The Down Low on Nanotechnology
Doctor Humphrey Carter, a Research and Development Engineer with Southern Spars, gives a brief insight into Nanotechnology and its applications to spar construction.
Researchers have been studying ‘nanotechnology’ and its effect on the performance of composite materials for more than 10 years. However, it has only been in the last few years that such materials have become available in commercial quantities and applied to products that the ‘man in the street’ can access.
In this context, the term ‘nano’ refers to the scale of a class of particles. A nanometre is equal to one billionth of a metre (approximately 100,000 times smaller than a human hair). A nanoparticle has a width between 1 and 100 nanometres. On a structural level the most talked about of the nanomaterials is the carbon nanotube. These are a hollow cylinder of carbon atoms bonded to each other with double covalent bonds in a hexagonal pattern giving it the incredible specific properties in strength and stiffness yet being flexible enough to bend back around itself. Carbon nanotubes have densities as low as 1.3 g/cm3 Young’s Modulus is considered greater than 1000 GPa and the strength for a carbon nanotube has been measured up to 150 GPa.
In the world of yachting, nano-enhanced materials are used where the ultimate in structural performance is sought, in particular spar construction. Accordingly over the past 24 months, Southern Spars in conjunction with technology partner, Compotech, has been developing this technology and nowadays has built more spars utilising nanotechnology than any other manufacturer.
Nanotechnology is incorporated in the majority of Southern’s fibre laid one-design spars. Testing has shown improved longitudinal compressive and transverse tensile strength with the use of carbon nanotube enhanced resin. The improvement in transverse strength means that there can be a reduction in the amount of off-axis laminate and therefore weight in the spar. The fibre laying process adjusts the angle and the amount of fibre in each layer in order to obtain the optimum strength/weight ratio.
Looking to the future, Southern’s R&D Department have also been trialling nanotechnology in spars constructed from pre-preg materials. Test results are showing significant increases in ‘notched’ compressive strength with a nanocomposite pre-preg. This is important as notched compressive strength is often the critical property in the design of a composite spar.
For now though, having followed similar extensive trials and testing, classes such as the Tour De France a la Voile M34 class, the Elliott 6 Olympic women’s match race class and the ‘2009 One Design Boat of the Year’ Audi Melges 20 have emerged demonstrating Southern’s technological feat and can be seen out on the water sporting these breakthrough technologies.