New technologies offer alternatives to traditional products
In 2016, at SMM and other marine exhibitions, a new anti-fouling product was displayed that, although applied to the outer hull, is not a coating in the accepted sense. Micanti Antifouling film is a physical barrier against fouling and therefore movement of the vessel is not needed for it to be effective. The product comes on a roll and is applied to the vessel in strips such as wallpaper is applied to walls. It is described by its Netherlands-based developer as a self-adhesive foil consisting of backing paper, pressure sensitive modified acrylic adhesive, a 12μm polyester carrier foil and antifouling layer or cured acrylic adhesive with embedded nylon fibres.
The product feels like coarse velvet but the maker says this texture prevents settlement of organisms and the total weight as applied is comparable with a typical anti-fouling coating system. Micanti has been tested for more than 10 years in cooperation with institutions including MARIN, TNO and Delft University of Technology as well as in practice on a variety of vessel types.
Another new type product that is not yet available on the market but was announced as in development in early 2016, combines the concepts of traditional coatings and application from a roll. PPG, which makes Sigma products, is working on the eco-friendly Ship Hull film system with fouling release and fuel-saving properties (eSHaRk) project drawing on the work of a development group including PPG, MACtac, Meyer Werft/ND Coatings, VertiDrive and Hamburg Ship Model Basin HSVA.
The project, which secured EU funding through to November 2018, aimed to establish an automatic application process which enables a self-adhesive fouling-release film to be used on commercial ocean-going vessels. The project end-date when first announced was 30 November 2018 and at the time of writing in mid-December 2018, no report on the full project had been made public. The most-recent entry on the project website was the interim report issued in July 2017.
Its process will allow shipowners and operators to enjoy the fouling release properties and drag reduction capabilities of the PPG SIGMAGLIDE self-adhesive film. According to PPG, the new film is superior to existing paint-based solutions in terms of eco friendliness, ease of application, robustness and drag reduction effects. eSHaRk is expected to have superior drag reduction properties compared
with existing anti-fouling and fouling release technologies, up to 10% drag reduction as compared to the currently-available maximum 5%. The system incorporates a fine-tuned fouling release system, based on PPG’s premium 100% silicone binder technology, and a self-adhesive film specially designed by MACtac for underwater use.
As part of the eSHaRk project, a robot application technology is being developed by VertiDrive which will be used to apply the film automatically on large commercial vessels. The surface morphology of the film will be optimised to enhance drag reduction, increase fuel savings and reduce emissions to previously unattainable levels. A number of trial applications are underway.