| abstract |
Transparent, fire-resistant, glazing panels comprise at least one layer of intumescent material (3) bonded to at least one structural ply (1, 2) of the panel. Such a panel comprises a structural ply which is bonded to an intumescent layer, which has been formed by compacting grains of an intumescent hydrated metal salt, and which has a total water content in the range 20 to 26% inclusive. This promotes the retention of good optical properties despite ageing. Such a panel may be manufactured by a method in which grains of an intumescent hydrated metal salt having a total water content of between 22% and 26% by weight are distributed as a layer on a surface of a ply to be incorporated into the panel, and in which, while the layer of grains is sandwiched between a pair of moulding plates, that layer is subjected to heat and pressure conditions to degas and compact it and cause it to become bonded to that surface of the ply of the panel. That ply and one moulding plate may be one and the same, and the second moulding plate may also go to form a ply of the panel. <IMAGE> |