Industrial coatings provide structures such as bridges and offshore oil rigs with corrosion resistance and durability, helping to maintain their lifespan and minimise the need for maintenance. While powder-based coatings tend to offer better protection than water-based coatings, they do however present a number of disadvantages. “Powder-based coatings often contain hazardous compounds, and require a curing step in an oven,” notes KEMISTATIC project coordinator Yannick Pialat from Kemica Coatings in France. “This makes them energy-intensive. They are also not suitable for substrates such as wood, or structures made from natural polymers such as wind turbines.”
Attractive coating solutions
To meet market demand for an energy-efficient and environmentally sound coating solution, Pialat’s company set out to develop an alternative. The technology they applied is known as electrostatic spraying. The system works like this. Their patented coating – which is free from solvents and volatile organic compounds – is given a negative charge. This means that when sprayed, the coating is attracted to the substrate; the application of the coating is quicker, and there is less waste. “The coating is evenly spread thanks to the wraparound effect of the electrostatic spray,” explains Pialat. “We can control the thickness applied, and reduce it to a very thin layer.” The system offers other advantages as well. “We start with two separated components – a base and a hardener,” says Pialat. As soon as you mix them, a chemical reaction called polymerisation starts, and the product gets hard progressively. The speed of this reaction can be adjusted.” The goal of the KEMISTATIC project was to optimise the firm’s prototype electrostatic spraying system for a wider range of applications, and to scale up the system for industrial use. “We really wanted to open up the field of application,” remarks Pialat. “At the moment, it is difficult to use our coating on smaller objects. We could imagine our solution eventually being used to coat chairs or pens along a production line.” To achieve this, the existing demonstrator was scaled up with new equipment, to be able to deliver industrial solutions ranging from coating window frames and doors to large-scale infrastructure. It is this ability to offer flexible and tailor-made solutions that Pialat believes will make this innovation a success.
Opening market access
“The ultimate goal is for this disruptive technology to replace conventional powder coating and liquid paint coating systems,” adds Pialat. “This project really pushed us forward, by enabling us to develop viable industrial solutions. There is no equivalent on the market today that can spray electrostatically two component resins without solvent.” Importantly, the solution is solvent and BPA-free and can be cured at room temperature. This means no extra energy is required to harden the coating. One of the coatings developed has been approved for food and potable water contact. “The project also enabled us to show that the coating offers good technical properties,” says Pialat. “It is adhesive, follows the movement of the substrate (important if the coating is applied to moving parts) and provides chemical resistance.” The company is looking to move swiftly towards commercialisation, and is starting to organise in-house demonstrations. Potential industrial partnerships are also being sought, in order to speed up market access.
KEMISTATIC, coatings, electrostatic, solvents, paint, BPA, chemical