How circular thinking makes steel future-proof

A thoughtful surface treatment 

Steel is strong, reliable and - if properly protected - surprisingly durable. At a time when circular construction is becoming increasingly important, attention is growing to how steel is treated against corrosion.

Corrosion: the silent demolisher

Untreated steel is susceptible to rusting. That process, depending on the environment, can be surprisingly rapid. "Corrosion affects not only appearance, but also structural safety," they explain at Rotocoat. "That's something that is often not thought about until it's too late." Thoughtful surface treatment is therefore essential for those committed to sustainability.

Duplex system

An effective way to protect steel is to combine hot-dip galvanizing with powder coating. In hot-dip galvanizing, the steel is immersed in a bath of liquid zinc, creating a wear-resistant, adhesive layer. This layer acts as a physical barrier, but has a unique property of cathodic protection: even if the exterior is damaged, the underlying steel remains protected. By then finishing the zinc layer with a powder coating, a so-called duplex system is created. This duplex system significantly extends the life of steel.

Zincular® as a chain approach

To make the most of that long life and to think circularly in the full sense, Rotocoat developed the Zincular® concept. This is not a stand-alone product, but an integral approach to steel protection and operations, based on proven techniques and sustainable principles. Zinculair® has been awarded the Cradle to Cradle Silver certificate, an international standard for circular and environmentally friendly production chains.

The strength of Zincular® lies in the connection between design, production, use and reuse. Especially also the possibility of re-galvanizing. Steel that is discarded after decades can be de-galvanized, processed and re-treated. Both the steel and the zinc thus remain in the material chain. 

"We look beyond galvanizing itself," says Rotocoat. "Zincular® is about the whole process: from smart design to responsible production and reuse. By making parts demountable, de-galvanizing and re-galvanizing the steel, we create closed material cycles. This reduces the demand for new raw materials."

Sustainability in practice

Processes include the use of recycled zinc, green energy and recycled packaging materials. Among other things, residual zinc and waste heat are recovered, recycled where necessary and reused in the process. That means: minimal waste and reduced CO2 emissions. As a result, CO2 emissions from galvanizing activities at Rotocoat have been reduced by more than 50% since 2019. The ambition is to produce completely CO2 neutral by 2040. Yet it's not all about sustainability performance in numbers. "The most important thing is that we give steel a much longer life, which means that less new material is needed. And that at the end of that lifespan we can start again, without loss of quality."

Advice from design

Although the technology behind hot-dip galvanizing and powder coating has been proven for decades, good steel protection also requires insight and preparation. The design must consider functional details, such as countersink holes for proper flow of the zinc bath or joints that allow disassembly. Proper coating thicknesses and compliance with quality standards, such as those outlined in the ISO 1461 document, are also crucial to the end result.

In practice, Zincular® is applicable to a wide range of steel structures, from bridges and facades to fencing and light poles. By combining corrosion resistance, low-maintenance performance and circularity, the system offers a future-proof solution for clients who take sustainability seriously. So good steel protection goes beyond rust prevention. It is an investment in longevity, material preservation and environmental performance. Concepts such as Zincular® show that technical soundness and future-oriented thinking are perfectly compatible - as long as attention is paid to both design and treatment from the outset. In this way, steel is not only protected, but also used intelligently and responsibly for future generations.