Center for Light and Environmentally-Friendly Structures ZELUBA®

Research topic

Fire protection

In order to improve the fire protection of wood, wood-based materials, and hybrid material constructions, we develop industry-oriented intumescent fire-protection coatings, glowing combustion-protected wood-fiber insulation materials and flame-retardant composite materials. In addition to fire tests from small to large-scale, we characterize the materials by means of thermal analysis methods such as differential scanning calorimetry, thermogravimetric and thermomechanical analysis.


© Fraunhofer WKI | Manuela Lingnau
The glowing combustion test rig designed at the Fraunhofer WKI.
© Fraunhofer WKI | Manuela Lingnau
Testing rig for the determination of a building product’s propensity to continuous smoldering in accordance with DIN EN 16733
© Fraunhofer WKI | Torsten Kolb
Plywood test specimen, coated with intumescent fire protection paint, following subjection to the laboratory fire test

Materials which are used in construction must be characterized regarding their fire behavior in accordance with DIN 4102-1 or DIN EN 13501-1. According to the Musterbauordnung (standard building regulations) from 2002, a building material classification is required for each building material utilized. This means that materials which are applied from building class 4 (building height: ≥ 7 m) onwards are classified as “flame-retardant”. In the specialist field of fire protection, we develop solutions for the improvement of this building material classification. During the last few years, we have therefore produced intumescent fire protection coatings, both transparent and colored, for wood and wood-based materials, which we are constantly improving. Both coating variants upgraded the utilized wooden test specimens to fire protection class B1 (flame-resistant) in the fire shaft test in accordance with DIN 4102-15.

Furthermore, in the past three years, we have performed fundamental investigations into the glowing combustion of wood-fiber insulation materials in order to characterize the glowing combustion processes. Within the framework of the research activities, we have formulated a new characteristic material parameter: the glimmer acceleration. The knowledge gained will be channeled into the development of a glowing combustion protection agent for future projects.

In collaboration with the department “Technology for Wood and Natural Fiber-Based Materials”, we are developing flame-retardant wood-plastic composites (WPC) for application in facades.

We characterize all the developed materials by means of thermal analysis (differential scanning calorimetry, thermogravimetric and thermomechanical analysis). The resulting gases can be analyzed by means of FTIR spectroscopy and mass spectrometry. In addition to a self-developed laboratory fire test and glowing combustion test rig, the Fraunhofer WKI also possesses medium-scale fire testing facilities (fire shaft in accordance with DIN 4102-15 (test for flame retardancy), small test rig in accordance with DIN 4102-8, fire case in accordance with DIN 50050-1 (test for normal inflammability) and a non-combustibility oven in accordance with DIN 4102). Since the middle of 2016, our department has had an testing facility at its disposal for the determination of a building product's propensity to undergo continuous smoldering in accordance with DIN EN 16733.