A process for the preparation of a heat-insulating material based on silica fibres

摘要

The process according to the invention is characterized in that: & br / - silica fibers used are of the quartz fibers formed by quartz spraying; & br / - it predispersed the fibers in water until the formation of a homogeneous flowing slurry from which it is a green fibrous block, with simultaneous partial removal of water; & br / - green fibrous block is dispersed in water and mixed with an aqueous emulsion containing an organic binder to the silicon, a sintering adjuvant containing boron and a surfactant - the active agent; & br / - is a green billet from the suspension thus obtained, with the suction of water under vacuum; & br / - it compresses the green billet to obtain the desired height and dried, in the compressed state, at a temperature ranging up to 300degré c; & br / - it is released and the ingot is baked at high temperature. & br / application to the thermal protection, in particular for space vehicles or capsules.