Method of making a low density frothed mineral wool
AssigneeUSG Interiors, Inc.
InventorDavid G. Izard
Life of this patent
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Abstract
A method for the manufacture of very low density mineral wool structural panels on a moving foraminous support wire by frothing a dilute aqueous dispersion of mineral wool is disclosed. The forth, a mass of delicate, non-resilient and non-uniform bubbles among the entangled mineral wool fibers readily breaks, is stripped of water and dried without substantial loss of the highly open, porous structural configuration by a first controlled rate of maturation dewatering followed by brief pulses of high vacuum. Then the open structure is rapidly stripped of remaining water and dried by passing high volumes of heated dry air through the structure with continued vacuum. The drainage water may be recycled in the process to maintain a low level of binder and any frothing aid additions.
Claims19
A method for manufacturing a low density, porous structural panel of mineral fiber on a moving foraminous support wire which comprises:
- (1) forming a dilute aqueous mineral fiber slurry consisting essentially of mineral fibers, inorganic lightweight aggregate, binder and foaming aid;
- (2) mixing the slurry with air to form a frothlike, unstable mass of non-resilient, irregularly sized bubbles;
- (3) depositing the frothlike mass upon a continuous scrim bottom cover sheet;
- (4) maintaining the frothlike mass and scrim sheet under quiescent conditions in a flooded section of the foraminous wire wherein the mass rapidly dewaters by gravitational pull;
- (5) passing the frothlike mass into a high vacuum, pressure differential zone to collapse the bubbles and strip the water from the mineral fiber mass;
- (6) passing the mineral fiber mass into a lower pressure zone while passing high velocity, heated air through the mass whereby additional water is stripped from the mass;
- and
- (7) recovering a dried, mineral fiber, structural panel having a density of about 3 to about 10 pounds per cubic foot.
A method for manufacturing a low density, porous structural panel of mineral fiber on a moving foraminous support wire which comprises:
- (1) forming a dilute aqueous mineral fiber slurry consisting essentially of mineral fibers, inorganic lightweight aggregate, cellulose fibers, binder and foaming aid;
- (2) mixing the slurry with air to form a frothlike, unstable mass of non-resilient, irregularly sized bubbles;
- (3) depositing the frothlike mass upon a continuous scrim bottom cover sheet;
- (4) maintaining the frothlike mass and scrim sheet under quiescent conditions in a flooded section of the foraminous wire wherein the mass rapidly dewaters by gravitational pull;
- (5) passing the frothlike mass into a high vacuum, pressure differential zone to collapse the bubbles and strip the water from the mineral fiber mass;
- (6) passing the mineral fiber mass into a lower pressure zone while passing high velocity, heated air through the mass whereby additional water is stripped from the mass;
- and
- (7) recovering a dried, mineral fiber, structural panel having a density of about 3 to about 10 pounds per cubic foot.
A method for manufacturing a low density, porous structural panel of mineral fiber on a moving foraminous support wire which comprises:
- (1) forming a dilute aqueous mineral fiber slurry consisting essentially of mineral fibers, inorganic lightweight aggregate, cellulose fibers, a binder selected from starch and a resin latex containing acrylic, acetate or styrene-butadiene groups, and a foaming aid;
- (2) mixing the slurry with air to form a frothlike, unstable mass of non-resilient, irregularly sized bubbles;
- (3) depositing the frothlike mass upon a continuous scrim bottom cover sheet;
- (4) maintaining the frothlike mass and scrim sheet under quiescent conditions in a flooded section of the foraminous wire wherein the mass rapidly dewaters by gravitational pull;
- (5) passing the frothlike mass into a high vacuum, pressure differential zone to collapse the bubbles and strip the water from the mineral fiber mass;
- (6) passing the mineral fiber mass into a lower pressure zone while passing high velocity, heated air through the mass whereby additional water is stripped from the mass;
- and
- (7) recovering a dried, mineral fiber, structural panel having a density of about 3 to about 10 pounds per cubic foot.
Dependencies are inferred from the claim text.