New research field: fire protection chemicals and corresponding analysis
Building with wood is experiencing a renaissance and benefits from a society's demands that requires more sustainable building materials. From 2015 - 2019 alone, the proportion of approved residential buildings in timber construction increased by about 17 % - and thus made an essential contribution to the reduction of climate-damaging greenhouse gas emissions. However, wood is not only used in rural areas, but also offers an advantage in times of housing shortage in the cities due to its high strength and load-bearing capacity, with a comparatively low weight. These are exceptional properties for the required additional construction of already existing buildings (e.g., adding storeys) to increase living space.
To meet safety requirements and, if necessary, building law and technical regulations, it may be necessary to enhance the wood's fire protection properties. This is particularly interesting if, for example, encapsulation of the wood with gypsum boards is to be avoided for aesthetic reasons.
In the context of this exciting topic, the Department of Wood Biology and Wood Products is building up research capabilities and is investing in analytical devices. When selecting the equipment, it was important that the full range of wood and wood-based products can be analyzed - whether chipboard, MDF, (modified) solid wood or insulation board, an analysis is possible with the acquired equipment.
A Small Burner Box from NETZSCH TAURUS Instruments GmbH was purchased. This test device is used to analyze the flammability of products when subjected to direct impingement of flame according to the standard DIN EN ISO 11925-2 to determine the European fire classes B, C, D, and E. The test pieces are 250 x 90 mm² in size and can be up to 60 mm thick. The flammability and side effects, such as possible dripping of burning material, are analyzed. Furthermore, a mass loss calorimeter was purchased from Fire Testing Technology. This device determines the amount of heat released and the mass loss of 100 x 100 mm² samples with a maximum thickness of 50 mm according to ISO 17554 and EN ISO 13927. This instrument is of particular relevance since it can be used to predict the behavior in the complex and expensive Single Burning Item (SBI) test. The SBI is required for classification into the European fire classes A2, B, C, D. However, the test is time, material- and cost-intensive procedure - preliminary analysis and thus a pre-selection of the material to be tested is therefore useful and helps to save resources.
In order to improve this pre-selection even further and to be able to generate results in real-life dimensions, e.g., of facade elements, an unstandardized test was additionally built. Here the variable-sized test specimens can be flamed, and the corresponding loss of mass, burning time, and ignition timing can be determined. Subsequently, an analysis of the test specimens is possible, e.g., by scans of cross-sections or stepwise planed surfaces.