MODACRYLIC/COTTON/ARAMID FIBER BLENDS FOR ARC AND FLAME PROTECTION

Description

1. Field of the Invention

[0001] This invention relates to a blended yarn useful for the production of fabrics which possess arc and flame protective properties. This invention also relates to garments produced with such fabrics.

2. Description of Related Art

[0002] Individuals working near energized electrical equipment and emergency personnel who respond to incidents near electrical equipment are at risk from electrical arcs and flame hazards which could result from an arcing event. Electrical arcs are extremely violent events typically involving thousands of volts and thousands of amperes of electricity. Electrical arcs are formed in air when the potential difference (i.e. voltage) between two electrodes causes the atoms in the air to ionize and become able to conduct electricity.

[0003] Arc protective and flame resistant garments typically are uncomfortable to wear due to the poor moisture vapor transport of the protective fibers incorporated within. Individuals wearing protective apparel typically experience both tactile discomfort and heat stress as a result of the protective fibers incorporated in their protective garments.

[0004] United States Patent 5,208,105 to Ichibori et. al. discloses a flame retarded composite fiber blend comprising a halogen containing fiber having a large amount of an antimony compound and at least one fiber selected from the list consisting of natural fibers and chemical fibers. The fiber blend is woven into a fabric which is then tested for it Limited Oxygen Index as a measure of its flame resistance.

[0005] United States Patent 5,223,334 to Green discloses a fabric offering protection from radiant energy due to electrical arcs. Green makes no disclosure of the use of Modacrylic fibers within the blended yarn. Also, Green does not disclose a protective fabric formed from yarns comprising less than 50 percent cotton.

[0006] What is needed is a yarn fabric and garment to provide a high level of protection when the material is exposed to an electrical arc and also flame resistance to protect the wearer from secondary effects.

SUMMARY OF THE INVENTION

[0007] This invention relates to a yarn for use in arc and thermal protection fabrics and garments comprising:

(a) 40 to 75 weight percent modacrylic fiber,

(b) 10 to 40 weight percent cotton fiber and

(c) 1 to 25 weight percent aramid fiber,

said percentages on the basis of components (a), (b) and (c).

[0008] The yarn is useful for incorporation into a thermally and arc resistant fabric and a garment especially suited for protecting workers against electrical arc. Furthermore the fabric and garment may provide resistance to break open, flame and abrasion.

DETAILED DESCRIPTION OF THE INVENTION

[0009] This invention relates to providing a yarn, fabric and garment to provide both improved arc protection and flame resistance. Fabrics and garments comprising flame resistant fibers of low tensile strength when exposed to the intense thermal stress of an electrical arc can break open exposing the wearer to additional injury as a result of the incident energy. Electrical arcs typically involve thousands of volts and thousands of amperes of electrical current. The electrical arc is much more intense than the incident energy such as from flash fire. To offer protection to a wearer a garment or fabric must resist the transfer to energy through to the wearer. It is believed that this occurs both by the fabric absorbing a portion of the incident energy and by the fabric resisting breakopen. During breakopen a hole forms in the fabric directly exposing the surface or wearer to the incident energy.

[0010] Yarns, fabrics and garments of this invention when exposed to the intense thermal stress of an electrical arc resist the transfer of energy. It is believed that this invention reduces energy transfer by absorbing a portion of the incident energy and through charring allows a reduction in transmitted energy.

[0011] Yarns of this invention comprise a blend of modacrylic fiber, cotton fiber, and aramid fiber. Typically, yarns of this invention comprise 40 to 75 weight percent modacrylic fiber, 10 to 40 weight percent cotton fiber, and 1 to 40 weight percent aramid fiber. Preferably, yarns of this invention comprise 45 to 65 weight percent modacrylic fiber, 15 to 35 weight percent cotton fiber, and 5 to 30 weight percent aramid fiber. The above percentages are on the basis of the three named components.

[0012] By "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

[0013] By modacrylic fiber it is meant acrylic synthetic fiber made from a polymer comprising primarily acrylonitrile. Preferably the polymer is a copolymer comprising 30 to 70 weight percent of a acrylonitrile and 70 to 30 weight percent of a halogen-containing vinyl monomer. The halogen-containing vinyl monomer is at least one monomer selected, for example, from vinyl chloride, vinylidene chloride, vinyl bromide, vinylidene bromide, etc. Examples of copolymerizable vinyl monomers are acrylic acid, methacrylic acid, salts or esters of such acids, acyrlamide, methylacrylamide, vinyl acetate, etc.

[0014] The preferred modacrylic fibers of this invention are copolymers of acrylonitrile combined with vinylidene chloride, the copolymer having in addition an antimony oxide or antimony oxides for improved fire retardancy. Such useful modacrylic fibers include, but are not limited to, fibers disclosed in United States Patent No. 3,193,602 having 2 weight percent antimony trioxide, fibers disclosed in United States Patent No. 3,748,302 made with various antimony oxides that are present in an amount of at least 2 weight percent and preferably not greater than 8 weight percent, and fibers disclosed in United States Patent Nos. 5,208,105 & 5,506,042 having 8 to 40 weight percent of an antimony compound.

[0015] Within the yarns of this invention modacrylic fiber provides a flame resistant char forming fiber with an LOI typically at least 28 depending on the level of doping with antimony derivatives. Modacrylic fiber is also resistant to the spread of damage to the fiber due to exposure to flame. Modacrylic fiber while highly flame resistant does not by itself provide adequate tensile strength to a yarn or fabric made from the yarn to offer the desired level of breakopen resistance when exposed to an electrical arc.

[0016] As used herein, "aramid" is meant a polyamide wherein at least 85% of the amide (-CONH-) linkages are attached directly to two aromatic rings. Additives can be used with the aramid and, in fact, it has been found that up to as much as 10 percent, by weight, of other polymeric material can be blended with the aramid or that copolymers can be used having as much as 10 percent of other diamine substituted for the diamine of the aramid or as much as 10 percent of other diacid chloride substituted for the diacid chloride of the aramid. Suitable aramid fibers are described in Man-Made Fibers--Science and Technology, Volume 2, Section titled Fiber-Forming Aromatic Polyamides, page 297, W. Black et al., Interscience Publishers, 1968. Aramid fibers are, also, disclosed in U.S. Pat. Nos. 4,172,938; 3,869,429; 3,819,587; 3,673,143; 3, 354,127; and 3,094,511. M-aramid are those aramids where the amide linkages are in the meta position relative to each other, and p-aramids are those aramids where the amide linkages are in the para position relative to each other. In the practice of this invention the aramids most often used are poly(paraphenylene terephthalamide) and poly(metaphenylene isophthalamide).

[0017] It is within the scope of this invention that a single type of aramid fiber can be employed. Illustratively, either a meta-aramid or para-aramid fiber can be used.

[0018] However, in a preferred mode both para-aramid and meta-aramid fibers are employed. An illustrative percentage is 20 to 40 weight percent para-aramid fibers and 60 to 80 weight percent meta-aramid fibers. The above percentages are on a basis of the aramid only. A preferred range of these two aramids is 25 to 35 weight percent para-aramid and 65 to 75 weight percent meta-aramid.

[0019] Within yarns of this invention cotton fibers provide a flame resistant fiber that provides moisture transport within the yarn. Garments comprising cotton fibers improve the comfort of the wearer by wicking moisture away from the wearer. By allowing perspiration to wick away the heat stress to a wearer who is exerting themselves is reduced.

[0020] Additionally, to the yarn, fabric, or garment of this invention may be added an antistatic component such as steel fiber, carbon fiber, or a carbon coating to an existing fiber. The conductivity of carbon or a metal such as steel when incorporated in a yarn, fabric, or garment of this invention provides an electrical conduit to assist in dissipating the buildup of static electricity. Static electrical discharges can be hazardous for workers working with sensitive electrical equipment or near flammable vapors.

[0021] Yarns of this invention may be produced by any of the yarn spinning techniques commonly known in the art such as but not limited to ring spinning, core spinning, and air jet spinning or higher air spinning techniques such as Murata air jet spinning where air is used to twist staple fibers into a yarn. Typically the single yarns produced by any of the common techniques are then plied together to form a ply-twisted yarn comprising at least two single yarns prior to being converted into a fabric.

[0022] To provide protection from the intense thermal stresses caused by electrical arcs it is desirable that an arc protective fabric and garments formed from that fabric possess features such as an LOI above the concentration of oxygen in air for flame resistance, a short char length indicative of slow propagation of damage to the fabric, and good breakopen resistance to prevent incident energy from directly impinging on the surfaces below the protective layer.

[0023] Thermally protective garments such as firefighter turnout gear typically provide protection against the convective heat generated by an open flame. Such protective garments when exposed to the intense energy generated by an electrical arc can breakopen (i.e. an opening form in the fabric) resulting in the energy penetrating the garment and causing severe Injury to the wearer. Fabrics of this invention provide both protection against the convective heat of an open flame and offer increased resistance to breakopen and energy transfer when exposed to an electrical arc. The thickness of the fabric and overall weight of a protective garment such as a firefighter turnout coat typically worn can cause heat stress to a wearer by trapping body heat and perspiration next to the skin. Fabrics of this invention comprise a moisture transport fiber such as cotton within yarns of the fabric to provide a means for moisture due to perspiration to wick away from the wearer thus improving comfort and reducing heat stress.

[0024] Basis weight is a measure of the weight of a fabric per unit area. Typical units include ounces per square yard and grams per square meter (gpsm). The basis weights reported in this specification are reported in grams per square meter (ounces per square yard (OPSY)). As the amount of fabric per unit area increases the amount of material between a potential hazard and the subject to be protected increases. An increase in the basis weight of a material suggests that a corresponding increase in protective performance will be observed. An increase in basis weight of fabrics of this invention results in increased breakopen resistance, increased thermal protection factor, and increased arc protection. Basis weights of fabrics of this invention are typically greater than about 272 gpsm (8.0 opsy), preferably greater than about 293 gpsm (8.7 opsy) and most preferably greater than about 322 gpsm (9.5 opsy) It is believed fabrics of this invention with basis weights greater than 407 gpsm (12 opsy) would show increased stiffness and would thereby reduce the comfort of a garment produced from such fabric.

[0025] Char length is a measure of the flame resistance of a textile. A char is defined as a carbonaceous residue formed as the result of pyrolysis or incomplete combustion. The char length of a fabric under the conditions of test of ASTM 6413-99 as reported in this specification is defined as the distance from the fabric edge, which is directly exposed to the flame to the furthest point of visible fabric damage after a specified tearing force has been applied. Preferably fabric of this invention have a char length of less than 150 mm (6 inches) and preferably less than 115 mm (4.5 inches).

[0026] Fabrics of this invention may be used as a single layer or as part of a multi-layer protective garment. The yarns of this invention may be present in either the warp or fill of the fabric. Preferably the yarns of this invention are present in both the warp and fill of the resulting fabric.

TEST METHODS

Abrasion Test

[0027] The abrasion performance of fabrics of this invention is determined in accordance with ASTM D-3884-01 "Standard Guide for Abrasion Resistance of Textile Fabrics (Rotary Platform, Double Head Method)".

Arc Resistance Test

[0028] The arc resistance of fabrics of this invention is determined in accordance with ASTM F-1959-99 "Standard Test Method for Determining the Arc Thermal Performance Value of Materials for Clothing". Preferably fabrics of this invention have an arc resistance of at least 0.009 (0.8) calories and more preferably at least 0.013 (1.2) calories per square centimeter per gram per square centimeter (opsy).

Grab Test

[0029] The grab resistance of fabrics of this invention is determined in accordance with ASTM D-5034-95 "Standard Test Method for Breaking Strength and Elongation of Fabrics (Grab Test)".

Limited Oxygen Index Test

[0030] The limited oxygen index (LOI) of fabrics of this invention is determined in accordance with ASTM G-125-00 "Standard Test Method for Measuring Liquid and Solid Material Fire Limits in Gaseous Oxidants".

Tear Test

[0031] The tear resistance of fabrics of this invention is determined in accordance with ASTM D-5587-03 "Standard Test Method for Tearing of Fabrics by Trapezoid Procedure".

Thermal Protection Performance Test

[0032] The thermal protection performance of fabrics of this invention is determined in accordance with NFPA 2112 "Standard on Flame Resistant Garments for Protection of Industrial Personnel Against Flash Fire".

Vertical Flame Test

[0033] The char length of fabrics of this invention is determined in accordance with ASTM D-6413-99 "Standard Test Method for Flame Resistance of Textiles (Vertical Method)".

[0034] The term thermal protective performance (or TPP) relates to a fabric's ability to provide continuous and reliable protection to a wearer's skin beneath a fabric when the fabric is exposed to a direct flame or radiant heat.

Limited Oxygen Index (LOI)

From ASTM G 125 / D2863

[0035] The minimum concentration of oxygen, expressed as a volume percent, in a mixture of oxygen and nitrogen that will just support flaming combustion of a material initially at room temperature under the conditions of ASTM D2863.

[0036] To illustrate the present invention, the following examples are provided. All parts and percentages are by weight and degrees in Celsius unless otherwise indicated.

EXAMPLES

Modacrylic/Coffon/Aramid Fabric

Example 1

[0037] A comfortable and durable fabric was prepared having in the both warp and fill of ring spun yarns of intimate blends of Nomex® type 462, Kevlar® 29, Modacrylic and Cotton. Nomex® type 462 is 93% of poly(m-phenylene isophthalamide)(MPD-1), 5% of poly(p-phenylene terephthalamide)(PPD-T) and 2% of static dissipative fibers (P-140 from DuPont), Modacrylic is ACN/polyvinylidene chloride co-polymer with 15% antimony (known as Protex®M), and Kevlar® 29 is poly(p-phenylene terephthalamide)(PPD-T).

[0038] A picker blend sliver of 10 wt.% of Nomex® type 462, 10 wt.% of Kevlar® 29, 55 wt. % of Modacrylic and 25 wt. % of cotton was prepared and processed by the conventional cotton system into a spun yarn having twist multiply 3.7 using a ring spinning frame. The yarn so made was 24.6tex (24 cotton count) single yarn. Two single yarns are then plied on the plying machine to make a two-ply yarn. Using similar process and same twist and blend ratio, a 32.8tex(18 cotton count) yarn was made for using as fill yarn. The yarns were then two-plied to form a ply yarn.

[0039] The Nomex®/Kevlar®/Modacrylic/Cotton yarns were used as the warp and fill in a shuttle loom in a 3x1 twill construction. The greige twill fabric had a construction of 24ends x 15 picks per cm (60 ends x 39 picks per inch), and basis weight of 271.3 g/m^2 (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 jet dyed using basic dye.

Example 2

[0040] A comfortable and durable fabric was prepared having in the both warp and fill of ring spun yarns of intimate blends of Nomex® type 462, Kevlar® 29, Modacrylic and Cotton. Nomex® type 462 is 93% of poly(m-phenylene isophthalamide)(MPD-I), 5% of poly(p-phenylene terephthalamide)(PPD-T) and 2% of static dissipative fibers (P-140 from DuPont), Modacrylic is ACN/polyvinylidene chloride co-polymer with 15% antimony (known as Protex®M), and Kevlar® 29 is poly(p-phenylene terephthalamide)(PPD-T).

[0041] A picker blend sliver of 10 wt.% of Nomex® type 462, 10 wt.% of Kevlar® 29, 45 wt. % of Modacrylic and 35 wt. % of cotton was prepared and processed by the conventional cotton system into a spun yarn having twist multiply 3.7 using a ring spinning frame. The yarn so made was 24.6tex (24 cotton count) single yarn. Two single yarns are then plied on the plying machine to make a two-ply yarn. Using similar process and same twist, a 32.8tex(18 cotton count) yarn with blend of Nomex® type 462/Modacrylic at 50/50 ratio was made for using as fill yarn. The yarns were then two-plied to form a ply yarn.

[0042] The Nomex®/Kevlar®/Modacrylic/cotton yam was used as the warp and Nomex®/Modaxrylic yarn as the fill in a shuttle loom in a 3x1 twill construction. 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 (7.8oz/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 jet dyed using basic dye.

[0043] The following Table illustrates measured properties of Examples 1 and 2.

	Example 1	Example 2
Fabric Composition
Fabric Construction	2x1 twill	2x1 twill
Basis Weight gpsm (opsy)	227	227
	(6.7)	(6.7)
Char Length	102 x 102	84 x 91
(mm) (in) WarpxFill	(4 x 4)	(3.3 x 3.6)
TPP Value
(cal/cm2)	11.8	12.5
Grab Strength	445 x 427	525 x 396
(N) (lbf) WarpxFill	(100x96)	(118x89)
Trap Tear (N) (lbf) WarpxFill	60 x 52	61 x 48
	(13.6x11.7)	(13.8x10.8)
Taber Abrasion
(Cycles) CS-10/1000 g	352	317

Claims

1. A yarn suitable to provide arc and flame protection comprising:

(a) 40 to 75 weight percent modacrylic fiber,

(b) 10 to 40 weight percent cotton fiber and

(c) 1 to 40 weight percent aramid fiber,

said percentages on the basis of components (a), (b) and (c).

2. The yarn of claim 1 comprising:

(a) 45 to 60 weight percent modacrylic fiber

(b) 15 to 35 weight percent cotton fiber and

(c) 5 to 30 weight percent aramid fiber.

3. The yarn of claim 1 where the fiber includes both para-and meta-aramid fiber.

4. The yarn of claim 3 wherein the para-aramid fiber is present in a range from 20 to 40 weight percent and the meta-aramid fiber is present in a range from 60 to 80 weight percent on a basis of total aramid fiber.

5. The yarn of claim 4 wherein the para-aramid fiber is present in a range from 25 to 35 weight percent and the meta-aramid fiber is present in a range from 65 to 75 weight percent.

6. The yarn of claim 5 which additionally contains an anti-static component.

7. The yarn of claim 6 wherein the anti-static component is carbon or metal.

8. The yarn of claim 7 wherein the anti-static component is carbon.

9. The yarn of claim 1 which additionally contains an anti-static component.

10. The yarn of claim 9 wherein the anti-static component is carbon.

11. A fabric suitable to provide an arc and thermal protection comprising:

(a) 40 to 75 weight percent modacrylic fiber,

(b) 10 to 40 weight percent cotton fiber and

(c) 1 to 40 weight percent aramid fiber,

said percentages on the basis of components (a), (b) and (c).

12. The fabric of claim 11 comprising:

(a) 45 to 60 weight percent modacrylic fiber

(b) 15 to 35 weight percent cotton fiber and

(c) 5 to 30 weight percent aramid fiber.

13. The fabric of claim 11 wherein the char length according to ASTM D-6413-99 is less than 150 mm (6 inches).

14. The fabric of claim 11 wherein the char length according to ASTM D-6413-99 is less than 115 mm (4.5 inches).

15. The fabric of claim 11 wherein the fabric includes fibers of para- and meta-aramid.

16. The fabric of claim 15 wherein para-aramid fiber is present in a range from 20 to 40 weight percent and meta-aramid fiber is present in a range from 60 to 80 weight percent on a basis of total aramid fiber.

17. The fabric of claim 16 wherein the para-aramid fiber is present in a range from 25 to 35 weight percent and the meta-aramid fiber is present in a range from 65 to 75 weight percent.

18. The fabric of claim 11 which additionally contains an anti-static component.

19. A garment suitable to provide arc and thermal protection comprising:

(a) 40 to 75 weight percent modacrylic fiber,

(b) 10 to 40 weight percent cotton fiber and

(c) 1 to 40 weight percent aramid fiber,

said percentages on the basis of components (a) (b) and (c).

20. The garment of claim 9 comprising:

(a) 45 to 60 weight percent modacrylic fiber

(b) 15 to 35 weight percent cotton fiber and

(c) 5 to 30 weight percent aramid fiber.

Ansprüche

1. Garn, geeignet zum Bereitstellen von Lichtbogen- und Flammschutz, umfassend:

(a) 40 bis 75 Gewichtsprozent Modacrylfaser,

(b) 10 bis 40 Gewichtsprozent Baumwollfaser und

(c) 1 bis 40 Gewichtsprozent Aramidfaser,

wobei die Prozentgehalte auf der Basis der Komponenten (a), (b) und (c) sind.

2. Garn nach Anspruch 1, umfassend:

(a) 45 bis 60 Gewichtsprozent Modacrylfaser,

(b) 15 bis 35 Gewichtsprozent Baumwollfaser und

(c) 5 bis 30 Gewichtsprozent Aramidfaser.

3. Garn nach Anspruch 1, wo die Faser sowohl para- als auch meta-Aramidfaser einschließt.

4. Garn nach Anspruch 3, wobei auf einer Basis von Gesamt-Aramidfaser die para-Aramidfaser in einem Bereich von 20 bis 40 Gewichtsprozent vorhanden ist und die meta-Aramidfaser in einem Bereich von 60 bis 80 Gewichtsprozent vorhanden ist.

5. Garn nach Anspruch 4, wobei die para-Aramidfaser in einem Bereich von 25 bis 35 Gewichtsprozent vorhanden ist und die meta-Aramidfaser in einem Bereich von 65 bis 75 Gewichtsprozent vorhanden ist.

6. Garn nach Anspruch 5, welches zusätzlich eine antistatische Komponente enthält.

7. Garn nach Anspruch 6, wobei die antistatische Komponente Kohlenstoff oder Metall ist.

8. Garn nach Anspruch 7, wobei die antistatische Komponente Kohlenstoff ist.

9. Garn nach Anspruch 1, welches zusätzlich eine antistatische Komponente enthält.

10. Garn nach Anspruch 9, wobei die antistatische Komponente Kohlenstoff ist.

11. Stoff, geeignet zum Bereitstellen eines Lichtbogen- und Wärmeschutzes, umfassend:

(a) 40 bis 75 Gewichtsprozent Modacrylfaser,

(b) 10 bis 40 Gewichtsprozent Baumwollfaser und

(c) 1 bis 40 Gewichtsprozent Aramidfaser,

wobei die Prozentgehalte auf der Basis der Komponenten (a), (b) und (c) sind.

12. Stoff nach Anspruch 11, umfassend:

(a) 45 bis 60 Gewichtsprozent Modacrylfaser,

(b) 15 bis 35 Gewichtsprozent Baumwollfaser und

(c) 5 bis 30 Gewichtsprozent Aramidfaser.

13. Stoff nach Anspruch 11, wobei die Länge der Verkohlung entsprechend ASTM D-6413-99 weniger als 150 mm (6 Zoll) beträgt.

14. Stoff nach Anspruch 11, wobei die Länge der Verkohlung entsprechend ASTM D-6413-99 weniger als 115 mm (4,5 Zoll) beträgt.

15. Stoff nach Anspruch 11, wobei der Stoff Fasern von para- und meta-Aramid einschließt.

16. Stoff nach Anspruch 15, wobei auf einer Basis von Gesamt-Aramidfaser para-Aramidfaser in einem Bereich von 20 bis 40 Gewichtsprozent vorhanden ist und meta-Aramidfaser in einem Bereich von 60 bis 80 Gewichtsprozent vorhanden ist.

17. Stoff nach Anspruch 16, wobei die para-Aramidfaser in einem Bereich von 25 bis 35 Gewichtsprozent vorhanden ist und die meta-Aramidfaser in einem Bereich von 65 bis 75 Gewichtsprozent vorhanden ist.

18. Stoff nach Anspruch 11, welcher zusätzlich eine antistatische Komponente enthält.

19. Kleidungsstück, geeignet zum Bereitstellen von Lichtbogen- und Wärmeschutz, umfassend:

(a) 40 bis 75 Gewichtsprozent Modacrylfaser,

(b) 10 bis 40 Gewichtsprozent Baumwollfaser und

(c) 1 bis 40 Gewichtsprozent Aramidfaser,

wobei die Prozentgehalte auf der Basis der Komponenten (a), (b) und (c) sind.

20. Kleidungsstück nach Anspruch 19, umfassend:

(a) 45 bis 60 Gewichtsprozent Modacrylfaser,

(b) 15 bis 35 Gewichtsprozent Baumwollfaser und

(c) 5 bis 30 Gewichtsprozent Aramidfaser.

Revendications

1. Fil approprié pour conférer une protection contre les arcs et les flammes, qui comprend:

(a) de 40 à 75 pour cent en poids d'une fibre modacrylique,

(b) de 10 à 40 pour cent en poids d'une fibre de coton et

(c) de 1 à 40 pour cent en poids d'une fibre aramide,

lesdits pourcentages étant exprimés sur la base des composants (a), (b) et (c).

2. Fil de la revendication 1, qui comprend:

(a) de 45 à 60 pour cent en poids d'une fibre modacrylique,

(b) de 15 à 35 pour cent en poids d'une fibre de coton et

(c) de 5 à 30 pour cent en poids d'une fibre aramide.

3. Fil de la revendication 1, où la fibre contient à la fois des fibres para- et méta-aramides.

4. Fil de la revendication 3, dans lequel la fibre para-aramide est présente dans une plage comprise entre 20 et 40 pour cent en poids et la fibre méta-aramide dans une gamme comprise entre 60 et 80 pour cent en poids sur la base de la fibre aramide totale.

5. Fil de la revendication 4, dans lequel la fibre para-aramide est présente dans une plage comprise entre 25 et 35 pour cent en poids et la fibre méta-aramide dans une gamme comprise entre 65 et 75 pour cent en poids.

6. Fil de la revendication 5, qui contient également un composant antistatique.

7. Fil de la revendication 6, dans lequel le composant antistatique est le carbone ou un métal.

8. Fil de la revendication 7, dans lequel le composant antistatique est le carbone.

9. Fil de la revendication 1, qui contient également un composant antistatique.

10. Fil de la revendication 9, dans lequel le composant antistatique est le carbone.

11. Étoffe approprié pour conférer une protection contre les arcs et une protection thermique, qui comprend:

(a) de 40 à 75 pour cent en poids d'une fibre modacrylique,

(b) de 10 à 40 pour cent en poids d'une fibre de coton et

(c) de 1 à 40 pour cent en poids d'une fibre aramide,

lesdits pourcentages étant exprimés sur la base des composants (a), (b) et (c).

12. Étoffe de la revendication 11, qui comprend:

(a) de 45 à 60 pour cent en poids d'une fibre modacrylique,

(b) de 15 à 35 pour cent en poids d'une fibre de coton et

(c) de 5 à 30 pour cent en poids d'une fibre aramide.

13. Étoffe de la revendication 11, dont la longueur de surface carbonisée selon la norme ASTM D-6413-99 est inférieure à 150 mm (6 pouces).

14. Étoffe de la revendication 11, dont la longueur de surface carbonisée selon la norme ASTM D-6413-99 est inférieure à 115 mm (4,5 pouces).

15. Étoffe de la revendication 11, où le étoffe contient à la fois des fibres para- et méta-aramides.

16. Étoffe de la revendication 15, dans lequel la fibre para-aramide est présente dans une plage comprise entre 20 et 40 pour cent en poids et la fibre méta-aramide est présente dans une gamme comprise entre 60 et 80 pour cent en poids sur la base de la fibre aramide totale.

17. Étoffe de la revendication 16, dans lequel la fibre para-aramide est présente dans une plage comprise entre 25 et 35 pour cent en poids et la fibre méta-aramide est présente dans une gamme comprise entre 65 et 75 pour cent en poids.

18. Étoffe de la revendication 11, qui contient également un composant antistatique.

19. Vêtement approprié pour conférer une protection contre les arcs et une protection thermique, qui comprend:

(a) de 40 à 75 pour cent en poids d'une fibre modacrylique,

(b) de 10 à 40 pour cent en poids d'une fibre de coton et

(c) de 1 à 40 pour cent en poids d'une fibre aramide,

lesdits pourcentages étant exprimés sur la base des composants (a), (b) et (c).

20. Vêtement de la revendication 19, qui comprend:

(a) de 45 à 60 pour cent en poids d'une fibre modacrylique,

(b) de 15 à 35 pour cent en poids d'une fibre de coton et

(c) de 5 à 30 pour cent en poids d'une fibre aramide.