5. New TPU technologies

Materials with improved fire behavior

Some new TPUs have improved fire resistance, and there are even polyurethane thermoplastic grades that achieve VTM-O rating under UL 94. Fire-resistant TPUs have been available for many years, but in the past they derived their properties from halogens such as chlorine or bromine. Halogen-based flame-retardant systems are usually less expensive and, in thin layers, offer certain advantages over halogen-free systems, including better fire resistance. However, halogens can release corrosive and harmful emissions in the event of fire. Halogens also require inorganic synergistic compounds, which can complicate TPU manufacture. New halogen-free flame-retardant materials are competing with conventional systems; they are generally safer and more environmentally friendly. What's more, these new flame-retardant...