One of the first thermoforming applications for a new 15% glass-filled nylon 6 is a protective engine cover for a motorboat. It is formed from sheet extruded by Sustaplast AG in Germany (U.S. office in Edgewood, N.Y.). The resin is new Durethan DP2-2140/15 Z H2.0 from Lanxess (U.S. office in Pittsburgh).
This branched nylon has high viscosity at low shear and high melt strength, which enables it to be thermoformed. It can withstand continuous use at up to 140 C (285 F) and short-term exposure to 170 C (338 F), according to Lanxess. It also boasts high tensile strength (16,000 psi) and high stiffness (815,600 psi modulus), which allows for thinner walls than with other thermoformable materials. Nylon also resists oil, grease, and fuels. Lanxess has also developed a 25% glass-filled grade that is stiffer, stronger, and more heat-resistant.
Standard thermoforming equipment can be used although adjustments may be required to heat the material up to 230 C (445 F). The boat-engine covers, which replace sheet metal, are manufactured from 5-mm-thick sheet with a forming ratio of 1:2.5. The largest cover is 920 x 400 mm and weighs 2.75 lb. Other targeted applications include material-handling trays and automotive parts such as sound shields, air-flow components, and underbody assemblies.