BVC and Sirris join forces on fire-resistant coatings for composites

Composites do not generally have highly fire-resistant properties because of the flammable organic matrix which binds the reinforcement fibres. In order to meet the high fire-resistant demands made in applications such as aviation, construction and transport sector, the structure of the composite must be adapted for protection against fire. To this end BVC can rely on the joint forces of SLC-Lab and Smart Coating Application Lab. 

With the development of an innovative fire-resistant additive, BVC Development sprl from Oudergem wants to respond to the market demand to make sure it can resist fire for a longer period. This is a cooperation with Sirris: both SLC-Lab and the Smart Coating Application Lab were involved in the development and evaluation of fire-resistant composites.

Homogeneously sprayed gelcoat

The production of the composite material is based on a gelcoat with a fire-resistant additive added during the production process. This formulation is applied as a coating to a carrier material by means of spray coatings, which is covered with the reinforcing fibres and the matrix after a drying phase. 

Attempts were made to maximize the level of fire-resistant additive incorporated into the coating. Because rising additive concentrations gradually increase the viscosities of the formulations, the application parameters (dilution degree, nozzle opening, spray pressure) should be adjusted to allow the gelcoat to be homogeneously applied in the correct thickness (± 125 μm). The expertise of the Smart Coating Application Lab was relied upon for the application of the coating. 

Microscopic evaluation shows a good distribution of the additive and fire tests on the composites show the positive influence of the additive on fire resistance properties.

Broad field of application

In the course of the project it became obvious that the fireproof coating can effortlessly be applied as a gelcoat in 3D moulds, before the composite processing. It can also be applied as a functional topcoat on processed composite parts. In addition, the fire-resistant additive is suitable for both polyester and epoxy-based composites, in both prepreg technology and infusion processes, making it widely applicable.