Heat and sound absorbing material based on silicate fibres - which are mixed with caustic alkali soln., moulded to shape, and hardened in autoclave with steam

摘要

The fibres are treated with an aq. soln. contg. 3-8% caustic alklai, using a wt. ratio of fibres:soln. of 1:8-1:12. The resulting mixt. is moulded into a semifinished prod. (I) with simultaneous removal of water to obtain 60-100% moisture w.r.t. the wt. of the mixt. (I) is then heated at 120-225 degrees C. in a steam-air mixt. with pressure 0.2-2.6 MPa, for 0.5-36 hours, followed by drying at is not >200 degrees C. (I) is pref. mechanically compacted at 0.06-0.1 MPa and its vol. fixed mechanically before the steam treatment. The material uses no expensive polymer binders, and does not require a large amt. of thermal energy for its prodn.