TR2022013667T2 - FIRE AND WEAR RESISTANT YARN - Google Patents

Abstract

A method and system for creating fire and abrasion resistant threads is disclosed. Fire and abrasion resistant yarn consists of a fibrous bundle spun from a mixture of fire retardant fibers and non-flame retardant fibers. The fibrous bundle is wrapped and integrated with a filament that contains a refractory (FR) material and is added during the winding and twisting of the fibers of the fibrous bundle to aid in bonding the fibrous bundle. FR filament is selected from fire/heat resistant and abrasion resistant materials, while the fibers of the fibrous bundle can be selected from natural or synthetic fibers or filaments with additional desired properties.

Description

DESCRIPTION FIRE AND ABRASION RESISTANT YARN Cross-Reference to the related Application is a U.S. Provisional Patent Application. It is included herein by reference as described in the quoted form. Technical Field The present invention relates to fabrics and yarns and processes for making such yarns and fabrics. The present invention relates particularly to fabrics and yarns and processes for making lightweight yarns and fabrics with desirable performance characteristics such as increased fire and abrasion resistance. Prior Technical Fabrics made for basic training and combat situations in the military, as well as fabrics made for many industrial applications, generally meet state and/or industry standards for fire resistance and also abrasion resistance. For example, fabrics used to make military clothing, such as "Fire-Resistant Army Combat Uniforms" (FR ACU) and other industrial uniforms, need to exhibit high fire resistance to overcome fire hazards (such as exposure to explosives during combat) and preferably high abrasion resistance to ensure durability and longevity. It is also important that such fabrics are comfortable and flexible so as not to restrict the soldier's movement. Unfortunately, such fabrics are expensive, and in some fire-resistant fabrics, abrasion resistance is often compromised in exchange for other necessary properties such as increased fire resistance and user comfort. Consequently, clothing made from such fabrics may require more frequent replacements, leading to increased replacement costs and, in a battlefield scenario, potential injury or death to soldiers if replacements are not provided in a timely manner. Therefore, developing fabrics that are largely fire-resistant or non-flammable, but also possess good abrasion resistance, are comfortable and printable, and economical for use in both combat and non-combat situations, has been a goal of the US military. Accordingly, there is a continuous need for fire- and abrasion-resistant yarns and fabrics that address the aforementioned and other related and unrelated issues in technology. Summary of the Invention In summary, the present description is, in one aspect, directed towards methods and systems for creating fire- and abrasion-resistant yarns that can be used to create lightweight, comfortable fabrics with desired fire/flame and abrasion resistance performance characteristics. In one application, a method for making a fire- and abrasion-resistant composite yarn can be provided. A method for creating a fire-resistant composite yarn involves the formation of a fibrous blend with one or more fibers in a primary spinning process. For example, the fibers of the fibrous bundle may contain a mixture of fire- or flame-resistant fibers such as modacrylic fibers, cotton fibers, and so on. Modacrylic fibers can provide resistance to the spread of fire within the fibrous bundle when exposed to a flame. Other fibers, such as cotton fibers, can provide additional properties such as moisture absorption, softness, etc. In one application, the fibrous blend might contain a mixture of approximately 35% to 65% flame-resistant modacrylic fiber and approximately 65% to 35% cotton fiber. In another application, the fibrous blend might contain approximately 55% flame-resistant modacrylic fiber and approximately 45% cotton fiber. A primary filament is introduced into the spinning process and fed into an area where staple fiber series are spun around the primary filament and will be combined and/or interwoven with the fibrous bundle to form an integrated fibrous bundle. The primary filament will contain a flame-resistant material that may have high abrasion resistance, such as flame-resistant (FR) Nylon. Other flame-resistant filaments that make up the primary filament may include FR Polytrimethylene terephthalate (PTT), FR polyethylene, FR polypropylene, or FR polyester. For filaments/fibers that are not naturally flame-resistant, at least one flame retardant may be added to provide the "FR" marking, indicating a flame-resistant fiber. The first filament typically has a size of approximately 20 denier or larger (e.g., from approximately 20 denier to approximately 70-100 denier) and the fibers will be applied in approximately the same turns per inch as they are twisted to form the fibrous bundle, where they will be tightly wound or twisted and integrated into the fibrous bundle. Since the first filament is placed into the spinning frame by the spinning of the fibrous bundle, the fire resistances of the first filament and the FR fibers within the fibrous bundle bind the fibrous bundle in such a way as to protect the first filament from degradation due to heat and/or fire. During the spinning process, the primary filament is coiled around an outer circumference of the fibrous bundle, becoming entangled and/or embedded within the fibers of the bundle. As a result, when the integrated/embedded fibrous bundle and primary filament, such as FR nylon, are exposed to heat, the primary filament can shrink and compress around the fibrous bundle, thus producing a tighter and stronger composite yarn. Additionally, the shrinkage of the first filament when exposed to fire/flames causes the filament to tighten around the filament bundle, creating a tight bundle that eliminates the fibrous oxygen bundle necessary for combustion, thereby increasing the Limiting Oxygen Index (LCD) of the yarn and thus the flame resistance of the base yarn. Furthermore, the fibrous blend can be formed by spinning fibers from one or more filament rovings to form a largely homogeneous blend or a fibrous bundle that will be spun to form a core of spun fibers. As the fibrous bundle is spun and forms a core for the yarn, the first filament is inserted into the spinning frame at an angle equivalent to the same turns per inch as the fibrous bundle and wrapped around it, becoming largely embedded with the fibers that form the outer circumference of the fibrous bundle/core. The filament defines the fiber core as described by the first filament. The method may also involve doubling the yarn and twisting it during an additional twisting process. During this additional twisting process, the yarn may be twisted in the opposite direction to apply a counter-twist (e.g., a reverse Z or 8 twist) chosen/designed to largely neutralize and/or minimize the torque of the finished fire and abrasion-resistant yarn and also to increase abrasion resistance. Furthermore, a second filament or bundle of yarn may be added and spun with the first filament, i.e., the first filament, during the initial spinning process, so that both the first and second filaments are largely intertwined with the fibrous bundle, forming a wrapping or binding coating around the core of the twisted fibers to create a base yarn with an initial "8" or "Z" twist direction. It can be defined. The main yarn can be folded in half and twisted in the opposite direction to minimize the torque within it. Alternatively, the method may also involve folding one or more additional filaments (e.g., a second and/or third filament) within the main yarn at a specific angle and twisting the main yarn and the additional filament together in a second direction opposite to the first, sufficient to largely neutralize and/or balance the torque of the final composite yarn. In some applications, fire-resistant and abrasion-resistant composite yarn may contain a blend of composite yarn and approximately 25% to 35% cotton. For example, variations in the weight percentages of FR nylon, modacrylic, and cotton (or other staple fibers) may also be used. The blended yarn may consist of cotton and modacrylic fibers forming a fibrous bundle that will be bonded around the outer circumference or surface of an FR nylon filament, for example, an FR nylon filament of approximately 70-100 denier. It uses. As a result, while the fibrous bundle provides comfort and FR properties to the composite yarn, the FR nylon filament wrapped around the outer circumference of the fibrous bundle adds abrasion resistance to the surface of the yarn/fabric where abrasion resistance is most needed. The tight wrapping of the FR nylon filament also helps control the shrinkage of the yarn when exposed to flame or high heat, ensuring that the filament shrinks around the fibrous cotton and modacrylic bundle just enough to close any voids and limit oxygen within the yarn without excessive shrinkage or collapse of the yarn. Fire-resistant fabric made from fire-resistant composite yarn can be made from woven or knitted structures. For example, a fire-resistant fabric can be woven from 20Ne fire and abrasion-resistant composite yarn woven in both warp and weft directions, or it can be otherwise constructed and per linear yard. The fabric weight may be approximately 0.25-0.30 pounds. Fire-resistant fabric made from fire-resistant composite yarn generally exhibits high abrasion resistance and low thermal shrinkage (e.g., in some configurations, shrinkage of approximately 7% - 3% in the longitudinal and transverse directions), as well as low vertical flammability, is easily dyed and printed, and is economical. The various purposes, properties, and advantages of the present invention will be understood by experts in the relevant field by examining the detailed description below, together with the accompanying drawings. Brief Description of Figures For the simplicity and clarity of the description, it should be understood that the elements shown in the figures are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated compared to others. The current specification... Applications incorporating the teachings are shown and explained according to the drawings provided herein: Figure 1 provides a schematic representation of a system and method for making a fire- and abrasion-resistant composite yarn according to an application of the specification; Figure 2 shows another example system and method for making a fire- and abrasion-resistant composite yarn according to an application of the specification; Figure 3 shows an example of a fire- and abrasion-resistant composite yarn according to the principles of the specification; The use of the same reference symbols in different drawings indicates similar or identical elements. Detailed Explanation The following specification, together with the figures, is provided to aid in understanding the teachings described herein. The specification focuses on specific applications and concrete examples of the teachings and is provided to aid in explaining the teachings. This focus, This should not be interpreted as a limitation on the scope or applicability of the teachings. Generally, the present invention relates to systems and methods for the creation of fire- and abrasion-resistant composite spun yarns. In addition, these fire- and abrasion-resistant composite yarns will generally exhibit additional properties such as improved strength, moisture absorption, and comfort, as well as being easily knitted or woven to form lightweight fabrics that are flame/fire and abrasion resistant. Some applications of the present specification involve processes that help to impart useful performance characteristics to the finished fire-resistant composite yarns. These performance characteristics can then be transferred to fabrics made from such composite yarns and to garments made from them. Generally, the yarns of the present invention are designed to be produced using a loop or other type of spinning frame and spinning process. The finished yarns formed by these processes can also generally be used in various woven fabrics. Composite yarns are designed to withstand mechanical and physical abuse of knitting or weaving machines without physical damage during the knitting or weaving of yarns into lightweight, economically produced fabrics, or during the application of yarns, and also during other processes such as knitting, stitching, tufting, etc., to create non-woven performance fabrics. Finished fire and abrasion resistant fabrics made from composite yarns will be lightweight and flexible, while also incorporating enhanced performance properties such as increased strength, abrasion resistance, and fire/flame resistance, along with softness and other properties. Such fabrics are suitable for military uniforms or firefighter aprons, protective gear, where properties such as increased flame/fire or heat resistance and abrasion resistance, increased strength are improved, but also desirable properties such as softness or feel to provide improved mobility and/or flexibility of the fabrics. Gloves can be used in the creation of clothing such as protection against arc flash or various other types of clothing and items. Figure 1 shows an example application of a system and process (100) for making a fire and abrasion resistant composite yarn (122) according to an application of the description. The system will generally use a spinning machine (120) and the process involves adding a series of fibers (102) from at least one roving (103) to a series of drawing rollers (105) of the spinning frame (120) to form a fibrous bundle (107) and spinning the fiber string (102) to form a series of fibers. While Figure 1 shows a single roving (103) feeding the fibers (102), a single roving can be used to feed the fibers or more than one (i.e., two, as shown in Figure 2. Three, four, etc. wicks may also be used. The spinning frame (120) may include a spinning frame that can form part of a loop spinning process. The series of fibers (102) that make up the fiber bundle (107) may include a mixture of fire or flame resistant (FR) fibers such as modacrylic fibers and non-fire or flame resistant (non-FR) fibers such as cotton and other staple fibers. FR fibers can provide resistance to the spread of fire within the fiber bundle (107) when exposed to a flame, while fibers such as cotton and other staple fibers can provide additional properties such as moisture absorption, softness, etc. in addition to providing flame resistance. In some applications, fibers (102) may include para-aramids, meta-aramids, modacrylics, Vectran™, polybenzimidazole (PB1), polybenzoxazole (PBO), opan, Liquid crystal polymers such as pyroteX, Teflon, quinol, rayon, FR rayon, Tencel, nylon, FR nylon, acetate, acrylic, polyester, cotton and their blends can be selected from a group. Referring again to Figure 1, a fire-retardant (FR) filament (108) will be added to the first spinning process (120) and fed into the drafting area (106) where the fiber series (102) are spun together. The FR filament (108) is also generally applied with the fiber series (102) at approximately the same turns per inch so that it combines and/or blends with the fibers of the fibrous bundle (107) to form an integrated fibrous bundle as the first filament exits the spinning frame. Also, during spinning, the FR filament (108) is spirally wound around the fibrous bundle (107) and the twisted fibers define a core of a starting or master yarn (112) connected by the spiral winding and integration of the FR filament (108) around/with the fibrous bundle. In one application, the FR filament (108) can be inserted next to the fibrous bundle (107) before or as the fibrous bundle exits the first spinning frame (120). This insertion of the FR filament causes the FR filament to integrate with the fiber series (102) as it is twisted with the fibrous bundle, i.e. the blend, the FR filament is spirally wound and embedded as an integrated component with the fibers around the outer circumference of the resulting composite yarn (122). The FR filament (108) is also used in a high abrasion material such as flame-resistant (FR) Nylon. It contains a fire-resistant material with high resistance. Other flame-resistant filaments that make up the first filament may include liquid crystal polymers such as FR rayon, FR para-aramids, FR polyester, meta-aramid, polypropylene, Vectran™, FR PTT, and FR polyethylene. Other materials that are naturally abrasion-resistant can also be used, and a flame or fire retardant can be added to improve their fire resistance. The helical wrapping and incorporation of the FR filament around/into the fibrous bundle helps integrate the FR properties of the FR filament into the fibrous bundle; for example, when a composite yarn or fabric made from composite yarn is exposed to fire/flame or intense heat, it pulls and shrinks around the fibrous bundle. The tightening of the FR filament around the fibrous bundle removes oxygen from the fibers of the fibrous bundle between them. When the fibers of the yarn (112) are deoxygenated, the Limiting Oxygen Index (LOl) of the yarn (112) (and consequently of the fabrics made from it) increases. However, the shrinkage caused by the exposure of the yarn to fire/flame or intense heat will be greatly minimized because the FR filament integrates with the fibrous bundle (107) during spinning and is coiled around it, rather than being applied/walked along the axis of the fibrous bundle. As a result, the FR fibers in which the FR filament is embedded help protect the FR filament from deterioration and collapse, allowing the FR filament to be pulled around the fibrous bundle in a controlled, limited manner, ensuring tighter integration with the fibrous bundle without collapse, and consequently obtaining a stronger composite yarn that is fire and abrasion resistant and fabrics with higher fire resistance. The fire and abrasion resistant composite yarn, made from an integrated filament (108) and a fibrous bundle (107), is usually spun with a twist in a first direction. In one application, the first twist direction may be an 8-direction or counterclockwise twist direction. In another application, the first twist direction may be a Z-direction or clockwise twist direction. As the yarn (112) exits the first spinning process (120), the yarn (112) may be twisted or doubled with an additional yarn bundle or filament (110) as shown in Figure 2 and spun in a second twist direction (e.g., a reverse Z or 8 twist) for a series of turns or twists per inch designed to largely neutralize and/or balance the torque of the finished composite yarn (122) during an additional spinning process. For example, in one application, the composite of FR filament A fire-resistant master composite yarn (112) can be formed as a ring-spun yarn with a mass ratio of approximately 6% to approximately 83%, although such mass ratio ranges are sample ranges, and different mass ratio ranges can be considered to meet the specific desired properties of the resulting composite yarn. The yarn may include a fibrous bundle consisting of spun, twisted modacrylic and cotton fibers, with approximately 20-100 denier FR nylon filament wrapped/applied around the fibrous bundle with a Z-twist during an initial spinning process. After that, the yarn can be doubled and twisted in the opposite direction (e.g., with an S-twist) during a subsequent twisting process as shown in Figure 1 130. In the resulting fire-resistant and abrasion-resistant composite yarn (122) To minimize torque considerably, the doubled yarn is twisted in the second twist direction, opposite to the first twist direction. In another example application, the fibrous bundle may contain a blend of approximately 70 denier FR Nylon filament, comprising approximately 25-38% by weight of the yarn, spun with approximately 35% to 65% by weight modacrylic and approximately 65% to 35% by weight cotton. Other applications may involve varying the size of the FR filament as well as varying the weight/mass percentages of the FR and non-FR fiber types. For example, FR nylon filament can be used with a finished fire and abrasion resistant composite yarn containing approximately 20Ne ring yarn with a blend of 30% to 40% modacrylic and 25% to 35% cotton. These mass/weight ratio ranges are examples. These are ranges and different weight/mass ratio ranges can be considered to meet the desired fire resistance and abrasion resistance in the resulting composite yarn. As explained with reference to Figure 2a, the fiber series (102) may include a range of non-flame or non-refractory (Non-FR) fibers, including staple fibers such as cotton, wool, viscose fibers and other similar fibers, as well as a mixture of flame or non-refractory (FR) fibers, which may include modacrylic fibers, FR rayon, flame-resistant treated cotton, wool and other similar fibers. For example, fibers (102) may include para-aramids, meta-aramids, modacrylics, vectran, polybenzimidazole (PBl), polybenzoxazole (PBO), opan, pyroteX, Teflon, quinol, rayon, wool, Tencel, nylon, polyester, cotton and their It may include blends. FR fibers can provide resistance to the spread of fire within the fibrous bundle when exposed to a flame. Fibers such as cotton fibers can provide additional properties such as moisture absorption, softness, etc., in addition to flame resistance. The fiber series (102) will be spun together and will form a fibrous bundle (107) which can actually define a core or central bundle of the composite yarn. A first filament (108) will also be added during the spinning process, the first filament is spirally wrapped around the outer circumference of the fibrous bundle and embedded with its fibers. The first filament will contain a fire-resistant material with high abrasion resistance, such as flame-resistant (FR) Nylon. Other flame-resistant filaments that make up the first filament may include FR PTT, Teflon, FR para-aramids, FR polyester. These materials are natural. While they may be abrasion resistant, a flame or fire retardant can be added to them to improve their fire resistance. For example, other materials for the first filament may include polyester, nylon, lycra, para-aramids, high-density polyethylene and their blends. The first filament is usually introduced into the first spinning process (120) with a series of fibers (102) fed into the drafting zone (106) together with the fibers, where the first filament is spun helically or twisted around the fiber series (102) of the fibrous bundle to form a combined filament/fibrous bundle. In one application, the first filament can be introduced into the fiber bundle, for example, from the side, as shown in Figure 2, while the fibrous bundle is being formed or exiting the first spinning process (120). This type of introduction of the first filament (108) improves the first The filament integrates with the fiber series (102) to form a filament/fiber bundle (107) in which the combined filament/fiber bundle is largely enclosed in a middle or central part. Thus, the first filament (108) becomes essentially embedded on the surface as an integral component in the resulting base yarn. As shown in more detail in Figure 2, the main yarn (112) can also be spun with a second filament or another yarn (110) to add additional properties such as cut resistance etc. to the resulting composite yarn (122) and/or to provide more strength and protection when subjected to mechanical stresses during knitting, weaving etc. to form fabrics of fire and abrasion resistant composite yarn (122). The resulting fire and abrasion resistant composite yarns (122) can thus be made of cotton, modacrylics and/or FR and/or non-FR fibers. It is formed with a fibrous bundle containing a fiber blend such as FR nylon filament bonded around an outer circumference (e.g., approximately 20 denier to approximately 70-100 denier FR nylon filament). While the fibrous bundle provides comfort and FR properties to the composite yarn, the FR nylon filament wrapped around the outer circumference of the fibrous bundle adds abrasion resistance to the surface of the yarn/fabric where abrasion resistance is most needed. The tight wrapping of the FR nylon filament also helps control the shrinkage of the yarn when exposed to flame or high heat, ensuring that the filament shrinks around the fibrous cotton and modacrylic bundle just enough to close any voids and limit oxygen within the yarn without excessive shrinkage or collapse of the yarn. As stated, fire and abrasion resistant fabrics are characterized by increased fire or heat resistance and abrasion resistance. For use in creating lightweight protective clothing with fire-resistant composite yarns (122) shown in Figure 1-3, these fabrics can be made from fire-resistant composite yarns (122). These fabrics can be made from woven or knitted constructions. For example, fabrics made from fire-resistant and abrasion-resistant composite yarn (122) can be woven in a pattern (i.e., a plain pattern, a twill pattern, a basket weave pattern, a satin pattern, a leno pattern, a crepe pattern, a dobby pattern, a herringbone pattern, a Jacquard pattern, a pique pattern, a warp weave, or a weave structure). In other applications, such fabrics can be knitted to create garments such as a jersey, a rib knit, a purl, a fleece, a double weft, a tricot, a raschel, a warp knit, or a plain knit structure. The resulting fabrics can be used for various performance purposes. and/or can be used to create protective clothing. For example, a lightweight fabric with a fabric weight of approximately 261 g/m2 (approximately 7.7 oz./yd2) and possessing the following properties has been produced from fire and abrasion resistant woven fabrics, spun with approximately 34% modacrylic and approximately 28-29% cotton by weight, woven in both warp and weft directions, and made from a 20/1 Ne spun composite yarn with approximately 4 rips per inch. The fabric exhibits approximately 476% - 5% thermal shrinkage in the lengthwise direction and approximately 454% thermal shrinkage in the widthwise direction, measured/tested according to ASTM F-2894 (Standard Test Method for Evaluating the Heat Resistance of Materials, Protective Clothing and Equipment Using a Hot Air Circulating Oven); vertical burn resistance meeting or exceeding the requirements of Mil Spec GL-PD-07-12, with a maximum char length of 4.5 inches (after flash), 25.0 sec (after flame), and no measured melting/drip; and over 35,000 cycles before failure using a Martindale Abrasion tester (according to ASTM D4966-12). The fabric is also readily dyeable/printable and less expensive than similar, conventional fire and abrasion resistant fabrics. Although only a few example applications are described in detail here, experts in the field will readily understand that many modifications to the example applications are possible without significantly deviating from the new teachings and advantages of the applications of the present description. Accordingly, it is intended that all such modifications be included within the scope of the applications of the present description as defined in the following requirements. In the requirements, it is intended that the tool-plus-function clauses encompass structures that fulfill the function described herein and that fulfill not only structural equivalents but also equivalent structures.

Claims (1)

1.