The science and technology behind award-winning coating

Sherwin-Williams’ award-winning FIRETEX® FX6002 intumescent passive fire protection enables unrivalled curing in hours as opposed to days. Launched across Europe in 2019 and awarded a 2021 Queen’s Award for Enterprise: Innovation, this technology is gaining recognition as an efficient fire protective coating, which reduces bottlenecks and downtime on site, while offering cost saving benefits. The product, which has been used on some of Europe’s newest landmarks, is the result of ground-breaking binding technology that reduces thickness requirements while minimiSing volatile compounds and throughput times.

Here, Rick Perkins, Global Technical Manager for Passive Fire Protection of Sherwin-Williams Protective & Marine, provides answers to key questions about its development.

Question: What was the main aim of creating this product?

Answer: In-shop applicators who Sherwin-Williams works with have been a prime audience for this development. For them, the speed of curing is a major issue during the application process, as it creates bottlenecks in the availability of the steelwork in the construction.
Using FIRETEX FX6002, the reduced curing time enables much faster throughput in the paint shop with accurate film thickness checks being possible one to two hours after application. Not only do its curing capabilities allow for quicker production, they also reduce the lead-in time during which the fabricator and applicator begin preparing steelwork ahead of it being required on site. We have now had reports that using FX6002 can cut the lead-in time needed to supply to site by up to 50%.
The speed of curing and the ability to protect steel off-site so efficiently have benefits all round for high-value infrastructure projects, with one fewer item on the critical path for the main contractors on-site. There is also the added gain of fewer repairs – meaning reduced use of equipment and product, and lower carbon footprint.
For architects and designers, FX6002 offers a fine aesthetic finish on the exposed steel, with fewer imperfections affecting the look of the surfaces.

Question:How did you go about developing this coating?

Answer: In all, it took more than a decade of development work using our proprietary reactive binder technology (the chemically cured methacrylate binder system), which is new in the field of intumescent coatings.
The predominant technology in this field has been built on solvent-based coatings, which continue to be used for this purpose very effectively. Such coatings dry by solvent evaporation, making the intumescent drying the crucial step for application.
On the other hand, coatings which dry by a chemical reaction can bring more predictability to the drying process. Epoxy-based intumescent materials have been developed further with this goal in mind.
Achieving faster and more predictable drying, along with the enhanced durability of epoxy intumescent coatings, has previously been hampered by increased coating thickness required to achieve the required fire protection.
Our research and development chemists at Sherwin-Williams examined alternative binder technologies which could provide the sought-after speed and predictability of drying and durability – but without the increased thickness requirements seen with epoxy products.
Working closely with our specialist suppliers and having evaluated a large number of different technologies, a methyl methacrylate binder was identified and selected for the formulation of FIRETEX FX6002.
The properties of the binder system include inherent low viscosity – which supports the application process, rapid and predictable drying, and excellent mechanical and weathering durability. As a result, it significantly outperforms the traditional solvent-based products.
FIRETEX FX6002 captures these properties and requires lower coating thicknesses comparable to traditional solvent-based products in order to achieve the required fire protection.

Question: What about the environmental considerations?

Answer: The environmental concerns were an important consideration early on in the process. Our research and development teams discovered that the chemistry gave off 90% lower volatile organic compounds compared to similar products, and lower than some water-based intumescent products.
The applicators are exposed to fewer harmful emissions especially when applied in-shop in a controlled environment rather than on-site. The product is certified to EN 16516 for low volatile emissions.
There is also the reassurance of LEED 4.1 compliance, the leading green building project and performance management system.
This collaborative work is now gaining a following among specifiers, contractors, fabricators and applicators, particularly due to the large demand for construction environments which are greener and healthier to work in.

Question: Where is it being applied?

Answer: The take-up can be seen on steel constructions rising across Europe, such as Milan’s striking UnipolSai Tower being built and coated using FIRETEX FX6002, in addition to the CO-Met building complex in Orleans, France, and the Y-Towers in Amsterdam.
FX6002 can be used on a diverse range of steel section types, across corrosive environments up to C5 and for different fire protection scenarios, reducing the need for use of multiple products. It has been rigorously fire tested under the requirements of European fire testing standard EN13381-8 & 9 and British Standard BS 476-20 & 21 for structural steelwork and cellular beams.
With a life expectancy of more than 20 years, the innovation of FX6002 gives our customers an advantage for today and reassurance for the foreseeable future.

FACTSHEET– FIRETEX® FX6002

Average drying times:
To touch: @ 15 degrees C 1hr @ 23 degrees C 45mins
To recoat: @ 15 degrees C 1.5hr @ 23 degrees C 1hr
To handle: @ 15 degrees C 2hr @ 23 degrees C 1hr

Product characteristics:
Fire protection: 15–120mins
Volume solids: 92% (ISO 3233:1988)
VOC: 24g/lit
WFT (μm): 2000 max
DFT (μm): 1840 max

For further information, telephone +44 (0)1204 521 771 or visit the Sherwin-Williams Protective & Marine website.