Intumescent Paints And Coatings To Improve Heat Resistance

Using Intumescent Paints and Coatings to Improve Heat Resistance

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Intumescent materials are core components of passive fire protection. They are often used in paints and coatings to improve heat resistance and several other properties. Goonvean Fibres has a strong relationship with specialist paint manufacturers and has produced a wide selection of raw materials for paint formulations and high-performance coatings for many years. 

Our paint and coating fibres are key components for architectural, automotive, and industrial coating applications. Goonvean Fibres’ solutions include short-cut synthetic and natural fibres, flocks, and powders that help improve the mechanical and thermal properties of paint and coating products.

In this blog, we look at the result of applying intumescent fibres to paint and coatings using findings from our recent case study.

What is an Intumescent Material?

An intumescent material is a heat-activated substance that expands rapidly when exposed to high temperatures, forming a thick char layer that acts as an insulating barrier.

This expansion results in the intumescent material swelling up to 100 times its original volume, creating a foam-like barrier that can protect the underlying substrate from heat damage.

Intumescent Materials in Paints & Coatings

Intumescent materials are used in paint and coating applications with other ingredients, such as fibres, binders, pigments, and fillers, to create a product that can be applied to a wide range of surfaces to improve heat resistance.

Because an intumescent material is a substance that swells when exposed to the heat of 200 degrees or more, it helps to increase the volume and decrease the density in paint and coating applications. This is useful not just for paints and coating but also to create sealants and insulation boards.

Intumescent seals can quickly close gaps in the event of a fire for service penetration seals (fire protection systems designed to maintain fire resistance in buildings where cables, ducts, and other services pass through them).

Applying Intumescent Fibres to Paints and Coatings

We recently carried out a study to investigate the effects of fibres in intumescent paints and coatings. The aim was to improve the performance of these products by adding fibres to improve their heat resistance, by providing mechanical reinforcement supporting the structure and dispersion of intumescent materials.

The fibre we chose for the study was our PAN1(6.7dtex) 1mm acrylic fibre which possesses strong intumescent properties. When heated, the heat causes the intumescent material to swell and create a charred protective insulating layer over a substrate. This char layer increased the thickness by up to 50 times the original coating thickness.

In our study, we added 0.4-0.8% by weight of intumescent fibre to sample applications. The acrylic fibre’s property had uniform dispersion within the matrix and preferentially bridged with other intumescent materials through char bonding.

The thermal decomposition from 280-500 degrees and up to 60 per cent weight loss over this temperature resulted in air pockets developing in the char, and as other components degraded, gases were produced that caused the air pockets to expand, increasing the insulation properties and thickness of the char.

With our applied dosage of 0.4-0.8 per cent by weight, there was thermal stability of 550-620 degrees. This is the typical temperature range where steel reaches its critical failure temperature. The acrylic didn’t thermally degrade any further over these temperatures, and as a result, a stable char layer provided thermal insulation for the substrate underneath.

Goonvean Fibres has been working on solutions for the paints and coatings industry for many years, working with several specialist paint manufacturing clients. Not only can we help improve heat resistance, but our fibres can also be applied to increase strength, and longevity, prevent microcracking, and more. From decorative coatings to floor coatings, marine paint, primers, fire-resistant paints, anti-slip, and topcoats, we have a variety of quality solutions.


If you’re interested in finding out more about our fibre solutions for paints and coatings, why not contact us? We are happy to tailor to your specific needs and requirements.