Developed by the French firm RocTool, the Cage System allows an instantaneous heating of the mould surface only, while the rest of the mould remains cold.
"We are working in conjunction with RocTool to investigate the use of the Cage System for the production of composites with a class A surface finish," said Azdel president Ken Forden.
The technique involves passing an electrical current over the surface of the mould by means of inductors that are placed around it to form a cage. The mould cavity surface is heated within seconds, and it is possible to use high temperatures - up to about 400 °C - and to precisely manage temperature thresholds, even using spot heating.
This high level of localised control helps enable a considerable reduction in production cycle times and potentially therefore a reduction in the cost of manufacturing composite parts making it an excellent candidate for medium-run and mass production applications.
Furthermore, RocTool claims that the Cage System process offers a truly generic solution that can be adapted to all types of composites, as the heating power is applied at the mould surface only. With the heating by Joule effect principally taking place within the material itself, the mould can be rapidly cooled using a simple system of circulating water.
The technology is compatible with standard compression-moulding machines and requires only the addition of an induction generator and cooling unit. However, a process-specific mould, with integrated induction heating and water-cooling system is necessary.
By reducing cycle time, establishing higher production ratesand lowering energy consumption, the system might open the way for composites to be used in applications from which they have previously been excluded on the basis of high cost.
Azdel is a 50/50 joint venture of GE Advanced Materials and PPG Industries. The firm is a global leader in the manufacture and supply of high-performance composite materials serving a wide variety of markets and industries.