Production of water-laid felted mineral fiber panels including use of flocculating agent

Claim 1

THE METHOD COMPRISING MAKING SLURRY CONSISTING ESSENTIALLY OF WATER, 100 PARTS OF FELTABLE FIBER OF WHICH AT LEAST 75% ARE SYNTHETIC MINERAL FIBERS, FROM 10 TO 250 PARTS OF WATER-DISPERSIBLE PARTICULATE CERAMIC MATERIAL, AND STARCH GRAINS FOR BINDER, FLOCCULATING THE SLURRY BY ADDING A SURFACE-ACTIVE FLOCCULATING AGENT AND THEREBY FORMING FLOCS SUSPENDED IN SUBSTANTIALLY CLEAR WATER,THE AMOUNT OF SAID SURFACE-ACTIVE AGENT BEING IN THE RANGE FROM .013 TO .073% OF THE DRY WEIGHT OF THE SUSPENDED CONTENT OF THE SLURRY, DEWATERING THE RESULTING SUSPENSION OF FLOCS AND THEREBY FORMING A WET MAT OF SOLIDS CONSISTING ESSENTIALLY OF A FELTED NETWORK OF SAID FELTABLE FIBERS AND DISTRUBUTED IN AND CARRIED THEREBY SAID PARTICULATE CERAMIC MATERIAL AND SAID STARCH GRAINS, GELATINIZING THE STARCH IN THE WET MAT, AND FORMING A RIGID HANDLEEABLE BONDED POROUS DRY MAT BY DRYING THE RESULTING WET MAT.