METHOD FOR MANUFACTURING FIBROUS MOLDED ARTICLES Russian patent published in 1994 - IPC

FIELD: civil engineering. SUBSTANCE: mineral fiber is melted and mixed with freshly precipitated gel of aluminium hydroxide. The process is followed by casting thus prepared mass into mould, drying and by annealing. Basalt fiber having diameter up to 3 μm is used as mineral fiber. Its melting is carried out in aqueous medium. Thus prepared melted fiber is purified by regulus and impurities separation together with water. Purified fiber is mixed again with water, their quantities are 95-96.5 and 10000 mass parts respectively. Then 18% aqueous solution of aluminium sulfate (its quantity being 23.6-33.7 mass % ) and 20-25% aqueous solution of ammonia (its quantity being 12.5-22.3 mass parts) are added consequently by mixing. All the operations which are carried out before casting take places in the same apparatus by mixing. Drying is carried out within 10-15 h 100-120 C, annealing is carried out within 30-40 min at 500-550 C (rate of temperature increasing being not more 25 C/min, cooling rate being not more 80 C/min). Mixing takes place within 20-35 min, mixing rate being 250-300 r. p. m. Desired articles have volume weight to 0,12-0.16 g/cm², their heat conductivity is up to 0.040 W / m K. EFFECT: simplifies the method improves thermal properties of desired articles. 2 cl, 5 tbl