Rigid-hull inflatable boats (RIBs) can be over 12m long and hold more than 20 people. But most RIBs are smaller, designed to be stable on ocean waters and reach short-range destinations fast. Common uses for RIBs are rescue boats, dinghies for larger boats, and as pleasure crafts.
RIBs usually have v-shaped hulls surrounded by inflatable gunwale tubes that are constructed from industrial-quality coated materials. Tubes must be able to resist severe weather, abrasion and punctures, long exposure to UV radiation, salt-water exposure, and sometimes chemical exposure. For these applications, it is most common to use thick nylon or polyester base fabrics that are coated with either TPU (thermoplastic polyurethane) or Hypalon (aka rubber, now sold as CSM).
Weather and Temperature
Especially with ocean rescue boats, materials must perform well in extreme high and low temperatures. High temperatures increase oxidation rates and extreme low temperatures can cause many materials to lose their flexibility and crack or fail. Both these issues can affect rubber coatings to a greater degree than TPU coatings. TPU retains its performance properties in temperatures ranging from 70 C to minus 50 C.
TPU-coated materials are weldable. This means fewer leaks than glued-together materials. Plus, the welding process can be mechanized more easily, making manufacturing processes quicker and cheaper. Hypalon is not weldable and must be glued. Because glues and their fumes are toxic to humans, this difference can also be very important to many customers and employees who must live and work with the glues.
Marine environments subject boats to constant scraping and scratching. The ability to withstand and recover from such abuses is of paramount importance to RIB tubes. TPU is much more abrasion resistant than Hypalon. Thanks to these unique features the USA space agency, NASA, also uses TPU.
Hypalon and TPU both resist bacteria, but Erez TPU has a long-lasting, anti-bacterial additive that prevents bacteria from sticking. This makes our TPU more resistant to bacteria than Hypalon. This additive cannot be added to Hypalon. So, it does not offer the same antibacterial resistance.
If your boat will come in contact with chemicals, chemical compatibility needs to be considered. Hypalon will not break down in the presence of most chemicals. For that reason, it is the traditional and trusted material for these applications. While TPU is compatible with a wide range of chemicals, it is not compatible with acidic chemicals.
TPU is a special coating which defies common practices, in contrast to similar coatings such as Hypalon. While Hypalon`s chemical resistance and abrasion resistance is defined mainly by its weight, TPU can achieve the same or better properties with less weight.
Erez TPU-coated technical materials and Hypalon are both traditional choices for RIBs. But in nearly every applicable performance category, TPU-coated materials can outperform Hypalon.TPU creates a product which is easier to maneuver (handling), leading to better quality both for the manufacturer and the end customer. Give the trained Erez team a call to discuss your RIB project and get help deciding which material is best for you.