| 摘要 |
A mineral wool body suited for use as a sound insulating body having the ability of damping or absorbing both high frequence and low frequence sound, and in which at least the largest portion of the surfaces of the mineral wool body which are exposed to said high frequence and low frequence sound is covered with a binder in such amount and by such application method that practically all surface fibres of the mineral wool body are bound to each other and still the binder does not provide an integral, unbroken film of binder. The binder preferably is a solution of an inflammable alkali silicate, especially water glass, and it is applied to the mineral wool body in an amount of 75-150 or preferably 95-140 g dry matter content/m<2> of the mineral wool body, whereupon the solvent is allowed to evaporate or dry, preferably at a temperature of less than 120 DEG C. The binder can be pre-polymerized so that the viscosity at 20 DEG C and a dry matter content of 50% is more than 300 mPa.s, and the binder is applied in a concentration of less than 40% or preferably less than 38% dry matter content. |
