Designing Under-the-Hood Parts for High Temperature and Voltage

Requirements on Efficient Ingnition Control System
In the Direct Ignition System (DIS) the ignition system is connected directly to the spark plugs. This modern design brings considerable benefits, as it avoids the well-known electrical problems connected with humidity. An efficient ignition control system also reduces fuel consumption and so decreases environmental pollution. French manufacturer Electricfil, one of the market leaders in Europe, has developed, together with the PSA Group, an integrated DIS system with two induction coils for four cylinders.

PBT in Direct Ignition Module – High Temperature and Voltage
Working closely with Ticona, Electricfil selected Celanex® PBT polybutylene terephthalate for three important components. Firstly, the two induction coils and the connections are located in small housings made of the 20% glass fibre reinforced Celanex® PBT 2300 GV 1/20 grade. These are then encapsulated in epoxy resin, during which it is exposed to temperatures of up to 140°C for a period of two hours.

Secondly, the four external connectors are manufactured from Celanex® PBT 2300 GV 1/20 -the low glass fibre proportion of only 20 percent permits greater flexibility. And thirdly, the main housing is made of Celanex® PBT 2300 GV 1/30 reinforced with 30 % glass fibre. As the complete component is then again encapsulated in epoxy resin, the entire system and above all the material must be designed in such a way that it can tolerate this long exposure to high temperature (once again up to 140 °C). After this final process step the ignition distributor can be fitted directly to the engine block or the cylinder heads.