Pyroplex® Mineral Fibre Sheet has been specifically designed for use in fire resistant doorset assemblies, essential ironmongery such as locks, latches and concealed door closing devices. The product is supplied in two thicknesses 0.5mm and 1.0mm. When exposed to elevated temperatures, the product is designed to expand multidirectionally filling cavities and voids to provide a fire resistant barrier. The product is derived from a cellulose pulp incorporating expandable graphite with additional silicate fibres acting to aid char stability. When exposed to elevated temperatures, the material will expand up to 20:1 of its original volume producing a high resistant char.