04/27/2011

www.gupta-verlag.de/polyurethanes

Bayfomox - a new sprayable polyurethane system for use as fire resistant coating

Fire safety - a global concern
The main principle of fire safety considers the flammability of construction materials as well as the spread of fire in a building. The flammability of materials plays a decisive role in the ignition phase of a fire and can be influenced by the choice of materials and flame retardants. In a fully developed fire, the main concern is to control the flame spread and to avoid the propagation of the fire to other parts of the building. Therefore materials that can create fire stops to avoid and reduce the spread of fire are essential in creating a safe building environment.Fire stop materials or fire barriers are often based on intumescent systems, which can be applied as component parts or as coatings. In recognition of the growing worldwide demand for fire resistant products and coatings and the need for greater awareness of fire safety, especially in building and construction requirements, Lanxess has developed an innovative sprayable intumescent form of its existing Bayfomox polyurethane system. The system is a two-component system based upon a polyether polyol and PMDI isocyanate and contains no halogens, no asbestos or fibres, no heavy metals, no propellants or solvents. Modifying existing technology
In order to create a sprayable material that meets fire resistance requirements, the existing Bayfomox polyurethane technology has been modified. The ability to apply the material as a spray allows it to be applied quickly and efficiently whilst maintaining its excellent level of fire resistance. Spray technology also allows even complex geometric parts to be easily coated. This new technology offers additional, economic benefits to the customer. The new Bayfomox formulation now creates a coating that combines insulation properties, acoustics and fire protection in a single product, thereby avoiding the need for several installation steps (fig 1). Bayfomox spray foam coatings outperform conventional intumescent coatings when it comes to heat insulation. In addition, they boast soundproofing properties that can be adjusted if necessary. New spray technology
Due to the use of a solid flame retardant the polyurethane system is a dispersion rather than a liquid. Dispensing the system using conventional spray foam equipment initially caused problems, such as a blocked mixing head and uneven material flow. Therefore, the challenge has been to adjust the formulation to make it sprayable while offering maximum efficiency in terms of coating coverage.Fig. 2: FluidSystems' Reactor H-XP2 used for sprayingWorking with German equipment manufacturer FluidSystems GmbH & Co. KG from Haan, Lanxess has been successful in adapting both the chemical system and application equipment to provide a sprayable, fire resistant coating that can be applied to a variety of materials, including rigid and flexible substrates. A standard machine Reactor H-XP2 from FluidSystems was used for this development (fig. 2). Using lightweight, portable, spray equipment allows a contractor to easily apply a thin layer of Bayfomox coating to substrates in-situ, making it suitable for use in both new and retrofitting building projects. The product is also very versatile due to its excellent adhesion properties to various substrates, including wood and metals. The chemical system is also suitable for modification, so that different densities to meet a range of performance requirements can be obtained. Fig. 3: PIR panel coated with BayfomoxProduct approval
Bayfomox has been tested and approved by the Deutsches Institut für Bautechnik. The applied system has a density of 250 kg/m3 (16 pcf) and meets class B2 in DIN 4102 flammability tests and has a fire resistance time of 60 min when a 10 mm coating is applied to a 60 mm PIR panel (fig. 3). Under the motto "Pigments + Protection”, Lanxess recently presented its product portfolio for the coatings industry at the European Coatings Show in Nuremberg, Germany. This included the spray application for the intumescent foam Bayfomox as well as the phosphorus-based halogen-free flame-retardant additives Levagard and Disflamoll. The special properties of these transparent flame retardants also enable them to be used in paints and coatings as VOC-free solvents, viscosity depressants, dispersion and wetting agents or antifoams. Lanxess also highlighted its extensive Preventol range of biocides, the pigments of the lightfast, weather-stable and chemical-resistant Bayferrox and Colortherm lines, and the organic and inorganic pigment preparations Levanyl and Levanox.

www.gupta-verlag.de/polyurethanes