Abstract: A process is provided for making filled mineral fiber products which comprises applying mineral melt to a rotating fiberizing rotor and thereby throwing from the rotor as fibers and forming a substantially annular cloud of fibers, spraying binder into the annular cloud of fibers, carrying the fibers axially from the rotor towards a collector surface and collecting the fibers on the collector surface as a web. The process includes spraying into the substantially annular cloud a slurry which has specific gravity of at least 1.1, preferably at least 1.2, and which comprises a substantially stable liquid dispersion of particulate material in an aqueous binder.

Abstract: The invention relates to an arrangement for cleaning a wool chamber in the manufacture of mineral wool. In the manufacture of mineral wool a binder is added to the stream of fibers which is deflected towards the wool chamber and the binder deposits itself in fine droplets in the fibers. The binder-laden fibers which touch against the walls and roof of the wool chamber adhere to them because the binder hardens upon contact with the hot surfaces. Gradually a hard deposit of binder and fibers is formed upon the walls. According to the invention cleaning of the walls is substantially simplified by means of making the walls and/or roof of a double walled construction, perforating the inner walls and applying a reduced pressure in the cavity between the walls holding a detachable lining against the inner walls by means of suction.