Lofted lightly needlepunched flame-retardant nonwovens
The present invention concerns a flame retardant (FR) lofted lightly needlepunch nonwoven fabric useful in household goods and particularly for mattresses. The nonwoven fabric comprises at least one of FR rayon fiber, FR acrylic fiber, FR melamine fiber, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber and nonbonding, nonFR synthetic and/or natural fiber mechanically bound together by a needlepunch process. The present invention also contemplates a mattress constructed from the FR lofted lightly needlepunch nonwoven fabric comprising FR rayon fiber, FR acrylic fiber, FR melamine fiber, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber. The mattress from this construction passes the California Test Bulletin 603 stringent conditions for mattresses used in residential places. Preferably the nonwoven fabric has a batt weight of at least 2.25 oz./sq.yd. and preferably between 2.25 oz./sq.yd. and 20 oz./sq.yd.
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This application is a Continuation-In-Part of our co-pending U.S. patent application Ser. No. 10/714,132 filed Nov. 14, 2003, which is a Continuation-In-Part of our co-pending U.S. patent application Ser. No. 10/298,990 filed Nov. 18, 2002.
BACKGROUND OF THE INVENTION1) Field of the Invention
The present invention concerns a flame-retardant (FR) lofted lightly needlepunched nonwoven fabric that can be employed in many applications, particularly in household goods such as a fabric FR layer for comforters, pillows, or furniture; backing for curtains and rugs; and especially for mattress fabrics. The nonwoven fabric comprises at least one of FR rayon fiber, FR acrylic fiber, FR melamine fiber, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber; and non-bonding, non-FR synthetic fiber and/or natural fiber, all of which are mechanically bonded together through a needlepunch process. Nonwoven fabric prepared from these components, possessing a batt weight of greater than about 2.25 oz./sq.yd., has a batt thickness of between about ½ to about ¾ inch, and is capable of passing stringent flame-resistant tests.
2) Prior Art
Flame-retardant or flame-resistant (FR) materials are well known to those skilled in the textile art. Such materials can be woven or nonwoven, knitted, or laminates with other materials such that they pass various textile flame resistant or flame retardant tests such as California TB 117 & TB 133 for upholstery; NFPA 701 for curtains and drapes; and California Test Bulletin 603 dated Nov. 4, 2003 concerning a flammability test procedure for residential mattress/box spring sets.
Generally, the California Technical Bulletin 603 test for mattresses states that the mattress must not release too great a quantity of energy for a given exposure to a flame, based on certain conditions such as the position of the flame, the temperature of the flame, the source of fuel being used, etc. Furthermore, 30 minutes after the flame source has been initiated the test is terminated and certain conditions must be met, as more fully set for h herein.
Various FR fibers are well known to those skilled in the art. FR fibers based on polyester, rayon, melamine, nylon, acrylic, and polyolefin fibers such as polyethylene, or polypropylene fibers, are known and commercially available.
U.S. Pat. No. 6,214,058 issued to Kent et al. on Apr. 10, 2001 describes fabrics made from melamine fibers that may or may not be flame resistant fabrics. This reference describes a process for dyeing melamine fabrics including blends of melamine and natural fibers (such as wool or cotton) or other synthetic fibers such as rayon or polyester. As a passing comment it mentions that the melamine fiber may be FR.
U.S. Pat. No. 6,297,178 issued to Berbner et al. on Oct. 2, 2001 discloses flameproof fabrics based on FR melamine fibers and FR rayon fibers. The melamine and rayon fibers are made FR by coating the fiber with aluminum.
PCT application WO 03/023108 filed Sep. 11, 2002 in the name of Mater and Handermann discloses a highloft FR material composed of FR rayon or FR melamine that are inherently FR. Additionally the application also discloses and requires the use of modacrylic fibers. These materials have no coating thereon.
In spite of the above-mentioned patents and numerous other nonwoven FR fabrics, there is still a need in the industry to create inexpensive lofted lightly needlepunch nonwoven FR articles that pass the stringent guidelines for the California Technical Bulletin 603 testing as well as other tests for upholstery, curtains and drapes. Moreover, there is a need in the industry to produce such a nonwoven article from materials that are relatively inexpensive, and have light batt weights.
SUMMARY OF THE INVENTIONThe present invention relates to FR lofted lightly needlepunch nonwoven fabric that when incorporated into a mattress is capable of passing the California Technical Bulletin 603 test, as well as other tests employed for other household goods such as bed clothing and furniture.
The lofted lightly needlepunch nonwoven fabric/article of the present invention may be produced from a combination of FR synthetic fibers and/or from all natural fibers. In each case, the nonwoven article is created by mechanically interlocking the fibers of a web. No binder is employed or desired as it makes the resulting article stiff, compared to a highloft product, but flexible compared to traditional needlepunch nonwovens. The mechanical interlocking is achieved through a needlepunch operation. Additionally, the nonwoven article has at least one of FR rayon fibers, FR acrylic fibers, FR melamine fibers, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber.
In the broadest sense, the present invention relates to a FR lofted lightly needlepunch nonwoven article produced from at least one of FR rayon fibers, FR acrylic fibers, FR melamine fibers, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber; and nonbinding, non FR synthetic fibers and/or natural fibers.
In the broadest sense, the present invention also comprises a mattress having a core burnable material surrounded by a FR lofted lightly needlepunch nonwoven article produced from at least one of FR rayon fibers, FR acrylic fibers, FR melamine fibers, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber, and a non-binding, non-FR synthetic and/or natural fibers.
DESCRIPTION OF THE PREFERRED EMBODIMENTSThe FR lofted lightly needlepunch nonwoven article of the present invention is produced from materials generally known to those skilled in the art, however, before the present invention those materials have not been assembled into a nonwoven article like that of the present invention.
By “traditional needlepunch nonwoven” we mean a product that is generally less than about ¼ inch thick, has a basis weight of 2.25 oz./sq.yd. to 20 oz./sq.yd., is highly dense, rigid and self supporting in that when placed in a vertical position, it does not fold, bend or collapse upon itself. Furthermore when such a product is exposed to flame, as in the TB 603 test, its rigidity lends to high shrinkage and cracking of the barrier. No binder materials are employed in needlpunch nonwovens because the needlpunch process has sufficiently intermeshed the fibers with one another.
By “highloft nonwoven” we mean a product that has a low density fiber network structure characterized by a high ratio of thickness to weight per unit area. Highloft battings have no more than about 10% solids, by volume, and are greater than about ¼ inch in thickness. Typical highloft products are at least ½ inch thick and have a basis weight of 2.25 oz./sq.yd. to 20 oz./sq.yd. This product is flexible and deflects when it extends 12 inches beyond a supporting surface (when cantilevered 12 inches, it deflects). Furthermore the product is made with a binder that locks the fibers in position with respect to one another and has at least 50% resiliency after repeated compression. When exposed to flame, as in the TB 603 test, it chars and shrinks, but does not crack.
By “FR lofted lightly needlepunch nonwoven” we mean a product that contains no binder, is at least 25% air by volume, and is at least ½ inch to ¾ inch thick, has a basis weight of 2.25 oz./sq.yd. to 20 oz./sq.yd., and is flexible and deflects when it extends 12 inches beyond a supporting surface (when cantilevered 12 inches, it deflects). It has a resiliency of at least 80% after repeated compression. When exposed to flame, as in the TB 603 test, it chars and shrinks, but does not crack. At the same needlepunch stroke setting, a different barb needle is utilized. Barbs for this process are only penetrating in 1 direction (vs. both directions in a heavily needled “traditional needlepunch product”). This creates more strength in the machine direction of the fabric (than heavy needled fabric) and a loftier product. This allows a deeper penetration in the fabric without sacrificing loft. This nonwoven, compared to the traditional needlepunch nonwoven, generally has at least a 20% increase in both the machine direction and the cross direction tensiles of the nonwoven (and generally not more than about a 60% increase), and at least a 15% increase in after-burn tensiles and elongation at break (and generally not more than about a 40% increase).
Fiber in this invention is not meant to be a single fiber. Fiber and fibers have the same meaning.
Suitable FR fibers are those that can pass the various tests set forth below. FR fibers having too little flame resistance are not suitable for the present invention. Sufficient amounts of FR fibers must be present if the nonwoven article is to pass the California Test Bulletin 129 and 603 tests.
The FR fibers employed in the FR lofted lightly needlepunch nonwoven articles of the present invention may be an inherent flame resistant fiber or an FR fiber (natural or synthetic fibers) that are coated with an FR resin. An inherently flame resistant fiber may be one whose polymeric structure incorporates an FR component such as phosphorus or phosphorus compounds, an amine, modified aluminosilicate, or halogen based compounds. An especially preferred halogen based compound is a thermoplastic polyvinyl halide composition. Thermoplastic polyvinyl halide compositions, when exposed to a flame, generate oxygen depleting gases that help to extinguish the flame. Thus it is inherently flame resistant. Modacrylic fiber is a generic name for a synthetic manufactured copolymer fiber composed of between about 35 wt. % and 85 wt. % of acrylonitrile units (—CH2CH(CN)—), with the remainder being thermoplastic polyvinyl halide, such as vinyl chloride or vinylidene chloride monomers. Suitable modacrylic fibers are sold under the trade name of Modacrylic™ distributed by Mitsui Textile Corporation, Protex sold by Kaneka, or SEF Plus by Solutia, Inc. These modacrylic fibers are copolymers of acrylonitrile and vinyl chloride or vinylidene chloride. Other inherently flame resistant fibers are: a) rayon with aluminosilicate modified with silica and sold by Sateri Oy in Finland under the trademark Visil® fiber; b) a melamine fiber sold under the trademark Basofil® fiber by McKinnon-Land-Moran LLC.; and c) polyester with phosphalane (organo phosphorus compound) such as that sold under the trademark Trevira CS® fiber or Avora® Plus fiber by KoSa. These inherent flame resistant fibers are not coated, but have an FR component incorporated within the synthetic material (within its structural chemistry).
The natural or synthetic fibers coated with an FR resin contain one or more of the same type components mentioned above, namely phosphorus, phosphorus compound(s), red phosphorus, esters of phosphorus, and phosphorus complexes; amine compounds, boric acid, bromide, urea-formaldehyde compound(s), phosphate-urea compound(s), ammonium sulphate, or halogen based compounds. The typical FR resin is clear or translucent latex and is applied by spraying. Other non-clear FR resins are also known and are employed where color is not important. A suitable commercially available FR resin is sold under the trade name Guardex FR, or FFR which is produced by Glotex Chemicals in Spartanburg, S.C. While there are several different varieties of Guardex and Glotex FR resins, those skilled in the art can pick and choose among them to find that which is most compatible, taking into account such things as cost, appearance, smell, and the effect it may have on other fibers in the nonwoven batt (i.e., does it make the other fibers rough, or have a soft hand, or discolor the other fibers, etc.). FR resin may be applied to specific fibers in a range from about 6 to 25 weight % of the weight of the specific fibers. For example, the FR resin could be applied to natural or synthetic fibers before they are dry laid/air laid onto a conveyor belt. It is also within the scope of the present invention to purchase the fiber already coated with the desired FR resin coating, and merely blend them with the other fibers into the nonwoven fabric. The FR resin employed is a type that has no binding characteristics. Non-resin FR coatings like metallic coating are not suitable for the present invention, because they tend to flake-off after continuous use of the product.
While the above FR product (Guardex) is a liquid, other FR resin in solid form may be applied as a hot melt product to the fibers, or as a solid powder which is then melted into the fibers. Exactly how the fibers are coated with the FR resin is not a part of the present invention and any process is acceptable provided that the fibers when incorporated into a nonwoven can pass the TB 603 test.
The FR fibers come in different deniers from approximately 1.5 to about 15 dpf (denier per filament).
Suitable non-FR, nonbinding synthetic fibers can be polyester such as polyethylene terephthalate (PET) or poly butylenes terephthalate, etc., cellulose such as rayon or cellulose acetate, nylon such as nylon 6 or nylon 66, etc., polyolefin such as polyethylene fibers or poly propylene fibers, acrylic, melamine and combinations of these. When non-FR synthetic fibers are employed, they give the batt certain characteristics like loft, resilience (springiness), tensile strength, and thermal retention, useful for many different applications. Preferred are PET and rayon fibers.
Natural fibers may also be employed in the nonwoven batts of the present invention. Natural fibers such as flax, kenaf, hemp, cotton and wool may be employed, depending on the properties desired. Preferred is cotton.
Because the synthetic fibers and natural fibers are non-binding and are not flame resistant, such fibers can be used to dial-in desired characteristics and cost. As such it is also within the scope of the present invention to employ a mixture of synthetic and natural fibers.
The nonwoven batt may be constructed as follows. The various combinations of fibers that can be employed in the present invention may be weighed and then dry laid/air laid onto a moving conveyor belt, for example. The size or thickness of a nonwoven batt is generally measured in terms of ounces per square yard. The speed of the conveyor belt, for example, can determine or provide the desired batt weight. If a thick batt is required, the conveyor belt moves slower than for a thin batt.
Suitable FR lofted lightly needlepunch nonwoven fabrics of the present invention have a batt weight greater than about 2.25 oz./sq.yd. Preferably the batt weight ranges from 2.25 oz./sq.yd. to 20 oz./sq. yd, with the most preferred product being about 9 oz./sq.yd. Using a batt weight greater than about 20 oz./sq.yd. offers no significant improvement in performance and is more costly. Using a batt weight less than 2.25 oz./sq.yd causes cracking when exposed to flame in the TB 603 test conditions. If desired any rearrangement of the fibers such as by carding occurs next. Then the conveyor belt moves to an area where any spray-on material is added to the nonwoven batt, for example, the FR resin sprayed onto the nonwoven batt as a latex while the batt is still positioned on the conveyor belt. If the conveyor belt is foraminous, the excessive latex FR resin drips through the belt and may be collected for reuse later. After spraying the FR resin latex, it is transported to a dryer or oven. Once all the dried sprayed-on materials have been applied, if any, the conveyer belt can then move the nonwoven dry laid batt to the needlepunch loom where the fibers of the batt are mechanically oriented and interlocked.
In another embodiment of the invention, individual fibers are treated with the FR resin prior to the laying of the fibers (dry laid) onto the conveyor belt. Suitable fibers that have been pretreated with FR resins are commercially available. Utilizing the pretreated fibers eliminates the necessity to spray on the FR resin, and the drying time associated therewith.
The batt passes into the needlepunch loom between the bed plate on the bottom and the stripper plate on the top. Needles that are attached to one or more needle boards correspond to holes that are in one or both of the bed plate and the stripper plate. The needle board(s) moves up and down allowing the needles to pass through the plates, into and out of the batt. As the needles penetrate into the batt, barbs on the blade of the needle hook onto fibers in the batt, pulling the fibers the depth of the penetration. As the needle then moves out of the batt, the barbs release the hooked/pulled fibers, leaving the hooked/pulled fibers reoriented from a horizontal to a predominantly vertical position. This causes the fibers of the batt to become entangled, which creates the nonwoven fabric.
Generally, the more penetrations of the needles into a given area of the batt, i.e., an increase in the puncture density, the more dense and strong the web will become. This increase in web density can be achieved by increasing the density of the needles in the needle board, decreasing the rate of material feed, increasing the frequency of punching, or similarly changing other operational production parameters that would be obvious to one skilled in the art. The depth of penetration by the needles into the batt has a similar effect on the strength and density of the nonwoven fabric. With an increase in the depth of penetration, a greater number of barbs along the needle blade are employed, resulting in greater entanglement of the fibers within the batt, and therefore a stronger, denser web. The now entangled and interlocked batt is pulled through the loom with the aid of draw rolls and wound onto tubes. The nonwoven batt may be used as an outer wrap in conjunction with other stuffing materials. In this arrangement, the nonwoven web provides a flame resistant barrier around a typically non-flame resistant filling.
Currently there are test standards in effect for mattresses for home (residential) use known as California Technical Bulletin 603 with an implementation date of 2005. The purpose of this test is to provide a means of determining the burning behavior of mattress/foundation sets intended for residential use by measuring specific fire test responses when the test specimen, a mattress plus foundation, is subjected to a specified flaming ignition source under well-ventilated conditions.
The preferred FR lofted lightly needlepunch nonwoven is made from a blend of rayon fibers coated with an FR phosphorus-based coating and (nonbonding, nonFR) polyester fibers wherein the nonwoven has a batt weight of at least 2.25 oz./sq.yd. The FR coating is from about 6 to about 25 wt. % of the rayon fiber weight. The nonwoven has from about 60 to 80 wt. % of the FR phosphorus coated rayon fibers and from about 40 to about 20 wt. % polyester fibers, preferably PET fibers that are neither a binder fiber nor an FR fiber. Generally the maximum batt weight is about 20 oz./sq.yd. The thickness of the batt is between about ½ to ¾ inch.
A typical mattress has a foam core, the size (thickness) of which is not critical. The foam is burnable and is fuel in a fire. To prevent the fire from spreading or initially prevent the foam from catching fire, FR materials surround the foam. The FR materials can be a needlepunched nonwoven, a highloft, sheet like material known commercially as FR Nonskid, or preferably a combination of 2 or more of these. For example, a 2 sided flippable mattress is preferably constructed from needlepunched nonwoven border and an FR highloft material (for the top and bottom surfaces) such as that disclosed in U.S. Ser. No. 11/166,567 filed Jun. 24, 2005 titled Mattress With FR Highloft Material. A needlepunch nonwoven of the present invention is lightly needlepunched and has some loft, but is not as lofty as a highloft product and is less rigid than traditional needlepunch sheet like products. It has a basis weight of from 2.25 to about 20 oz./sq.yd. and has a thickness of about ½ to about ¾ inch. Contrast this with traditional sheet-like (flat) needlepunch material that has about the same basis weight, but has a thickness of less than about ¼ inch and is self-supporting (it does not bend due to its own weight when the product is cantilevered one foot from a supporting wall). On the other hand, the lofted lightly needlepunch product of the present invention is employed because it is stiffer and self-supporting (compared with the highloft material) and is used in the border or sides of a mattress. The lofted lightly needlepunch nonwoven barrier allows the mattress borders to maintain desired aesthetic properties, such as “fill”, dimension, and self-support. The highloft material is employed on the top and bottom surfaces—“sleep surfaces” of a flippable mattress because highloft provides a soft, pillow-like feel. A needlepunched product is too stiff and does not provide enough resiliency for the top and bottom surfaces of a flippable mattress. Typical highloft material has binder that structurally locks the fiber to one another thereby giving the product springiness after each repeated compression. The lightly needlepunch lofted border and the highlofted material are sewn together, forming an FR barrier, to completely enclose the flammable core of the mattress. A ticking is then sewn together to encase the entire FR barriers covered core as is known in the industry.
In a one-sided mattress, the border is still a lofted lightly needlepunched nonwoven and the top surface is still a highlofted nonwoven material. However, the bottom surface is typically an FR Nonskid product. This FR Nonskid product is more rigid than the lofted lightly needlepunched nonwoven border and is secured by sewing together the border and the FR Nonskid product. Therefore the foam is encased in an FR barrier structure. A ticking is then sewn together to encase the entire FR barrier covered core as is known in the industry.
Additionally, most mattresses have a foundation (such as a box spring) that has flammable material like wood in its core. It may also be desirable to enclose the flammable material of the foundation in an FR barrier product. Because the lofted lightly needlpunch border is less expensive than the highlofted nonwoven and because there is no need for a “pillow like” feel for the foundation, the lofted lightly needlepunch material of the present invention is also suitable for the enclosing the flammable material of the foundation.
Thus the lofted lightly needlepunch nonwoven has a pleasing aesthetic appearance of being plush, is rigid enough to provide support for the border, but also has great protection under flame (when subject to the Calf TB 603 test, for example). A traditional needlepunch, high-density product will crack under stress. When flame is applied to the border of a mattress having a traditional FR needlepunch nonwoven, the product shrinks and the tension causes cracking. At this point the flammable core is now exposed to the flame and the mattress fails the TB 603 test. If the foundation is also tested, it too fails for the same reason.
On the other hand, the lofted lightly needlepunch nonwoven of the present invention is more resilient under flame and although it still shrinks, it does not crack. Its ability to deform without cracking is due to its higher elongation at break properties than is typical in a heavily needled product. Consequently, a mattress made with the lofted lightly needlepunch nonwoven of the present invention does not expose the foam to the flame during the TB 603 test. When a mattress and foundation set are submitted to the TB 603 test, the ticking typically will immediately burn off of the mattress, leaving the next layer exposed which is the FR lofted lightly needled nonwoven barrier. The mattress and foundation borders are usually made with the lofted lightly needlepunch nonwoven, and will char, but do not burn or support a flame. The FR nonwoven barrier does not crack and the flammable core is not exposed to the flame. Such mattress and/or foundations pass the TB 603 test.
General ProceduresVarious fiber components, some FR fibers and some synthetic fibers (primarily employed for increasing physical properties of the nonwoven batt) are set forth in the various examples having a range of dpf between 1.5-15 as mentioned previously. Also, the weight of the fiber batt as well as a pilot burn test designed to mimic the California TB 603 testing protocol is set forth in the examples.
Additionally, some sample where tested under the California TB 603 test that requires the test specimen to be conditioned for 24 hours at above 54° F. and below 70% relative humidity. It was then placed on a steel frame, on a load cell platform along the far side of the test room. A pair of propane burners was placed on the top panel and border as specified in the test protocol. The computer data acquisition system was started, and the burners were ignited and allowed to burn for 70 seconds (top) and 50 seconds (border). The test was allowed to proceed until either all combustion ceased, or 30 mins passes.
The most important fire test response characteristic measured in this test is the rate of heat release, which quantifies the energy generated by the fire. The specimen does not meet the test requirements if any of the following criteria are exceeded:
1. Maximum rate of heat release of 200 KW.
2. Total heat release of 25 MJ in the first 10 minutes.
EXAMPLE 1Various combinations of FR fibers with other synthetic or natural fibers such as rayon, PET, flax and kenaf were produced. The various fibers were dry laid onto a moving conveyor belt as is known in the art. For Samples 1-5 and 11, where an FR resin was employed via saturation method, it was applied to individual fibers before they were laid onto the moving conveyor. The nonwoven fiber batt was transported via the conveyor belt to a card, then to a needlepunch loom where the individual fibers were mechanically entangled through the needling process to create the interlocked web.
These various nonwoven batts, at various weights, were then subjected to Western Nonwovens bench scale test. In the test the nonwoven fabric was wrapped once around the foam. A flame was applied directly to the nonwoven fabric for at least 600 seconds and the structural integrity was noted. All of the test samples maintained their structural integrity for at least the time indicated, and the flame did not reach the foam. The burn time is listed in seconds. The batt weight is listed in ounces per square yard.
In all samples where FR resin was employed (Samples 1-5, 11 and 12) GUARDEX FR resin was used. All Samples containing an FR rayon employed Visil® fiber as the FR rayon. The FR resin is based on the total weight of the fibers employed to make up the nonwoven batt, except Sample 11 where the FR resin was employed only on the rayon. In all samples, the nonwoven web was interlocked together using needlepunch techniques generally known in the art.
When FR components, including but not limited to FR rayon fiber, FR acrylic fiber, FR melamine fiber, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber, are employed in the nonwoven batt they should be present in a concentration from about 25 to about 90 weight %, and preferably from about 30 to about 85 weight %. Synthetic fibers, which can be polyester and in particular PET fibers, are present from about 10 to about 70 weight %, and preferably from about 15 to about 65 weight % when employed in the nonwoven batt.
In all Samples except 12, the nonwoven batt was constructed of PET and varying amounts of FR rayon, FR acrylic, and/or FR melamine. Each batt had a final weight of about 9.0 oz/yd2. The batt was then wrapped around a piece of foam and subjected to a burn test as described above. Each batt was subjected to burn time test of over 600 seconds. All of the test samples maintained their structural integrity for at least the time indicated, and the flame did not reach the foam.
Sample 9 was also employed to construct twin-size mattresses and submitted for California TB 603 testing. The mattresses consisted of a foam core, wrapped in and FR material comprising a FR lofted lightly needlepunch nonwoven border, and a FR highlofted nonwoven material in the bottom and top of the 2-sided mattress. The FR materials were sewn together and a typical ticking covered the FR material. For the 1-sided mattress, its foam core was wrapped in the FR lofted lightly needlepunch nonwoven border, a FR highlofted nonwoven material on the top, and an FR nonskid product on the bottom. These FR materials were sewn together to encase the foam and a typical ticking covered the FR material. The Sample 9 mattresses had a border with 9 oz/yd2 and were tested at in a 1-sided, pillow top design; and also a 2 sided bed. Sample 9 successfully passed in both bed constructions.
Sample 12 contains natural fibers—flax and kenaf, and synthetic PET fiber. These fibers are made into a batt and all the fibers were coated with an FR resin. The amount of FR resin was 20 wt. % based on the weight of the natural and synthetic fibers. The FR resin spray coated on the fibers was GuardEx FFR from Glo-Tex. This batt was not tested.
Lastly, the nonwoven batt from Sample 13 was constructed from Visil® fiber and PET fiber. It was constructed into a twin size mattress constructed like the 2-sided mattress of Sample 9, except the batt's weight was 5.85 oz/yd2. The construction was in compliance with and as described in California Technical Bulletin 603. The mattress was then subjected to the full Flammability Test Procedure for Residential Mattresses that is described in TB 603. As indicated, a flame was applied directly to the mattress's upper surface (70 seconds) and side surface (50 seconds) utilizing a pair of propane burners. The structural integrity of the mattress was noted thereafter for a period of 30 minutes. The flame did not penetrate the nonwoven ticking employed around the mattress. There was no appreciable heat release during the burn time testing. The mattress employing Sample 13 nonwoven needlepunch successfully passed TB 603.
The weight % of the total fibers in the batt is 100%. This doesn't include the weight of the FR resin since it is not in fiber form. All key data and results, if any, are summarized in Table 1.
Note:
Samples 1-6, 11 and 12 have not been tested.
This example shows the results from a bench scale burn test conducted for 90 seconds. A comparison between FR lofted lightly needlepunch nonwoven batts and traditional FR needlepunch nonwoven batts was made with batt weights of 7.2 oz./sq.yd. for all samples and the only difference being that of lofted lightly (LNP) versus traditional flat construction (NP). The batts were ¼inch for the traditional needlepunch article and ½ inch loft for the lofted lightly needlepunch articles. A flame was applied to one side of the nonwoven and the temperature, in degrees Fahrenheit, was measured every 10 seconds on the opposite side. Three samples of each type were tested and the temperatures were averaged, and the delta or difference was determined at each time. The results are set forth in Table 2.
Burn Performance:
The LNP product (this is the lightly needled product of the present invention) has lower heat transmission through the fabric over the 90 sec period in comparison to the same product that is heavily needled. In the row identified as “delta” that there is a significant difference in burn temperatures at each increment of time (this is statistically different) and was repeatable on the 3 samples tested for each blend type. This is indicative of the added “loft” benefit and product reaction to heat.
Pre-Burn Tensile:
Tensile testing was completed on the needlepunch nonwovens noted above (NP and LNP, 7.28 oz/sq.yd.) before the material was exposed to the flame of the TB 603 testing. The tensile results showed that the overall LNP fabric of the present invention is stronger in both the machine and cross directions.
(measured in lbs @ break)
Post Burn Tensile:
Tensile testing was completed on the same needlepunch nonwovens noted above after testing on the bench scale burn test. The tensile results show that the overall LNP fabric is stronger and has better elongation properties which are critical during actual burn testing for deformation without cracking. The values measured are a different scale than pre-burn tensiles because the tensile test equipment utilized a different weighted load cell.
1(measured in lbs @ break- for tensile strength
2(measured in inches deflected)
Thus, it is apparent that there has been provided, in accordance with the invention, a FR lofted lightly needlepunch nonwoven fabric that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. According, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the invention.
Claims
1) A mattress having a flammable core, an FR barrier enclosing the core, and a ticking covering the FR barrier, said FR barrier comprising a FR lofted lightly needlepunch nonwoven in the border and a FR highlofted nonwoven on the top of the mattress, and an FR material on the bottom of said mattress, wherein said FR lofted lightly needlepunch nonwoven has a basis weight of at least 2.25 oz./sq.yd to about 20 oz./sq.yd. and comprises a blend of rayon fibers coated with an FR phosphorus-based coating and polyester fibers, said FR phosphorus-based coating is from about 6 to about 25 wt. % of the rayon fiber weight, said FR phosphorus coated rayon fibers comprise about 60 to 80 wt. % of said FR lofted lightly needlepunch nonwoven and from about 40 to about 20 wt. % polyester fibers.
2) The mattress of claim 1, wherein said FR lofted lightly needlepunch nonwoven has a thickness of about ½ to ¾ inch.
3) The mattress of claim 1, wherein said FR lofted lightly needlepunch nonwoven has a post-burn TB 603 tensile strength of at least about a 20% increase in both the machine and cross directions compared to a conventional needlepunch nonwoven.
4) The mattress of claim 1, wherein said FR lofted lightly needlpunch nonwoven has a post-burn TB 603 tensile and elongation at break of at least about a 15% increase compared to conventional needlepunch nonwoven.
5) A mattress having a flammable core, an FR barrier enclosing the core, and a ticking covering the FR barrier, said FR barrier comprising a FR lofted lightly needlepunch nonwoven in the border and a FR highlofted nonwoven on the top of the mattress and an FR material on the bottom of said mattress, wherein said FR lofted lightly needlepunch nonwoven has a basis weight of from about 2.25 oz./sq.yd. to about 20 oz./sq.yd. and has a thickness of about ½ to ¾ inch and comprises a blend of at least one of the group consisting of FR rayon fiber, FR acrylic fiber, FR melamine fiber, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber; and also synthetic non-FR, nonbinder fibers.
6) The mattress of claim 5, wherein said synthetic fiber is selected from the group consisting of rayon, polyester, or a mixture thereof.
7) The mattress of claim 5, wherein said synthetic fiber comprises from about 40 wt. % to about 20 wt. % of said FR lofted lightly needlepunch nonwoven, and wherein the sum of said FR rayon fiber, said FR acrylic fiber, said FR melamine fiber, said FR polyester fiber, said FR polyolefin fiber, and said FR resin coated fiber comprises from about 60 to about 80 weight % of said FR lofted lightly needlepunch nonwoven.
8) The mattress of claim 5, wherein said FR lofted lightly needlepunch nonwoven has a post-burn TB 603 tensile strength of at least about a 20% increase in both the machine and cross directions compared to a conventional needlpunch nonwoven.
9) The mattress of claim 5, wherein said FR lofted lightly needlpunch nonwoven has a post-burn TB 603 tensile and elongation of at least about a 15% increase compared to conventional needlpunch nonwoven.
10) A FR lofted lightly needlepunch nonwoven comprising at least one of the group consisting of FR rayon fiber, FR acrylic fiber, FR melamine fiber, FR polyester fiber, FR polyolefin fiber, or FR resin coated fiber; and nonbonding synthetic or natural fiber, wherein said nonwoven has a basis weight of from about 2.25 to about 20 oz./sq.yd. and has a thickness of about ½ to ¾ inch, said nonwoven has a tensile strength of at least about a 20% increase and less than about a 60% increase in both the machine and cross directions compared to conventional needlepunch nonwoven, and a tensile and elongation at break after-burn of at least about 15% increase to less than about 40% increase compared to conventional needlepunch nonwoven.
11) The nonwoven of claim 10, wherein said nonbonding synthetic fiber is selected from the group consisting of rayon, polyester, or a mixture thereof.
12) The nonwoven of claim 10, wherein said FR resin is selected from the group consisting of phosphorus, phosphorus compound(s), red phosphorus, esters of phosphorus, and phosphorus complexes; amine compounds, boric acid, bromide, urea-formaldehyde compound(s), phosphate-urea compound(s), ammonium sulphate, or halogen based compounds compatible with said nonbonding synthetic fiber.
13) The nonwoven of claim 10, wherein said synthetic fiber comprises from about 40 to about 20 weight % of said nonwoven, said synthetic fiber further comprising polyester, and wherein the sum of said FR rayon fiber, said FR acrylic fiber, said FR melamine fiber, said FR polyester fiber, said FR polyolefin fiber, and said FR resin coated fiber comprises from about 60 to about 80 weight % of said nonwoven.
14) The nonwoven of claim 10, wherein said natural fiber is flax, kenaf, hemp, cotton, wool, or a mixture thereof.
15) The nonwoven of claim 10, wherein said FR rayon is a rayon fiber coated with FR resin.
16) The nonwoven of claim 15, wherein said resin coating is from 6 to about 25 wt. % of said rayon fiber.
Type: Application
Filed: Feb 13, 2006
Publication Date: Jul 13, 2006
Applicant:
Inventors: Sheri McGuire (Orange Park, FL), Thomas Taylor (Charlotte, NC)
Application Number: 11/352,769
International Classification: A47C 17/00 (20060101);
