Towards an integrated CADCAM process for the production of forming shoulders with exact geometry

This paper considers the application of advanced CADCAM techniques for the production of the complex machine tooling used in packaging fast-moving consumer goods. In particular, the paper discusses the practical considerations and design issues that need to be addressed in order to construct CNC machined tooling with exact geometry. The paper considers in detail the design of 'forming shoulders', a common means to form bags, and begins with a mathematical model for defining its complex geometry. A CADCAM method for producing a forming shoulder with exact geometry is then summarized. In practice, it is necessary to modify the geometry of the forming shoulder in order to produce an overlap of material for the creation of a bag. This process also demands that the geometry of the forming shoulder 'overlaps', which has certain implications for the CNC machining of the surface. These considerations and the means by which they are overcome are discussed with respect to a series of prototypes and experimental trials. The performance of a forming shoulder, produced by way of the integrated CADCAM process, during extended production trials is then discussed.