TECNOFLAME INTUMESCENT SEALS

The product examined, which considers multiple products according to the table above, is an intumescent seal designed for application on fire-rated doors. Its function is to undergo a significant volumetric expansion when exposed to elevated temperatures or direct flame, thereby providing a non combustible or self-extinguishing barrier. All items assessed are manufactured via extrusion; the only difference is that some seals are produced through standard extrusion, whereas others undergo co-extrusion, where a coloured outer film is added solely for aesthetic purposes. Marvon’s intumescent seals are engineered components used in fire-rated doors and other passive-fire protection systems. Their function is to expand when exposed to heat, sealing gaps and preventing the passage of flames, hot gases and smoke. When a door is exposed to fire, temperatures rise rapidly; the seal begins to activate at around 180°C and can reach expansion ratios of up to ten times its original thickness, generating pressures of roughly 5 bar. This expansion creates a compact, stable and slightly elastic foam that remains effective even at temperatures around 450°C. The product range is designed to cover a broad spectrum of installation needs. The seals are offered in a different size and profile, with the possibility of coloured co-extrusion for applications where both performance and aesthetic are relevant. They can be supplied with or without adhesive backing, in standard 100-metre rolls or in customised lengths. All variants are moisture-resistant, insensitive to atmospheric agents and free from organic solvents, which facilitates storage and handling. From a materials standpoint, the seals are produced using a thermoplastic matrix composed of PVC resin, plasticisers, environmentally friendly stabilisers and a mixture of fire-retardant fillers. The key reactive component is intumescent graphite, which drives the expansion process when exposed to heat. The formulation is designed to ensure reliable activation, strong adhesion to substrates and stability during long-term service. Applications span fire-rated wooden, steel and composite doors, as well as ceiling joints, penetrations, expansion joints and modular panel connections.