Science Taking Coatings Into a New Era
The challenge of developing intumescent coatings to provide fire protection for steelwork used in new complex buildings that can dry rapidly whilst retaining their durability has long been the holy grail of the industry. Now it has arrived.
Experts at Sherwin-Williams have been listening to its customers to understand their frustrations and their needs for the future as the industry tries to balance demands for quality products with new architectural designs and materials and the sheer speed of construction required of developments across major cities in the UK and worldwide.
The result of their tireless research and development is FIRETEX FX6002, an intumescent coating offering 20 years durability in most environments without the need for a top coat – with a drying speed as fast as an hour.
Chemists started working behind the scenes to develop a coating that would meet the changing demands of the fast-moving design of today’s modern complex buildings made of structural steel.
Working against the criteria outlined by customers who want wider painting windows, faster drying times and increased durability, the chemists continued their painstaking work in search of the formulations that would bring the desired results.
Increasingly, architects and designers have been specifying complex designs using lots of structural steel, with new demands of the coating.
In the civil construction industry, most intumescent coatings typically dry by a process of water or solvent evaporation and when applied at a high film thickness can take some time in the process. More recently, a number of intumescent coatings have come to market that dry by a chemical reaction process, based on epoxy technology originally developed for use in the petrochemical industry.
Supplied in two parts the products consist of an epoxy resin which is crosslinked with a co-reactant or hardener. Epoxy coatings are formulated based upon the performance requirements for the end product. When properly catalyzed and applied, epoxies produce a hard, chemical- and solvent-resistant finish.
Employing a chemical reaction to harden can accelerate the drying process, but epoxy intumescent coatings typically require a higher thickness than traditional materials to achieve the same fire protection.
The chemistry formulated in the new FX6002 series uses a reactive binder, meaning the coating is dry and ready to handle in as little as an hour with a high aesthetic finish.
Comparing the different technologies used to provide 120-minute protection to a circular hollow section, with water-solvent based, or epoxy intumescent coating, the application would take several coats over one, two or even more days. The epoxy intumescent could then harden in around a further 24-hour period. However, it would take days, even up to a week or more, for the water-based and solvent-based coatings to dry and harden. The entire process using FX6002 could be completed in a shift.
For in-shop applicators of intumescent fire protection, FX6002 has Volatile Organic Content (VOC) levels as low as many of today’s water-based intumescent products. It also dries to leave a smooth and aesthetically pleasing finish, worlds apart from that typically achieved with some other exterior durable products.
Additionally, when looking to optimize project costs, in many scenarios FX6002 may be specified with or without both primer and top coat depending on the project and applicator’s requirements.
Rigorously fire tested under the requirements of British Standards BS476 parts 20 and 21, and the ASFP Yellow Book (Edition 5), and European Norms EN13381 parts 8 & 9, FX6002 can offer up to 120 minutes fire protection to traditional rolled steel elements and cell beams. When coupled with the expertise of the Fire Engineering & Estimation Team in prescriptive and fire engineered solutions, and Sherwin-Williams’ independently accredited Fire Design Estimator (FDE) software, FIRETEX FX6002 can be fully integrated into a project’s design model and BIM operations.
For on-site application, it means there are fewer risks with bad weather and the likelihood of the project being affected by rain, so the timeframe for coating becomes wider. The rapid curing time also means there is less risk of any mechanical or handover damage as the steel is passed through the supply chain.
The significant savings can be reflected in a more certain scheduling and delivery for the asset owner or manager, with the confidence that brings.
At Sherwin-Williams, we have developed a working partnership with Trimble, one of the world’s leading suppliers and providers of technology for the steel and concrete industries and the built environment. We recognized the need for a technology that would allow an accurate and risk-free design process to allow the dry film thicknesses (DFTs) of our intumescent coatings to be seamlessly incorporated into the steel fabricator’s 3D model.
With Trimble, we have developed a secure plug-in linked to our own software, which enables accurate calculations for complex projects as modern building design becomes ever more complex. This handles every complexity imaginable, giving the added benefit of color filtering to allow 3D analysis of the coating properties.
Steel fabricators rely almost entirely on such 3D models to effectively run their operations with the BIM platform, producing contract drawings and enabling the ordering of materials such as steel and bolts. So why not intumescent coating too?
The new FIRETEX FX6000 technology was recently applied to Whitechapel Station in London, bringing benefits in time and cost, and proving its worth for on-site application, and FX6002 has already received enthusiastic and positive feedback from customers using the product.
Sherwin-Williams has supplied its diverse range of fire protection coatings to a number of landmark construction and engineering projects including London’s The Shard, the Leadenhall Building and Azerbaijan’s Flame Towers.
The fire protection performance of the patented FIRETEX FX6000 and FX6002 technologies are independently certified under the Certifire scheme, and in durability testing under EN16623 it meets the requirements for Type X, internal, semi-exposed and exposed locations.
For more information, visit http://sherwin-williams.com/protectiveEMEA.