AU2005338024B2 - Flame resistant fiber blends, fire and heat barrier fabrics and related process - Google Patents

Abstract

A flame resistant (FR) fiber blend comprises amorphous silica fibers; and at least one fiber selected from the group consisting of FR fibers, binder fibers and mixtures thereof. A barrier fabric, manufactured from a blend of fibers comprises amorphous silica fibers; and at least one fiber selected from the group consisting of flame resistant (FR) fibers, binder fibers and mixtures thereof. A flame resistant fabric, manufactured from a blend of fibers comprises amorphous silica fibers; and at least one fiber selected from the group consisting of flame resistant (FR) fibers, binder fibers and mixtures thereof. A process for protecting materials in a product from fire and heat comprises assembling a flame resistant fabric adjacent to at least one component that comprises a material susceptible to damage due to exposure to fire and heat, occasioned by exposure to open flames.

Description

FLAME RESISTANT FIBER BLENDS, FIRE AND HEAT BARRIER FABRICS AND RELATED PROCESSES CROss-REFERENCE TO RELATED APPLICATIONS 5 [1] This application is a continuation-in-part of U.S. Serial No. 11/001,539, filed November 30, 2004 and also claims the benefit of U.S. provisional application, U.S. Serial No. 60/660,620, filed March 11, 2005. 0 BACKGROUND OF THE INVENTION [2] This invention relates to a flame resistant fiber blend useful in preparing fabrics having flame resistance, including particularly non-woven flame resistant materials such as barrier fabrics. This invention also relates to a single layer non woven fabric useful in protecting items from fire and the related heat and a process .5 for protecting adjacent materials in an assembly using the fire and heat barrier fabric. [3] Flame resistant (FR) materials are employed in many textile applications. For example, FR materials are useful as barrier layers between the exterior fabric and the inner stuffing of furniture, comforters, pillows, and mattresses. Such materials can be woven or non-woven, knitted, or laminated with other materials. .0 [4] Flame resistance is defined by ASTM as "the property of a material whereby flaming combustion is prevented, terminated, or inhibited following application of a flaming or non-flaming source of ignition, with or without the subsequent removal of the ignition source." The material that is flame resistant may be a polymer, fiber, or fabric. A flame retardant is defined by ASTM as "a chemical .5 used to impart flame resistance." [5] Flame-blocking, heat-blocking and flame-resistant fabrics are commonly employed as protective barriers for other materials in an assembly. Recent examples of the escalating need for protective barriers include mattresses, bedding sets, upholstered furniture and bed clothing; all regulatory driven with most beginning through efforts by the State of California, in particular, the Bureau of Home Furnishings and Thermal Insulation of the Department of Consumer Affairs of the State of California. The State of California led the drive to regulate these materials in an attempt to reduce the number of lives lost in fires by restricting the quantity of 5 released energy when the item is exposed to open flame. [6] In the case of mattresses and mattress sets, the proposed regulation became law January 1, 2005 in the State of California and is expected that similar national legislation will follow in 2007. Based on the market history established to date, the value to the end consumer is limited. Because significantly higher costs associated LO with meeting the newly imposed standards cannot be passed along, mattress manufacturers have demonstrated a need for low-cost, high performance barrier fabrics. [7] The flame resistance properties of such FR materials are typically determined according to various standard methods, such as California TB117 and TB 133 for 15 upholstery; NFPA701 for curtains and drapes; California Test Bulletin 129, dated October 1992, concerning flammability test procedures for mattresses in public buildings, and California Test Bulletin 603 concerning mattresses for residential use. Desirably, the FR material does not melt or shrink away from the flame, but forms a char that helps control the burn and shield the materials surrounded by the fabric. 20 [8] The protection required of the flame and heat barrier fabric is related to the other components used in the final assembly of the desired product. For example, mattresses normally contain layers of foam and fiber batting for cushioning and ticking for durable cover. Most cushioning material is comprised of foam and fibers that burn when exposed to open flame. Much of the regulatory-driven effort to date 25 has gone towards shielding the inner cushioning layers from open flame or ignition from the heat of the open flame without compromising the comfort or aesthetics of the mattress. [9] Other desirable properties of FR barrier fabrics include a white or other neutral color so as to not contaminate the manufacturing facility or change the look of the 30 composite article; the ability to remain unaffected by ultraviolet light so as not to 3 yellow and change the look of light-colored mattress ticking or upholstery fabrics; being soft to the touch, thereby imparting the feel desired by the consumer; and cost effectiveness. [10] Some fibers are known to have FR properties, such as halogen-containing, 5 phosphorus-containing, and antimony-containing materials. These materials, however, are heavier than similar types of non-FR materials, and they have reduced wear life. [11] There is still a need in the industry to create non-woven barrier fabric that can pass the stringent flammability testing guidelines. Moreover, there is a need in the 10 industry to produce such a non-woven article from materials that are relatively inexpensive and have light batt weights. Additionally, other industries would benefit from the availability of flame resistant fabrics, made from fibers having flame resistant properties, to use in lieu of fabrics that do not have such properties. [12] As an example, baghouse filters are widely used to control particulate 15 pollutants in many industries such as, food processing, cement, mineral, and aggregate processing, metal processing, power generation, and in production of various chemicals. A filter fabric of this type ideally will have (1) a sufficient mechanical strength to withstand pressures developed during use and multiple cycles of flexing, (2) a resistance toward harsh chemicals for long periods of time, (3) an 20 ability to be unaffected by continuous operating temperatures as high as 482* C (900 * F), (4) a resistance toward hot sparks, (5) less than about 1% shrinkage at use temperature, (6) a high filtration efficiency, and (7) a resistance to being attacked by microorganisms. [13] There still remains a need for lower-cost flame and heat barrier fabrics that 25 protect other components of an assembly of a desired product so that the assembly meets all customer and regulatory requirements. Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

C:\NRPorbl\DCOGAV\1661373_1 DOC-6/2/211 -4 BRIEF SUMMARY OF THE INVENTION [14] Deleted [15] Deleted [16] Deleted 5 [17] Deleted [17A] According to the present invention there is provided a flame resistant (FR) fiber blend comprising: amorphous silica fibers comprising a mixture of about 94 to about 97% by weight Si0 2 , about 3 to about 4% by weight A1 2 0 3 , about 0. 1 to about 0.3% by weight Na 2 0, 10 about 0.03 to about 1.3% by weight CoO, and about 0.01 to about 1.2% by weight SO 3 ; and at least one fiber selected from the group consisting of FR fibers, binder fibers and mixtures thereof. [18] Fiber blends containing amorphous silica may show improved char strength when 15 formed into non-woven fabric, compared to non-woven fabric not containing amorphous silica. The char strength to weight ratio of non-woven fabric containing amorphous silica may also be improved, when compared to non-woven fabric containing other fibers conventionally used to improve char strength, such as para-aramid fibers and melamine fibers. 20 BRIEF DESCRIPTION OF THE DRAWINGS [19] The drawing figure is a perspective view exploded to show assembly of a tuft button test apparatus. 25 DETAILED DESCRIPTION OF THE INVENTION [20] Practice of the present invention includes two types of fiber blends: a first, comprising amorphous silica fibers and at least one type of FR fiber and a second, comprising amorphous silica fibers and at least one type of binder fiber. As will be bYN.i".M'UU43 explained in greater detail herein, the fiber blends can then be used to form fabrics, both nonwovens and woven fabrics, for a variety of uses. [21] Generally, any amorphous silica fiber that improves the char strength when added to a fiber blend may be used. The term "silica" refers to silicon dioxide which 5 occurs naturally in a variety of crystalline and amorphous forms. Silica is considered to be crystalline when the basic structure of the molecule (silicon tetrahedra arranged such that each oxygen atom is common to two tetrahedral) is repeated and symmetrical. Silica is considered to be amorphous if the molecule lacks crystalline structure. The SiO 2 molecule is randomly linked, forming no repeating pattern. 0 Crystalline silica is not desired because of the associated health effects related to fragmentation of its brittle crystalline structure into fragments of respirable size. [22] The amorphous silica fiber is a high-content silica fiber having a silica (Si0 2 ) content of at least about 90 percent by weight, based upon the total weight of the high silica fiber. In one or more embodiments, the high silica fibers have a silica 5 content of at least 95 percent by weight, and in other embodiments, the high silica fibers have a silica content of at least 98 percent by weight. For example, the high silica fibers may contain about 98 percent by weight silica, with the balance predominantly containing alumina. In certain embodiments, the amount of halogen in the high silica fiber is de minimus, less than 120 parts per million by weight. .0 [23] As noted above, the silica fibers are substantially amorphous. While the fibers may contain some crystalline material, a substantial amount of crystallinity is not desired. Suitable silica fiber is commercially available, for example from Polotsk Steklovokno, Belarus. [24] In one embodiment, the starting material composition for the high silica fibers 25 is: from about 72 to about 77% Si0 2 , from about 2.5 to about 3.5% A1 2 0 3 , from about 20 to about 25% Na 2 0, from about 0.01 to about 1.0% CoO and from about 0.01 to about 0.5% SO 3 , all percents by weight, based upon the total weight of the composition. The composition may be melted at about 1480 ± 10 0 C to form a continuous fiber. This fiber may then be leached using hot sulfuric acid having a 30 concentration of 2N at a temperature of about 98 ± 20 C with a dwell time of about 60 minutes. The fiber may then be rinsed with tap water until the pH is about 3-5. In this embodiment, the resulting fiber has a SiO 2 content of from about 95 to about 99% ± 1 percent by weight, with the remainder being predominantly A1 2 0 3 . [25] A high silica glass composition and process for making high silica fibers is 5 described in Russian Pat. No. 2,165,393 (the '393 patent), the disclosure of which is hereby incorporated by reference herein. The high silica fibers of the '393 patent are described as having a lower coefficient of variation in the strength of the basic filaments, which gives the possibility to stabilize the strength characteristics of the resultant fiber, especially at exposure to high temperature. The following description 10 of high silica fibers is taken from the '393 patent for exemplary purposes and should not be construed to limit the present invention. [26] In one or more embodiments, a precursor glass composition may include SiO 2 , A1 2 0 3 and Na 2 0, as well as CoO and SO 3 in the following proportions (percent mass): A1 2 0 3 : 2.5-3.5 15 Na 2 0: 20-25 Coo: 0.01-1.0

SO

3 : 0.01-1.0 SiO 2 : remaining [27] The glass may further contain at least one oxide from the group CaO, 20 MgO, ZrO 2 , TiO 2 , Fe 2 0 3 in the following quantities (percent mass): CaO: 0.01-0.5 MgO: 0.01-0.5 TiO 2 : 0.01-0.1 Fe20 3 : 0.01-0.5 25 ZrO 2 : 0.01-0.5 [28] A resultant, high-temperature silica fiber from the glass composition about would then include SiO 2 and A1 2 0 3 , but also would contain Na2, CoO and SO 3 in the following proportions (percent mass): SiO 2 : 94-96 30 Al 2 0 3 : 3-4 NaTO: 0.01-1.0 coo: 0.01-1.0 SO: 0.01-1.0 [29] The silica fiber may also contain at least one oxide from the group CaO, 5 MgO, TiO 2 , Fe 2 0 3 , ZrO 2 in the following quantities (percent mass): CaO: 0.01-0.5 MgO: 0.01-0.5 TiO 2 : 0.01-0.1 Fe 2 0 3 : 0.01-0.5 10 ZrO 2 : 0.01-0.5 [30] In one embodiment, the silica fibers are substantially free of any metal oxide coating. [31] Diameter of the silica fibers may range from about 5.6 microns to about 12.6 microns and, in one embodiment, the diameter is about 8 microns. Length of 15 the silica fibers may range from about 50 millimeters to about 125 millimeters and, in one embodiment, the length is about 75 millimeters, (shorter and longer fibers are available by adjusting the cut length of the fiber, but are not practical for needlepunch applications). [32] One method of preparation of the silica fibers according to the 20 aforementioned Russian patent, No. 2,165,393, as set forth in Example 1 hereinbelow, may be conducted as follows: To produce continuous filament glass fiber of the proposed composition, a vessel containing (percent mass) SiO 2 :72.39, A1 2 0 3 :2.5, Na 2 0:25, CoO:0.01, S0 3 :0.1 may be prepared. The vessel may be loaded into a furnace, and the composition melted at a temperature of about 1480 ± 10'C. 25 From the molten glass mass, a continuous glass fiber may be formed with a diameter of 6-9 microns at a temperature of about 1260 ± 500 C using 400-hole glass-forming aggregates. The resultant fiber has been shown to have a strength of about 1030 Mpa and a surface tension of about 0.318 H/m. [33] Leaching of the continuous glass fiber may then take place using a hot 30 sulfuric acid solution having a concentration of about 2N (about 10%) at a C:\NRPonblDCC\GAVW661373_1 DOC-4/2/2011 -8 temperature of about 98 ± 20 C. Contact time for the fiber in the solution is 60 minutes. The leaching solution, reaction products, and sizing remains are then washed away from the leached fiber with tap water until the pH is at about 3-5. Final washing of the fiber is conducted with deionized water and simultaneous dehydration. 5 [34] The preparation of the glass composition, its processing and leaching for Examples 2 and 3 below are analogous to that as set forth above for Example 1, but with different amounts of starting materials. Table I presents the starting amounts for the glass as well as the amounts of materials for the resultant silica compositions. Table 2 presents the characteristics of the molten product, the characteristics of processing, and the 10 characteristics of the glass and silica fibers. Table 3 provides strength characteristics of the silica materials after exposure to 10000 C. [35] Tables 1-3 also provide data confirming the introduction of cobalt and SO 3 into the glass composition increases the heterogeneity of the glass mass, lowers its surface tension, decreases the fragility of the fiber during processing and also increases the stability of the 15 technical characteristics of the silica fiber and resultant materials based on this fiber. TABLE 1 GLASS COMPOSITIONS AND RESULTANT SILICA COMPOSITIONS Component Glass Composition Silica Composition Example No. 1 2 3 1 2 3 SiO 2 72.39 73.0 76.94 95.65 93.87 96.58 A120 3 2.5 3.5 3.0 2.8 3.9 3.2 Na 2 O 2 5 22 20 0.32 0.23 0.12 Coo 0.01. 1.0 0.05 0.03 1.3 0.08

SO

3 0.1 0.5 0.01 1.2 0.7 0.02 SYN.P.PUU4b 7 TABLE 2 GLASS AND SILICA FIBER PROPERTIES Glass or Silica Composition No. Example No. 1 2 3 prototype Precursor Glass Fiber Strength, Mpa 1030 1150 1220 1020 Coefficient of strength variation,% 12.2 10.6 9.2 14.7 Coefficient of useful work (CUW) for crucible 0.75 0.72 0.78 0.68 during glass production Surface tension of molten glass, before 0.318 0.27 0.29 0.228 fiber (N/m) Silica Fiber Strength, Mpa 800 860 925 750 Coefficient of strength variation, % 12.4 11.7 9.6 15.9 Silica Yarn Strength, Mpa 61 69 73 -- Coefficient of strength variation, % 14.8 12.6 10.9 Silica Tape Strength, Mpa 1700 1920 2150 -- Coefficient of strength variation, % 13.2 12.7 10.3 -- 5 TABLE 3 BREAKING LOAD SILICA MATERIAL AFTER HEAT PROCESSING AT 1000*C, N 0 Example No. Silica Yarn Silica Tape 1 12.1 142 2 14.3 157 3 18.1 164 [36] Tables 4 and 5 show various glass fiber compositions from which it can be seen that the silica fibers taught by the Russian Pat. No. 2,165,393 differ from all 5 other glass fiber types by the presence of trace amounts of CoO and SO,.

10 U.0 0 0 U. ~0 0 0 0 0 q q 0 Z 0 c6 0 0 0 0 I0 z 0 0L 0 Lf 0 W 9n 0 n 0C 00 ~ 9 0 Lf 0 .CJ 4 6C? 0 qO 0~~ 0 L 0 C;~~o c6 9 oLA9o 00 0 000 9 9 cq 0 0 0 0 N 6 (/ q q ~ %O q, q Ui D % , , Y 0 , V Ln U? U? U, Ul %9 %0 ~~ ~ ~ ~ e.n. Ln L)ci 0 o 'r I n% o. C: E- c- E-0 o 0 8 ,U ,U , U , 31= , uo 'a,8U, do u C~~~* 'n(1 n c A ( n t ) 0 n V) En C 0 0):D : t", U, C N CL OCJ Cl Co >U CD o3 6 C1 o1 0 0 C; 0 0 N ci C '! 090 0L LA 0 0 L c') 6- 6 N iLA 6 0 A Ln LA LA LA S LA LA 6 LA C Ln LA L I ZU 12 (i) u z F- z 0 o 0 u U0 - 0 v Ui 099 0 0 0n -~ ~~ ~ "LcJ0-cn LOA6 6 -= 6 66 0 0 Li 0 00 CD a 9 <0 60 0- 0 0Z '6l % i 6 0z - 0 060 6o 60 0 llo q~ O6.O ,i m0 4 c 01 -" C .0 - . 0 6 0 '~60 6oc>6o 60 60 6o ,0 0 V: C4 ui ui6 6 'c66 c6 '6 Ar- i 0 ~ t > >oo o~ 0 -0 0 0 u 0j 00 co >.E LLa Zu z IA .0 - . F - 0 '. C U , C' t r L ,'~ >n 0 z > 13 0 8 c0 C; 0 co o co 0 0 00 0~ 00C'4 +) No C4 oo 00 0 CL 6'9 V ~0 0 ci 0 0 0~u~ 6 o 6o~ 6 0 0 o .0~ 0202 U~ NO0w g 00t 0 V) V)E ( n Ln 00 0. 0o0 in0 Z.0 cn 66 i:02 eL)Q q'0ntj z~~ ~ ~ ~ 66o l Q eC L. O SYN.P.PC0045 14 [37] Having discussed the amorphous silica component of the present inventions, the additive fibers will be discussed next. As noted hereinabove, the present invention includes two embodiments, one employing flame resistant (FR) fibers and another employing binder fibers. In the following discussion, use of the 5 term "silica fiber" shall be understood to mean those fibers containing amorphous (as opposed to crystalline) silica. [38] Beginning with the first type of additive fibers, namely the FR fibers, the amount of silica fiber in the fiber blend can vary, depending upon the other fibers used. In one embodiment, the amount of silica fiber in the blend is from about 5 to 10 about 65 weight percent, based upon the total weight of the blend. In another embodiment, the amount of silica fiber in the blend is from about 15 to about 50 weight percent. In another embodiment, the amount of silica fiber in the blend is from about 20 to about 30 weight percent. The remaining fibers in the blend include the necessary amount of non-amorphous fibers, namely the FR fibers, to equal 100 15 weight percent. [39] Various FR fibers are known in the art. The FR fibers employed in the fabrics of the present invention may be an inherent flame resistant fiber or a fiber (natural or synthetic) that is coated with an FR resin. The inherent flame resistant fibers are not coated, but have an FR component incorporated within the structural 20 chemistry of the fiber. The term FR fiber, as used herein, includes both the inherent flame resistant fibers as well as fibers that are not inherently flame resistant, but are coated with FR resins. Accordingly, by way of example, a polypropylene fiber coated with an FR resin would be an FR polypropylene fiber. [40] Suitable inherently flame resistant fibers include polymer fibers having a 25 phosphorus-containing group, an amine, a modified aluminosilicate, or a halogen containing group. Examples of inherently flame resistant fibers include melamines, meta-aramids, para-aramids, polybenzimidazole, polyimides, polyamideimides, partially oxidized polyacrylonitriles, novoloids, poly(p-phenylene benzobisoxazoles), poly (p-phenylenebenzothiazoles), polyphenylene sulfides, flame retardant viscose SYN.P.PC0045 15 rayons; (e. g., a viscose rayon based fiber containing 30% aluminosilicate modified silica, SiO 2 +Al 2 03), polyetheretherketones, polyketones, polyetherimides, and combinations thereof). [41] Melamines include those sold under the tradenames Basofil by 5 McKinnon-Land-Moran LLC. Meta-aramids include poly (m-phenylene isophthalamide), for example sold under the tradenames NOMEX@ by E.I. Du Pont de Nemours and Co., TEIJINCONEXO and CONEX® by Teijin Limited and FENYLENE® by Russian State Complex. Para-aramids include poly (p-phenylene terephthalamide), for example sold under the tradename KEVLAR® by E.I. Du Pont de Nemours and 10 Co., and poly (diphenylether para-aramid), for example sold under the tradename TECHNORA® by Teijin Limited, and under the tradenames TWARON® by Acordis and FENYLENE ST (Russian State Complex). [42] Polybenzimidazole is sold under the tradename PBI by Hoechst Celanese Acetate LLC. Polyimides include those sold under the tradenames P-840 by Inspec 15 Fibers and KAPTON® by E.I. Du Pont de Nemours and Co. Polyamideimides include for example those sold under the tradename KERMEL@ by Rhone-Poulenc. Partially oxidized polyacrylonitriles include, for example, those sold under the tradenames FORTAFIL OPF® by Fortafil Fibers Inc., AVOX® by Textron Inc., PYRON® by Zoltek Corp., PANOX® by SGL Technik, THORNEL® by American Fibers and Fabrics and 20 PYROMEX® by Toho Rayon Corp. [43] Novoloids include, for example, phenol-formaldehyde novolac, such as that sold under the tradename KYNOLO by Gun Ei Chemical Industry Co. Poly (p-phenylene benzobisoxazole) (PBO) is sold under the tradename ZYLON® by Toyobo Co. Poly (p-phenylene benzothiazole) is also known as PBT. Polyphenylene 25 sulfide (PPS) includes those sold under the tradenames RYTON® by American Fibers and Fabrics, TORAY PPSO by Toray Industries Inc., FORTRONO by Kureha Chemical Industry Co. and PROCON® by Toyobo Co. [44] Flame retardant viscose rayons include, for example, those sold under the tradenames LENZING FR® by Lenzing A. G. and VISILO by Sateri Oy Finland.

SYN.P.PC0045 16 Polyetheretherketones (PEEK) include, for example, that sold under the tradename ZYEXO by Zyex Ltd. Polyketones (PEK) include, for example, that sold under the tradename ULTRAPEKO by BASF. Polyetherimides (PEI) include, for example, that sold under the tradename ULTEM5 by General Electric Co. 5 [45] Modacrylic fibers are made from copolymers of acrylonitrile and other materials such as vinyl chloride, vinylidene chloride or vinyl bromide. Flame retardant materials such as antimony oxide can be added to further enhance flame resistant property. Modacrylic fibers used in this invention are manufactured by Kaneka under the product names KANECARON PBX and PROTEX-M, PROTEX-G, .0 PROTEX-S and PROTEX-PBX. The latter products contain at least 75% of acrylonitile - vinylidene chloride copolymer. SEF PLUS by Solutia is a modacrylic fiber as well with flame retardant properties. [46] Further examples of inherent FR fibers suitable for use in the blend of the present invention include polyester with phosphalane such as that sold under the 5 trademark TREVIRA CS® fiber or AVORA® PLUS FIBER by KoSa. [47] Also useful are chloropolymeric fibers, such as those sold under the tradenames THERMOVYL® L9S & ZCS, FIRBRAVYLP L9F, RETRACTYL® L9R, ISOVYLP MPS by Rhovyl S.A., PIVIACIDO, Thueringische, VICLON® by Kureha Chemical Industry Co., TEVIRONO by Teijin Ltd., ENVILONO by Toyo Chemical Co., .0 VICRONO, SARAN@ by Pittsfield Weaving, KREHALONO by Kureha Chemical Industry Co., OMNI-SARANO by Fibrasomni, S.A. de C.V., and combinations thereof. Fluoropolymeric fibers such as polytetrafluoroethylene (PTFE), poly(ethylene chlorotrifluoroethylene (E-CTFE), polyvinylidene fluoride (PVDF), polyperfluoroalkoxy (PFA), and polyfluorinated ethylene-propylene (FEP) and .5 combinations thereof are also useful. [48] Natural or synthetic fibers coated with an FR resin are also useful in the fiber blend of the present invention. Suitable fibers coated with an FR resin include those where the resin contains one or more of phosphorus, phosphorus compounds, red phosphorus, esters of phosphorus, and phosphorus complexes; amine SYN.P.PC0045 17 compounds, boric acid, bromide, urea-formaldehyde compounds, phosphate-urea compounds, ammonium sulfate, or halogen based compounds. Non-resin coatings like metallic coating are not generally employed for the present invention, because they tend to flake-off after continuous use of the product. Suitable commercially 5 available FR resins are sold under the trade names GUARDEX FRO, and FFR® by Glotex Chemicals in Spartanburg, S.C. [49] The manner in which the resin is coated onto the fiber is not particularly limited. In one embodiment, the FR resin is a liquid product that can be applied as a spray. In another embodiment, the FR resin is a solid that may be applied as a hot 10 melt product to the fibers, or as a solid powder that is then melted into the fibers. In one embodiment, the FR resin is applied to the fibers in an amount of from about 6 to about 25 weight %, based upon the total weight of the coated fibers. [50] The amount of coated FR fiber in the blend can vary, but is from about 35 to about 95 weight percent, based upon the total weight of the blend. In one 15 embodiment, the amount of coated FR fiber in the blend is from about 40 to about 90 weight percent. In another embodiment, the amount of coated FR fiber in the blend is from about 45 to about 85 weight percent. [51] The denier of the FR fibers is from about 1.5 to about 15 dpf (denier per filament). The foregoing listing of FR fibers is not to be construed as a limiting the 20 practice invention but instead to illustrate the fact that any FR fiber known can be employed with an amorphous silica fiber and utilized in the practice of the present invention. Thus, fiber types includes multifilament and monofilament yams, having a variety of cross-sections and shapes as well as fibrillated yams, typically manufactured from slit films or tapes. 25 [52] The fiber blend of the present invention may further contain one or more non-FR fibers. The non-FR fibers may be synthetic or natural fibers. Suitable non-FR synthetic fibers include polyester such as polyethylene terephthalate (PET); cellulosics, such as rayon and/or lyocell; nylon; polyolefin such as polypropylene fibers; acrylic; melamine and combinations thereof. The lyocell fibers are a generic SYN.P.PCO04S 18 classification for solvent-spun cellulosic fibers. These fibers are commercially available under the name TENCELO. Natural fibers include flax, kenaf, hemp, cotton and wool. In one embodiment, non-FR fibers are employed to enhance certain characteristics such as loft, resilience or springiness, tensile strength, and thermal 5 retention. [53] The fiber blend includes amorphous silica fiber and at least one type of FR fiber. Therefore, the present invention is embodied by a fiber blend that contains amorphous silica fiber, an FR fiber, optionally additional FR fibers, and optionally one or more non-FR fibers. In one embodiment, the fiber blend includes: modacrylic 10 fiber; a cellulosic fiber, lyocell, and amorphous silica fiber. [54] In another embodiment, the fiber blend further includes more than one type of FR fiber. In another embodiment, the fiber blend includes amorphous silica fiber, modacrylic fiber, and VISIL. In yet another embodiment, the fiber blend includes modacrylic fiber, FR rayon fiber, and amorphous silica fiber. 15 [55] In another embodiment, the fiber blend includes modacrylic fibers, VISIL (FR viscose rayon) fibers, amorphous silica fibers, and FR polypropylene fibers. The amounts of each component can vary; however, advantageous char strength is obtained when a needlepunched fabric is prepared from a blend containing about 40 weight percent modacrylic, about 40 weight percent VISIL, about 15 weight percent 20 amorphous silica, and about 5 weight percent FR polypropylene fibers. [56] The fibers of the present invention can be used to manufacture fabrics, where FR properties are desired or would be useful. Essentially any type of fabric, produced from fibers, such as non-woven fabrics; woven fabrics, both open and closed weave; knitted fabrics and various laminates can be made using the fibers of 25 the present invention. The manufacture of such fabrics is not limited to a particular method or apparatus. For woven fabrics, it is possible to employ amorphous silica fibers in the machine direction or the cross machine direction, alternating with one or more of the FR fibers. Alternatively, the fibers can be alternated in the machine direction and woven with either an amorphous or an FR fiber in the cross machine SYN.P.PCO04s 19 direction. As a percentage, woven fabrics according to the present invention can comprise the compositions stated above for the blend of amorphous and FR fibers. [57] The non-woven fabric of the present invention may be produced by mechanically interlocking the fibers of a web. The mechanical interlocking can be 5 achieved through a needlepunch operation. Needlepunch methods of preparing non woven fabric are known in the art. In one embodiment, the nonwoven fabric, sometimes called a batt, may be constructed as follows: the fiber blend may be weighed and then dry laid/air laid onto a moving conveyor belt. The speed of the conveyor belt can be adjusted to provide the desired batt weight. Multiple layers of 0 batts are fed through a needle loom where barbed needles are driven through the layers to provide entanglement. [58] There are several other known methods for producing nonwoven fabrics including hydroentanglement (spunlace), thermal bonding (calendering and/or though-air), latex bonding or adhesive bonding processes. The spunlace method is 5 similar to needlepunch except waterjets are used to entangle the fibers instead of needles. Thermal bonding requires either some type if thermoplastic fiber or powder to act as a binder. It is to be appreciated that all forms of nonwovens can be made with the FR fiber blends of the present invention to produce barrier fabrics having FR properties. Accordingly, reference to nonwoven fabrics herein includes all forms of 0 manufacture. [59] Suitable non-woven fabrics of the present invention have a batt weight greater than about 2.25 oz./sq. yd. (osy). In one embodiment, the batt weight ranges from about 2.25 osy to about 20 osy. In another embodiment, the batt weight is about 3.5 osy. In one embodiment, the fibers are carded. Then the conveyor belt 5 moves to an area where spray-on material may optionally be added to the nonwoven batt. For example, the FR resin may be sprayed onto the nonwoven batt as a latex. In one embodiment, the conveyor belt is foraminous, and the excess latex spray material drips through the belt and may be collected for reuse later. After the optional spraying, the fiber blend is transported to a dryer or oven. The fibers may be SYN.P.PCO04S 20 transported by conveyer belt to the needlepunch loom where the fibers of the batt are mechanically oriented and interlocked to form a non-woven fabric. [60] The non-woven FR fabric is useful as a barrier fabric for bedding materials and bed clothing. The fabric is also useful in upholstery and drapery applications 5 where flame resistance is desired. Another use for such fabrics is as hot gas filtration fabrics. Additionally, fabrics other than non-wovens can be made from the fibers of the present invention, where an FR fabric is desired. GENERAL EXPERIMENTAL 0 [61] In order to demonstrate the efficacy of various fiber blends as FR materials, a number of samples were prepared and tested, as described hereinbelow. The examples have been provided to demonstrate practice of the present invention and should not be construed as limitations of the invention or its practice. .5 EXAMPLES Example Nos. 4-15 [62] The samples were prepared on a miniature card and needleloom. The fiber was first hand-opened and layered on the card feed apron. The carded sample was run 0 back through the card a second time to assure intimate blending of fibers. The carded web, layered around the wind-up roll, was cut transversely and removed from the card. Then it was fed into the needlepunch line for needling. A second pass was performed to accomplish needling from the opposite side. [63] Standard tensile strength testers were modified to measure the char strength of 25 the barrier fabric of the present invention. More specifically, the fabric stiffness test typically used with pocket coil material was modified to measure the amount of force, measured and reported in pounds, required to push a fabric sample through a hole with a plunger. To force the material to break, a template was fabricated so that the fabric could be sandwiched between the template and the existing test plate.

SYN.P.PCo045 21 [64] Specimens of the barrier fabric were cut into 4" by 8" (10 by 16 cm) samples and weighed. The samples were placed in a charring frame and charred by using a Bunsen burner. The frame was then mounted into the modified stiffness tester and the char strength of the sample was measured. Table 6 summarizes the results for 5 Example Nos. 4-15. As a standard, a blend comprising 40% modacrylic and 60%Visil was selected (Ex. No. 4). The following types of fiber were used: Basofile (abbreviated Bas); modacrylic fiber KANECARON PBX; VISIL® (abbreviated Vis); polyethylene terephthalate (abbreviated PET); and amorphous silica (abbreviated Sil). Examples 5-11 and 13-14 are comparative examples of fabric prepared from LO various fiber blends as indicated. Examples 5 and 6 contained 10% Basofil fibers as a replacement for equal amounts of modacrylic fiber or Visil fiber; Examples 7 and 8 contained 10% and 20% PET fibers as a replacement for equal amounts of Visil fiber; Example 9 comprised a blend 10% Basofil fibers with PET fibers, modacrylic fiber and Visil fiber; Examples 10 and 11 contained 10% and 15% PET fibers as a 15 replacement for varying amounts of modacrylic fiber and Visil fiber; Examples 13 and 14 contained 10% Basofil fibers as a replacement for varying amounts of modacrylic fiber and Visil fiber; Examples 12 and 15 were prepared from fiber blends containing amorphous silica fibers, according to the present invention.

SYN.P.PC0045 22 TABLE 6 CHAR STRENGTH TO WEIGHT RATIO FOR NON-WOVEN FABRIC MADE FROM VARIOUS FIBER BLENDS Ex. No. FIBER BLEND Strength Weight Strength/ Weight (pounds) (ounces) 4 40 PBX/60 Vis 0.32 5.4 0.06 5 10 Bas/30 PBX/60 Vis 0.31 5.9 0.05 6 10 Bas/40 PBX/50 Vis 0.36 6.9 0.05 7 10 PET/40 PBX/50 Vis 0.32 6.7 0.05 8 20 PET/40 PBX/40 Vis 0.32 6.5 0.05 9 10 Bas/10 PET/25 PBX/ 0.32 4.2 0.08 55 Vis 10 10 PET/25 PBX/65 Vis 0.30 4.7 0.06 11 15 PET/25 PBX/60 Vis 0.29 5.0 0.06 12 10 Sil/35 PBX/55 Vis 0.42 5.3 0.08 13 10 Bas/30 PBX/60 Vis 0.30 3.2 0.09 14 10 Bas/40 PBX/50 Vis 0.30 3.3 0.09 15 10 Sil/35 PBX/55 Vis 0.31 2.9 0.10 5 [65] It can be seen that when the char strength of the fabric is correlated to the weight of the sample, the fabric formed from fiber blends containing amorphous silica (Examples No. 12 and 15) show a strength to weight ratio of from 0.08 to about 0.10.

SYN.P.PC0045 23 Example Nos. 16-45 [66] Examples 16-45 were prepared and tested as for Examples 4-15, except that different blends of fiber were used, as summarized in Table 7. Strength of each fabric is reported in pounds, as discussed hereinabove. The fabrics have been 5 reported in six groups of four blends and two groups of three blends. Examples 19, 23, 27, 31, 34, 38, 41, and 45 report a base fabric and the examples immediately preceding report the addition of various types of FR fiber. Char strength, in pounds, was measured and the results have been reported by decreasing values for each group. 0 [67] For example, FR rayon and modacrylic fibers were used to prepare Example 19, denoted FR Rayon/Modacrylic Base Fabric. Examples 16-18 are variations of this base fabric, because in each case one other type of FR fiber was added: para-aramid fibers were added to Example 16, melamine fibers were added to Example 17, and amorphous silica fibers were added to Example 18, according to the 5 present invention. [68] Similarly, Example 23 was prepared from FR rayon fibers and is denoted FR Rayon Base Fabric, while Examples 20-22 were variations of this base fabric: para-aramid fibers were added to Example 20, melamine fibers were added to Example 21, and amorphous silica fibers were added to Example 22, according to the o present invention. [69] Likewise, Example 27 is a rayon/modacrylic base fabric, and Examples 24 26 were variations of this base fabric: melamine fibers were added to Example 24, para-aramid fibers were added to Example 25, and amorphous silica fibers were added to Example 26, according to the present invention. 5 [70] Example 31 is a lyocell/modacrylic base fabric, and Examples 28-30 were variations of this base fabric: para-aramid fibers were added to Example 28, melamine fibers were added to Example 29, and amorphous silica fibers were added to Example 30, according to the present invention.

SYN.P.PCo045 24 [71] In the next series, Example 34 is the Visil/modacrylic base fabric, and Examples 32, 33 and 35 were variations of this base fabric: para-aramid fibers were added to Example 32, amorphous silica fibers were added to Example 33, according to the present invention; and melamine fibers were added to Example 35. 5 [72] Example 38 is a Visil base fabric, while Examples 36-37 were variations of this base fabric: melamine fibers were added to Example 36, and amorphous silica fibers were added to Example 37, according to the present invention. [73] Example 41 is a rayon base fabric, while Example 39 contains rayon and melamine, and Example 40 contains rayon and amorphous silica, according to the 0 present invention. [74] Example 45 is a lyocell base fabric, while Example 42 contains para aramid, Example 43 contains lyocell and melamine, and Example 44 contains lyocell and amorphous silica, according to the present invention. 5 TABLE 7 CHAR STRENGTH OF NON-WOVEN FABRIC MADE FROM VARIOUS FIBER BLENDS Ex. No. FABRIC STRENGTH 16 FR Rayon/Modacrylic/10% para aramid 3.22 17 FR Rayon/Modacrylic/10% melamine 2.39 18 FR Rayon/Modacrylic/10% silica 2.23 19 FR Rayon/Modacrylic Base Fabric 1.77 20 FR Rayon/10% para aramid 2.98 21 FR Rayon/10% melamine 2.37 22 FR Rayon/10% silica 1.39 23 FR Rayon Base Fabric 0.63 24 Rayon/Modacrylic/10% melamine 2.85 sYN.P.PC0045 25 25 Rayon/Modacrylic/10% para aramid 2.34 26 Rayon/Modacrylic/10% silica 2.12 27 Rayon/Modacrylic Base Fabric 0.74 28 Lyocell/Modacrylic/10% para aramid 2.37 29 Lyocell/Modacrylic/10% melamine 1.49 30 Lyocell/Modacrylic/10% silica 1.43 31 Lyocell/Modacrylic Base Fabric 0.64 32 Visil/Modacrylic/10% para aramid 2.08 33 Visil/Modacrylic/10% silica 1.76 34 Visil/Modacrylic Base Fabric 1.54 35 Visil/Modacrylic/ 10% melamine 1.32 36 Visil/10% melamine 1.65 37 Visil/10% silica 1.29 38 Visil Base Fabric 0.92 39 Rayon/10% melamine 1.55 40 Rayon/10% silica 1.36 41 Rayon Base Fabric 0.01 42 Lyocell/10% para aramid 1.27 43 Lyocell/10% melamine 0.37 44 Lyocell/10% silica 0.32 45 Lyocell Base Fabric 0.01 [75] It can be seen from the data in Table 7 that fabric containing 10 percent by weight amorphous silica shows improved char strength as compared to that same base fabric without amorphous silica e.g., Example No. 18 compared to Example No.

SYN.P.PCO045 26 19. It will be noted that while the use of other FR materials, namely para-aramid and melamine, with the base fabric generally provided greater strength than the blend containing amorphous silica, the former two materials are far more costly than the silica. In addition, the aramids present a golden yellow color to the fabric, while the 5 melamines present an off-white color. The amorphous silica does neither and thus, the resulting fabric is white without the addition of pigments. Finally, the char strength of the fabrics comprising amorphous silica is more that adequate for usefulness in bedding, clothing, furniture, drapery and related purposes. 0 Example Nos. 46-53 [76] Examples 46-53 were prepared by using a needlepunch line including a 12 inch card, a crosslapper, and a 24 inch Dilo OD-1 needle loom. Example No. 46 was the base blend (8 osy) comprising 40 % modacrylic and 60 % Visil) and in the Examples following, various materials or FR fibers were employed. Example 47 15 comprised a blend of the base blend (79 %) and leno weave carpet backing, 2.1 osy, (21%). Example 48 comprised a blend of the base blend(89 %) and Conwed scrim, 1 osy, (11 %). Conwed is a very lightweight polypropylene material with the "warp" and "fill" monofilaments "welded" together at the vertices to provide a "leno type" appearance. Example 49 comprised a blend of the base blend (85 %) and Basofil 20 (melamine)(15 %). Example 50 comprised a blend of the base blend (85 %) and Conex (15 %). Conex is a meta-aramid. Example 51 comprised a blend of the base blend(85 %) and amorphous silica (15 %). Example 52 comprised a blend of the base blend(85 %) and Kynol (phenol-formaldehyde novolac) (15 %). Example 53 comprised a blend of amorphous silica (15 %), modacrylic fiber (40 %) and Visil 25 fiber (45 %). Example No. 53 represents a fabric of the present invention. [77] A tuft button simulation was designed to expose the charred fabric to stresses that it might see in an actual mattress burn, and gives a pass/fail indication of fabric strength. A small test rig was constructed out of wood. Components were assembled shown in the drawing figure to form tuft button test apparatus 10.

SYN.P.PCO045 27 Mattress components including 4 inch foam 12, two 1 inch super-soft foams 14,16, barrier fabric 18, which was 0.5 ounces per square foot (osf), PET fiber fill 20, and a PET ticking fabric 22 were assembled as described below, and then burned under tension. 5 [78] The components were assembled on top of upper plate 24. The foam components 12, 14 and 16, were compressed and the barrier fabric 18, fiber fill 20, and ticking 22 were wrapped around all sides of upper plate 24. Lower plate 26 was positioned to sandwich fabrics 18, 20, 22 between upper plate 24 and lower plate 26. A tuft button simulator 28, was welded to threaded rod 30, and rod 30 was pushed 10 through all of the mattress components, and through aligned holes 32, 34 in upper and lower plates 24, 26. Wing nut 36 was fastened to rod 30 to apply tension to the assembly and draw tuft button simulator 28 down into the foam. [79] A TB 603 top burner 28 was placed in the center of tuft button simulator 10, ignited, and allowed to burn for 70 seconds. Results are summarized in Table 8.

28 a) -co C C v; ~~a V) (A ( a*= ' ) "0Z Cd4J 0- .- > r. z) a:1 C ) w) 0 0 0 0 0 uAl: u u u U U 7 C4 cn a4 a) (A V) (n 0 0 0D o tn 0o C N cn cn N H .5 m~ VU Uz z Uz -D sc 0 r-4 U Iac" c~ PC u Zi'~ uI u/ ui u/ I '0) '0 o~~ o w a) Q) ( 0) 0- d ) cd, Ln u o cn E n :-D z ) u Q cu Q) ae cz 0 .0 1o 0 co tn Cd, zz -o 5 )u Li) ) 0) 0)m 0 -~ d) d) Cd, ~ ' '0 zz Ca 'CT co m ' 0n '-i NLO Lni V) V) Ln rA If) U) ) SYN.P.PC0045 29 [80] In several previous full-mattress burns of various constructions, an 8 osy needlepunch fabric of 60% Visil/40% modacrylic had successfully passed according to the criteria set forth in California Test Bulletin 603. Only in constructions where this barrier was subjected to tension after charring was this fabric not successful. As a 5 control, to show that known fabric performance in full scale testing performed comparably with this bench test, the 8 osy fabric was used (Ex No. 46). The sample cracked in the area surrounding the tuft button within 30 seconds, and the entire assembly was fully aflame within 40 seconds. This was the desired performance, since it accurately portrayed the performance of this fabric in full-scale bums. Ex No. 0 47 used the 8osy fabric in a composite with a 2.1 osy leno weave secondary carpet backing fabric. Likewise, it cracked within 20 seconds, and was withdrawn as a possible solution. Similarly, Ex No 48 used a polypropylene scrim, very light in wt (about 1 osy) that had a "leno-weave look" to it. Though it was not a woven fabric, the vertices of the "warp" and "fill" monofilaments were fused together. This sample 5 also cracked well under 1 minute. [81] The remaining samples prepared were not composites, but needled blends of fibers performed on a pilot line card/crosslapper/needleloom assembly. These samples were also produced at lower weights to gain economic advantages. The first fabric evaluated, Ex No. 49, was a 6 osy fabric consisting of 15% melamine, and 85% 0 "base blend" of 60/40 Visil/modacrylic. This fabric cracked within 30 seconds and flamed out of control. It was eliminated as a candidate for this application. Ex. No. 50, a 6 osy fabric consisting of 15% meta aramid, and 85% "base blend" of 60/40 Visil/modacrylic, also cracked and burned out of control within 25 seconds. Ex. No. 51, a 6 osy fabric consisting of 15% amorphous silica, and 85% "base blend" of 5 60/40 Visil/modacrylic did not crack, and the full assembly self-extinguished within 8 minutes of ignition. Similarly, Ex No. 52, a 6 osy fabric consisting of 15% novoloid, and 85% "base blend" of 60/40 Visil/modacrylic did not crack, and self-extinguished within 11.5 minutes. Though many other fibers were considered for this demonstration, the higher cost of some fibers prevented them from being considered 0 economical. In a follow-up to these trials, a fabric according to the present invention, SYN.P.PC0045 30 Ex. No. 53, a 5 osy fabric consisting of 15% amorphous silica, 40% modacrylic, and 45% Visil, was assembled in the tuft button simulator rig, and it also did not crack, and in fact, self-extinguished in about 13 minutes. [82] Having demonstrated that the use of amorphous silica fibers with FR S fibers is highly effective in providing FR fabrics, the second embodiment shall be discussed next. [83] As noted hereinabove, this invention is directed to a single layer nonwoven fabric useful in protecting items from fire and the related heat; and a process for protecting adjacent materials in an assembly using the fire and heat 10 barrier fabric. The nonwoven barrier is of at least about 0.45 ounces per square yard of an amorphous silica fiber and at least about 0.45 ounces per square yard of a binder fiber; the single layer nonwoven fabric having a basis weight of at least about 3.0 ounces per square yard. The fiber blend by weight of the nonwoven fabric comprises about 15 to about 80 percent by weight amorphous silica fiber, about 15 15 to about 85 percent by weight binder fiber and may, but not necessarily, contain up to about 70 percent by weight of complimentary fibers with a reduction of the other two fibers to total 100 percent by weight without falling below the minimum amounts. [84] As stated previously, the amorphous silica fiber is always present in the 20 nonwoven fabric composition and comprises at least about 15 percent by weight of the fiber blend, but no more than about 80 percent. In one embodiment the amorphous silica fiber comprises between about 35 and about 50 percent by weight of the fiber blend. As the blend percentage by weight of the silica fiber is reduced, the effectiveness of the single layer nonwoven to shield open flames and heat 25 diminishes. Although the individual amorphous silica fibers continue to resist burning and melting at levels lower than about 15 percent by weight in the nonwoven, at least this level must be maintained to offer adequate structure and integrity within the nonwoven fabric construction during and after exposure to an open flame. At least about 15 percent by weight of the amorphous fibers by weight 30 are required in the nonwoven to maintain any acceptable level of char strength.

SYN.P.PCO045 31 [85] The blend percentage by weight of the amorphous silica is limited to no more than about 80 percent by weight in the described nonwoven to preserve the functional characteristics required of a fire and heat barrier fabric. The fiber-to-fiber cohesion of the amorphous silica is such that at least about 20 percent by weight of 5 more cohesive fibers are required for sufficient fiber web strength and fiber entanglement in the nonwoven. It is this entanglement combined with the thermal bond that makes this single layer nonwoven unique. The combination of the mechanical and thermal bond results in a nonwoven construction, in at least one embodiment, capable of at least one of the following without limiting its ability to 10 shield flames and heat, in another embodiment, capable of a majority of the following without limiting its ability to shield flames and heat and, in another embodiment, capable of all of the following without limiting its ability to shield flames and heat: 15 i) capable of maintaining a needled stitch in a sewn assembly without the support of additional fabric layers as required by conventional thermally bonded nonwovens for support and reinforcement ii) capable of maintaining a thermal stitch in an ultrasonically 20 welded assembly without the support of additional fabric layers as required by conventional thermally bonded nonwovens for support and reinforcement iii) capable of maintaining a thermal stitch in a heat welded assembly without the support of additional fabric layers as 25 required by conventional thermally bonded nonwovens for support and reinforcement iv) capable of maintaining the integrity of its nonwoven construction as the surface layer of an assembly without excessive abrasion along the exposed surface, especially as 30 compared to materials utilizing FR surface coatings SYN.P.PC0045 32 v) capable of blending colors to avoid aesthetically displeasing contrasts in assembly of different materials and colors common with many conventional flame-resistant materials (natural color is white and blending hues are achieved by heathering in colors 5 of the binder fiber or other additional fibers) vi) capable of use in a moving and/or contacted assembly without excessive noise related to its nonwoven construction vii) capable of sufficient loft, lower density and greater thickness, to provide satisfactory quilted seam depth considered aesthetically 0 pleasing in a needle-sewn assembly (conventional needlepunch constructions are not) viii) capable of sufficient loft, lower density and greater thickness, to provide satisfactory quilted seam depth considered aesthetically pleasing in an ultrasonically welded assembly (conventional 5 needlepunch constructions are not) ix) capable of sufficient loft, lower density and greater thickness, to provide satisfactory quilted seam depth considered aesthetically pleasing in a heat welded assembly (conventional needlepunch constructions are not) .0 x) capable of maintaining flame and heat shielding efficiency after exposure to moisture (no performance-based aqueous solutions that might be washed away) xi) capable of providing sufficient stiffness of hand to prevent wrinkling and/or gathering around cutting surfaces which is 25 commonly an issue with softer constructions. [86] In addition to the amorphous silica fiber, a binder fiber is always present in the nonwoven fabric composition and comprises at least 15 percent by weight of the fiber blend. In one embodiment, the amorphous silica fiber comprises between 30 50 and 65 percent by weight of the fiber blend. The binder fiber is necessary for the SYN.P.PCO045 33 required thermal bonding of the nonwoven barrier fabric, but a multi-component binder fiber may also serve both a mechanical and a thermal role in the nonwoven fabric construction. Mechanically, at least one fiber must offer sufficient fiber-to fiber cohesion to maintain the integrity of the fiber web and sufficient structure after 5 thermal bonding to maintain entanglement of the fibers among the amorphous silica fibers. This cohesive fiber may be a component of the binder fiber (in the case of a multi-component binder fiber) that remains intact after thermal bonding, or it may be a fiber, or fibers, additive to the amorphous silica and binder fiber in the blend. [87] The binder fiber may be a single component, low melting point fiber that 0 strictly acts as a binding agent for the thermal bond necessary in the nonwoven. Exemplary single component fibers include low-melt polyethylene terephthalate, polypropylene, polyethylene, low-density polyethylene, linear low-density polyethylene, polylactic acid, polytrimethylene terepthalate, polycyclohexanediol terephthalate, polyethylene terephthalate glycol, nylon 6, nylon 6,6, nylon 11, nylon 5 12, polymethyl pentene and other thermoplastic polymers that have sufficiently low melting points, whether inherent or modified..By "sufficiently low" is meant that such thermoplastic fibers will have the lowest melting point of all the component fibers present. Some polymers will inherently have the lowest melting point while others, such as the polyesters, may need to be modified with an appropriate additive to yield 0 a lower melting point than inherently possessed by the unmodified polymer. [88] The single-component binder fiber comprises at least 15 percent by weight of the fiber blend in the nonwoven. With regard to this invention, any instance where a single-component binder fiber is used requires the addition of at least 15 percent by weight of a higher cohesion fiber for mechanical fiber interlock after 5 thermal bonding. The single-component binder fiber must have a melting temperature no less than 107* C, but the melting temperature cannot exceed a value 100 C less than the lowest melting temperature of any other structural fiber in the fiber blend of the nonwoven. [89] The maximum melt temperature of the single-component binder fiber 0 allows for the binder fiber to melt and flow, forming a binding matrix along and SYN.P.PC0045 34 between structural fibers as these fibers are left intact at a temperature lower than their melting point. The minimum temperature varies by end-use application of the nonwoven fire/heat barrier and is based on a temperature higher than the maximum temperature exposure of the nonwoven barrier in subsequent assembly processes and 5 day-to-day operational use and environs. Optimally the melt temperature of the single-component binder fiber is minimized within the range to reduce the energy and time required to thermally bond the nonwoven barrier fabric. [90] Diameter of the single-component binder fiber ranges from about 20 microns to about 60 microns and in one embodiment, it is about 31 microns. Length 10 of the single-component fiber ranges from about 50 millimeters to about 125 millimeters and in one embodiment, it is about 75 millimeters, for needlepunch applications. The single-component binder fiber should not act as a contributory fuel source for an open flame. [91] The binder fiber may be a multiple component, low melting point fiber 15 that acts strictly as a binding agent for the thermal bond necessary in the nonwoven. Exemplary multiple component fibers include those fibers of co-extruded polymers in combinations containing at least two of the following polymers: polyethylene terephthalate, polypropylene, polyethylene, low-density polyethylene, linear low density polyethylene, polylactic acid, polytrimethylene terpthalate, 20 polycyclohexanediol terephthalate, polyethylene terephthalate glycol, nylon 6, nylon 6,6, nylon 11, nylon 12, polymethyl pentene and other thermoplastic polymers that have sufficiently low melting points, whether inherent or modified. The term "sufficiently low" has the same meaning as set forth above for the single-component fibers. Similar to the single-component fibers, the multi-component fibers provide 25 two polymers that melt to provide thermal bonding. [92] This multi-component thermal binding fiber comprises at least about 15 percent by weight of the fiber blend in the nonwoven. With regard to this invention, any case where a multi-component binder fiber acts only as a thermal binding agent, its use requires the addition of at least about 15 percent by weight of a higher 30 cohesion fiber, but no more than about 70 percent by weight, for mechanical fiber SYN.P.PC0045 35 interlock after thermal bonding. This multi-component thermal binding fiber must have a melting temperature no less than 1070 C, but the melting temperature cannot exceed a value 100 C less than the lowest melting temperature of any other structural fiber in the fiber blend of the nonwoven. 5 [93] The maximum melt temperature of the multi-component thermal binding fiber allows for the binder fiber to melt and flow, forming a binding matrix along and between structural fibers as these fibers are left intact at a temperature lower than their melting point. The minimum temperature varies by end-use application of the nonwoven fire/heat barrier and is based on a temperature higher than the maximum 0 temperature exposure of the nonwoven barrier in subsequent assembly processes and day-to-day operational use and environs. Optimally the melt temperature of the multi-component binding fiber is minimized within the range to reduce the energy and time required to thermally bond the nonwoven barrier fabric. [94] Diameter of the multi-component binder fiber ranges from about 20 5 microns to about 60 microns and in one embodiment, it is about 31 microns. Length of the single-component fiber ranges from about 50 millimeters to about 125 millimeters and in one embodiment, it is about 75 millimeters, for needlepunch applications. The multi-component binder fiber should not act as a contributory fuel source for an open flame. 0 [95] The binder fiber may be a multiple component, multi-binding (both mechanical and thermal binding functions) low melting point fiber that acts as a binding agent for the thermal bond necessary in the nonwoven and as a mechanical actor that has fiber-to-fiber cohesion sufficient to maintain entanglement of the nonwoven fiber matrix. Exemplary multiple component, multi-binding component 5 fibers include those fibers of co-extruded polymers in combinations containing at least two of the following polymers: polyethylene terephthalate, polypropylene, polyethylene, low-density polyethylene, linear low-density polyethylene, polylactic acid, polytrimethylene terpthalate, polycyclohexanediol terephthalate, polyethylene terephthalate glycol, nylon 6, nylon 6,6, nylon 11, nylon 12, polymethyl pentene and 0 other thermoplastic polymers that have sufficiently low melting points, whether SYN.P.PCO045 :30 inherent or modified. The term "sufficiently low" has the same meaning as set forth above for the single-component fibers. Similar to the single-component fibers, the multi-component, multi-binding fibers provide a polymer that melts to provide thermal bonding; however, the second polymer does not melt and provides the 5 mechanical function for fiber entanglement. This latter difference is a distinction between the multi-component fibers and the multi-component multi-binding fibers. [96] In other words, the multi-component multi-binding fibers must contain at least one component comprised of a lower-melt binding agent and a higher melt point component that remains intact after exposure to heat in the thermal bonding 0 stage. This latter difference is a distinction between the multi-component fibers and the multi-component, multi-binding fibers. [97] The multi-component multi-binding fiber comprises at least 15 percent by weight of the fiber blend in the nonwoven. With regards to this invention, any case where a multi-component multi-binding fiber is used does not necessarily require the 5 addition of another higher cohesion fiber for mechanical fiber interlock after thermal bonding provided all described criteria are met. [98] Diameter of the multi-component multi-binding fiber ranges from about 20 microns to about 60 microns and in one embodiment, it is about 31 microns. Length of the single-component fiber ranges from about 50 millimeters to about 125 0 millimeters and in one embodiment, it is about 75 millimeters, for needlepunch applications. The multi-component multi-binding fiber should not act as a contributory fuel source for an open flame and may, in fact, be flame resistant. [99] The multi-component, multi-binding fibers may be any of several different fiber configurations (e.g. concentric sheath/core, eccentric sheath/core, side-by-side 5 or bilateral, pie wedge, hollow pie wedge, islands-in-the-sea or matrix, and the like.), but it must retain core fibers of near original length after thermal bonding. These remaining core fibers must have strength sufficient to maintain mechanical entanglement under stress and must not act as a contributory fuel source to an open flame. In one embodiment, a minimum of about 10 percent, but no more than about 30 90 percent, by weight of the individual fiber acts as the thermal binding agent and SYN.PPCo045 37 must have a melting temperature no less than about 107* C, but no more than about 1500 C. In another embodiment the melting temperature is about 110* C. The previously described core fiber comprises a minimum of about 10 percent, but no more than about 90 percent, by weight of the individual fiber and must have a 5 melting temperature no less than about 1150 C. [100] A useful binder fiber is a core/sheath bi-component configuration comprised of a polyethylene terephthalate (PET) core and a lower melt temperature PET sheath wherein the sheath is about 60 percent by weight of the individual fiber and the core is the remaining 40 percent. The sheath acts as the thermal binding 10 agent forming the outer surface of the binder fiber and has a melting temperature of about 1100 C and the core has a melting temperature of about 1300 C. Such a core/sheath bi-component binder fiber is available from Huvis Corporation in Korea. In one embodiment, core/sheath bi-component binder fiber comprises between 50 and 65 percent by weight of the fiber blend in the nonwoven barrier. 15 [101] Other multi-component multi-binding fibers that may also be employed include those fibers of co-extruded polymers in combinations containing at least two of the following polymers: polyethylene terephthalate, polypropylene, polyethylene, low-density polyethylene, linear low-density polyethylene, polylactic acid, polytrimethylene terepthalate, polycyclohexanediol terephthalate, polyethylene 20 terephthalate glycol, nylon 6, nylon 6,6, nylon 11, nylon 12, polymethyl pentene and other thermoplastic polymers that have sufficiently low melting points, whether inherent or modified, or any natural cellulosic fibers (cotton, flax, ramie, jute, kenaf, hemp, and the like) or protein fibers (wool, cashmere, camel hair, mohair, other animal hair, silk, and the like) coated or joined together with any of the 25 aforementioned thermoplastic polymers. The term "sufficiently low" has the same meaning as set forth above for the single-component fibers. [102] These multi-component multi-binding fibers must contain more than one component comprised of a lower-melt binding agent and a higher melt point component that remains intact after exposure to heat in the thermal bonding stage, 30 similar to the multi-component, multi-binding fibers described hereinabove. The SYN.P.PCO045 38 binding agent may be any synthetic fiber with a melting temperature within the aforementioned range that does act as a contributory fuel source for an open flame. The remaining core portion may be any synthetic or natural fiber with a melting temperature no less than 1150 C, does not act as a contributory fuel source for an 5 open flame, and has fiber-to-fiber cohesion sufficient to maintain fiber web integrity and hold entanglement among fibers after needling. [103] For the purposes of this invention, a fiber must have a minimum Limiting Oxygen Index (LOI) of at least about 21 to be considered a non-contributory fuel source. LOI is a relative measure of flammability that is determined by igniting a 0 sample in an oxygen/nitrogen atmosphere and then adjusting the oxygen content to the minimum amount required to sustain steady burning. The higher the value, the less flammable a material is considered. The limiting oxygen index (LOI), also called the critical oxygen index (COI) or oxygen index (01), is defined as: [02 (conc)] .5 LOI = [02 (conc)] + [N 2 ] where [02 (conc)] and [N 2 ] are the minimum oxygen concentration in the inflow gases required to pass the "minimum burning length"' criterion and the nitrogen ?0 concentration in the inflow gases respectively. If the inflow gases are maintained at constant pressure then the denominator of the equation is constant since any reduction in the partial pressure (concentration) of oxygen is balanced by a corresponding increase in the partial pressure (concentration) of nitrogen. Limiting oxygen index is more commonly reported as a percentage rather than fraction. 25 [104] Since air comprises about 20.95% oxygen by volume, any material with a limiting oxygen index less than this will burn easily in air. Conversely, the burning behavior and tendency to propagate flame for a polymer with a limiting oxygen index greater than 20.95 will be reduced or even zero after removal of the igniting source. Self-sustaining combustion is not possible if LOI> 100, such values are not physically 30 meaningful. Examples of the LOI of various compounds are set forth below in Table SYN.P.PCO045 39 9. TABLE9 LIMITING OXYGEN INDEX (LOI) OF VARIOUS COMPOUNDS Polyolefin 18 Cotton 18 Wool 25 Polyamide 22 Polyesters 21 Polyphenylene Sulfide (PPS) 34 Para-aramid 28 Meta-aramid 30 Polyacrylonitrile (PAN) 55 Polytetrafluoroethylene (PTFE) 95 Fiberglass 100 Amorphous silica 100 5 [105] Some examples of binder fibers commercially available for practice of the present invention include the following specialty single polymer fibers, all of which are available from Fiber Innovations Technology (FIT) of Johnson City, Tennessee, the product code of each being provided in parentheses: PETG binder fiber 10 (undrawn) (T-135), PETG binder fiber (drawn) (T-137), PCT (T-180), FR (flame resistant) PET (T-190) and FR PET for yam spinning (T-191). Other examples of binder fibers include the following concentric sheath/core bi-component fibers, also available from FIT and having the product code set forth in parentheses: 110 0 C "melt" CoPET/PET (T-201), 185 0 C melt CoPET/PET (T-202), Dawn Grey version of 15 T-201 (T-203), Black version of T-202 (T-204), 130 0 C melt CoPET/PET (T-207), 150 0 C melt high crystallinity CoPET/PET (T-215), Black version of T-215 (T-225), PCT/PP (T-230), PCT/PET (T-231), PETG/PET (T-235), 185*C, high Tg coPET/PET (T-236), HDPE/PET (T-250), HDPE/PP (FDA food contact) (T-251), LLDPE/PET (T 252), PP/PET (T-260), Nylon 6/ nylon 6,6 (T-270), and Black version of T-270 (T- SYN.P.PCO045 40 271). Polyethylene terephthalate (PET) is particularly useful for practice of the present invention, but a wide variety of binder fiber types exist. [106] Still other binder fibers available from FIT include PET (polyester), coPET, Tm = 110 0 C , coPET, Tm=125 0 C, coPET, Tm = 180 0 C, coPET, Tm = 200 0 C , PIA 5 (polylactic acid), Tm = 130 0 C, PLA, Tm =150 0 C, PLA, Tm = 1700C, PTT (polytrimethylene terephthalate) available under the tradename Corterra', PCT (polycyclohexanediol terephthalate), PETG (PET glycol), HDPE (high density polyethylene, LLDPE linear low density polyethylene, PP (polypropylene, PE/PP copolymer, PMP (polymethyl pentene), nylon 6, nylon 6,6, nylon 11 and nylon 12. LO [107] In addition to the above, polyester binder fibers may be used in some instances. Examples of polyester binder fibers include those available from Wellman, Inc. of Fort Mill, South Carolina, under various type names such as 209, H1305, H1295, H1432, M1440, M1429, M1427, M1425, M1428, and M1431. [108] In addition to the required amorphous silica fiber and the required binder 15 fiber, the nonwoven fabric composition may comprise up to 70 percent by weight of other fibers, i.e., complimentary fibers, considered to be a non-contributory fuel source. With regard to this invention, any embodiment comprised of a thermal-only binder fiber, such as a single component binder fiber containing a low melt polymer, requires the addition of at least 15 percent by weight of a higher cohesion fiber to 20 provide mechanical fiber interlock after thermal bonding. One embodiment of the present invention comprises between about 35 and 50 percent by weight of the amorphous silica, between 50 and 65 percent by weight of the binder fiber, wherein the binder fibers is of a core/sheath bi-component configuration comprised of a polyethylene terephthalate (PET) core and a lower melt temperature PET sheath, and 25 between 5 and 10 percent by weight of a complimentary fiber such as a solution dyed (pigmented) PET fiber for color in the single layer nonwoven fire and heat barrier fabric. [109] It may also be possible to include up to about 15 percent by weight and, in one embodiment up to about 10 percent by weight, and in another embodiment, 30 up to about 5 percent by weight of complimentary fibers that are not considered to SYN.P.PCO045 41 be a "non-contributory" fuel source (as defined hereinabove), ie., having a LOI of less than 21. However, any such fibers employed will have limited application in the production of flame resistant fabrics or fabrics resistant to fire and heat. [110] This invention also relates to the method of producing the single layer 5 nonwoven fabric through slight mechanical entanglement of a web of the fibers and further thermal bonding to reduce physical property directional bias, maintain fuller length of individual fibers, encapsulate and contain individual fibers, and to reduce density per area of the nonwoven fabric without significantly diminishing the integrity of the fabric. 0 [111] The nonwoven fabric may be constructed as follows. The various combinations of fibers that can be employed in the present invention may be weighed and dry or wet formed into a fiber web. The web may be formed by any of several different methods: 5 1. Web forming by the dry laying, carding method. Bales of each fiber type are fed into the process where the clumps and bundles of fibers are separated (opened). The opened fibers of each type are weighed in process and are fed together into a blended web laydown calculated by percent fiber type weight of the total. This web 0 laydown is then fed into a card which uses rotating cylinders with fine teeth to orient the fibers into parallel arrays. This carded web is then transferred directly to the bonding process or is crosslapped onto a conveyor moving at a right angle allowing layering of carded web to increase web width, web weight and/or cross-directional strength 5 before moving on to the bonding process. 2) Web forming by air laying method. Bales of each fiber type are fed into the process where the clumps and bundles of fibers are separated (opened). The opened fibers of each 0 type are weighed in process and are fed together into a blended web SYN.P.PC0045 ft laydown calculated by percent fiber type weight of the total. This web laydown is formed by suspending the fibers in the air and then collecting them as a batt on a screen that separates the fibers from the air. This web is then transferred directly to the bonding process or is 5 crosslapped onto a conveyor moving at a right angle allowing layering of carded web to increase web width and/or web weight before moving on to the bonding process. [112] With regard to the present invention, a useful method of web formation is 10 the dry-laid carded process. [113] The useful fabric formation is mechanical fiber entanglement by needlepunching the web and then thermal bonding through the application of heat above the melting temperature of the binder, but below the melting temperature of the structural fibers that mechanically bind the fabric through entanglement. 15 [114] It is also possible to hydroentangle the fibers through the use of high pressure water jets, although the water jets tend to be more damaging to the more delicate amorphous silica fibers than the needlepunching. [115] Although one embodiment is a nonwoven fabric with mechanically entangled fibers that are then heat bonded, it is also possible to blend the fibers in a 20 woven configuration and then thermally bond. For woven fabrics, it is possible to employ amorphous silica fibers in the machine direction or the cross machine direction, alternating with one or more of the FR or the binder fibers. Alternatively, the fibers can be alternated in the machine direction and woven with either an amorphous or an FR or a binder fiber in the cross machine direction. As a 25 percentage, woven fabrics according to the present invention can comprise the compositions stated above for the blend of amorphous silica and FR fibers as well as amorphous silica and binder fibers. The particular weave construction for open weave fabrics is not a limitation of the present invention and thus, all ranges of end counts in both the machine and cross machine directions are included.

SYN.P.PC0045 43 [116] The blend in the woven is possible through various yarn structures ("types"= fiber types for blend): 1) Single Yams: a) Blending multiple types of staple fiber before spinning them 5 into a continuous yarn. b) Blending multiple types of continuous filaments before twisting or entangling them together into a continuous yarn. 2) Ply/Cord Yams: a) Twisting together two or more single yarns of different types 0 into a resultant ply yarn. b) Twisting together two or more ply yams of different types into a resultant cord yam. 3) Core-Spun/Wrapped Yarns: a) A central core of a continuous yam or filament around which 5 another type fiber is wrapped or twisted, resulting in a continuous yam with one fiber type as the core and another type making up the exterior layer. [117] The blend in the woven is also possible through woven construction of 0 yarns of different fiber types: 1) The warp yams may be of one type and the weft yams of another type. 2) Yams of different fiber types may be combined in the warp at some interval. 25 3) Yams of different fiber types may be combined in the weft at some interval. 4) Yams of different fiber types may be combined in both the warp and the weft directions.

SYN.P.PC0045 44 [118] This invention relates to a fabric useful in protecting items, or products, such as mattresses, from fire and the related heat; a process for producing the fabric; and a process for protecting materials in a product by using the fire and heat barrier fabric. One such process for protecting materials in a product using the fire and heat 5 barrier is by ultrasonically bonding or ultrasonically welding the barrier fabric directly to at least one component that is also present in the product. Such a component comprises a material that is susceptible to damage due to fire and heat, occasioned by exposure to open flames and therefore, requires barrier protection. Ultrasonic bonding is well known in the art, but the ability directly incorporate a fire 10 and heat barrier into a sub-assembly is novel. Ultrasonic bonding uses ultrasonic energy to join layers of thermoplastic materials. High speed ultrasonic vibrations result in welds between thermoplastics fusing the materials together. This fusing, or welding, requires similar thermoplastic materials to form the bond. [119] As an example, many traditional mattress constructions are covered by a 15 surface assembly of a high-loft fiber batt between an outside layer of ticking fabric and an inner layer of a lightweight fabric (typically spunbond) to hold the backstitch of the needle-and-thread quilted assembly. The quilted assembly forms a surface that is both soft and visually appealing due to the lofty quilted pattern. Because the high loft fiber batt is conventionally PET, and because both the outer ticking layer and the 20 inner structural layer are available in PET or a majority-blend PET, these and similar assemblies, or products, e.g., furnishings, transportation seats and surfaces, bed clothing and the like, are sometimes quilted by ultrasonic bonding means, rather than by the traditional needle-and-thread sew quilting. [120] Using ultrasonic bonding for the production of quilted assemblies typically 25 has advantages over the sewing method because of the higher throughput speeds possible, fewer raw materials (no thread) required, less mechanical wear (no needle breaks; fewer moving parts), and is capable of forming a bond between the layers comparable, or better, than the sewn seams of traditional quilting. [121] Many materials and material blends capable of forming an adequate flame 30 and thermal barrier are not thermoplastic, and those that are vary significantly from SYN.P.PCO04s 45 the other thermoplastic components used in the end product. Therefore, as products are increasingly required to meet new open flame requirements, the possibility to utilize ultrasonic bonding to quilt is lost. [122] The blends and resultant fabrics of the present invention are such that 5 they allow for the ultrasonically bonded quilting of an assembly containing a flame and thermal barrier. Within the described range of blends, those blends comprising at least 40 percent by weight PET, or other suitable thermoplastic, are suitable for ultrasonic bonding to other materials containing a minimum of 40 percent of the same or similar thermoplastic. One embodiment is for the flame and thermal barrier 10 fabric to comprise a minimum of 50 percent PET by weight, and the other layers of the assembly contain at least 50 percent by weight of PET or similar thermoplastic. [123] Assemblies for mattress construction may be produced in any number of configurations (no inner layer is necessary) such as the following: 1. The flame and thermal barrier fabric may be ultrasonically bonded to the 15 outer ticking layer at points across the full width and along the length of the assembly. 2. The flame and thermal barrier fabric may be ultrasonically bonded to the outer ticking layer at points only along the assembly edges. 20 3. For additional softness or depth of quilted pattern along the planar surface, termed "pop" in the mattress industry, layer(s) of high-loft batt may be added between the flame and thermal barrier fabric and the ticking before bonding as described in 1, hereinabove. 25 4. For additional softness along the planar surface, layer(s) of high-loft batt may be added between the flame and thermal barrier fabric and the ticking before bonding as described in 2, hereinabove. 30 5. The configurations outlined in items 2 and 4, hereinabove allow for TN.fr.LUUi, -tv improved flame and thermal shielding because the body of the barrier fabric contains no bond points. The nature of ultrasonic bonding requires pressure between the horn and anvil. This results in compression of the layers at each bonding point and these compressed points typically result 5 in greater thermal transfer through the materials and possibly weaken the char strength of the materials when exposed to open flame. If the smooth surface resultant from assembly configurations 2 and 4 is not desired, it is taught here that high-loft batt or other loft fabric may be ultrasonically bonded directly to the outside ticking layer in the manner described in 1 10 and 3, before the flame and thermal barrier fabric is subsequently ultrasonically bonded at points along the assembly edge as the inner layer. 6. Variations of configuration 3 offering the same or similar effect are 15 possible by layering the flame and thermal barrier fabric directly to the ticking layer and the high-loft batt is layered to the inside before ultrasonically bonding as described in 1, hereinabove. 7. Variations of configuration 4 offering the same or similar effect are 20 possible by layering the flame and thermal barrier fabric directly to the ticking layer and the high-loft batt is layered to the inside before ultrasonically bonding as described in 2, hereinabove. [124] Another product used in mattress construction, is the border fabric, or 25 side fabric material. As an example, satisfactory border assemblies for mattresses and/or box springs may be produced in any of the above configurations using full width roll-good materials up to approximately 120-inches in width (theoretically the width is unlimited because the ultrasonic horns and anvils may be arranged in a modular format, but practically, the width is limited to currently available widths of 30 roll-good ticking and high-loft batt as well as currently available supporting equipment). The body quilt pattern is ultrasonically bonded using a series of wide horns applied across the width of a patterned cylinder anvil. The typical width of a border assembly ranges from about 9 inches to about 14 inches (or more). These individual widths may be ultrasonically slit and the edges ultrasonically sealed with a 5 stitch pattern (or other pattern) using an in-line or off-line series of horns and slitter/sealing anvils. [125] Fabrics of the present invention are particularly useful for mattress borders because the need for comfort is not present, as it is in the tops and bottoms of mattresses, the panels, which will incorporate batting to give the panel softness 0 and loft. Accordingly, in the borders, the FR fabric is readily assembled to the ticking, as by ultrasonic welding, to form that product, which can be thought of a sub assembly of the complete product, the mattress. [126] An example process setup for ultrasonic sealing would employ 1.1kW power supplies to 9-inch horns in series across the width of a cylinder anvil patterned 5 to the quilting design desired in the body of the assembly. After the layers are fed from and unwound into this portion of the process, additional layers may be introduced if desired before flowing through a series of one inch diameter horns spaced at the desired widths of the border assemblies to be simultaneously slit and sealed (if desired) using a 1.1kW power supply to each horn. Process variables such ) as pressure, speed, amplitude, power boosters and loadings differ based on the types of materials used and the mass. [127] In order to demonstrate the effectiveness of fabrics according to the present invention, a number of fabric samples were subjected to open flame testing to determine their respective resistances to fire and related heat and in turn, ability to provide protection to the item. It should be appreciated that testing of the protected item is often times specific to the end-use application of the protected item and the test includes that item as a whole rather than testing of the individual components that make up that item. Testing of the fabric as a component to predict or correlate results in the finished item usually differs between manufacturers of the item. Preliminary testing was conducted with a variety of barrier fabrics comprising a range of amorphous silica to binder fiber ratios. As a result of this screening, it was determined that for use in mattresses, a 40 percent amorphous silica content was a useful amount, as it balanced costs against needed barrier protection. Nonetheless, greater or lesser amounts of amorphous silica may well have use in other 5 environments (products) where barrier property requirements may differ as will permissible costs to product the fabric. Such other uses are discussed hereinbelow. [128] For development of the fire and thermal barrier fabrics of the present invention, for use in the mattress industry, a proprietary test at an independent test lab was employed to establish a performance baseline and track progress versus that 0 baseline. Although the specifics of the test are held confidential by the independent lab, it can be revealed that the test is based on an open flame in contact with the face of the fabric for a set period of time. After the open flame is removed, the fabric is allowed to continue to burn until it fully extinguishes itself. The maximum temperature is measured on the side opposite the flame over the length of the test. 5 The mass of the sample is measured before and after exposure to the flame to calculate mass loss. The strength of the fabric at the point of exposure may be tested to determine retained strength or char strength (depending on the application, this could be tensile, puncture, inspection for cracking or other). Test results are reported in Table 10 that follows: 0 49 r cn C) w C 0 Lfl N N 1- NO - C xC m E j0 N m f o r- m %o o~ r, o - v- 1- 6 0 x 0 -c ccN ClON C 00 N ' S. t 0. cu0. vO u u I, " 0 5 m 0.c.0L.0 c.0. C c.0.C 00 000I u~ ~ . ZF ZF . 9 O -O n ov ,-" Ro o 0 0o o o In "'. ' N N 0' N ' ' N S C13 co 0ON ~ 0 0 0- N C tL '0 N CO 0' 0 0~ N 0l S - A A A A A A 0 0 0 0 0 0 '0 '0 0 '0 N N N N N En L n c - V - I SYN.P.PC0045 50 [129] Although the specifics of the test are proprietary, the results shared demonstrate the performance of this invention, amorphous silica blends, as compared to other flame and thermal barriers when exposed to open flame. The "mass per unit area", "maximum temperature" and "percent mass loss" values are 5 averages of six tested specimens for each blend or product. The testing performed by the independent lab established a baseline of performance for products currently in use as flame and thermal barrier fabrics in mattress industry ("Incumbent Market Product", Examples No. 54-56). Without representing that the results of this test direcdy correlate to the performance of a bedding set tested per the earlier described 0 TB603 California open flame standard, nevertheless, the results are an indicator of the ability of a component fabric to withstand exposure to an open flame without excessive mass loss or excessive thermal transfer through the fabric. [130] What is, or is not, "excessive" may differ between mattress manufacturers, but tests of this kind allow for direct comparison of candidate fabrics against 5 established component fabrics that have been extensively tested in the finished bedding sets. The fabrics tested include 10 examples (Nos. 54-63) of fabrics outside the present invention, followed by 11 examples (Nos. 64-74) of fabrics according to the present invention. With reference to the data in Table 10, it can be seen that the use of barrier fabrics comprising 40 percent of amorphous silica, provided acceptable 0 protection, as compared to the incumbent products. It should be noted that while Examples 66 and67 did show higher percent mass loss, this was attributable to the lower mass per unit area (4.9 and 4.7) compared to the other fabrics. Also, Example 73 showed both a greater maximum temperature and mass loss, which was due to the presence of the 8 percent PP fiber, a complimentary fiber which may be a fuel 5 source, i.e., not a "non-contributory" fuel source, added to provide a colored, or pigmented, fabric. [131] In view of the foregoing disclosure, it is to be appreciated that possible end uses for the FR fabrics of the present invention in various items include the following: SYN.P.PCO045 51 1. Bedding - barrier beneath ticking or exposed on the bottom of one-sided mattresses or on the top and/or bottom of the box springs. Borders, as discussed above, are also products that benefit by the presence of the barrier. 5 2. Furniture - barrier beneath upholstery of furniture or exposed on the underside of furniture or other unseen areas. 3. Transportation - barrier beneath upholstery of seating or exposed on the 0 underside of the seating or other unseen areas. Barrier behind wall covering materials or attached to the backside of or within layers of curtains or drapes. Lining for engine and cargo bays or areas that need shielding from extreme heats. 4. Bed clothing - layered within blankets, comforters, pillows and the like. 5 5. Apparel - layered within personal protective apparel to protect against flames and heat. Uses include firemen, military, astronauts, industry, laboratories and the like, in items such as coats, pants, gloves, boots and the like. o 6. Auto - inner lining of engine bays, pipe wrap, barrier within seats and behind carpeting and upholstered surfaces. 7. Construction/Home/Industry - house wrap, inner wall protective layer, fire blankets, linings of storage areas for combustibles, welding drapes, lining of 5 landfills and the like emitting potentially flammable gases, hot gas filtration, backing of scatter rugs and carpets, kitchen pot holders and gloves and the like. [132] The present invention therefore, includes any of the foregoing products produced by the process of the present invention.

CkNRPonbr\DCOGAVWA1d73_ .DOC-6/2/(I11 - 52 [133] Thus, it should be evident that the use of amorphous silica fibers is highly effective in providing FR blends and fabrics. The invention can be practiced by combining amorphous silica fibers with at least one other flame resistant fiber, or a binder fiber but is necessarily limited thereto. Nor, is practice limited to the selection of a particular FR fiber 5 or binder fiber so long as the one or more selected are combined with amorphous silica fibers. The fiber blends of the present invention can be utilized to manufacture flame resistant fabrics for a variety of purposes including, but not limited to barrier fabrics for upholstery, bedding and bed clothing applications. Moreover, the fabrics are not limited to non-woven types. 10 [134] Based upon the foregoing disclosure, it should now be apparent that the use of the fiber blends described herein are novel and will provide barrier fabrics and flame resistant fabrics, as set forth herein. It is, therefore, to be understood that any variations evident fall within the scope of the claimed invention and thus, the selection of specific component elements can be determined without departing from the spirit of the invention herein 15 disclosed and described. Thus, the scope of the invention shall include all modifications and variations that may fall within the scope of the attached claims. [135] Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group 20 of integers or steps but not the exclusion of any other integer or step or group of integers or steps. [136] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or 25 information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims (21)

1. A flame resistant (FR) fiber blend comprising: amorphous silica fibers comprising a mixture of about 94 to about 97% by weight 5 Si0 2 , about 3 to about 4% by weight A1 2 0 3 , about 0.1 to about 0.3% by weight Na 2 0, about 0.03 to about 1.3% by weight CoO, and about 0.01 to about 1.2% by weight S03; and at least one fiber selected from the group consisting of FR fibers, binder fibers and mixtures thereof. 10

2. The fiber blend of claim 1, wherein said FR fibers are selected from the group consisting of modacrylics, polyester with phosphalene, melamines, meta-aramids, para aramids, polybenzimidazole, polyimides, polyamideimides, partially oxidized polyacrylonitriles, novoloids, poly(p-phenylene benzobisoxazoles, poly(p 15 phenylenebenzothiazoles), polyphenylene sulfides, flame resistant viscose rayons, viscose rayon containing aluminosilicate-modified silica, cellulosics, polyetherketones, polyketones, polyetherimides, natural or synthetic fibers coated with an FR resin, or mixtures thereof. 20

3. The fiber blend of claim 1, wherein the blend comprises at least about 5 weight percent amorphous silica fibers, based upon the total weight of fibers in the blend.

4. The fiber blend of claim 3, wherein the blend comprises from about 5 to about 65 weight percent amorphous silica fibers and from about 35 to about 95 weight percent of 25 said FR fibers.

5. The fiber blend of claim 2, comprising amorphous silica fibers, modacrylic fibers, and FR rayon fibers. 30

6. The fiber blend of claim 2, comprising amorphous silica fibers, modacrylic fibers, and viscose rayon fibers. C\NRPorbDCC\GA\366J33_1 DOC412/2011 - 54

7. The fiber blend of claim 2, comprising amorphous silica fibers, modacrylic fibers, and cellulosic fibers. 5

8. The fiber blend of claim 2, comprising amorphous silica fibers and FR rayon fibers.

9. The fiber blend of claim 2, comprising amorphous silica fibers, modacrylic fibers, viscose rayon fibers, and FR polypropylene fibers.

10 10. The fiber blend of claim 1, wherein said binder fibers are selected from the group consisting of single component, multi-component, multi-binding fibers and complimentary fibers, said fibers having a melting temperature of not less than I 07C.

11. The fiber blend of claim 10, wherein said single-component, multi-component and, 15 multi-binding fibers and complimentary fibers, provide thermal bonding properties and wherein said multi-component, multi-binding fibers and complimentary fibers additionally provide mechanical properties.

12. The fiber blend of claim 10, wherein said blend comprises at least about 15 weight 20 percent amorphous silica fibers, based upon the total weight of fibers in the blend.

13. The fiber blend of claim 12, wherein said blend comprises from about 15 to about 80 weight percent amorphous silica fibers; from about 15 to about 85 weight percent of said binder fibers and up to about 70 weight percent of complimentary fibers, with a 25 reduction of the other two fibers to total 100 percent by weight, without falling below the above-stated minimum amounts.

14. The fiber blend of claim 13, wherein said blend comprises from about 15 to about 80 weight percent amorphous silica fibers; from about 15 to about 85 weight percent of 30 said single-component binder fibers and at least about 15 weight percent of said complimentary fibers. C:\NRPorbl\DCC\GAW6631% IDOC-6/2/2I)I -55

15. The fiber blend of claim 11, wherein said single component binder fibers are selected from the group consisting of low-melt polyethylene terephthalate, polypropylene, polyethylene, low-density polyethylene, linear low-density polyethylene, polylactic acid, 5 polytrimethylene terephthalate, polycyclohexanediol terephthalate, polyethylene terephthalate glycol, nylon 6, nylon 6, 6, nylon 11, nylon 12, polymethyl pentene and other thermoplastic fibers selected to have the lowest melting point of the polymers present.

16. The fiber blend of claim 11, wherein said multiple component binder fibers 10 comprise those fibers of co-extruded polymers in combinations containing at least two polymers selected from the group consisting of polyethylene terephthalate, polypropylene, polyethylene, low-density polyethylene, linear low-density polyethylene, polylactic acid, polytrimethylene terephthalate, polycyclohexanediol terephthalate, polyethylene terephthalate glycol, nylon 6, nylon 6, 6, nylon 11, nylon 12, polymethyl pentene and other 15 thermoplastic fibers selected to have the lowest melting point of the polymers present.

17. The fiber blend of claim 11, wherein said multiple component, multi-binding binder fibers are selected from the group consisting of sheath/core, eccentric sheath/core, side-by-side or bilateral, pie wedge, hollow pie wedge, islands-in-the-sea or matrix 20 constructions and mixtures thereof, which retain core fibers of substantially original length after thermal bonding.

18. The fiber blend of claim 17, wherein said multiple component binder fibers comprise those fibers of co-extruded polymers in combinations containing at least two 25 polymers selected from the group consisting of polyethylene terephthalate, polypropylene, polyethylene, low-density polyethylene, linear low-density polyethylene, polylactic acid, polytrimethylene terephthalate, polycyclohexanediol terephthalate, polyethylene terephthalate glycol, nylon 6, nylon 6, 6, nylon 11, nylon 12, polymethyl pentene and other thermoplastic fibers selected to have the lowest melting point of the polymers present; said 30 multiple component, multi-binding fibers containing at least one component comprised of C:\NRPortbr\DCOGAV\661373_l.DOC-6/2/20)1 -56 a lower melt polymer and a higher melt point polymer that remain intact after exposure to heat sufficient to melt said lower melt polymer.

19. The fiber blend of claim 18, wherein said multiple component, multi-biding 5 binding fibers comprise a core/sheath bi-component configuration comprised of a polyethylene terephthalate (PET) core and a lower melt temperature PET sheath whereas the sheath is about 60 percent by weight of the individual fiber and the core is the remaining 40 percent. 10

20. The fiber blend of claim 11, wherein said complimentary fibers comprise those fibers of co-extruded polymers in combinations containing at least two polymers selected from the group consisting of polyethylene terephthalate, polypropylene, polyethylene, low density polyethylene, linear low-density polyethylene, polylactic acid, polytrimethylene terephthalate, polycyclohexanediol terephthalate, polyethylene terephthalate glycol, nylon 15 6, nylon 6, 6, nylon 11, nylon 12, polymethyl pentene and other thermoplastic fibers selected to have the lowest melting point of the polymers present, as well as natural cellulosic fibers and protein fibers, coated or joined together with any of the aforementioned polymers; said multiple component, multi-binding fibers containing at least one component comprised of a lower melt polymer and a higher melt point polymer 20 that remains intact after exposure to heat sufficient to melt said lower melt polymer.

21. A flame resistant (FR) fiber blend substantially as hereinbefore described, with reference to the accompanying drawings.