Duct wrap and method for fire protecting a duct

• US 20060182915A1
• Filed: 02/11/2005
• Published: 08/17/2006
• Est. Priority Date: 02/11/2005
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Brady, John T., Frost, George W., Cordts, Brandon L.
• Granted Patent: US 8,178,177 B2
• Time in Patent Office: Days
• US Class Current: 428/36.900
• CPC Class Codes: B32B 1/00 Layered products having a non-planar shape
• CPC Class Codes: B32B 1/08 Tubular products
• CPC Class Codes: B32B 19/00 Layered products comprising a layer of natural mineral fibres or particles, e.g. asbestos, mica
• CPC Class Codes: B32B 19/04 next to another layer of the same or of a different material next to a glass layer B32B17/067
• CPC Class Codes: B32B 19/06 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 2250/20 All layers being fibrous or filamentary
• CPC Class Codes: B32B 2250/42 Alternating layers, e.g. ABAB(C), AABBAABB(C)
• CPC Class Codes: B32B 2260/023 Two or more layers
• CPC Class Codes: B32B 2260/04 Impregnation, embedding, or binder material
• CPC Class Codes: B32B 2262/00 Composition or structural features of fibres which form a fibrous or filamentary layer or are present as additives
• CPC Class Codes: B32B 2262/10 Inorganic fibres layered products comprising a layer of natural mineral fibres B32B19/00
• CPC Class Codes: B32B 2262/101 Glass fibres
• CPC Class Codes: B32B 2262/105 Ceramic fibres
• CPC Class Codes: B32B 2264/00 Composition or properties of particles which form a particulate layer or are present as additives
• CPC Class Codes: B32B 2264/10 Inorganic particles
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2264/108 Carbon, e.g. graphite particles
• CPC Class Codes: B32B 2264/12 Mixture of at least two particles made of different materials
• CPC Class Codes: B32B 2307/30 having particular thermal properties
• CPC Class Codes: B32B 2307/304 Insulating
• CPC Class Codes: B32B 2307/306 : Resistant to heat
• CPC Class Codes: B32B 2307/3065 : Flame resistant or retardant, fire resistant or retardant
• CPC Class Codes: B32B 2419/00 : Buildings or parts thereof walls, panels B32B2607/00
• CPC Class Codes: B32B 5/00 : Layered products characterised by the non- homogeneity or physical structure , i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
• CPC Class Codes: B32B 5/02 : characterised by structural features of a fibrous or filamentary layer layer formed of metallic wires B32B15/02; layer formed of natural mineral fibres B32B19/02; layer formed of wood fibres B32B21/02
• CPC Class Codes: B32B 5/022 : Non-woven fabric
• CPC Class Codes: B32B 5/04 : characterised by a layer being specifically extensible by reason of its structure or arrangement , e.g. by reason of the chemical nature of the fibres or filaments
• CPC Class Codes: B32B 5/06 : characterised by a fibrous or filamentary layer mechanically connected, e.g. by needling to another layer, e.g. of fibres, of paper
• CPC Class Codes: B32B 5/14 : characterised by a layer differing constitutionally or physically in different parts, e.g. denser near its faces
• CPC Class Codes: B32B 5/16 : characterised by features of a layer formed of particles, e.g. chips, powder or granules layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02
• CPC Class Codes: B32B 5/22 : characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed layer formed of natural mineral fibres or particles next to a foam layer B32B19/047, next to a layer made of particles B32B19/048, or next to a fibrous or filamentary layer B32B19/06; paper layer or cardboard layer next to a paper layer or cardboard layer B32B29/005, next to a foam layer B32B29/007, next to a fibrous or filamentary layer B32B29/02, or next to a particulate layer B32B29/04
• CPC Class Codes: B32B 5/24 : one layer being a fibrous or filamentary layer
• CPC Class Codes: B32B 5/26 : another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: B32B 5/30 : one layer being formed of particles, e.g. chips, granules, powder
• CPC Class Codes: B32B 7/00 : Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
• CPC Class Codes: B32B 9/00 : Layered products comprising a layer of a particular substance not covered by groups B32B11/00 - B32B29/00
• CPC Class Codes: F16L 57/04 : against fire or other external sources of extreme heat
• CPC Class Codes: F16L 59/029 : layered
• CPC Class Codes: F16L 59/145 : providing fire-resistance in general F16L57/04
• CPC Class Codes: F24F 13/0263 : Insulation for air ducts
• CPC Class Codes: Y10T 428/1314 : Contains fabric, fiber particle, or filament made of glass, ceramic, or sintered, fused, fired, or calcined metal oxide, or metal carbide or other inorganic compound [e.g., fiber glass, mineral fiber, sand, etc.]
• CPC Class Codes: Y10T 428/1334 : Nonself-supporting tubular film or bag [e.g., pouch, envelope, packet, etc.]
• CPC Class Codes: Y10T 428/1338 : Elemental metal containing
• CPC Class Codes: Y10T 428/1345 : Single layer [continuous layer]
• CPC Class Codes: Y10T 428/139 : Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

An article for fire protecting a duct includes a first layer of a first material including a noncombustible fibrous material and a second layer of a second material including an intumescent material. The first layer is adjacent the second layer. The article is non-self-supporting and has an initial thickness of less than about three inches when in a first application condition, and an expanded thickness when in a second heated condition. The expanded thickness is greater than the initial thickness. At the expanded thickness, the article meets Section 5.5 of AC101 Acceptance Criteria for Grease Duct Enclosure Assemblies, as specified in April 2001 by the International Council of Building Officials (ICBO-ES).

Claims

1. An article for fire protecting a duct comprising:

a first layer of a first material including a noncombustible fibrous material; and

a second layer of a second material including an intumescent material, wherein the first layer is adjacent the second layer;

wherein the article is non-self-supporting and has an initial thickness of less than about three inches when in a first application condition and an expanded, reactive thickness when in a second heated condition, wherein the expanded thickness is greater than the initial thickness, and wherein at the expanded thickness, the article meets Section 5.5 of AC101 Acceptance Criteria for Grease Duct Enclosure Assemblies, as specified in April 2001 by the International Council of Building Officials.

2. The article of claim 1, wherein the initial thickness is about one inch to about two inches.

3. The article of claim 1, wherein the expanded thickness is greater than or equal to about 3.5 inches.

4. The article of claim 1, wherein the first layer further includes the intumescent material dispersed throughout the fibrous material.

5. The article of claim 4, wherein the second layer includes more of the intumescent material than the first layer.

6. The article of claim 1, wherein the first material and the second material are substantially similar.

7. The article of claim 1, wherein the noncombustible fibrous material is selected from a group consisting of mineral fibers, fiberglass, ceramic fibers, and blends thereof.

8. The article of claim 1, wherein the noncombustible fibrous material has a melting point of greater than or equal to 600 degrees Fahrenheit.

9. The article of claim 1, wherein the intumescent material is selected from a group consisting of graphite, sodium silicate, vermiculite, and blends thereof.

10. The article of claim 1, wherein the article comprises about 20 percent to about 80 percent by weight of the intumescent material.

11. The article of claim 10, wherein the article comprises about 25 percent to about 45 percent by weight of the intumescent material.

12. The article of claim 10, wherein the article comprises:

about 0 to about 70 percent by weight of fiberglass;

about 0 to about 70 percent by weight of mineral fibers; and

about 30 to about 50 percent by weight of graphite.

13. The article of claim 10, wherein the article comprises:

about 0 to about 70 percent by weight of fiberglass;

about 0 to about 70 percent by weight of ceramic fibers; and

about 30 to about 50 percent by weight of graphite.

14. The article of claim 1, wherein the article is fitted around a duct as part of a fire-rated duct assembly.

15. The article of claim 14, wherein the duct is selected from a group consisting of a grease duct, a chemical exhaust duct, and a heating, ventilation, and air conditioning duct.

16. A non-self-supporting sheet for fire protecting a duct, the sheet comprising:

a noncombustible fibrous material; and

an intumescent material dispersed throughout the noncombustible fibrous material, wherein the sheet has an initial thickness of less than about three inches when in a first application condition, and has a reactive thickness that is greater than the initial thickness when in a second heated condition.

17. The non-self-supporting sheet of claim 16, wherein the reactive thickness is greater than or equal to about 3.5 inches.

18. The non-self-supporting sheet of claim 16, wherein the sheet comprises about 20 percent to about 80 percent by weight of the intumescent material.

19. The non-self-supporting sheet of claim 16, wherein the sheet is formed of a plurality of layers of the noncombustible fibrous material, the plurality of layers including a first layer and a second layer, wherein the first layer has less intumescent material than the second layer.

20. A method of fire protecting a duct comprising:

fitting a non-self-supporting fire-protecting article around the duct in a layer having a thickness of less than about three inches, wherein the fire-protecting article comprises a noncombustible fibrous material and an intumescent material, and wherein the layer of the fire-protecting article meets Section 5.5 of AC101 Acceptance Criteria for Grease Duct Enclosure Assemblies, as specified in April 2001 by the International Council of Building Officials; and

securing the fire-protecting article to the duct.

21. The method of fire protecting a duct of claim 20, wherein the fire-protecting article is formed of a plurality of layers of the noncombustible fibrous material interspersed with the intumescent material, the plurality of layers including a first layer and a second layer, wherein the first layer has less intumescent material than the second layer.

22. The method of fire protecting a duct of claim 20, wherein the noncombustible fibrous material is disposed as a layer, and the intumescent material is disposed as a discrete layer of an intumescent material adjacent the layer of fibrous material.