The present invention generally relates to flame resistant knit fabrics for use as coverings for support articles such as mattresses.
It is well known in the textile industry to produce fire resistant products for use in upholstered furniture, mattresses, foundations, automotive seating, public transportation seating, aircraft seating and the like, using needlepunched, highloft, spunbond or spunlace nonwoven or woven or conventional knit fabrics formed of natural or synthetic fibers, and then treating these fabrics with fire retarding chemicals. Conventional fire retarding (FR) chemicals include borate-based, halogen-based, phosphorus-based, melamine-based and/or antimony-based chemicals. Unfortunately, such treated fabrics are heavier than similar types of non-fire retardant fabrics and have reduced wear life. Although flame resistant chemically treated fabrics will self-extinguish and exhibit limited melt behavior when a flame is removed, they typically form brittle chars, shrink and crack open after exposure to a direct flame allowing the underlying materials to ignite. There is a need for low cost, but high performing barrier materials for use in support articles.
A flame resistant knit fabric having a first weft yarn set and a second weft yarn set. The first weft yarn set contains flame resistant yarns and the second weft yarn set contains second weft yarns. The knit fabric is knitted such that the first weft yarns are interlinked with one another by a plurality of knit stitches, the second weft yarns are interlinked with one another by a plurality of knit stitches, and the first weft yarns are not interlinked with the second weft yarns. A flame resistant support article containing the flame resistant knit fabric as well as methods for making the knit fabric and support article are also disclosed.
“Flame resistant”, in this application means a material that provides a thermal barrier and reduces body burn as described in NFPA 1971 and allows the user time to escape the flames and/or fire. Such a fiber, yarn, fabric, or article would preferably resist ignition and be self-extinguishing. In its preferred usage in the present application, the term “flame barrier” means a product incorporated into or on top of a composite article that when tested with a composite type test method, such as: CPSC (Consumer Product Safety Council) CFR 1633, California Test Bulletin 129 (TB 129) or California Test Bulletin 603 (TB603) for mattresses and foundations and California Test Bulletin 133 (TB 133) for upholstered furniture, the flame barrier allows for the continued use of conventional materials such as dress cover fabrics, fiber-fillings and polyurethane foams, while still passing these stringent large open flame tests. It is understood by someone skilled in the art that flame bafflers made of the tubular knit flame barriers described in this invention, even at overall lower basis weights, can be made to pass less stringent open flame tests such California's Revised Test Bulletin 117 (TB 117—draft 02/02 version) and British Standard 5852.
The flame resistant knit fabric may be formed in any suitable manner and pattern. In one embodiment, the knit fabric is a tubular fabric, and in another embodiment, the knit fabric is a circular knit. These knits are advantageous for use as a barrier material for support articles such as mattresses as the knit would only require two seams to enclose the mattress.
Referring now to
In the embodiment shown in
Some examples of other suitable patterns include a knit stitch, a welt, and a welt or a knit stitch, a knit stitch, and a welt. Any combination and repeat pattern of knit stitches, tuck stitches, welts, and any other stitch may be used in the first and/or second weft yarn sets so long as the first weft yarn set is interlinked. Preferably, the second weft yarns are interlinked with one another by a plurality of knit stitches and the first weft yarns and the second weft yarns are not interlinked.
The first weft yarns 100 of the first weft yarn set are flame resistant yarns. These may be any suitable flame resistant yarn including inherently flame resistant yarns and chemically treated flame resistant yarns. In one preferred embodiment, the flame resistant yarns comprise continuous filament silica fibers also referred to as fiberglass fibers. In another embodiment, the flame resistant yarns can be flame resistant core spun yarns which has a core of a typically flame resistant material surrounded by at least one sheath of other fibers/yarns. More information on the core spun yarns and the method of making the yarns may be found in U.S. Pat. No. 6,410,140 (Land et al.), which is incorporated herein in its entirety.
The size of the product yarn will vary depending on the final application of the yarn and the particular fabric characteristics desired but is preferably within the range of from about 30/1 to 1/1 conventional cotton count, preferably from about 21/1 to 5/1 conventional cotton count for one embodiment.
The second weft yarns 200 of the second weft yarn set may be any suitable yarn. In one embodiment, the second weft yarns 200 are flame resistant spun yarns. In another embodiment, the second weft yarns do not contain continuous fibers such as monofilament or multifilament fibers. In another embodiment, the second weft yarns do not contain fiberglass. In another embodiment, the second weft yarns comprise monofilament or multifilament fibers. In one preferred embodiment, the second weft yarns 200 are formed from a blend of at least two of the following: fire resistant rayon, modacrylic, and cotton, polyester staple fibers. When exposed to flame, the second weft yarns may melt and/or degrade.
In one embodiment, shown in
The flame resistant knit fabric has an upper surface and a lower surface (thought the upper and lower surfaces can be reversed and do not indicate the orientation that the fabric is used in a finished article), wherein the majority of the upper surface comprises the first weft yarns and the majority of the lower surface comprises the second weft yarns. Majority means greater than 50% by weight.
After the flame resistant knit fabric is exposed to heat and/or flame, in one embodiment, the second weft yarns 200 and are compromised. These yarns may be completely melted, disintegrated, or have a significant reduction in their physical properties. The first weft yarns 100 will remain and provide the integrity of the knit fabric. Because the first weft yarns are interlinked with one another through the plurality of knit stitches, the first weft yarns will still form an interconnected grid and the knit will still have integrity after burning. An illustration of the knit fabric 15 having the second weft yarns 200 removed through burning is shown in
The flame resistant knit fabric 10 may be used as a flame barrier to any suitable article.
The support article may be any article providing support and flame resistance. Some examples of support articles include, but are not limited to, upholstered furniture, mattresses, foundations, automotive seating, public transportation seating, aircraft seating, and the like. In one preferred embodiment, the support article is a mattress.
The first weft yarn set was yarns of continuous filament fiberglass. The second weft yarn set was in an alternating pattern of A yarns and B yarns such as illustrated in
The first and second weft yarn sets were circular knitted into a 3.4 ounce per square yard single knit, knit welt knit construction as shown in
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. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. 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 to 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. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
This application claims priority to co-pending US Provisional Patent Application 62/991,662 filed on Mar. 19, 2020, which is herein incorporated by reference in its entirety.
Number | Date | Country | |
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62991662 | Mar 2020 | US |