Cleaner coatings for ships
Clean Ocean Coatings is developing an environmentally friendly alternative
“Water is life, and that life will inevitably show itself,” says Christina Linke. Any object that ends up in the ocean will soon be colonised. First, a biofilm forms, followed by algae, and eventually barnacles. “In the end, things become coral reefs.” This is something you don’t want on a ship because it makes it heavier and slows it down. To prevent this, ships are coated with anti-fouling paints. However, these contain tin- and copper-based biocides, along with microplastics. “They are designed to erode over time,” says Linke. “This hinders the initial build-up but also releases toxic substances into the water —100,000 tons per year,” she says. “The world’s largest legal environmental pollution.” The coatings continue to receive approval, with only certain ingredients being banned.
Christina Linke and Patricia Griem, founders of the company Clean Ocean Coatings, have developed a biocide- and solvent-free alternative, which they are now bringing to market. “Our coating has been tested on cargo ships for nearly eight years and has proven its effectiveness,” says managing director Linke. There is far less fouling, and it is easier to clean. “Our customers have been asking: When can we buy this coating?”
They wanted to take time to refine the product. In addition to being effective, the coating had to be suitable for large-scale application. This also meant it had to be easy to apply, durable, the ingredients storable, and so on. To conduct the necessary tests, the Hamburg-based startup established a second branch at the Adlershof start-up centre. Here, they found suitable labs where the three staff members can now perform durability tests, studies on toxicology, and coat model ships for trade fairs.
The coating consists of nanostructured particles embedded in a polymer matrix. The original concept was developed at Phi-Stone AG under Griem’s leadership. When research funding ran out, the formula was at risk of being shelved. That’s when Griem, a materials scientist, happened to meet Linke, who has a PhD in food technology but also a lifelong passion for marine biology—and was equally enthusiastic about the anti-fouling coating’s potential. Together, the two women founded Clean Ocean Coatings in May 2021 to bring the environmentally friendly coating to market.
The best part: It’s solvent-free and creates a completely smooth, non-porous surface. This prevents organisms from attaching themselves to the hull, while allowing ships to glide through water more efficiently. Fluid dynamics tests at TU Berlin showed that this alone cuts fuel consumption by seven percent compared to conventional coatings. Added to this are savings because the hull doesn’t turn into a reef over time. In particularly severe cases, says Linke, the growth increases fuel consumption by up to 40 percent. “Because our coating lasts up to three times longer, requires half the number of layers, and lowers fuel consumption, our solution benefits both the environment and shipping companies and shipowners,” she says. After all, every day that a ship spends in a dry dock is a day it’s not making money.
Currently, four cargo ships are used to test the coating under real-world conditions, along with a sailing yacht and Limanda, the University of Rostock’s new research catamaran. Four more pilot ships will get a new coating as part of the EU project SEAGLOW this year. The founders are hopeful when it comes their primary goal: commercial shipping. Regulatory approval has been obtained, and initial offers are on the table. Linke has counted 150 potential customers who have expressed interest. This would increase the demand for materials enormously. For instance, a 160-metre cargo ship with an underwater surface area of 6,500 square metres would require about 4,000 litres of coating. “Our manufacturer can handle it and can ramp up production significantly. “By 2030, the company aims to generate 70 million euros in revenue, equating to 250 fully coated ships. Looking at around 90,000 ships that operate globally, this is still a drop in the ocean. But another step towards making shipping more sustainable.
Ralf Nestler for Adlershof Journal