Robotic tacking of high-quality composite preforms

A new manufacturing methodology, termed shape-inclusive lay-up, has been de veloped for manufacture of dry-fibre preforms using non-crimp fabric (NCF). Shape-inclusive lay-up enables preforms for three-dimensional components t o be produced and stored flat, introducing the shape only when the preform is loaded into the mould. The lay-up process is jigless, and complex compon ents can be produced as a single preform, reducing both preform production and moulding times. Aerospace components with varying degrees of complexity can be manufactured using this technique, including skin components and re inforcement structures. A range of technologies has been developed for auto mating the lay-up process. This paper focuses on the requirements of the jo ining process. The various methods of ply attachment investigated are descr ibed. The method that both satisfies the process requirements and is suitab le for automation is single-sided stitching using a loose chain stitch. The stitching process has been studied and implemented for the production of d ry carbon preforms. A stitching device in the form of a robotic end-effecto r is described. Prototype testing is detailed and the results of these test s are discussed.