Winkelmann Powertrain Components, a firm based in Ahlen, Germany, relies on thermoset materials for the production of belt pulleys for car engines. Wittmann Battenfeld supplies the machines to make Winkelmann’s pulleys using the injection core compression moulding process.
Using the injection core compression moulding process enables the group to make their belt pulleys tough and long lasting. Winkelmann also specialises in other production lines like drive system components, torsional vibration dampers and fuel distribution systems.
Thermoset processing with injection-stamping technology is used to create extremely strong plastics. In the injection core compression moulding process, phenolic resin is injected into the mould at a low pressure and this prevents the orientation of the fiberglass particles.
After that the stamping core is shifted in the mould to generate the right pressure to make the final geometry of part of the mould. Pressure is maintained until chemical cross-linking of the resin has taken place. This process cannot be reversed and because of this the plastic can undergo serious thermal stress.
The need to make cars more fuel efficient, economical and environmentally friendly has been a priority of the EU for many years. Making cars lighter is a priority to car manufactures as will increase power and performance but also will reduce emission levels.
Heavy metal parts in the engine and in the bodywork are being replaced with much lighter plastic alternatives. Extremely hardwearing plastics are becoming more vital in car manufacturing.
There are many advantages in using this process, but it also costs less to manufacture and the finished product has a long life expectancy. This is due to the resin on the outer skin made in the manufacturing process.
There is a lot of potential for plastics in the car industry due to the reduction in weight compared to the steel or aluminium alternatives. Also there are dramatic cost savings by using plastics. Winkelmann is also manufacturing hybrid pulleys that are thermoset plastics that can combine with metal, thermoplastics and elastomers.
The plastic also has a high wear-resistance surface and a high sound absorption level. Also due to the fiberglass not being oriented in a preferred direction it has excellent homogeneity and high media resistance.
Through research that Winkelmann has also done they have found that this method is favourable to fibreglass-reinforced thermoplastics. Thermoplastics are too expensive and do not have the thermo stability so are not comparable to thermoset plastics.
The main applications for thermoset belt pulleys made by Winkelmann are: air-conditioning compressors, water pumps and power steering pumps. Winkelmann is now expanding and testing for new applications for the pulleys, including: camshaft drive systems, crankshaft dampers and belt drive systems for power steering.
