For Toyota, the ability to achieve large-scale production was a key reason to adopt composites, but because of the blend of materials it turned to an untried process. The company applied vacuum infusion molding, using the method for the first time in Japan for the mass production of the boat. The process enabled high-strength molding with improved material density. It was selected, according to Toyota’s spokesperson, for its ability to integrally bind the various components that make up the multi-layer hull.
During design, vessels using only aluminum had technical limitations. However, the hybrid hull opened up a great deal of freedom in terms of design, Toyota found. The mixture of materials was pivotal in gaining the desired combination of strength, comfort and maneuverability.
The design was unable to achieve enough rigidity of the hybrid hull simply through enhancing the rigidity of the FRP through the vacuum infusion process, according to the Toyota spokesperson. By adding aluminum at the top of the stringer, rigidity was improved. Carbon fiber is used on the ship’s bottom, where waves would create the most shock, to improve riding comfort. Moreover, the vacuum infusion process allowed the manufacturer to mold more complicated curved shapes, which also improved maneuverability for the boat.
The end result was a hull that reportedly achieves seven times the rigidity of a standard FRP hull, while weighing roughly 10 percent less than a similarly-sized craft with an aluminum hull.
Exploring New Blends
Composites have played a role in each of these industries for many years. Long enough, certainly, to demonstrate that composites on their own can provide a good solution. However, they can often provide even greater levels of strength, durability and rigidity when combined with other materials. Moreover, fabricators may find that pairing composite solutions with traditional materials could improve the odds of adoption.
As these examples indicate, it’s often the engineering processes – and misguided preconceptions – that limit the use of composites. But over time, manufacturing processes will catch up, and tomorrow’s engineers will have successful installations and applications to study. By making predictable metals a part of the mix, fabricators gain added opportunities to demonstrate the benefits that composites can offer.