WO2019217097A1

WO2019217097A1 - Fabric and method of using the same

Info

Publication number: WO2019217097A1
Application number: PCT/US2019/029362
Authority: WO
Inventors: Shulong Li; Richard A. Mayernik
Original assignee: Milliken & Company
Priority date: 2018-05-08
Filing date: 2019-04-26
Publication date: 2019-11-14
Also published as: CA3099157A1; EP3791013A1; US20190343204A1

Abstract

A fabric comprises a plurality of yarns, at least a portion of which comprises polyphenylene sulfide fibres and regenerated cellulose fibres. The fabric comprises 35 wt.% or more polyphenylene sulfide fibres. A fabric comprises a plurality of yarns, each yarn comprising a plurality of polyphenylene sulfide staple fibres and a plurality of regenerated cellulose staple fibres. A method of protecting an individual from injury caused by molten metal splashes comprises the steps of providing a fabric, providing a source of molten metal, disposing the fabric between the source of molten metal and an individual, whereby the fabric serves as a barrier to protect the individual from molten metal splashes.

Description

FABRIC AND METHOD OF USING THE SAME

TECHNICAL FIELD OF THE INVENTION

[0001] The invention provides fabrics and method of using the same. More particularly, the fabrics are designed to provide protection against injuries caused by molten metal splashes.

BACKGROUND

[0002] Molten metal handling can be a dangerous affair. The techniques used in transferring and handling molten metals in foundry settings can produce showers of sparks and splashes of molten metal. These molten metal splashes can pose significant threats to individuals in the vicinity, such as foundry workers. Given these risks, the industry has endeavored to create and mandate the use of equipment (e.g., protective garments) that is intended to protect foundry workers from injury caused by molten metal splashes. While this equipment provides protection against some molten metal hazards, the garments either use undesirable fibers blends (e.g., contain significant amounts of wool fibers) and/or do not afford adequate protection against a variety of molten metals. For example, many commercially-available materials do not afford adequate protection against molten aluminum and/or molten cryolite splashes at acceptable areal densities.

[0003] A need therefore remains for fabrics that afford adequate protection against a variety of molten metals at acceptable area densities (i.e., at areal densities that are sufficiently low that the garments are comfortable to wear in a foundry environment). Further, a need remains for fabrics that do not rely on significant amounts of wool fibers to provide such protection. Applicant believes that the fabrics described herein provide such protection.

BRIEF SUMMARY OF THE INVENTION

[0004] In a first embodiment, the invention provides a fabric comprising a plurality of yarns, wherein at least a portion of the yarns comprise polyphenylene sulfide fibers and regenerated cellulose fibers, wherein the fabric comprises 35 wt.% or more polyphenylene sulfide fibers, and wherein the regenerated cellulose fibers are selected from the group consisting of flame resistant rayon fibers, flame resistant lyocell fibers, and mixtures thereof.

[0005] In a second embodiment, the invention provides a fabric comprising a plurality of yarns, each yarn comprising a plurality of polyphenylene sulfide staple fibers and a plurality of regenerated cellulose staple fibers, wherein the regenerated cellulose staple fibers are selected from the group consisting of flame resistant rayon staple fibers, flame resistant lyocell staple fibers, and mixtures thereof.

[0006] In a third embodiment, the invention provides a method of protecting an individual from injury caused by molten metal splashes, the method comprising the steps of:

(a) providing a fabric as described herein;

(b) providing a source of molten metal; and

(c) disposing the fabric between the source of molten metal and an individual, whereby the fabric serves as a barrier to protect the individual from molten metal splashes.

DETAILED DESCRIPTION OF THE INVENTION

[0007] In a first embodiment, the invention provides a fabric comprising a plurality of yarns. The yarns can be woven together in any suitable pattern to yield a woven fabric. Suitable woven patterns include, but are not limited to, plain weaves, satin weaves, and twill weaves. Alternatively, the yarns can be interlooped to provide a knit fabric. Preferably, the fabric is a woven fabric, with plain weaves, twill weaves, and satin weaves being particularly preferred.

[0008] The yarns making up the fabric can be either filament yarns, spun yarns, or a combination of the two. For example, a woven fabric can contain spun warp yarns and filament weft yarns. Alternatively, the woven fabric can contain spun warp yarns with filament weft yarns and spun weft yarns alternating in any suitable pattern. Suitable filament yarns include filament yarns made from a single type of filament (e.g., polyphenylene sulfide filaments) or two or more types of filaments (e.g., a blend of polyphenylene sulfide filaments and regenerated cellulose filaments). Likewise, suitable spun yarns include spun yarns made from a single type of staple fiber (e.g., polyphenylene sulfide staple fibers) or a blend of two or more types of stable fibers (e.g., an intimate blend of polyphenylene sulfide staple fibers and regenerated cellulose staple fibers). The spun yarns in the fabrics of the invention can be formed by any suitable spinning process. Suitable yarn spinning processes include, but are not limited to, open-end spinning, ring spinning, jet spinning, vortex spinning, rotor-spun spinning, and Siro-spun spinning. Preferably, the spun yarns are formed by open-end spinning, ring spinning, or vortex spinning.

In ring spinning, the staple fibers in the yarn have a substantially consistent fiber orientation. Most of the fibers are oriented to the same angle, so most of the fibers help contribute to the yarn strength. Vortex spun yarns, although not typically as strong as ring spun yarns, approximate the structure of a ring spun yarn and are also preferred. Unlike the fiber orientation seen in ring spun and vortex spun yarns, the fiber orientation in an open-end spun yarn tends to be more random and

inconsistent. Two or more spun yarns can also be twisted together to provide two ply or multiple ply yarns.

[0009] In the first embodiment of the fabric, at least a portion of the yarns comprise polyphenylene sulfide fibers. The polyphenylene sulfide fibers present in the yarns can be any suitable polyphenylene sulfide fibers. The polyphenylene sulfide fibers can comprise any suitable polyphenylene sulfide polymer. The polyphenylene sulfide polymer can have any suitable molar mass. Preferably, the polyphenylene sulfide polymer has a mass average molar mass of about 20,000 g/mol or more. More preferably, the polyphenylene sulfide polymer has a mass average molar mass of about 30,000 g/mol or more, about 40,000 g/mol or more, or about 50,000 g/mol or more. Preferably, the polyphenylene sulfide polymer has a mass average molar mass of about 100,000 g/mol or less. More preferably, the polyphenylene sulfide polymer has a mass average molar mass of about 80,000 g/mol or less, about 70,000 g/mol or less, or about 60,000 g/mol or less. In a particularly preferred embodiment, the polyphenylene sulfide polymer has a mass average molar mass of about 40,000 g/mol to about 60,000 g/mol. The

polyphenylene sulfide polymer can have any suitable melt viscosity. Preferably, the polyphenylene sulfide polymer has a melt viscosity of about 1 ,000 poise or more when measured at 300 °C and an apparent shear rate of 400 s^_1 in accordance with ASTM Test Method 3835. More preferably, the polyphenylene sulfide polymer has a melt viscosity of about 1 ,000 poise to about 3,000 poise or about 1 ,000 poise to about 2,200 poise when measured as described above.

[0010] The polyphenylene sulfide polymer can exhibit any suitable degree of crystallinity. Preferably, the percent crystallinity of the polyphenylene sulfide polymer is 10% or more. More preferably, the percent crystallinity of the polyphenylene sulfide polymer is about 20% or more, about 25% or more, or about 30% or more. The percent crystallinity of the polyphenylene sulfide polymer preferably is about 80% or less. More preferably, the percent crystallinity of the polyphenylene sulfide polymer is about 75% or less. Thus, in a series of preferred embodiments, the percent crystallinity of the polyphenylene sulfide polymer is from 10% to about 80%, about 20% to about 80%, or about 30% to about 75%.

[0011] The polyphenylene sulfide fibers present in the fabric can be dyed to provide a desired shade. The polyphenylene sulfide fibers can be dyed using any suitable dye, but disperse dyes are particularly preferred. Preferably, the dye is a disperse dye selected from the group consisting of disperse dyes having a molar mass of about 350 g/mol or more, disperse dyes comprising a nitro group, and mixtures thereof. In another preferred embodiment, the dye is a disperse dye selected from the group consisting of disperse dyes having a molar mass of about 400 g/mol or more, disperse dyes comprising a nitro group, and mixtures thereof. While not wishing to be bound to any particular mechanism or theory, it has been observed that disperse dyes having a higher molar mass (e.g., about 350 g/mol or more or about 400 g/mol or more) and/or a polar nature (such as disperse dyes containing a nitro group) are capable of satisfactorily dyeing the polyphenylene sulfide fibers, whereas disperse dyes that do not possess either of these

characteristics are not. For example, it has been observed that dyes that do not possess either of these characteristics do not become sufficiently fixed in the polyphenylene sulfide fiber. With the exception of nitrodiphenylamine disperse dyes, the disperse dye preferably has a boiling point of 590 °C or more, more preferably about 600 °C or more. With the exception of nitrodiphenylamine disperse dyes, the disperse dye preferably has a flash point of 300 °C or more, more preferably about 310 °C or more. In a particular embodiment, the disperse dye has a boiling point of 590 °C or more (e.g., about 600 °C or more) and a flash point of 300 °C or more (e.g., about 310 °C or more).

[0012] The disperse dye can be any suitable disperse dye that possesses one or more of the characteristics described above. In a more specific preferred embodiment, the disperse dye is selected from the group consisting of azo dyes (e.g., azothiophene dyes, azobenzothiazole dyes), diazo dyes, anthraquinone dyes, nitro dyes (e.g., nitrodiphenylamine dyes), quinoline dyes, dibenzofuran dyes, naphthalimide dyes (e.g., aminoketone dyes), and mixtures thereof. Specific disperse dyes that have been found useful in dyeing the polyphenylene sulfide fibers include, but are not limited to, C.l. Disperse Red 356, C.l. Disperse Red 167, C.l. Disperse Blue 77, C.l. Disperse Orange 30, C.l. Disperse Orange 44, C.l. Disperse Red 91 , C.l. Disperse Blue 77, C.l. Disperse Blue 27, C.l. Disperse Blue 60, C.l. Disperse Yellow 86, C.l. Disperse Yellow 42, C.l. Disperse Yellow 58, C.l. Disperse Yellow 163, C.l. Disperse Red 86, C.l. Disperse Violet 57, C.l. Disperse Red 159,

C.l. Disperse Red 279, C.l. Disperse Yellow 1 14, C.l. Disperse Blue 56, C.l.

Disperse Blue 165, C.l. Disperse Red 153, C.l. Disperse Brown 1 , C.l. Disperse Violet 33, C.l. Disperse Red 92, and C.l. Disperse Blue 87. Any of the above- mentioned dyes can be used in combination to produce polyphenylene sulfide fibers and textile materials exhibiting the desired color and shade.

[0013] The disperse dye preferably is distributed substantially evenly throughout the thickness of the polyphenylene sulfide fibers. In other words, the disperse dye preferably is distributed substantially evenly across the cross-sectional area of the polyphenylene sulfide fibers. This distribution of the disperse dye within the polyphenylene sulfide fibers is believed to be unique. For example, prior attempts to dye polyphenylene sulfide fibers have relied upon surrounding the polyphenylene sulfide polymer with a sheath of an easily-dyed polymer (e.g., a polyamide). In such products, the dye only penetrates and fixes in the sheath, and the polyphenylene sulfide polymer remains undyed (or contains very little dye at the interface between the polyphenylene polymer and the sheath). The distribution of the disperse dye through the thickness or across the cross-sectional area can be determined by any suitable technique. For example, individual polyphenylene sulfide fibers can be sectioned and the coloration of the fibers can be examined, for instance, using an optical microscope. When the coloration of the fibers is observed to be substantially even through the thickness or across the cross-sectional area of the fibers, one has confirmed that the dye is substantially evenly distributed through the thickness or across the cross-sectional area of the fiber. The dyed

polyphenylene fibers described above and the process for making the same is described more fully in co-pending U.S. Patent Application No. 15/785,772 filed on November 17, 2017, the entire contents of which are hereby incorporated by reference.

[0014] In this first embodiment, the yarns can comprise other fibers in addition to the polyphenylene sulfide fibers described above. In one embodiment, at least a portion of the yarns comprise regenerated cellulose fibers in addition to the polyphenylene sulfide fibers. The regenerated cellulose fibers present in the yarns can be any suitable regenerated cellulose fibers. In a preferred embodiment, the regenerated cellulose fibers are selected from the group consisting of flame resistant rayon fibers (e.g., viscose rayon fibers, high wet modulus rayon fibers, modal fibers, and polynosic fibers), flame resistant lyocell fibers, and mixtures thereof. Such fibers typically have been rendered flame resistant by incorporating one or more flame retardants into the cellulose solution from which the fibers are spun and formed. For example, the regenerated cellulose fibers can comprise the flame retardant

2,2'-oxybis(5,5-dimethyl-1 ,3,2-dioxaphosphinane)-2,2'-disulfide. In a preferred embodiment, the regenerated cellulose fibers are flame resistant rayon fibers.

[0015] The fabric and/or the yarns from which the fabric is made can comprise other fibers in addition to the polyphenylene sulfide fibers and regenerated cellulose fibers. Suitable examples of such addition fibers include, but are not limited to, natural fibers, synthetic fibers, and inherent flame-resistant fibers. Suitable natural fibers include, but are not limited to, cotton fibers and silk fibers. Suitable synthetic fibers include synthetic cellulose fibers (e.g., rayon fibers and lyocell fibers) and thermoplastic synthetic fibers. Suitable thermoplastic synthetic fibers include, but are not necessarily limited to, polyester fibers (e.g., polyethylene terephthalate) fibers, polypropylene terephthalate) fibers, poly(trimethylene terephthalate) fibers), polyputylene terephthalate) fibers, and blends thereof), polyamide fibers (e.g., nylon 6 fibers, nylon 6,6 fibers, nylon 4,6 fibers, and nylon 12 fibers), polyvinyl alcohol fibers, and combinations, mixtures, or blends thereof. Preferably, the thermoplastic synthetic fibers are selected from the group consisting of polyester fibers, polyamide fibers, and mixtures thereof.

[0016] When the fabric comprises thermoplastic synthetic fibers, the fabric can further comprise a flame retardant that is added to improve the flame resistance of the thermoplastic synthetic fibers and the fabric containing the same. Any flame retardant suitable for use with thermoplastic synthetic fibers can be used in such embodiments.

[0017] As utilized herein, the term“inherent flame-resistant fibers” refers to synthetic fibers which, due to the chemical composition of the material from which they are made, exhibit flame resistance without the need for an additional flame retardant treatment. In such embodiments, the inherent flame resistant fibers can be any suitable inherent flame resistant fibers, such as polyoxadiazole fibers,

polysulfonamide fibers, poly(benzimidazole) fibers, aramid fibers (e.g., meta- aramid fibers and para- aramid fibers), polypyridobisimidazole fibers, polybenzylthiazole fibers, polybenzyloxazole fibers, melamine-formaldehyde polymer fibers, phenol- formaldehyde polymer fibers, oxidized polyacrylonitrile fibers, polyamide-imide fibers, modacrylic fibers, and combinations, mixtures, or blends thereof.

[0018] In this first embodiment, the yarns comprising the polyphenylene sulfide fibers and the regenerated cellulose fibers can be filament yarns comprising a blend of polyphenylene sulfide filaments and regenerated cellulose filaments or spun yarns comprising an intimate blend of polyphenylene sulfide staple fibers and regenerated cellulose staple fibers. In a preferred embodiment, the fabric comprises spun yarns comprising an intimate blend of polyphenylene sulfide staple fibers and regenerated cellulose staple fibers.

[0019] The polyphenylene sulfide fibers and the regenerated cellulose fibers can be present in the fabric in any suitable amount. In a preferred embodiment, the fabric comprises 35 wt.% or more of the polyphenylene sulfide fibers. More preferably, the fabric comprises about 40 wt.% or more, or about 50 wt.% or more of the polyphenylene sulfide fibers. The fabric preferably comprises about 80 wt.% or less of the polyphenylene sulfide fibers. Thus, in a series of preferred

embodiments, the fabric comprises 35 wt.% to about 80 wt.%, about 40 wt.% to about 80 wt.%, or about 50 wt.% to about 80 wt.% of the polyphenylene sulfide fibers. In a preferred embodiment, the fabric comprises about 10 wt.% or more, about 15 wt.% or more, or about 20 wt.% or more of the regenerated cellulose fibers (e.g., the flame resistant regenerated cellulose fibers). The fabric preferably comprises about 65 wt.% or less, about 60 wt.% or less, or about 50 wt.% or less of the regenerated cellulose fibers. Thus, in a series of preferred embodiments, the fabric comprises about 10 wt.% to about 65 wt.%, about 15 wt.% to about 65 wt.%, about 20 wt.% to about 65 wt.%, about 20 wt.% to about 60 wt.%, or about 20 wt.% to about 50 wt.% of the regenerated cellulose fibers.

[0020] As noted above, the fabric can comprise other fibers in addition to the polyphenylene sulfide fibers and the regenerated cellulose fibers. In a preferred embodiment, the fabric further comprises additional fibers selected from the group consisting of cotton fibers, polyamide fibers, polyester fibers, polyoxadiazole fibers, modacrylic fibers, aramid fibers, and mixtures thereof. In a particularly preferred embodiment, the fabric further comprises polyoxadiazole fibers. These additional fibers (i.e., any fiber(s) in addition to the polyphenylene sulfide fibers and the regenerated cellulose fibers) can be present in the fabric in any suitable amount, though the additional fibers are typically present in a relatively minor amount as compared to the polyphenylene sulfide fibers and regenerated cellulose fibers. In a preferred embodiment, the fabric comprises about 0.5 wt.% or more, about 1 wt.% or more, about 2 wt.% or more, about 3 wt.% or more, about 4 wt.% or more, or about 5 wt.% or more of the additional fibers. In another preferred embodiment, the fabric comprises about 10 wt.% or less, about 9 wt.% or less, about 8 wt.% or less, about 7 wt.% or less, or about 6 wt.% or less of the additional fibers. Thus, in a particularly preferred embodiment, the fabric comprises about 0.5 wt.% to about 10 wt.%, about 1 wt.% to about 9 wt.%, or about 2 wt.% to about 8 wt.% (e.g., about 2 wt.% to about 7 wt.%, about 2 wt.% to about 6 wt.%, or about 2 wt.% to about 5 wt.%) of the additional fibers.

[0021] As noted above, the fabric of the first embodiment of the invention can be a woven fabric. In a preferred embodiment, the woven fabric comprises a plurality of first yarns and a plurality of second yarns disposed substantially perpendicular to and interwoven with the first yarns, where the first yarns comprise polyphenylene sulfide staple fibers and regenerated cellulose staple fibers, and the second yarns comprise polyphenylene sulfide filaments. In such an embodiment, the first yarns (i.e., the yarns comprising polyphenylene sulfide staple fibers and regenerated cellulose staple fibers) preferably comprise about 50 wt.% or more polyphenylene sulfide staple fibers. In another preferred embodiment, the second yarns (i.e., the yarns comprising polyphenylene sulfide filaments) comprise about 90 wt.% or more polyphenylene sulfide filaments. In such a woven fabric, the fabric can further comprise a plurality of third yarns disposed substantially parallel to the second yarns and substantially perpendicular to and interwoven with the first yarns, where the third yarns comprise polyphenylene sulfide staple fibers and regenerated cellulose staple fibers. In such an embodiment, the third yarns can have the same fiber content (i.e., percentages of polyphenylene sulfide staple fibers, regenerated cellulose staple fibers, and, if present, additional fibers) as the first yarns, or the third yarns can have a different fiber content than the first yarns. Preferably, the third yarns comprise about 50 wt.% or more polyphenylene sulfide staple fibers. In an embodiment comprising the third yarns, the second and third yarns can be arranged in any suitable pattern, such as alternating in a one for one pattern, two second yarns followed by one third yarn, three second yarns followed by one third yarn, one second yarn followed by two third yarns, or one second yarn followed by three third yarns.

[0022] In a second embodiment, the invention provides a fabric comprising a plurality of yarns, each yarn comprising a plurality of polyphenylene sulfide staple fibers and a plurality of regenerated cellulose staple fibers. The fabric of this second embodiment can be of any suitable construction, including those described above for the fabric of the first embodiment. The polyphenylene sulfide staple fibers present in the fabric of this second embodiment can be any suitable polyphenylene sulfide staple fibers, including those discussed above in connection with the first

embodiment of the invention. Further, the regenerated cellulose staple fibers present in the fabric of this second embodiment can be any suitable regenerated cellulose staple fibers, including those discussed above in connection with the first embodiment of the invention. Preferably, the regenerated cellulose staple fibers are selected from the group consisting of flame resistant rayon staple fibers, flame resistant lyocell staple fibers, and mixtures thereof.

[0023] Further, the polyphenylene sulfide stable fibers and the regenerated cellulose staple fibers can be present in this fabric of the second embodiment in any suitable amounts, including those discussed above in connection with the first embodiment of the invention. In a preferred embodiment, the fabric comprises 35 wt.% or more, more preferably about 50 wt.% or more, polyphenylene sulfide staple fibers. In another preferred embodiment, the fabric comprises about 20 wt.% to about 70 wt.% regenerated cellulose staple fibers.

[0024] The fabric of the second embodiment can, as was the case with the fabric of the first embodiment, contain other fibers in addition to the polyphenylene sulfide staple fibers and regenerated cellulose staple fibers. These additional fibers can be any suitable fibers, including the additional fibers discussed above in connection with the fabric of the first embodiment. In a preferred embodiment, the fabric further comprises additional fibers selected from the group consisting of cotton fibers, polyamide fibers, polyester fibers, polyoxadiazole fibers, modacrylic fibers, aramid fibers, and mixtures thereof. In a particularly preferred embodiment, the fabric further comprises polyoxadiazole fibers. These additional fibers can be present in the fabric of the second embodiment in any suitable amount, including those amounts discussed above in connection with the fabric of the first

embodiment. In a preferred embodiment, the fabric comprises about 0.5 wt.% to about 10 wt.% of the additional fibers.

[0025] In a preferred embodiment, the fabric of the second embodiment is a woven fabric. In such an embodiment, the woven fabric comprises a plurality of first yarns and a plurality of second yarns disposed substantially perpendicular to and interwoven with the first yarns. The first and second yarns can have the same fiber content (i.e., percentages of polyphenylene sulfide staple fibers, regenerated cellulose staple fibers, and, if present, additional fibers), or the first and second yarns can have different fiber contents. In a preferred embodiment, the first and second yarns have different fiber contents. More specifically, the first yarns comprise a first amount of polyphenylene sulfide staple fibers, the second yarns comprise a second amount of polyphenylene sulfide staple fibers, and the first amount is greater than the second amount by about 5 weight percentage points or more.

[0026] The fabrics of the invention can be dyed a desired shade by any suitable process. As noted above, the polyphenylene sulfide fibers can be dyed using the process described in co-pending U.S. Patent Application No. 15/785,772. Those fabrics containing regenerated cellulose fibers and/or cotton fibers can also be dyed using the process described in co-pending U.S. Patent Application No. 15/785,772.

[0027] While the fabrics described above (i.e., the fabric of the first

embodiment and the fabric of the second embodiment) can comprise other fibers in addition to the polyphenylene sulfide fibers and regenerated cellulose fibers described above, the fabric preferably is substantially free of wool fibers. Wool fibers are frequently used in fabrics and garments intended for use in protecting the wearer from molten metal splashes. However, Applicants have found fabrics containing wool fibers to be undesirable for several reasons. First, fabrics containing significant amounts of wool fiber tend to be uncomfortable because they trap the wearer’s body heat, which is only exacerbated when the fabrics are worn in the hot environments in which molten metals are processed. Second, fabrics containing significant amounts of wool fiber can begin to develop an unpleasant odor over time, the unpleasantness of which can be compounded by the accumulation of the wearer’s sweat and body oils in the fabric. Third, fabrics containing significant amounts of wool fiber tend to shrink excessively when they are laundered. All these factors combine to make fabrics containing appreciable amounts of wool fiber undesirable. Thus, in a preferred embodiment, the fabrics described herein contains about 10 wt.% or less, about 5 wt.% or less, about 4 wt.% or less, about 3 wt.% or less, about 2 wt.% or less, or about 1 wt.% or less wool fibers.

[0028] The fabrics of the first and second embodiment can have any suitable areal density. However, the areal density of the fabrics should not be so low that the fabrics do not provide sufficient protection to the wearer, and the areal density of the fabrics should not be so high as to render the fabrics prohibitively uncomfortable to wear. The fabrics preferably have an areal density of about 50 g/m² or more, about 70 g/m² or more, about 85 g/m² or more, about 100 g/m² or more, about 120 g/m² or more, or about 135 g/m² or more. In another preferred embodiment, the fabrics have an areal density of about 305 g/m² or less, about 290 g/m² or less, about 270 g/m² or less, about 255 g/m² or less, or about 235 g/m² or less. In a series of preferred embodiments, the fabrics preferably have an areal density of about 50 g/m² to about 305 g/m², about 70 g/m² to about 290 g/m², about 85 g/m² to about 270 g/m², about 100 g/m² to about 255 g/m², about 120 g/m² to about 235 g/m², or about 135 g/m² to about 235 g/m².

[0029] The fabrics of the invention are believed to be well-suited for use in making protective apparel for those who work with molten metals and are at risk for injury by molten metal splashes. While fabrics for molten metal splash protection are known, these fabrics either use undesirable fibers blends (e.g., contain significant amounts of wool fibers) and/or do not afford adequate protection from various molten metals. For example, many commercially-available materials do not afford adequate protection against molten aluminum and/or molten cryolite splashes at acceptable areal densities. Indeed, Applicant has observed molten aluminum and/or molten cryolite adhering to the surface of some commercially-available materials, which would cause severe burns to the skin of anyone wearing such fabrics. Thus, when measured in accordance with ISO 1 1612, the fabrics of the invention preferably provide a molten aluminum protection rating of D1 or greater (e.g., D2 or D3) at an areal density of 305 g/m² or less. Preferably, the fabrics of the invention provide a molten aluminum protection rating of D2 or greater at an areal density of about 240 g/m².

[0030] In addition to providing protection from molten metal splashes, the fabrics of the invention have also been observed to exhibit satisfactory flame- resistant properties. For example, when measured in accordance with ASTM

D6413, the fabrics of the invention exhibit a char length of less than 4 inches (10.16 cm). This relatively low char length is surprising given that the fabrics of the invention can contain relatively large amounts of thermoplastic fibers (e.g., polyphenylene sulfide fibers). Such short char lengths are typically difficult to achieve with high thermoplastic content (e.g., above 35 wt.%) because

thermoplastics typically melt and crack or break during the test, resulting in char length that exceeds the 4-inch limit set by industry standards, such as NFPA 21 12 for flame resistant protective clothing.

[0031] While the fabrics of the invention deliver satisfactory flame resistance, this flame resistance preferably is achieved without the use of

tetrahydroxymethylphosphonium-based flame retardants (e.g., flame retardants based on tetrahydroxymethylphosphonium sulfate, tetrahydroxymethylphosphonium chloride, and condensation polymers of the same with nitrogen-containing

compounds). The presence of such flame retardants has been observed to cause molten metal, especially molten aluminum and/or molten cryolite to adhere to the surface of the fabric. As noted above, when the molten metal adheres to the surface of a fabric, the result can be severe burns to the skin of anyone wearing such fabrics. Similarly, other flame retardant chemical treatments or coatings that are applied to a fabric typically are undesired and preferably are not used on the fabrics of the present invention.

[0032] In view of the flame resistance and molten metal protection afforded by the fabrics of the invention, the invention also provides a method of using a fabric of the invention to protect an individual. Thus, in a third embodiment, the invention provides a method of protecting an individual from injury caused by molten metal splashes, the method comprising the steps of: (a) providing a fabric as described herein; (b) providing a source of molten metal; and (c) disposing the fabric between the source of molten metal and an individual, whereby the fabric serves as a barrier to protect the individual from molten metal splashes. The fabric utilized in the method can be any of the fabrics of the invention described in the preceding paragraphs. The source of molten metal can be any suitable source of molten metal, such as a furnace, crucible, or foundry ladle. Further, the molten metal can be any metal or combination of metals. As noted above, the fabrics of the invention are particularly effective at protecting against injury from molten aluminum splashes, so the source of molten metal can contain molten aluminum or molten cryolite. As used in this context, the term“molten aluminum” refers not only to molten aluminum metal, but also molten aluminum alloys.

[0033] In the method of the invention, the fabric can be disposed at any suitable point between the individual and the source of molten metal. For example, the fabric can be deployed as a screen (e.g., a screen affixed to a frame) that is positioned between the source of molten metal and the individual. However, to ensure that the fabric is positioned to afford the greatest degree of protection to the individual, the fabric preferably forms part of a garment worn by the individual.

Suitable garments include, but are not limited to, shirts, pants, coats, hoods, aprons, gaiters, overboots, and gloves. In a preferred embodiment, the outward-facing textile portions of a garment worn by the individual (i.e., those portions of the garment facing towards the source of molten metal when the garment is being worn by the individual) consist essentially of (or even more preferably consist of) a fabric according to the invention. The fabrics described herein may also be used in so- called“secondary protective clothing,” which are garments that are typically worn by a worker underneath primary protective clothing. In this context, the primary protective clothing, which typically consists of an aluminized film laminated to a heavy textile substrate overlaying a thick, heat-insulating felt/batting inner layer, provides a first line of defense for those working in a high risk job or situation. Due to their construction and bulk, the primary protective clothing typically is

uncomfortable to wear and not washable. Secondary protective clothing made from the fabric of the invention can be used in combination with such primary protective clothing in high risk jobs or situations to provide optimal protection and comfort for safe and effective worker performance. Such secondary protective clothing can increase worker comfort by providing a“buffer” between the worker and the uncomfortable, bulky primary protective clothing. Also, such secondary protective clothing can be laundered to remove the sweat and other bodily excretions that accumulate on the fabric when it is worn. Alternatively, secondary protective clothing made from the fabric of the invention can be used alone in low and medium risk jobs or situations, where the risk and potential severity of injuries are lower.

[0034] The following examples further illustrate the subject matter described above but, of course, should not be construed as in any way limiting the scope thereof. EXAMPLE 1

[0035] A PPS staple fiber (2 denier, 52 mm cut length, obtained from Jeffco Fibres, Inc.) and a flame-resistant rayon staple fiber, Lenzing FR (2 denier, 51 mm cut length, obtained from Lenzing AG), were blended at about 65% (PPS) and 35% Lenzing FR by weight to form a sliver. The sliver was subsequently spun into a single ply 10 count yarn using a ring spinning method. The blended yarn was used as both warp and weft yarns to form a woven fabric in a 3x1 left hand twill pattern at about 58 ends/inch and 54 picks/inch weaving density. The resulting fabric had an areal density of about 305 g/m² (about 9 ounces per square yard).

[0036] The fabric was dyed with the dye formula from Table 1 (including both disperse dyes and vat dyes) to provide a Navy color.

Table 1. Dye liquor formulation.

[0037] The fabric was impregnated with the dye liquor from Table 1 at about 50% weight pickup, dried in an infrared dryer, a convection drying oven, and lastly heated in another convection oven at 425 °F for about 1.5 minutes. The fabric was then cooled.

[0038] To fix vat dyes on the rayon fibers, the fabric was subsequently immersed in an aqueous solution containing 3% sodium hydroxide and 6% sodium hydrosulfite. The fabric was then placed in a saturated steamer for approximately 3 minutes, followed by rinsing in hot water and immersion in a 6% hydrogen peroxide solution. The fabric was lastly rinsed in hot water and dried. The dyed fabric felt very soft and comfortable.

[0039] The dyed fabric was tested for color fastness to light according to AATCC Test Method 16.3. The fabric exhibited light fastness ratings of 3.5 - 4.0 after 20 hours and 40 hours of exposure to xenon light.

[0040] The dyed fabric was tested for flame resistance according to ASTM D6413 method. The fabric exhibited a zero second afterflame time and a char length of about 2.5 inches in both the warp and weft directions.

[0041] The dyed fabric was tested for grab tensile strength according to ASTM D5034. The fabric exhibited tensile strengths of 213 pounds force (947 N) in the warp direction and 265 pounds force (1 ,180 N) in the filling direction.

[0042] The fabric was tested for wash shrinkage according to AATCC Test Method 135. The fabric exhibited wash shrinkage of 1.2% in the warp direction and 0.4% in the filling direction after 5 repeated laundry cycles with washing temperature at 120 °F (49 °C).

[0043] The dyed fabric was tested in accordance with ISO 9185 method for molten aluminum splash resistance. When approximately 360 grams of molten aluminum was poured onto the fabric, no residual aluminum was observed on the fabric surface. The skin simulant placed on the back side of the fabric also showed no visible physical damage after the molten aluminum splash test. In view of these results, the fabric can be classified as“D3” according to ISO 1 1612 standard for molten metal protection performance.

EXAMPLE 2

[0044] A fabric similar to that described in Example 1 was made, except that the fabric was woven with a looser construction to obtain a lower areal density of about 240 g/m² (about 7 ounces per square yard). The fabric was tested in accordance to ISO 9185 method. When approximately 200 grams of molten aluminum was poured onto the fabric, no metal residue was observed on the fabric surface, and the skin simulant film showed no visible damage. In view of these results, the fabric can be classified as“D2” for molten metal protection performance according to ISO 1 1612 standard.

EXAMPLE 3

[0045] A fabric similar to that described in Example 1 was made, except that the yarns were made with a blend of 50% PPS fiber and 50% FR Rayon fiber, and the warp yarns were single ply 14 cotton count instead of 10 cotton count. The resulting fabric weight was about 320 grams/m².

[0046] The dyed fabric was tested in accordance with ISO 9185 method for molten aluminum splash resistance. When approximately 290 grams of molten aluminum was poured onto the fabric, no residual aluminum was observed on the fabric surface. The skin simulant placed on the back side of the fabric also showed no visible physical damages after the molten aluminum splash test. In view of these results, the fabric can be classified as“D2” according to ISO 1 1612 standard for molten metal protection performance.

[0047] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0048] The use of the terms“a” and“an” and“the” and similar referents in the context of describing the subject matter of this application (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,”“having,”“including,” and“containing” are to be construed as open- ended terms (i.e., meaning“including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g.,“such as”) provided herein, is intended merely to better illuminate the subject matter of the application and does not pose a limitation on the scope of the subject matter unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the subject matter described herein.

[0049] Preferred embodiments of the subject matter of this application are described herein, including the best mode known to the inventors for carrying out the claimed subject matter. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the subject matter described herein to be practiced otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above- described elements in all possible variations thereof is encompassed by the present disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

WHAT IS CLAIMED IS:

1. A fabric comprising a plurality of yarns, wherein at least a portion of the yarns comprise polyphenylene sulfide fibers and regenerated cellulose fibers, wherein the fabric comprises 35 wt.% or more polyphenylene sulfide fibers, and wherein the regenerated cellulose fibers are selected from the group consisting of flame resistant rayon fibers, flame resistant lyocell fibers, and mixtures thereof.

2. The fabric of claim 1 , wherein the fabric comprises about 40 wt.% or more polyphenylene sulfide fibers.

3. The fabric of claim 2, wherein the fabric comprises about 50 wt.% or more polyphenylene sulfide fibers.

4. The fabric of any of claims 1 -3, wherein the fabric comprises about 80 wt.% or less polyphenylene sulfide fibers.

5. The fabric of any of claims 1 -4, wherein the fabric comprises about 20 wt.% to about 65 wt.% regenerated cellulose fibers.

6. The fabric of any of claims 1 -5, wherein the fabric further comprises additional fibers selected from the group consisting of cotton fibers, polyamide fibers, polyester fibers, polyoxadiazole fibers, modacrylic fibers, aramid fibers, and mixtures thereof.

7. The fabric of claim 6, wherein the fabric comprises about 0.5 wt.% to about 10 wt.% of the additional fibers.

8. The fabric of any of claims 1 -7, wherein the fabric is a woven fabric.

9. The fabric of claim 8, wherein the woven fabric comprises a plurality of first yarns and a plurality of second yarns disposed substantially perpendicular to and interwoven with the first yarns, wherein the first yarns comprise polyphenylene sulfide staple fibers and regenerated cellulose staple fibers, and wherein the second yarns comprise polyphenylene sulfide filaments.

10. The fabric of claim 9, wherein the first yarns comprise about 50 wt.% or more polyphenylene sulfide staple fibers.

1 1. The fabric of claim 9 or claim 10, wherein the second yarns comprise about 90 wt.% or more polyphenylene sulfide filaments.

12. The fabric of any of claims 9-1 1 , wherein fabric further comprises a plurality of third yarns disposed substantially parallel to the second yarns and substantially perpendicular to and interwoven with the first yarns, wherein the third yarns comprise polyphenylene sulfide staple fibers and regenerated cellulose staple fibers.

13. The fabric of claim 12, wherein the third yarns comprise about 50 wt.% or more polyphenylene sulfide staple fibers.

14. A fabric comprising a plurality of yarns, each yarn comprising a plurality of polyphenylene sulfide staple fibers and a plurality of regenerated cellulose staple fibers, wherein the regenerated cellulose staple fibers are selected from the group consisting of flame resistant rayon staple fibers, flame resistant lyocell staple fibers, and mixtures thereof.

15. The fabric of claim 14, wherein the fabric comprises 35 wt.% or more polyphenylene sulfide staple fibers.

16. The fabric of claim 15, wherein the fabric comprises about 50 wt.% or more polyphenylene sulfide staple fibers.

17. The fabric of any of claims 14-16, wherein the fabric comprises about 20 wt.% to about 70 wt.% regenerated cellulose staple fibers.

18. The fabric of any of claims 14-17, wherein the fabric further comprises additional fibers selected from the group consisting of cotton fibers, polyamide fibers, polyester fibers, polyoxadiazole fibers, modacrylic fibers, aramid fibers, and mixtures thereof.

19. The fabric of claim 18, wherein the fabric comprises about 0.5 wt.% to about 10 wt.% of the additional fibers.

20. The fabric of any of claims 14-19, wherein the fabric is a woven fabric.

21. The fabric of claim 20, wherein the woven fabric comprises a plurality of first yarns and a plurality of second yarns disposed substantially perpendicular to and interwoven with the first yarns, wherein the first yarns comprise a first amount of polyphenylene sulfide staple fibers, wherein the second yarns comprise a second amount of polyphenylene sulfide staple fibers, and wherein the first amount is greater than the second amount by about 5 weight percentage points or more.

22. A method of protecting an individual from injury caused by molten metal splashes, the method comprising the steps of:

(a) providing the fabric of any of claims 1 -21 ;

(b) providing a source of molten metal; and

23. The method of claim 22, wherein the fabric is provided as a fabric panel of a garment worn by the individual.