The use of systems such as 9762-Z ensures efficiency and safety in the shipbuilding industry. Although traditional casting is the predominant method for insulating holds, spraying with S-403 HFO spray is also an effective solution, as we will see below.
Large vessels such as trawlers and tuna vessels face enormous challenges when operating in offshore fishing grounds. For this reason, they must have good-sized holds in which to store catches and goods, and which are adequately insulated. This is necessary not only to protect the cargo, but also to minimise energy losses, which is key to energy efficiency and operational cost savings on long voyages.
This two-component polyurethane system, polyol and isocyanate, has been developed with the fourth generation of blowing agents, so its contribution to global warming is very low. It is applied in situ by spraying, using high-pressure equipment with heating systems, thus obtaining rigid, closed-cell foams.
In addition, S-403 HFO spray has a density that varies in the range of 43-53 g/l, a high adhesion to the substrate and a reduced thermal conductivity of between 0.028 to 0.025 W/mK, depending on the thickness of the foam.
The properties of polyurethane in marine applications make it the perfect partner for the marine industry. Rigid closed-cell polyurethane foam has low thermal conductivity, making it a highly effective insulation. It should be noted that, with its installation, insulation and waterproofing are achieved in a single process. It also stands out for its rigidity, which makes it highly resistant to external aggressions. On the other hand, polyurethane helps to maintain humidity within the established parameters, thanks to its limited water absorption and its vapour barrier effect.
The in-situ application of closed-cell polyurethane foams allows a perfect adaptation to the thickness of the hull of the boat and its strong adhesion guarantees a perfect seal at the perimeter between the hull and the deck. All while preserving the boat's buoyancy, given its lightness.
In the marine industry, the application of polyurethane is essential for insulation on ships equipped with cold rooms or freezers. Located in the lower part of the boat, in the holds, they are in close contact with a "custom-made sandwich panel" combining the hull with closed-cell polyurethane. But it is also applied in the filling of boat hulls, making them more rigid and impact-resistant, as well as more waterproof.
The S-403 spray must be applied on a clean, dry substrate, free of dust, grease, rust and corrosion. It should be noted that the performance of the foam will depend on the atmospheric conditions (mainly temperature and humidity, both of the substrate and of the environment), the setting of the machinery, the type of application (vertical, horizontal) and the way of application (layer thickness).
The layer thickness can be controlled and modified by changing the application speed or the mixing chamber of the spray gun, but a thickness between 10 and 20 mm is recommended. At higher thicknesses there is a risk of pocket formation.
The application of polyurethane in ship hulls and hold insulation is crucial for cargo preservation, energy efficiency and successful operations in distant fishing grounds. It ensures product quality, reduces operating costs and guarantees the integrity of goods on long voyages.