As a long-time supplier of innovative coatings to the marine market, PPG was able to anticipate the trend of rising marine fuel costs to produce its most advanced pure silicone fouling release systems to date.
This has helped shipowners save money over the last decade and comes into focus again from January 2020 when new regulations will see the industry move to low sulfur fuels whose costs could be far higher than current levels.
With regulators enacting new rules covering greenhouse gas emissions from shipping, there is a need for further efficiencies. As a result, shipowners are demanding marine coatings whose properties extend from improving operational performance to those that can reduce greenhouse gas emissions.
One of the well-known challenges for fouling release technologies is that their effectiveness decreases over time. PPG engineered its SIGMAGLIDE 1290® coating with dynamic surface regeneration properties which allow water to act as a catalyst to lower the surface energy of the coating back to its original state and thus restart its surface configuration properties.
This regeneration preserves the coating’s effectiveness over time, meaning that it will experience no loss in performance and stability of the product throughout its lifetime. Its low environmental impact means that it can be applied to vessels trading in the most ecologically-delicate environments.
When the Eco-friendly Ship Hull film system (eSHaRK) project was first announced in 2016, its objective was ambitious but simple; bring to market a fouling protection technology which not only maintains current state-of-the-art protection standards but is superior to existing paint-based solutions in terms of eco friendliness, ease of application, robustness and drag reduction effects.
The project took its inspiration in part from recent developments in hi-tech swimsuits which can enhance a swimmer’s performance by reducing drag as they move through the water. In fact, the eSHaRk partners have described their ambition in creating a new fouling release solution as wanting to pull the ship as though it was wearing a high speed swimming suit.
Backed by European Union-funding, a consortium consisting of some the world’s leading marine experts and engineers are working together to create an innovative new fouling protection system. eSHaRK consists of a self-adhesive and non-toxic fouling release foil, produced by applying a state-of-the-art PPG SIGMAGLIDE 1290 fouling release coating onto a self-adhesive film.
Recent developments have seen the eSHaRk project team (PPG, MACtac, Meyer Werft/ND Coatings, VertiDrive and Hamburg Ship Model Basin HSVA) develop and produce a prototype for the embossed fouling release foil, a concept proven by tests performed at HSVA test institute.
Progress has also been made towards production of an automated lamination system that will apply the foil to the underwater hull of a vessel.
A number of trial applications are underway and the advantages of the system are already being demonstrated. So far the foil system has been able to offer clear advantages on newbuild projects in terms of productivity improvements and minimized environmental impact.
On the smaller vessels that have been selected as testbeds, the foil is applied manually due to hull size and shape. For these vessels PPG has developed a highly sustainable combination of the very tough PPG SIGMASHIELD 1200 anticorrosion coating to providing an extended lifespan basecoat, with the foil removed by hydrojetting and renewed after a prolonged period.
This innovative new technology not only maintains current fouling protection standards but is superior to existing solutions in terms of eco-friendliness, ease of application, durability and drag-reduction, all of which will lead to fuel savings and a reduction in greenhouse gas emissions.
The industrial application process allows an exact and optimally smooth silicon layer produced under controlled application and curing conditions. These two elements are essential in boosting fouling release properties as the optimum surface characteristics of the silicone film are perfectly established.
The self-adhesive properties allow efficient application without release of solvents and do not create any problems of silicone spread to the surrounding environment. Application of the foil is a one-coat operation which thus reduces overall application time. Industrial application also allows impression of surface texture - similar to the hi-tech swimsuits - lowering drag resistance.
Though the eSHaRk project is far from complete, the early results suggest that it will lead to fuel savings and reduction of GHG emissions greater to those of existing paint-based anti-fouling and fouling release technologies. The result will be an increased reduction in drag compared to the conventional spray-based application of PPG SIGMAGLIDE 1290 fouling release coating.
*Attributable to PPG eSHaRK Project leader, Peter Schoneveld