The computer aided designs are presently being evolved into prototypes using rapid prototyping systems. For this the W&M team uses state-of-the-art 3D printing methods for composites as well as metals and metal alloys. Advanced instruments such as SLM 280 HL and 500 HL in conjunction with SC3DP (Singapore’s centre for 3D printing) are used for metal and metal alloys’ coupon and component level printing. SLM 500 HL is equipped with patented multi beam technology, simultaneous quad fibre lasers (4 x 400 W) which yields into a 90% increase in build-up rate when compared with the traditional dual beam build up. The specifications of 3D printers that is used for metal alloys, polymers and composites.
Composites manufacturing setup
With the addition of new 3.2m length autoclave (operating at 15 bar pressure and 400 °C), the W&M team can manufacture scaled wind and tidal turbines of less than 3m length with fibre volume fractions greater than 60%, which otherwise will not be possible with vacuum infusion. The manufacturing time can be reduced significantly with the help of elevated pressure and temperature curing (typically out-of-autoclave process would require > 15 hours for curing). Also, the elevated pressure capability opens up opportunities for making blades / components with thermoplastics. Additionally, composite manufacturing is done by resin transfer process: pre-preg composites using compression moulding in a 130 T ‘high flexible’ laboratory press, with a pressing area of 800 x 600 mm2, and a cooling / heating stage (up to 250 °C).