Fire-retardant mattress

Background of the Invention

The systems and methods described herein relate to fire retardant mattresses and methods for manufacturing fire retardant mattresses.

In general, mattresses are manufactured by covering an assembly of coil springs with a combination of polyurethane form and/or matting which is then enclosed in a cover ticking or other material. This combination provides a light durable and comfortable mattress at a reasonable cost.

Every home, hotel, dormitory, hospital and many other facilities have several to dozens of mattresses, and mattresses tend to be large items that are kept in mainly living areas. Recently, fire prevention efforts have directed some attention to developing new mattresses that have a reduced likelihood to catch on fire or bum during a fire. To this end, mattress manufacturers have developed a number of different fire retardant mattresses, each of which offers some benefits for reducing the likelihood that a fire will start or spread because the material used in the construction of a mattress represents a large amount of fuel able to support that fire.

For example, bed pads have been developed that can be placed on top of a bed and cover the sides of a bed. These bed pads are generally made of fire retardant materials that protect the mattress from exposure to a flame or heat and tend to reduce the likeliness that the mattress will catch on fire. Although these bed pads have been effective, they are uncomfortable and unsightly. Consequently consumers have a tendency to remove these bed pads after a period of time and once removed the efficacy of the bed pad is negated.

To address this issue, other mattress manufacturer have developed mattresses that have flame and/or fire retardant material built into the mattress cover. Typically, these fire retardant materials include fiberglass, asbestos, or metal foil and work well in reducing the likelihood that the mattress will catch on fire. However, these materials are uncomfortable to sleep on and are therefore disfavored by consumers. Metal foils made of, for example aluminum, have several drawbacks, such as a limited breathability of the fabric and a reduced cushioning aspect of the upholstered article. Other these materials have a tendency to dry out, to become flaky, and to ultimately break down, making the visible sleeping surface if not unusable, so at least unsightly. Consequently, the life expectancy of a flame retardant mattress that includes a layer of fiberglass, asbestos and/or aluminum foil, can be significantly less than the expectant product life of a normal mattress.

Because of the need for changing the established mattress manufacturing process to accommodate the new materials and the perceived reluctance of consumers to accept the different feel and/or appearance of the sleeping surface, mattress manufacturers have so far been unmotivated to develop fire retardant mattresses.

Accordingly, there is a need in the art for a fire retardant mattress that is facile to manufacture, has competitive product life and provides the comfort and durability expected by consumers purchasing a mattress.

Summary of the Invention

The invention is directed to a fire-retardant quilt panel for a mattress and to a fire-retardant mattress construction. The invention is further directed to a method for manufacturing a fire-retardant mattress.

According to one aspect of the invention, a fire-retardant quilt panel for a mattress includes a mattress padding layer, an outer ticking forming a sleep surface, and a fire barrier fabric disposed between the mattress padding layer and the outer ticking layer.

According to another aspect of the invention, a fire-retardant mattress includes a frame, an upholstery topper layer adjacent to at least a top surface of the frame, an outer ticking forming a sleep surface, and a fire barrier fabric disposed between the upholstery topper layer and the outer ticking layer.

Embodiments of the invention may include one or more of the following features. The fire barrier fabric can be in direct contact with the outer ticking layer and more particularly can be affixed to the outer ticking layer, for example, by gluing with an adhesive or by stitching. The fire barrier fabric can also be placed underneath the border panel extending around the sides of the mattress frame. The quilt panel advantageously is constructed to meet regulatory requirements for flammability, such as the California Bureau of Home Furnishings Technical Bulletin 129 Flammability Test Procedure.

According to yet another embodiment of the invention, a method of manufacturing a fire-retardant mattress includes the acts of providing a mattress frame, placing an upholstery topper layer adjacent to at least a top surface of the frame, placing a fire barrier fabric on the upholstery topper layer, and placing an outer ticking over and in direct contact with the fire barrier fabric, said outer ticking layer forming a sleep surface.

Further features and advantages of the present invention will be apparent from the following description of preferred embodiments and from the claims.

Brief Description of the Drawings

The following figures depict certain illustrative embodiments of the invention in which like reference numerals refer to like elements. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way.

• FIG. 1 is an illustrative partially exploded view of an innerspring construction, padding and ticking layers with a fire-barrier layer
• FIGS. 2A and 2B show in greater detail exemplary embodiments of a mattress cover with a fire-barrier layer;
• FIG. 3 shows the sample weight loss of the tested mattress during the test;
• FIG. 4 shows the heat release rate of the tested mattress during the test; and
• FIG. 5 shows the total heat release of the tested mattress during the test.

Description of the Illustrated Embodiments

A mattress construction with a quilted ticking is described that incorporates an effective fire-retardant barrier without changing the appearance and feel of the mattress sleeping surface. In particular, described herein are mattresses, toppers and methods for making mattresses that provide bedding products having improved resistance to open flame ignition. Although the systems and methods described herein relate to mattress and other bedding products, it will be apparent to those of skill in the art that other products may result from the methods described herein, without departing from the scope of the invention.

Referring first to FIG. 1, a mattress 10, shown here in a partially exploded view, consists of an innerspring indicated by reference numerals 11 and 13 having at least one upholstery topper layer 16, and a second optional layer 18 and at least one quilt layer 12 about the top and bottom surfaces of the innerspring. The level of support and comfort provided by such a mattress, often referred to as "firmness," is a function of both the number and characteristics of the upholstery topper and the quilting panel layers about the top and bottom of the innerspring and of the performance characteristics of the innerspring.

The innerspring (not shown in detail) generally comprises border wires forming a rectangular structure and, within the structure, a plurality of interconnected coil springs. The coil springs are generally disposed in rows and columns over the entire area of the rectangular structure. When designing an innerspring, a number of variables which affect innerspring performance must be taken into consideration. Some of these variables include the coil count, the coil density, the coil shape, the number of turns of the coil, the gauge of the wire, the heat treatment of the wire, the technique used to assemble the innerspring, and the edge treatment. The innerspring construction may be an open-coil construction as illustrated, or may also be a pocketed-coil type as identified in U.S. Pat. No. 4,234,933 to Stumpf, which is incorporated herein by reference. However, any suitable innerspring or innercore may be employed. For example, the innercore may be foam, latex, open coil, pocketed coil, or a combination thereof. The size of the innercore may vary according the application and for example, may support the entire sleeping surface, or may be somewhat smaller and provide space for one or more edge supports that sit at the peripheral edge of the mattress. Examples of edge supports may include foam rails placed along the side of the mattress or pocketed springs having a selected firmness.

As depicted, each upholstery topper layer commonly includes an insulating layer 18 of material in direct contact with the innerspring 11 which may mask or insulate from the sleeper the noise produced by the interaction between the components of the innerspring and also to prevent softer upholstery materials from falling or pocketing into the innerspring. This insulating layer 18 can be constructed of, for example, wire mesh, plastic mesh, woven fabric, or non-woven fabric, or any suitable material. Each upholstery topper layer can further include a layer of padding material 16 which affects the firmness of the mattress. This layer of padding material may be located directly adjacent to the insulating layer 18 and can be constructed of natural fibers such as, for example, cotton, synthetic fibers, foam, or a fiber/foam combination. It should be understood that additional layers of padding can be provided for each upholstery topper layer, the number of padding layers depending upon the comfort level and quality of the mattress. The upper layer or the topper may include a layer 14 of a woven material that adds to the firmness of the mattress 10.

As shown in more detail in FIG. 2A, a quilt panel layer 21 is provided adjacent to each upholstery layer 28. The quilt panel layer 21 of the mattress 10 provides the direct contact with the sleeper and thus the immediate perception of softness or "feel." Each quilt panel layer 21 commonly includes a layer of mesh or cloth bottom or backing material 28, a layer of foam material 26 positioned over the backing material 28, a layer of fiber or filler material (quilt fill) may optionally be positioned over the foam 26, and finally a layer of ticking forming the cover 22. The number of layers of foam and quilt fill 26 in the quilt panel layer can vary depending on the desired comfort level, quality, and expense of the mattress. The entire layer can be stitched together, typically in a conventional quilting machine (not shown) with thread to form a quilt pattern. The quilt pattern holds the components of the layer together and provides a composite structure to the quilt panel layer.

In the exemplary fire-retardant mattress, a fire barrier fabric 24 which can be incorporated in the quilt panel structure 21 during the quilting operation is interposed between the layer of fiber or filler material 26 and the ticking 22. The ticking layer 22 may be a conventional ticking layer, or a layer of lace, cotton fabric or any other suitable material. The fire barrier fabric 24 can also be attached to one of the layers, for example, the cover, with an adhesive, or bonded in some other way to the lower surface of the ticking 22. The fire barrier fabric 24, when used as the backing material, can significantly reduce the fire hazard due to the material properties of the fire barrier fabric 24 that will hinder the propagation of a fire to the entire mattress body. For added fire protection, the fire barrier fabric 24 can also be placed directly under the border ticking layer.

As described above, the fire barrier layer 24, in any embodiment, may be applied to the top surface, as well as the border panels, including header and footer and optionally, the lower surface.

FIG. 2B depicts an alternate embodiment of the mattresses described herein. In particular, FIG. 2B depicts a mattress topper 21 that includes a foam/fill layer 26 that is disposed between two opposing layers of ticking 22 and two opposing layers of fire barrier material 24. The mattress topper 21 depicted in FIG. 2B may be a pillow top topper of the type commonly attached to the upper surface of a mattress, including a mattress 10 having a fire barrier layer disposed beneath the ticking layer 22 on the exterior surface of the mattress. As described with reference to FIG. 2B, the fire barrier layers 22, may be stitched, glued or other wise bonded to the ticking layer, to facilitate providing a quitable layer of material that provides for a mattress tops that meets the aesthetic expectations of the consumer. The joining of the fire barrier and the ticking material forms a laminate that reduces the likelihood that an open flame will ignite the inner material of the mattress 10, and at the same time provides a cosmetically appealing exterior surface.

The exemplary quilted mattress cover depicted in FIGS. 2A and 2B and tested in the manner described below included Ultrawool, % " P7L and 3/8 " P34 polyester over 1 ¾ " convoluted foam, as well as ½" P-34 Poly and S4-FI fiber next to the coil unit. The dimensions of the tested mattress were 38" x 74 ½" with a total mattress weight of 46 lbs. The fire blocking layer consists of Firegard® LWB, sold by Chiquola Industrial Products, LLC, Honea Path, SC, USA, and extends over the mattress panels and the borders.

The flammability of the outer ticking was tested under the California Bureau of Home Furnishings Technical Bulletin 129 Flammability Test Procedure for Mattresses for

Use in Public Buildings. The purpose of this test method is to determine the burning behavior of mattresses used in public occupancies by measuring specific fire-test responses when the mattress is subjected to a specified flaming ignition source under well ventilated conditions. A mattress fails to meet the requirements of this test procedure if any of the following criteria are exceeded: (1) weight loss due to combustion of 3 pounds or greater in the first 10 minutes of the test; (2) a maximum rate of heat release of 100 kW or greater; or (3) a total heat release of 25 MJ or greater in the first 10 minutes of the test. The type of ignition chosen (flaming source) is common in both accidental and intentional fires, for example, ignition by cigarettes. The recorded test data typically include room smoke opacity; weight loss; smoke release rate; total smoke release; carbon monoxide concentration; heat release rate; total heat release; and temperature measurements above and around the mattress.

The fire was simulated by placing a propane burner centrally and parallel to the bottom horizontal surface at a distance of 1" from the vertical side panel of the mattress. The burner was allowed to burn for 180 seconds. Two seconds after the test started, the mattress ticking material started to melt and ignited after 4 seconds. A little more than 1 minute after the start of the test, molten ticking started to drip onto the floor. Flames ceased 6 minutes into the test, and after 17 minutes all smoke and smoldering ceased.

FIG. 3 depicts graphically the weight loss in lbs of the exemplary tested fire-retardant mattress during the test duration of 18 minutes. The total weight loss 10 minutes into the test is less than 0.1 lb, which is significantly smaller than the maximum total weight loss of 3 lbs permissible under the Bulletin 129 test procedure.

FIG. 4 shows a graph of the heat release rate in kW for the same mattress during the test. The maximum heat of approximately 15 kW is released 2.5 minutes into the test. Again, this value is significantly smaller than the maximum rate of heat release of 100 kW permissible under the Bulletin 129 test procedure.

FIG. 5 shows a graph of the total heat release in MJ during the same test. The total heat release during the first 10 minutes into the test is 2.75 MJ, which is significantly smaller than the maximum heat release of 25 MJ permissible under the Bulletin 129 test procedure.

The other recorded test data (e.g., temperature, carbon monoxide, smoke and toxic gas released) were also all significantly smaller than the maximum values permitted under the Bulletin 129 test procedure.

In summary, mattresses constructed with a fire barrier fabric placed between the quilt panel layer and the ticking that provides direct contact with the sleeper as well as underneath the border panel have been shown to withstand ignition and combustion by open fire and exceed the requirements of the rigorous California Bureau of Home Furnishings Technical Bulletin 129 Flammability Test Procedure.

While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. For example, the fire barrier fabric can be applied directly behind the standard ticking material with an adhesive or stitched or quilted, either with standard threads or with fire-retardant threads. Additionally, the barrier material can be used to replace current materials such as a bottom cover for non-flip products, a top panel for foundations, and/or a complete, or partial wrap-around cover for foundations. Additionally, in other embodiments, barrier materials can be used as the sole filling material beneath the fabric. Further, the systems and methods described herein may be employed with mattresses for conventional beds, day beds, futons and other bedding applications. The mattresses may be two-sided or one sided. In the case of one-sided mattresses, the sleeping surface may comprise a an upper sleeping surface with a topper as described above with reference to FIG. 2. The lower mattress surface, may be formed of a foam padding selected to minimize compaction, and may be a high density polyurethane foam. This provides a relatively rigid bottom layer, that provides a non-sleeping surface. Although foam is often employed, other rigid materials may be used in place of the foam layer, such as plastic, wood, or other nonyielding rigid materials. To the extent such materials for the lower layer yield to pressure, such materials must have at least a high degree of recoverability once the pressure has been removed so that the materials are not compacted. Other means known in the art for assembling a mattress can also be used when incorporating the fire barrier fabric. Accordingly, the spirit and scope of the present invention is to be limited only by the following claims.