaina, UK.Since installation, the infrared system has proved to be considerably more energy-efficient compared with a convection oven and has required much less space. The fast response of the emitters and the flexibility of the control system have also allowed the company to deal effectively with changes in line speed and with line stoppages.
Advance Carpet Tiles produces a range of tufted carpet tiles, for commercial, industrial and domestic applications. The manufacturing process is a high speed operation and involves the application of hot bitumen onto a backing stucture. It is important that the carpet is as "relaxed" as possible before it is applied to the bitumen base, as this will ensure that the bitumen penetrates into carpet and effects a good lamination. "Relaxing" involves heating the carpet before it arrives at nipping rollers and, conventionally, this is carried out by passing the carpet through a gas convection oven.
A convection oven requires a significant amount of space and consumes a lot of energy, as it must be switched on all the time. It is also not very responsive to changes in the production process, such as variations in line speed and stoppages. Consequently, Advanced Carpet Tiles decided to contact Heraeus to investigate the possibility of using infrared for the relaxation procedure.
Tests were carried out at Heraeus's Test Centre and as a result a full-scale system was installed at the Blaina factory. This consists of two, 34 kW infrared modules, each containing six fast response medium wave emitters. The system is controlled by a closed loop arrangement, incorporating pyrometers. Thyristors first turn on the heater bank to reach a predetermined level of around 30% of the rated output for a predetermined time. This allows the carpet to be heated on start-up, so that when the line is started, the pyrometers register a warm product and slowly demand increased power until a pre-set temperature level is reached. Without the pre-heat, the pyrometer would demand instantaneous full power and then begin to flash. As the system is operated, an adaptive tuning programme prevents any flashing problem. The control system also includes a 5-position selector to allow the operator to selectively bring in four banks of three elements to suit the relevant line speed.
Application:
- Heating of carpet before laminating to bitumen base
Technology:
- Two 34 kW infrared modules with Heraeus fast response medium wave heaters
- Control by a closed loop system with pyrometers
Advantages:
- less engergy consumption than convection oven
- space saving
- fast response of heaters to changes of line speed
Further information:
Infrared heat for textiles
Product information about IR modular systems
Information about the Heraeus application centers
Contact Heraeus
