Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
  • D02G3/04—Blended or other yarns or threads containing components made from different materials
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
  • D02G3/04—Blended or other yarns or threads containing components made from different materials
  • D02G3/047—Blended or other yarns or threads containing components made from different materials including aramid fibres
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/443—Heat-resistant, fireproof or flame-retardant yarns or threads
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2321/00—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D10B2321/10—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds polymers of unsaturated nitriles, e.g. polyacrylonitrile, polyvinylidene cyanide
  • D10B2321/101—Fibres made from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds polymers of unsaturated nitriles, e.g. polyacrylonitrile, polyvinylidene cyanide modacrylic
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/02—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/02—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides
  • D10B2331/021—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides aromatic polyamides, e.g. aramides
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber

Definitions

• flame retardant also referred to as fire resistant, fabrics that can be used to make clothing suitable for people who work near flames, high temperatures, or electric arc flashes.
• an effective flame retardant fabric should be durable, comfortable, and produced at low cost.
• fabrics made of inherently flame retardant fibers have been very useful in protective garments, certain characteristics of these fibers present problems. For instance, these fibers can be difficult to dye, provide uncomfortable fabric textures, and are expensive.
• inherently flame retardant fibers have been blended with fibers made of other materials. Fiber blending can be used to obtain an end fabric that combines the beneficial characteristics of each of the constituent fibers. However, such blending often comes at the expense of durability and thermal performance.
• the invention is an intimate blend of staple fibers comprising 10 to 75 parts by weight of at least one aramid staple fiber, 15 to 80 parts by weight of at least one modacrylic staple fiber, and 5 to 30 parts by weight of at least one polyamide staple fiber.
• the invention is an intimate blend of staple fibers comprising 20 to 40 parts by weight of at least one aramid staple fiber, 50 to 80 parts by weight of at least one modacrylic staple fiber, and 1 5 to 20 parts by weight of at least one polyamide staple fiber.
• the invention is one of the intimate blends described above, wherein the at least one aramid staple fiber is poly(metaphenylene isophthalamide) and the at least one modacrylic staple fiber is a copolymer of acrylonitrile and vinylidene chloride.
• the modacrylic staple fiber of this invention preferably contains an antimony additive.
• the preferred antimony additive is an antimony oxide.
• the intimate blends of this invention may be used to make a yarn, which in turn may be used to make a flame retardant fabric for use in flame retardant articles such as clothing. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration only, because various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
• An intimate blend of staple fibers of this invention comprises aramid fibers, modacrylic fibers, and polyamide fibers. The proportions of each component are important to achieve the necessary combination of physical qualities.
• the intimate blend is formed by combining aramid fibers, modacrylic fibers, and polyamide fibers in the fiber form, and then spinning into a single strand of yarn.
• yarn is meant an assemblage of fibers spun or twisted together to form a continuous strand, which can be used in weaving, knitting, braiding, or plaiting, or otherwise made into a textile material or fabric.
• Such yarns can be made by conventional methods for spinning staple fibers into yarns, such as, for example, ring-spinning, or higher speed air spinning techniques such as Murata air-jet spinning where air is used to twist the staple into a yarn.
• the intimate blend of staple fibers of this invention includes aramid fibers, which are inherently flame retardant.
• aramid fiber is meant one or more fibers made from one or more aromatic polyamides, wherein at least 85% of the amide (-CONH-) linkages are attached directly to two aromatic rings.
• Aromatic polyamides are formed by reactions of aromatic diacid chlorides with aromatic diamines to produce amide linkages in an amide solvent.
• Aramid fibers may be spun by dry or wet spinning using any number of processes, however, U.S. Patent Nos.
• Aramid fibers are typically available in two distinct classes, namely meta-aramid fibers, or m-aramid fibers, one of which is composed of poly(metaphenylene isophthalamide), which is also referred to as MPD-I, and para-aramid fibers, or p-aramid fibers, one of which is composed of poly(paraphenylene terephthalamide), also referred to as PPD-T.
• Meta- aramid fibers are currently available from E. I. du Pont de Nemours of
• NOMEX T-450® is 100% meta-aramid; NOMEX T-455® is a blend of 95%
• NOMEX® and 5% KEVLAR® (para-aramid); and NOMEX IMA® also be considered as KEVLAR® (para-aramid); and NOMEX IMA® (also
• NOMEX T-462® 93% NOMEX®, 5% KEVLAR®, and 2%
• meta-aramid fibers are available under the trademarks CONEX® and APYEIL® which are produced by Teijin, Ltd. of
• aramid fibers are currently available under the trademarks KEVLAR® from
• the at least one aramid staple fiber is poly(metaphenylene isophthalamide).
• the intimate blend of staple fibers of this invention also includes modacrylic fibers.
• Modacrylic fibers are manufactured fibers in which the fiberforming substance is any long chain synthetic polymer composed of less than 85%, but at least 35%, by weight of acrylonitrile (-CH 2 CH[CN]-) X units. Modacrylic fibers are made from resins that are copolymers
• Modacrylic fibers are inherently flame retardant because they are copolymerized with these other compounds such as vinyl chloride, vinylidene chloride, or vinyl bromide. Modacrylic fibers are commercially available under various conditions
• the at least one modacrylic fiber is a copolymer of acrylonitrile and vinylidene chloride.
• the modacrylic staple fibers of this invention preferably contain an antimony additive.
• the preferred antimony additive is an antimony oxide, preferably added in an amount greater than two percent by weight.
• the intimate blend of staple fibers of this invention also includes polyamide fibers.
• polyamide fibers is meant one or more fibers made from one or more aliphatic polyamide polymers, generically referred to as nylon.
• nylon fibers are generally spun by extrusion of a melt of the polymer through a capillary into a gaseous congealing medium.
• nylon is the polyamide fiber in the intimate blend of staple fibers forming a yarn, such yarn preferably is used as the warp yarn when forming a fabric to enhance protection against soft surface abrasion in the finished fabric or garment made from such fabric.
• nylon fiber has a linear density from 1 to 3 dtex. In another embodiment the nylon fiber has a linear density from 1 to 1.5 dtex. In yet another embodiment the nylon fiber has a linear density of about 1.1 dtex.
• the intimate blend of staple fibers of this invention can be used to make yarns and fabrics that are flame retardant.
• flame retardant articles such as flame retardant garments and clothing, which are particularly useful for firefighters and other workers who are put in close proximity to flames, high temperatures, or electric arc flashes.
• flame retardant is meant that the fabric does not support flame in air after coming in contact with a flame for a short period of time. More precisely, “flame retardant” can be defined in terms of the Vertical Flame Test, described below. Flame retardant fabrics preferably have a char length of less than six inches after a twelve second exposure to a flame.
• flame retardant for use in spinning yarns are generally of a particular length and of a particular linear density.
• synthetic fiber staple lengths of 2.5 to 15 centimeters (1 to 6 inches) and as long as 25 centimeters (10 inches) can be used, and lengths of 3.8 to 11.4 centimeters (1.5 to 4.5 inches) are preferred.
• Yarns made from such fibers having staple lengths of less than 2.5 centimeters have been found to require excessively high levels of twist to maintain strength for processing. Yarns made from such fibers having staple lengths of more than lb centimeters are more difficult to make due to the tendency for long staple fibers to become entangled and broken, resulting in short fibers.
• the synthetic staple fibers can be crimped or not, as desired for any particular purpose.
• the staple fibers of this invention are generally made by cutting continuous filaments to certain predetermined lengths.
• staple fibers can be made by other means, such as by stretch- breaking, and yarns can be made from such fibers as well as from a variety or distribution of different staple fiber lengths.
• the yarn of this invention can be used to make a flame retardant fabric, which is a cloth produced by weaving, knitting, or otherwise combining the yarn of this invention.
• Flame retardant fabrics can be constructed having warp yarn comprising the yarns of this invention, fill yarn comprising the yarns of this invention, or both warp and fill yarns comprising the yarns of this invention.
• fabrics use the yarn of this invention in only one direction (i.e., as only fill or only warp), other suitable yarns may be used in the other direction according to the desired fabric characteristics.
• the yarn of this invention is used in the warp direction since warp yarn typically forms most of the direct contact surface of a fabric. This translates into better abrasion performance of the outer surface of the fabric in garment form.
• the flame retardant fabric has a basis weight of from 4 and 15 ounces per square yard. In another embodiment of this invention the flame retardant fabric has a basis weight of from 5.5 to 11 ounces per square yard.
• Such fabrics can be made into articles of clothing, such as shirts, pants, coveralls, aprons, jacket, or any other single or multi-layer form for flash fire or electric arc protection. The articles of the invention will be further described below with reference to the working examples.
• TEST METHODS The following test methods were used in the following Examples. Thermal Protective Performance Test (TPP). The predicted protective performance of a fabric in heat and flame was measured using the "Thermal Protective Performance Test" (NFPA 2112). A flame was directed at a section of fabric mounted in a horizontal position at a specified heat flux (typically 84 kW/m 2 ). The test measures the transmitted heat energy from the source through the specimen using a copper slug calorimeter with no space between the fabric and heat source.
• TPP Thermal Protective Performance Test
• the test endpoint was characterized by the time required to attain a predicted second-degree skin burn injury using a simplified model developed by Stoll & Chianta, "Transactions New York Academy Science", 1971 , 33 p 649.
• the value assigned to a specimen in this test denoted as the "TPP value,” is the total heat energy required to attain the endpoint, or the direct heat source exposure time to the predicted burn injury multiplied by the incident heat flux. Higher TPP values denote better insulation performance.
• Vertical Flame Test The "Vertical Flame Test” (ASTM D6413) is generally used as a screening test to determine whether a fabric burns, as a predictor for whether an article of clothing has any flame retarding properties.
• a fabric can be considered flame retardant, or fire resistant, if it has a char length of less than six inches after a twelve second exposure to a flame.
• Abrasion Resistance Test Abrasion resistance was determined using ASTM method D3884, with a H-18 wheel, 500 gms load on a Taber abrasion resistance meter available from Teledyne Taber, 455 Bryant St., North Tonawanda, N.Y. 14120. Taber abrasion resistance was reported as cycles to failure. Tear Strength Test. The tear strength measurement is based on
• the tear strength of textile fabrics was measured by the trapezoid procedure using a recording constant-rate-of-extension-type (CRE) tensile testing machine. Tear strength, as measured in this test method, requires that the tear be initiated before testing.
• the specimen was slit at the center of the smallest base of the trapezoid to start the tear.
• the nonparallel sides of the marked trapezoid were clamped in parallel jaws of a tensile testing machine.
• the separation of the jaws was increased continuously to apply a force to propagate the tear across the specimen. At the same time, the force developed was recorded.
• the force to continue the tear was calculated from autographic chart recorders , or microprocessor data collection systems.
• Example 1 is a fabric of this invention comprising an intimate blend of this invention for both the warp and fill yarns.
• Example 2 is a fabric of this invention comprising an intimate blend of this invention for the warp yarn and an intimate blend of aramid and modacrylic, for the fill yarn.
• Comparative Example A is not a fabric of this invention, but instead comprises an intimate blend of aramid and modacrylic, with no nylon, for both the warp and fill yarns.
• warp and fill ring spun yarns comprising an intimate blend of Nomex® type
• Nomex® type 462 is 93% poly(m-phenylene
• the modacrylic fibers in this example were ACN/poIyvinylidene chloride co-polymer (available under
• weight percent of the modacrylic and 15 weight percent of the nylon was prepared and processed by the conventional cotton system into a spun yam having twist multiplier of 3.7 using a ring spinning frame.
• the yarn so made was a 24.6 tex (24 cotton count) single yarn.
• Two single yarns were then plied on a plying machine to make a two-ply yarn for use as a warp yarn.
• a 32.8 tex (18 cotton count) single yarn was made and then two of these yarns were plied for use as a fill yarn.
• the Nomex®/modacrylic/nylon yarns were used as the warp and fill
• Example 2 A comfortable and durable fabric was prepared comprising ring
• Nomex® type 462 is 93% poly(m-phenylene isophthalamide)(IVIPD-
• poly(p-phenylene terephthalamide)(PPD-T) 5% poly(p-phenylene terephthalamide)(PPD-T) and 2% static dissipative fibers (Type P-140, available from E. I. du Pont de Nemours of Wilmington, Delaware).
• the modacrylic in this example was ACN/polyvinylidene chloride co-polymer (available under the trademark
• weight percent of the modacrylic and 15 weight percent of the nylon was prepared and processed by the conventional cotton system into a spun yarn having twist multiplier of 3.7 using a ring spinning frame.
• the yarn so made was a 24.6 tex (24 cotton count) single yarn.
• Two single yarns were then plied on a plying machine to make a two-ply yarn for use as a warp yarn.
• Nomex®/modaxrylic yarn was used as the fill in a shuttle loom in a 3x1
• the greige twill fabric had a construction of 23 ends x 16 picks per cm (58 ends x 40 picks per inch), and basis weight of 264.5 g/m 2 (7.8 oz/yd 2 ).
• the greige twill fabric prepared as described above was scoured in hot water and dried under low tension. The scoured fabric was then dyed using acid dye. The finished fabric was then tested for its thermal and mechanical properties. The results of these tests are shown in Table 1. Comparative Example A A comfortable and durable fabric was prepared comprising ring
• spun warp yarns made from an intimate blend of Nomex® type 462 and
• Nomex® type 462 is 93% poly(m-phenylene isophthalamide)(MPD-
• poly(p-phenylene terephthalamide)(PPD-T) 5% poly(p-phenylene terephthalamide)(PPD-T) and 2% static dissipative fibers (Type P-140, available from E .I. du Pont de Nemours of Wilmington, Delaware).
• the modacrylic in this example was ACN/poIyvinylidene chloride co-polymer (available under the trademark
• 50 weight percent of the modacrylic was prepared and processed by the conventional cotton system into a spun yarn having twist multiplier of 3.7 using a ring spinning frame.
• the yarn so made was a 24.6 tex (24 cotton count) single yarn. Two of these single yarns were then plied on a plying machine to make a two-ply yarn for use as a warp yarn.
• a 32.8 tex (18 cotton count) single yarn with a blend of 50 weight percent Nomex® type 462 and 50 weight percent of the modacrylic was made and then two of these single yarns were plied for use as a fill yarn.
• the Nomex®/modacrylic yarn was used as the warp and the fill in a shuttle loom in a 3x1 twill construction.
• the greige twill fabric had a construction of 23 ends x 15 picks per cm (58 ends x 38 picks per inch), and basis weight of 254 g/m 2 (7.5 oz/yd 2 ).
• the greige twill fabric prepared as described above was scoured in hot water and dried under low tension. The scoured fabric was then dyed using acid dye. The finished fabric was then tested by its thermal and mechanical properties. The results of these tests are shown in Table 1.

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• 2003
  • 2003-07-28 US US10/629,299 patent/US20050025963A1/en not_active Abandoned
• 2004
  • 2004-07-28 MX MXPA06001010A patent/MXPA06001010A/es active IP Right Grant
  • 2004-07-28 BR BRPI0411627-5A patent/BRPI0411627A/pt not_active IP Right Cessation
  • 2004-07-28 DE DE602004004792T patent/DE602004004792T2/de active Active
  • 2004-07-28 JP JP2006522055A patent/JP2007500802A/ja active Pending
  • 2004-07-28 KR KR1020067001910A patent/KR20060041293A/ko not_active Application Discontinuation
  • 2004-07-28 WO PCT/US2004/024460 patent/WO2005033382A2/en active IP Right Grant
  • 2004-07-28 CA CA002529923A patent/CA2529923A1/en not_active Abandoned
  • 2004-07-28 CN CNA2004800218608A patent/CN1829831A/zh active Pending
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