IMPROVEMENTS IN THE PRODUCTION OF LOW-DENSITY AIR-PLEASANT FILM-LIKE MATERIALS CONTAINING PARTICULATE SOLID.

摘要

PCT No. PCT/GB90/01895 Sec. 371 Date Jun. 4, 1992 Sec. 102(e) Date Jun. 4, 1992 PCT Filed Dec. 5, 1990 PCT Pub. No. WO91/08037 PCT Pub. Date Jun. 13, 1991.A method of producing a particulate-solid-bearing air-permeable sheet of material of other than woven and knitted material selected from non-woven fabrics and open cell foam materials includes the following steps: entraining a particulate solid in a gaseous carrier in the substantial absence of fibrous material; disposing one face of a preformed air-permeable sheet material, which material has a density at or below 0.25 g/cm3, in the path of a stream of the gaseous carrier and entrained particulate solid, whilst maintaining a pressure drop across the thickness of the preformed air-permeable sheet material from the one face to the other face of the air-permeable sheet material, whereby to entrap some or all of the entrained particulate solid on or on and in the air-permeable material; and fixing the retained particulate solid on or on and in the air-permeable material with a binder. The mean pore size of the preformed sheet material is greater than the mean particle size of the particulate solid.