Modelling component cost in compression moulding of thermoplastic composite and sandwich components

Thermoplastic composite and sandwich materials offer a potential of reducing component weight and improving recyclability while at the same time enhancing process economy through reduced manufacturing cycle time. The economical aspects of compression moulding of three different thermoplastic composite and sandwich material systems are modelled herein and are compared to compression moulding of a thermoset sheet moulding compound and stamping of sheet metal. A program has been developed which predicts component cost for different component sizes and complexities. It is found that raw material cost strongly dominates component cost for compression moulding of composite components, while in sheet metal stamping component cost is dominated by equipment costs. The model shows that thermoplastic composites are cost competitive for small to medium sized components and short production series of large components. The sandwich concepts offers a potential of further reducing component cost compared to composites, thus making the concept interesting for larger components, but still for short to intermediate production series, which is illustrated by calculating component cost for compression moulding of a sandwich tailgate. (C) 2000 Elsevier Science Ltd. All rights reserved.