Rethinking preventive fire protection: flexible silicate-based film laminates

For the first time, recently developed silicate films allow to produce flexible and transparent laminates based on commercial polymer films. In the event of a fire, the silicate foams and absorbs the fire’s energy, forming an insulating and radiation-reducing barrier (Fig. 1).

Transparent plastic films are used in many areas of industry, construction and transportation. For some applications, they need to come with flame-retardant properties to meet certain fire classes. In the event of a fire, they themselves are not flammable. However, they do not offer significant resistance against fire and can melt and drip away. 

Preventive fire protection could be significantly improved if the transparent plastic films used were able to form a barrier in the event of a fire, serving as a heat shield instead of decomposing into toxic products.  

The new fire protection film laminates, developed at Fraunhofer IKTS with an industry partner, are based on sodium silicate layers, which have been used in fire-resistant glazing for decades and have proven to be highly effective in that application. The new silicate formulation was modified in such a way that transparent and flexible films can be produced from these. The films are laminated, resulting in transparent and flexible film laminates for preventive fire protection (Fig. 2). These laminates can be produced by combining existing film technologies available at Fraunhofer IKTS (Fig. 3).

Applications for these laminates could be possible in many areas: improved fire protection (prevention and containment) for various materials, e.g. textiles, plastics, metals, building materials or glass. Target markets include structural fire protection, battery technology and e-mobility, textile fire protection, protection of electrical systems and solar technology, packaging, protection of industrial plants and transportation vehicles, cables and electronic circuits.