Bjornsson, A., Lindback, J., Eklund, D., and Jonsson, M., "Low-cost Automation for Prepreg Handling - Two Cases from the Aerospace Industry," SAE Int. J. Mater. Manf. 9(1):68-74, 2016, doi:10.4271/2015-01-2606.
With an increased use of composite materials within the aerospace industry follows a need for rational and cost-effective methods for composite manufacturing. Manual operations are still common for low to medium manufacturing volumes and complex products. Manual operations can for example be found in material handling, when picking prepreg plies from a cutter table and stacking them to form a plane laminate in preparation for a subsequent forming operation. Stacking operations of this kind often involves a great number of different ply geometries and removal of backing paper and other protecting materials like plastic. In this paper two different demonstrator cells for automated picking of prepreg plies and stacking of plane laminates are presented. One demonstrator is utilizing a standard industrial robot and an advanced end-effector to handle the ply variants. The other demonstrator is using a dual arm robot which allow for simpler end-effector design. In combination with a previously developed system for automated removal of backing papers both systems have shown to be capable of automatically picking prepreg plies from a plane surface and stack them to generate a flat multistack laminate. The dual arm approach has shown advantageous since it result in simpler end-effector design and a successive lay down sequence that result in good adhesion between the plies in the laminate.