Fire door core

• US 4,159,302 A
• Filed: 01/09/1978
• Issued: 06/26/1979
• Est. Priority Date: 10/14/1975
• Status: Expired due to Term

• Current Assignee: G-P Gypsum Corporation (Golden Eagle Industries, Inc.)
• Original Assignee: Georgia-Pacific Corporation
• Inventors: Greve, Dale R., Richards, Turner W.
• Primary Examiner(s): Lesmes, George F.
• Assistant Examiner(s): Hess, Bruce H.
• Application Number:
  US05/868,037
• Time in Patent Office: 533 Days
• Field of Search: 106/89, 106/90, 106/94, 106/97, 106/99, 106/111, 106/116, 106/DIG. 2, 156/71, 264/333, 428/310, 428/314, 428/446, 428/448, 428/320-322, 428/920, 428/921
• US Class Current: 264/333
• CPC Class Codes: B32B 13/02 with fibres or particles being present as additives in the layer
• CPC Class Codes: B32B 13/10 of wood; of wood particle board
• CPC Class Codes: B32B 2262/101 Glass fibres
• CPC Class Codes: B32B 2307/3065 Flame resistant or retardant, fire resistant or retardant
• CPC Class Codes: C04B 14/10 Clay sepiolite C04B14/042; grog C04B18/025
• CPC Class Codes: C04B 14/185 expanded
• CPC Class Codes: C04B 14/202 Vermiculite
• CPC Class Codes: C04B 14/42 Glass
• CPC Class Codes: C04B 20/0048 Fibrous materials
• CPC Class Codes: C04B 2111/28 Fire resistance, i.e. materials resistant to accidental fires or high temperatures
• CPC Class Codes: C04B 24/26 obtained by reactions only involving carbon-to-carbon unsaturated bonds C04B24/243 takes precedence
• CPC Class Codes: C04B 24/383 Cellulose or derivatives thereof
• CPC Class Codes: C04B 28/14 containing calcium sulfate cements gypsum-paper plates E04C
• CPC Class Codes: C04B 40/00 Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability active ingredients C04B22/00 - C04B24/00; hardening of a well-defined composition C04B26/00 - C04B28/00; making porous, cellular or lightening C04B38/00; mechanical aspects B28, e.g. conditioning the materials prior to shaping B28B17/02
• CPC Class Codes: C04B 40/0071 making use of a rise in pressure
• CPC Class Codes: C04B 7/00 Hydraulic cements calcium sulfate cements C04B11/00
• CPC Class Codes: C04B 7/02 Portland cement
• CPC Class Codes: E06B 2003/7026 of granular type
• CPC Class Codes: E06B 2003/7036 of plaster
• CPC Class Codes: E06B 5/16 Fireproof doors or similar closures; Adaptations of fixed constructions therefor
• CPC Class Codes: Y10S 106/02 : Perlite
• CPC Class Codes: Y10S 428/92 : Fire or heat protection feature

Abstract

A fire door core in which the major ingredient is expanded perlite and including, as minor ingredients, set gypsum, set hydraulic cement and an organic binder, and having a density of no greater than about 30 lbs. per cubic foot, and preferably including unexpanded vermiculite, clay, and fibrous reinforcements, and a process for making said fire door core, and also a fire door including said core.

Claims

1. A method for making a fire door core from a mixture of materials including a compressible filler, which method comprises dry premixing particulate hydraulic cement and calcined gypsum, intermixing said premixed ingredients with a particulate compressible filler, organic binder and water, said filler being prexpanded compressible perlite of density less than about 6.5 lb./cu. ft., the weight quantities of cement, gypsum, perlite and binder in the mixture being:

space="preserve" listing-type="tabular">______________________________________ cement 10-20% gypsum 10-30% perlite 50-70% binder 1- 5%;

______________________________________

and the quantity of water being in excess of the stoichiometric amount needed to hydrate the cement and gypsum and sufficient to provide a damp mixture but less than the amount which would produce an aqueous slurry of the intermixed ingredients, placing a charge of the damp mixture in a pressure mold of slab form, applying sufficient pressure to the damp charge in the mold to compress the charge to about 25% to 33% of its original volume and maintaining the pressure until the compression strength of the compressed charge is at least about 50 psi, removing the molded slab from the mold and thereafter drying the slab by heating it sufficiently to remove excess water, and forming a fire door core piece from the dried slab.

2. A method as defined in claim 1 in which the binder is polyvinyl alcohol.

3. A method as defined in claim 1 in which the intermixed ingredients further include unexpanded vermiculite in an amount not greater than about 4 wt. % of the dry ingredients.

4. A method as defined in claim 1 in which the intermixed ingredients further include clay in an amount not greater than about 4 wt. % of the dry ingredients.

5. A method as defined in claim 1 in which the intermixed ingredients further include fibrous reinforcements in an amount not greater than about 1 wt. % of the dry ingredients.

6. A method for making a fire door core comprising dry premixing particulate hydraulic cement, calcined gypsum, unexpanded vermiculite, clay and fibrous reinforcements, intermixing said premixed ingredients with a particulate compressible filler, organic binder and water, said filler being preexpanded compressible perlite of density less than about 6.5 lb./cu. ft., the weight quantities of cement, gypsum, vermiculite, clay, reinforcements, perlite and binder in the mixture being:

space="preserve" listing-type="tabular">______________________________________ cement 10-20% gypsum 10-30% vermiculite 0-4% clay 0-4% reinforcements 0-1% perlite 50-70% binder 1-5%;

______________________________________

and the quantity of water being in excess of the stoichiometric amount needed to hydrate the cement and gypsum and sufficient to provide a damp mixture but less than the amount which would produce an aqueous slurry of the intermixed ingredients, placing a charge of the damp mixture in a pressure mold of slab form, applying sufficient pressure to the damp charge in the mold to compress the charge to about 25% to 33% of its original volume and maintaining the pressure until the compression strength of the compressed charge is at least about 50 psi, removing the molded slab from the mold and thereafter drying the slab by heating it sufficiently to remove excess water, and forming a fire door core piece from the dried slab.

7. A method for making a fire door core comprising dry premixing particulate hydraulic cement, calcined gypsum, unexpanded vermiculite, clay and fibrous reinforcements, intermixing said premixed ingredients with a particulate compressible filler, organic binder and water, said filler being preexpanded compressible perlite of density less than about 6.5 lb./cu. ft., the weight quantities of the ingredients of the mixture being:

space="preserve" listing-type="tabular">______________________________________ cement 10-15% gypsum 20-25% perlite 50-55% binder 1.5-5% vermiculite 1.5-4% clay 1.5-4% reinforcements 0.2-1% water 25-60% of the weight of the other ingredients ______________________________________

and the quantity of water being in excess of the stoichiometric amount needed to hydrate the cement and gypsum and sufficient to provide a damp mixture but less than the amount which would produce an aqueous slurry of the intermixed ingredients, placing a charge of the damp mixture in a pressure mold of slab form, applying sufficient pressure to the damp charge in the mold to compress the charge to about 25% to 33% of its original volume and maintaining the pressure until the compression strength of the compressed charge is at least about 50 psi, removing the molded slab from the mold and thereafter drying the slab by heating it sufficiently to remove excess water, and forming a fire door core piece from the dried slab.