| 摘要 |
Process comprising particularly an impregnation step under vacuum in one or a plurality of stages (15, 16) and a coagulation-bleaching step. The thermal stages of the coagulation-bleaching may be effected with an over-pressure of 2-15 bar. A sealing of the pores is induced by forming a gel, and therefore an expansion of the channels which promotes the impregnation. Furthermore, an easily removable gas is injected to favour the control of multiple impregnations. Qualitative and quantitative improvement of the product. |
