Patent Application
20120102656
This invention pertains to mattresses and, in particular, to a fire-retardant mattress and a method for manufacturing the same.
Since at least the late 1960s, mattress manufacturers have been concerned with fires in mattresses that have been associated with bedroom fires. During this time, some 30,000 bedroom fires were attributed to mattresses as most of the fires were determined to be caused by cigarette ignition of the mattress resulting from people smoking in bed. An additional 22,000 fires were attributed to open flame ignition of the mattress. Given the large number of fires attributed to cigarette smoking, federal standards were introduced in an attempt to limit the spread of fires that originated on a mattress.
In the late 1980s, open flame ignition surpassed cigarette ignition as the main cause of mattress fires. Later it was determined, through several studies, that the primary source of bedroom fires was the burning of bedclothes located on top of the mattress. Furthermore, it was found that the majority of these fires were caused by children playing with ignition sources such as lighters, matches and candles which then ignited the top-of-the-bed accessories such as sheets, blankets and pillows.
As a result of these surveys, studies were conducted to improve the understanding of mattress fires. These studies led to the development of a test apparatus that could accurately and consistently simulate the burning bedclothes ignition source.
The tests involved placing a mattress/foundation on top of a steel twin-sized bed frame which, in turn, rested on a cement fiberboard surface that formed the bottom of a catch pan. A pair of gas burners was designed to mimic the thermal impact of burning bedclothes. One burner was placed so as to impinge on the top of a mattress surface while the second impinges nearby on the mattress side. The flame generated by the side burner was allowed to burn for 50 seconds while the flame from the top burner burned for 70 seconds. The fires generated by these burners were monitored and it was observed that a typical mattress reached flash-over value in approximately three minutes.
As a result of these studies, California established a regulation (Technical Bulletin 603) that required that a fire on a mattress could not exceed 25 mega joules of heat in the first 10 minutes of the fire, or a peak rate of heat release of 200 kW over a 30-minute period. A problem associated with reaching this criterion is that it is difficult to place a fire-retardant barrier on the outside of the mattress as the treatment that allows a barrier to be fire retardant makes the mattress surface hard and uncomfortable to the touch. For this reason, the outer layer of a mattress is typically some type of quilt or ticking material that burns fairly easily and is considered sacrificial material.
In residential bedroom fires, three different types of people are at risk from the fire. The first of these is the person in the room in which the fire originates and is intimate with the fire. This person would normally be someone on the mattress. The second person is in the room in which the fire originates, but is not intimate with the fire. This could be someone sitting in a chair in the bedroom in which the mattress catches fire or a child who started the fire and is hiding behind a dresser. The third person is someone who is not in the room in which the fire originates and is also not intimate with the fire. This would include someone located in another room in the house in which the mattress catches fire.
The regulation promulgated in Technical Bulletin 603 provides a valuable 30-minute window for the people at risk to detect and escape a fire. Furthermore, the low-peak-heat-release limit will substantially delay the growth and intensity of a fire. Combined, these requirements significantly reduce the risk of rapid flashover to other parts of the residence and thus substantially expand the opportunity for consumers to escape a bedroom fire.
By reducing the size and growth rate of a fire, it is possible to reduce bed fire casualties by one-half to two-thirds. This is because extra time to escape the residence is provided, particularly for those individuals who are not intimate with the fire. Furthermore, additional time is also provided for a person on the mattress to escape with only isolated burns, if any.
In practice, mattress manufacturers follow either or both of two approaches to fire risk reduction: (a) reduce the likelihood of sustained ignition and (b) mitigate the consequences of an ignition. To help achieve these goals, typical fire-resistant mattresses have a fire-resistant barrier located near the outer layer of the mattress, with the outer layer being made of a quilt or ticking material. This fire-resistant barrier works most of the time; however, should the barrier fail, there is no way of preventing the fire from spreading rapidly through the mattress to the inner support compartment, thereby causing a flashover and engulfing the entire mattress in flames. For this reason, the ability to slow the spread of fire that has breached the first fire-resistant barrier would be an important improvement in the art.
The invention is directed to a fire-resistant mattress having material compartmentalized between fire-resistant layers that significantly reduce fire growth of the mattress. In one embodiment, the fire-resistant mattress is comprised of an inner support compartment, a first layer of fire-resistant material adjacent to at least one side of the inner support compartment, at least one layer of material adjacent to the first layer of fire-resistant material, and a second layer of fire-resistant material adjacent to the at least one layer, the second layer of fire-resistant material being distal to the first layer of fire-resistant material.
In still another embodiment of the invention, the inner support compartment has six sides, a first layer of fire-retardant material is adjacent to each side of the inner support compartment, at least one layer of material is adjacent to the first layer of fire-retardant material on each side of the inner support compartment, and a second layer of fire-retardant material is adjacent to the at least one layer of material on each side of the inner support compartment distal to the first layer of fire-retardant material.
In yet another embodiment of the invention, the mattress is comprised of an inner support compartment, a fire-resistant insulation layer having a first side and a second side, with the first side being adjacent to at least one side of the inner support compartment, a first layer of material being adjacent to the second side of the fire-resistant layer, a quilt layer having a first side and a second side, with the first side of the quilt layer being adjacent to the first layer of material distal from the fire-resistant layer, a second layer of material being adjacent to the second side of the quilt layer, a second fire-resistant upholstery layer adjacent to the second layer of material and distal from the quilt layer, and an outer ticking layer adjacent to the second fire-resistant layer.
The invention also includes a method for manufacturing a fire-resistant mattress.
The fire-resistant advantages of the invention will be apparent from the description of the invention provided herein.
As shown in
For purposes of this invention, flashover is that point in time where the articles burning in a room generate enough energy to cause all room ingredients to burn essentially simultaneously. This point is normally accepted to be about 1,000 kW in a regular sized bedroom. Furthermore, for the purposes of this invention, the terms fire resistant and fire retardant are used interchangeably.
The at least one layer of material 16 that is compartmentalized between the fire-resistant layers 14, 18 can be a combustible material as well as a cushioning material. Furthermore, the layer of material 16 may be combustible material that has been treated with a fire-resistant chemical.
The compartmentalization of the material 16 results in fire-resistant integrity for the mattress 10 in much the same way that watertight doors provide watertight integrity in the event of flooding in a ship. That is, by containing the flooding within a specific compartment, the complete flooding of the ship is prevented, thereby increasing the chances of saving the entire ship. In the inventive mattress 10, fire is contained within the compartment 20 between the fire-resistant layers 14, 18 even in the event of the fire breaching one of the layers.
As shown in
When in use, should a fire start on the top of the mattress 10 shown in
The layers of fire-resistant material 14, 18 used in the mattress 10 can be manufactured as a barrier sheet or a high loft batt. The layers 14, 18 may be made of blends of synthetic or natural fibers. Such fire-resistant layers 14, 18 are manufactured by several companies including, but not limited to, Basofil Fibers, LLC, Leggett & Platt, and Jones Fiber.
Should the second layer of fire-resistant material 18 be breached as a result of a tear in the fire-resistant layer, a flaw in the material, or any other reason, the fire will then spread through the layer(s) of material 16 immediately beneath the second fire-resistant layer 18. The fire will continue to advance in a controlled manner until it reaches the first layer of fire-resistant material 14 where it will once again be slowed, thereby delaying the involvement of the entire mattress 10.
This additional barrier of protection resulting from the first (i.e., inner) layer of fire-resistant material 14 helps contain the fire within the compartment 20 bordered by the two layers of fire-resistant material 14, 18. This compartmentalization of the fire slows or prevents the mattress 10 from being completely engulfed by fire, thereby increasing the length of time an occupant in the room or building housing the mattress has to flee to safety.
Although not 100% foolproof, the extra protection offered by the first (i.e., inner) layer of fire-resistant material 14 helps reduce the amount of heat generated by the fire, thereby allowing the mattress to burn for 30 minutes without exceeding 200 kW.
The inner support compartment 12 of the inventive mattress may be filled with any suitable material known in the art, including springs, air, water, foam or fiber.
In another embodiment of the invention, as shown in
In still another embodiment of the invention, as shown in
The compartmentalization of the at least one layer of material 34 on the second side 15 of the inner support compartment 12 works in the same way as does the compartmentalization on the first side 13. That is, the third and fourth layers of fire-resistant material 32, 36 act to contain any fire in the area between them, much in the same manner that two watertight doors contain flooding within a particular compartment on a ship. As with the single-sided mattress, the at least one layer of material 34 located between the third and fourth layers of fire-resistant material 32, 36 may be made of a combustible material and/or a cushioning material including, but not limited to, foam. The layer 34 may also be made of a combustible material that has been treated with a fire-resistant chemical.
The invention also includes a method for manufacturing a fire-resistant mattress. This method of manufacturing involves the steps of: (a) providing an inner support compartment; (b) placing a first layer of fire-resistant material on a first side of the inner support compartment; (c) positioning at least one layer of combustible material adjacent to the first fire-resistant layer of material; (d) aligning a second layer of fire-resistant material on the at least one layer of combustible material distal to the first layer of fire-resistant material; and (e) placing a second layer of sacrificial combustible material outboard of the second layer of fire-resistant material distal to the inner support compartment. These materials may be independent or contained in a quilt.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential of the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. It should be understood that the illustrated embodiments are exemplary only, and should not be taken as limiting the scope of the invention.
This application is a continuation of, and claims priority to, U.S. application Ser. No. 10/934,971, filed Sep. 3, 2004, entitled “Fire-Resistant Mattress Having Combustible Material Compartmentalized Between Fire-Resistant Layers,” which is incorporated, in its entirety, herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10934971 | Sep 2004 | US |
| Child | 13198631 | US |
