1. HIGH SPEED, HIGH PRECISION MANUFACTURING OF DRY PRE-PREGS Avinash Ramsaroop Department of Mechanical Engineering Durban University of Technology November 2007

2. Slide 2 © CSIR 2006 www.csir.co.za INTRODUCTION Composite materials are being used in various engineering applications Advantageous strength-to-weight and stiffness-to-weight ratios Ability to be tailored to suit specific applications Disadvantage of slow manufacturing techniques Difficulty in orientating fibres

3. Slide 3 © CSIR 2006 www.csir.co.za MANUFACTURING TECHNIQUES HAND LAY-UP and TAPE LAYING Common methods – hand lay-up and tape laying Very labour intensive and inefficient Difficult to keep fibres orientated in the required direction Low repeatability High material scrap rate

4. Slide 4 © CSIR 2006 www.csir.co.za MANUFACTURING TECHNIQUES VARIM and RTM Other methods – Vacuum Assisted Resin Infusion Moulding (VARIM) and Resin Transfer Moulding (RTM) More efficient due to even resin distribution Low material scrap rate Good repeatability Better control of fibre orientation but techniques are still slow and laborious

5. Slide 5 © CSIR 2006 www.csir.co.za MANUFACTURING TECHNIQUES FILAMENT WINDING Parts with high fibre volume fractions Controlled fibre orientation Products include missile casings and aircraft fuselages Can only use continuous fibres Concave shapes cannot be fabricated

6. Slide 6 © CSIR 2006 www.csir.co.za MANUFACTURING TECHNIQUES SUMMARY Previous techniques are adequate for once-off / small batch productions Most time taken to place and orientate fibres Ideal system – low material scrap rate, less laborious, high repeatability, high production rates

7. Slide 7 © CSIR 2006 www.csir.co.za ROBOTIC FIBRE PLACEMENT ADVANTAGES Cutting and restarting of fibre tows Debulking and consolidation of material in situ Increased flexibility Convex as well as concave shapes Continuous or chopped fibres or combination Thermoset and thermoplastic components

8. Slide 8 © CSIR 2006 www.csir.co.za ROBOTIC FIBRE PLACEMENT THE NEXT LEVEL Design an algorithm that can perform the following: Determine critical stress areas in a component design Evaluate orientation of the fibres Decide on matrix and fibre types Use robotic fibre placement to fabricate component

9. Slide 9 © CSIR 2006 www.csir.co.za ROBOTIC FIBRE PLACEMENT THE NEXT LEVEL

10. Slide 10 © CSIR 2006 www.csir.co.za ROBOTIC FIBRE PLACEMENT RESEARCH LAYOUT Preliminary studies on common manufacturing techniques Design and manufacture of robotic manipulator - pull / cut / orientate / place / spray Design of algorithm / hierarchal meshing Programming of robotic arm Manufacture of components Testing

11. Slide 11 © CSIR 2006 www.csir.co.za Thank you Kentron for the support through the Hystou programme