Automation of carbon fibre preform manufacture for affordable aerospace applications

Abstract

At the present time, the weight and durability benefits of carbon fibre composites for aircraft structure components cannot be provided without very large manufacturing cost premiums. The new processing techniques of liquid and resin film moulding have to date only been proven to be justifiable for complex high value parts. This has primarily resulted from the high materials and labour costs required to manufacture the carbon fibre preform prior to moulding. A three year EPSRC (UK Research Council)/aerospace industry funded project, INFACS, addressed the automation of carbon fibre preform manufacture using low cost materials. The manufacture of a unidirectional tape using a binder coated thread was developed to form a low cost feed-stock for a preform laminating machine. A machine was conceived, designed and built to laminate single curvature parts to net shape with tailored thickness up to a size of 3 m by 1.5 m. It has achieved a net laminating rate of 45 kg/h. For the attachment of details such as stiffeners, the techniques of stitching and pinning were developed into effective processes. Components were processed by the Resin Transfer Moulding (RTM) method to a fibre volume fraction of 58%. Cost modelling of the manufacture of a range of sizes of skin components showed large reductions using the technology developed on the project compared to the current ‘state of the art’ manufacturing technology of automated pre-preg tape laying and autoclave curing. For a regional aircraft tail-plane skin the modelled cost reduction was 60%. The machine and preform development work is continuing within the EPSRC IMI Aerospace Sector project Automated Manufacture of Integrated Composite components (AMICC).