Melt-spun filaments, yarns and methods of making same

Abstract

Various implementations include melt-spun filaments (or fibers), a spinneret for producing melt-spun filaments, and a method of manufacturing melt-spun filaments. According to some implementations, the melt-spun filaments have a soft hand similar to natural cotton fibers and are more elastic, less absorbent, and easier to clean. Furthermore, according to some implementations, the melt-spun filaments produce softer and more fluffy yarns compared to conventional trilobal filaments having the same denier per filament.

Description

[0001] Citations of relevant applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 116,339, filed November 20, 2020, the contents of which are incorporated herein by reference in their entirety. Background Technology

[0003] Cotton fibers have a soft hand feel, but they can only be used as short fibers, which requires twisting and bonding them together to increase the strength of the yarn. Cotton also easily gets dirty and absorbs liquids, making it difficult to use in carpets and other textiles and difficult to keep clean. Therefore, there is a need in the art to provide cotton with a soft hand feel but longer and with liquid-repellent properties, such as melt-spun filaments (or fibers). Summary of the Invention

[0004] According to the first aspect, the melt-spun fiber has an outer surface and a central axis. The cross-section of the outer surface has a first peripheral section, a second peripheral section, a third peripheral section, and a fourth peripheral section. The first and third peripheral sections are spaced apart from each other, and the second and fourth peripheral sections, extending between the first and third peripheral sections, are also spaced apart from each other. The first, second, and third peripheral sections are arc-shaped and convex when viewed from the outside of their respective peripheral sections, and the fourth peripheral section is arc-shaped and concave when viewed from the outside of its fourth peripheral section. The cross-sectional shape of the outer surface is viewed in a plane extending perpendicular to the central axis of the melt-spun fiber (e.g., an end view of the melt-spun fiber).

[0005] In some implementations, the radii of curvature of the first and third peripheral sections are smaller than the radius of curvature of the second peripheral section.

[0006] In some implementations, the radius of curvature of the fourth peripheral section is smaller than the radius of curvature of the second peripheral section.

[0007] In some implementations, the radius of curvature of the fourth peripheral section is greater than the radius of curvature of the second peripheral section.

[0008] In some implementations, the arc length of the second peripheral section is greater than the arc length of the fourth peripheral section.

[0009] In some implementations, the filaments define at least one axial gap.

[0010] In some embodiments, at least one gap has a cross-sectional shape corresponding to the outer surface of the filament.

[0011] In some embodiments, the filament also includes a bridging section extending between the second and fourth peripheral sections adjacent to the central axis of the filament, wherein the bridging section defines a first gap with the first, second and fourth peripheral sections, and the bridging section defines a second gap with the second, third and fourth peripheral sections.

[0012] In some implementations, the average radial thickness of each peripheral section is the same.

[0013] In some embodiments, the filaments comprise at least one thermoplastic material.

[0014] In some embodiments, the thermoplastic material is selected from the group consisting of one or more polyesters, one or more polyamides (PAs), one or more polyolefins, or combinations thereof. In some embodiments, one or more polyesters are selected from the group consisting of polypropylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene terephthalate (PET), and combinations thereof.

[0015] In some implementations, the denier per filament is between 2 and 35.

[0016] According to the second aspect, a fiber bundle comprising multiple melt-spun filaments is provided.

[0017] According to the third aspect, a yarn comprising bundles of filaments is provided.

[0018] In some embodiments, the yarn is a bulked continuous filament (BCF) yarn.

[0019] In some embodiments, the melt-spun fibers according to the first aspect are converted into multiple short fibers.

[0020] According to the fourth aspect, a spun yarn comprising short fibers is provided.

[0021] According to the fifth aspect, a carpet comprising a pile made of yarn according to the third or fourth aspect is provided.

[0022] According to the sixth aspect, garments containing yarns according to the third or fourth aspect are provided.

[0023] According to a seventh aspect, a spinneret is provided for producing melt-spun fibers according to a first aspect. The spinneret includes one or more capillaries, and each capillary defines a pair of outlet openings. Each opening has a C-shaped cross-section, and each pair of C-shaped openings is arranged relative to each other such that the ends of the C-shaped openings face each other and are spaced apart, and the distance between the middle portions of the openings is greater than the distance between the ends of the openings. The cross-sectional shape of the outlet openings is viewed in a plane extending perpendicular to the central axis of the capillary (e.g., an end view of the capillary).

[0024] In some implementations, the arc extends between the ends of each opening, is spaced apart from the ends of each opening, and bisects the middle portion of each pair of C-shaped openings.

[0025] In some implementations, the radius of the arc is in the range of 0.04 to 0.09 inches, the central angle of the arc is in the range of 40 to 80 degrees, and the width of the arc, measured along a chord extending between the ends of the arc, is in the range of 0.06 to 0.2 inches.

[0026] In some implementations, each pair of C-shaped openings has a radial width, and the radial width is in the range of 0.004 to 0.03 inches.

[0027] According to an eighth aspect, a method for manufacturing melt-spun fibers according to a first aspect is provided. The method includes: (1) providing a spinneret comprising one or more capillaries, each capillary defining a pair of outlet openings, wherein each opening has a C-shaped cross-section, wherein each pair of C-shaped openings is arranged relative to each other such that the ends of the C-shaped openings face each other and are spaced apart, and the distance between the intermediate portions of the openings is greater than the distance between the ends of the openings; and (2) feeding at least one molten thermoplastic polymer through the capillaries.

[0028] In some implementations, the arc extends between the ends of each opening, is spaced apart from the ends of each opening, and bisects the middle portion of each pair of C-shaped openings.

[0029] In some implementations, the radius of the arc is in the range of 0.04 to 0.09 inches, the central angle of the arc is in the range of 40 to 80 degrees, and the width of the arc, measured along a chord extending between the ends of the arc, is in the range of 0.06 to 0.2 inches.

[0030] In some implementations, each pair of C-shaped openings has a radial width, and the radial width is in the range of 0.004 to 0.03 inches.

[0031] According to the ninth aspect, the melt-spun filament has an outer surface and a central axis. The cross-sectional shape of the outer surface is figure eight, and the filament defines a first gap and a second gap extending axially through the filament. The first gap is on one side of the central axis, and the second gap is on the other side of the central axis.

[0032] According to the tenth aspect, a yarn comprising multiple melt-spun filaments as described in the ninth aspect is provided.

[0033] According to the eleventh aspect, the yarn comprises at least one first melt-spun fiber according to the ninth aspect and at least one second melt-spun fiber according to the first aspect. Attached Figure Description

[0034] Exemplary features and embodiments are disclosed in the accompanying drawings. However, this disclosure is not limited to the precise arrangement shown, and the drawings are not necessarily drawn to scale.

[0035] Figure 1 A perspective end view of a melt-spun fiber according to one embodiment is shown.

[0036] Figure 2A A plan view of a portion of a spinneret defining a plurality of capillaries is shown according to one embodiment. Figure 2B The image shown is taken in a plane including the central axis of the capillary. Figure 2A A cross-sectional view of one of the capillaries in the image. Furthermore, Figure 2C It shows Figure 2B End view of the capillary tube.

[0037] Figure 3 Through Figure 2A Multiple melt-spun fibers (such as those produced by the spinneret in the middle) are spun from the spinneret. Figure 1 A photograph of an end view of the melt-spun fiber shown.

[0038] Figure 4A A plan view of a portion of a spinneret defining a plurality of capillaries according to another embodiment is shown. Figure 4B The image shown is taken in a plane including the central axis of the capillary. Figure 4A A cross-sectional view of one of the capillaries in the image. Furthermore, Figure 4C It shows Figure 4B End view of the capillary tube.

[0039] Figure 5 It consists of multiple melt-spun filaments (such as those produced by melting and spinning). Figure 4A A photograph of the end view of melt-spun fibers spun from a spinneret.

[0040] Figure 6A A plan view of a portion of a spinneret defining a plurality of capillaries according to another embodiment is shown. Figure 6BThe image shown is taken in a plane including the central axis of the capillary. Figure 6A A cross-sectional view of one of the capillaries in the image. Furthermore, Figure 6C It shows Figure 6B End view of the capillary tube.

[0041] Figure 7 It consists of multiple melt-spun filaments (such as those produced by melting and spinning). Figure 6A A photograph of the end view of melt-spun fibers spun from a spinneret.

[0042] Figure 8 It shows Figure 2C , Figure 4C and Figure 6C The end view of the capillary shown and Figure 3 , Figure 5 and Figure 7 The photograph shows an end view of the melt-spun fiber.

[0043] Figures 9-11 It shows the results from... Figures 2A-2C , Figures 4A-4C and Figures 6A-6C Various photos of melt-spun fibers produced by spinnerets.

[0044] Figure 12 Showing natural untreated cotton staple fiber, natural mercerized cotton staple fiber, Figure 3 The melt-spun fibers shown, and those with Figure 3 The different denier per yarn and filament per yarn count of the multiple filaments shown are obtained through... Figure 2A A photograph of the end view of melt-spun fibers spun from a spinneret.

[0045] Figure 13 It shows natural cotton fibers and Figure 3 The photographs show the end view and axial view of the melt-spun fiber.

[0046] Figure 14 It shows from Figures 2A-2C , Figures 4A-4C and Figures 6A-6C End view of various melt-spun fibers spun from a spinneret. Detailed Implementation

[0047] Various embodiments include melt-spun fibers (or fibers), spinnerets for producing melt-spun fibers, and methods for manufacturing melt-spun fibers. According to some embodiments, melt-spun fibers have a soft hand feel similar to natural cotton fibers, and are more elastic, less absorbent, and easier to clean. Furthermore, according to some embodiments, melt-spun fibers produce softer and fluffier yarns compared to conventional trefoil fibers with the same filament denier. Additionally, according to some embodiments, because these melt-spun fibers have a matte appearance, Ti-O2 additives are not required or less Ti-O2 is needed compared to conventional trefoil fibers. Moreover, local softeners can be omitted from the fibers, as melt-spun fibers according to some embodiments described herein are softer than trefoil fibers with local softeners at the same filament denier.

[0048] According to the first aspect, the melt-spun filament has an outer surface and a central axis. The cross-section of the outer surface has a first peripheral section, a second peripheral section, a third peripheral section, and a fourth peripheral section. The first and third peripheral sections are spaced apart from each other, and the second and fourth peripheral sections, extending between the first and third peripheral sections, are also spaced apart from each other. The first, second, and third peripheral sections are arc-shaped and convex when viewed from the outside of their respective peripheral sections, and the fourth peripheral section is arc-shaped and concave when viewed from the outside of its fourth peripheral section. The cross-sectional shape of the outer surface is viewed in a plane extending perpendicular to the central axis of the melt-spun filament (e.g., an end view of the filament).

[0049] According to the second aspect, a fiber bundle comprising multiple melt-spun filaments is provided.

[0050] According to a third aspect, a yarn comprising bundles of filaments is provided. For example, in some embodiments, the yarn is a bulked continuous filament (BCF) yarn.

[0051] In some embodiments, the melt-spun fibers according to the first aspect are converted into multiple short fibers.

[0052] According to the fourth aspect, a spun yarn comprising short fibers is provided.

[0053] According to the fifth aspect, a carpet comprising pile made of yarn according to the third or fourth aspect is provided.

[0054] According to the sixth aspect, garments containing yarns according to the third or fourth aspect are provided.

[0055] According to a seventh aspect, a spinneret is provided for producing melt-spun fibers according to a first aspect. The spinneret includes one or more capillaries, and each capillary defines a pair of outlet openings. Each opening has a C-shaped cross-section, and each pair of C-shaped openings is arranged relative to each other such that the ends of the C-shaped openings face each other and are spaced apart, and the distance between the middle portions of the openings is greater than the distance between the ends of the openings. The cross-sectional shape of the outlet openings is viewed in a plane extending perpendicular to the central axis of the capillary (e.g., an end view of the capillary).

[0056] According to an eighth aspect, a method for manufacturing melt-spun fibers according to a first aspect is provided. The method includes: (1) providing a spinneret comprising one or more capillaries, each capillary defining a pair of outlet openings, wherein each opening has a C-shaped cross-section, wherein each pair of C-shaped openings is arranged relative to each other such that the ends of the C-shaped openings face each other and are spaced apart, and the distance between the intermediate portions of the openings is greater than the distance between the ends of the openings; and (2) feeding at least one molten thermoplastic polymer through the capillaries. The cross-sectional shape of the outlet openings is viewed in a plane extending perpendicular to the central axis of the capillary (e.g., an end view of the capillary). In some embodiments, an arc extends between the ends of each opening, spaced apart from the ends of each opening, and bisects the intermediate portion of each pair of C-shaped openings.

[0057] According to the ninth aspect, the melt-spun filament has an outer surface and a central axis. The cross-sectional shape of the outer surface is figure-eight shaped, and the filament defines a first gap and a second gap extending axially through the filament. The first gap is on one side of the central axis and the second gap is on the other side of the central axis. The cross-sectional shape of the outer surface is viewed in a plane extending perpendicular to the central axis of the melt-spun filament (e.g., an end view of the melt-spun filament).

[0058] According to the tenth aspect, a yarn comprising multiple melt-spun filaments as described in the ninth aspect is provided.

[0059] According to the eleventh aspect, the yarn comprises at least one first melt-spun fiber according to the ninth aspect and at least one second melt-spun fiber according to the first aspect.

[0060] For example, Figure 1An exemplary melt-spun fiber 10 according to one embodiment is shown. The melt-spun fiber 10 has an outer surface 12 and a central axis 14. The cross-section of the outer surface 12 has a first peripheral section 16, a second peripheral section 18, a third peripheral section 20, and a fourth peripheral section 22. The first peripheral section 16 and the third peripheral section 20 are spaced apart from each other, and the second peripheral section 18 and the fourth peripheral section 22, extending between the first peripheral section 16 and the third peripheral section 20, are also spaced apart from each other. The first peripheral section 16, the second peripheral section 18, and the third peripheral section 20 are arcuate-shaped and convex when viewed from the outside of each respective peripheral section, and the fourth peripheral section 22 is arcuate and concave when viewed from the outside of the fourth peripheral section 22. The cross-sectional shape of the outer surface 12 is viewed in a plane extending perpendicular to the central axis 14.

[0061] The radii of curvature of the first peripheral section 16 and the third peripheral section 20 are smaller than the radii of curvature of the second peripheral section 18. Furthermore, the radius of curvature of the fourth peripheral section 22 is smaller than that of the second peripheral section 18. The relative radii of curvature of the second and fourth peripheral sections can depend on the shape of the openings in the spinneret, the type of polymer, the temperature of the polymer spun through the spinneret openings (e.g., relative to the polymer's melting temperature), and / or the processing speed of the spinning process. Additionally, the arc length of the second peripheral section 18 is greater than the arc length of the fourth peripheral section 22.

[0062] The melt-spun fiber 10 defines an axial void 24. The void 24 has a cross-sectional shape corresponding to the outer surface 12 of the melt-spun fiber. However, in other embodiments, the void may have a cross-sectional shape different from that of the outer surface 12. The cross-sectional shape of the void is the shape of the void as observed in a plane extending perpendicular to the central axis of the melt-spun fiber (e.g., an end view of the melt-spun fiber). The cross-sectional shape of the void depends at least in part on how the melt-spun fiber portions exiting the spinneret outlet opening coalesce to form filaments. This coalescing can depend on the type of polymer, the temperature of the polymer during spinning (e.g., relative to the melting temperature of the polymer), how heat is transferred from the spun filament to the quenching air, and / or the processing speed of the spinning process.

[0063] The average radial thickness of each peripheral section 16, 18, 20, and 22 is the same. The radial thickness of each peripheral section 16, 18, 20, and 22 is measured in the radial direction relative to the central axis 12.

[0064] Melt-spun filament 10 comprises at least one thermoplastic material. For example, the thermoplastic material may be selected from the group consisting of one or more polyesters, one or more polyamides (PAs), one or more polyolefins, or combinations thereof. Exemplary polyesters include polypropylene terephthalate (PTT), polybutylene terephthalate (PBT), and polyethylene terephthalate (PET). Exemplary polyamides include nylon 6 and nylon 6,6. Exemplary polyolefins include polypropylene (PP) and polyethylene (PE). Melt-spun filament 10 is a single-component filament, but in other embodiments, the melt-spun filament may be a multi-component filament. In some embodiments, the first or second material may include polyolefins and carbon fillers to produce antistatic yarns. According to some embodiments, the thermoplastic material resin may be virgin or recycled grade.

[0065] The fineness of each fiber or filament (also known as "denier single fiber", "denier single fiber", or "dpf") is in the range of 2 to 35 dpf (e.g., 9 dpf).

[0066] The melt-spun filament 10 can be twisted around its axis 12. Twisting occurs because the arc length of the second peripheral section differs from the arc length of the fourth peripheral section. The twisting level is the result of one or more factors, such as the type of polymer, its viscosity, the temperature of the polymer during spinning (e.g., relative to the polymer's melt temperature), quenching settings, and extruder settings.

[0067] Figure 3 From Figures 2A-2C Photographs of end views of multiple melt-spun filaments spun by the spinneret 200, shown and described below. As shown, the multiple melt-spun filaments include one or more melt-spun filaments 10, and one or more melt-spun filaments (such as melt-spun filaments 30 and 45) having end shapes slightly different from those of melt-spun filaments 10. The variation in shape may be due to the type of polymer and / or the temperature of the polymer during spinning.

[0068] For example, melt-spun fiber 30 is similar to melt-spun fiber 10 but includes two voids. Melt-spun fiber 30 includes a bridge section 46 extending between a second peripheral section 38 and a fourth peripheral section 42 adjacent to the central axis of melt-spun fiber 30. Bridge section 46, together with the first peripheral section 36, the second peripheral section 38, and the fourth peripheral section 42, defines a first void 44a, and bridge section 46, together with the second peripheral section 38, the third peripheral section 40, and the fourth peripheral section 42, defines a second void 44b. Viewed in a plane perpendicular to the central axis, the outer surface of melt-spun fiber 30 is figure-eight shaped, with the first void 44a on one side of the central axis of fiber 30 and the second void 44b on the other side of the central axis. In other embodiments not shown, the melt-spun fiber may have no voids or have two or more voids.

[0069] Melt-spun fiber 45 is similar to melt-spun fiber 10, but the radius of curvature of the fourth peripheral section 52 is greater than the radius of curvature of the second peripheral section 48.

[0070] like Figure 3 As shown, multiple melt-spun filaments (such as one or more of melt-spun filaments 10, 30, and 45) can be combined together to form a filament bundle 100, and the filament bundle 100 can be assembled into a yarn. For example, the yarn can be a bulked continuous filament (BCF) yarn. Alternatively, the melt-spun filaments can be converted into multiple short fibers, and the short fibers can be combined to spin into a yarn.

[0071] Any of the above yarns can be used as pile yarn in carpets or clothing.

[0072] Figures 2A-2C A spinneret 200 for spinning molten thermoplastic material into filaments (such as filaments 10, 30, and 45) according to one embodiment is shown. The spinneret 200 defines one or more capillaries 202, and each capillary 202 defines a pair of outlet openings 204, 206. Each opening 204, 206 has a C-shaped cross-section, and each pair of C-shaped openings 204, 206 is arranged relative to each other such that the ends 208a, 208b, 210a, 210b of the C-shaped openings 204, 206 face each other and are spaced apart, and the distance between the intermediate portions 212, 214 of the openings 204, 206 is greater than the distance between the ends 208a-b, 210a-b of the openings 204, 206.

[0073] like Figure 2B As shown, each capillary 202 has a first end 222, a second end 224, and an intermediate portion 223 therebetween. This intermediate portion has a constant cross-sectional area along the length of the capillary 202. Each end is tapered. The surfaces of each end 222, 224 are inclined at an angle α of 45° to 80°. For example, Figure 2B The angle α shown is 45°. The first end 222 has a cross-sectional area decreasing axially from a first end 222a to a second end 222b, wherein the first end 222a is defined by a first surface 200a of the spinneret 200. The second end 224 has a cross-sectional area decreasing axially from a first end 224a to a second end 224b, wherein the second end 224b is defined by a second surface of the spinneret 100.

[0074] like Figure 2CAs shown, arc A extends and is spaced apart from the ends 208a-b, 210a-b of each opening 204, 206, and bisects the middle portions 212, 214 of each pair of C-shaped openings 204, 206. The radius of curvature of arc A is in the range of 0.04 to 0.09 inches, the central angle of the arc is in the range of 40 to 80 degrees, and the width of the arc, measured along the chord extending at the ends of the arc, is in the range of 0.06 to 0.2 inches. Each pair of C-shaped openings 204, 206 has a radial width in the range of 0.004 to 0.03 inches. These dimensions are examples of suitable dimensions for spinning PET to form melt-spun filaments (such as those described herein), but other dimensions and / or outlet opening shapes may be selected depending on the properties of the polymer, such as its flow characteristics.

[0075] Figure 3 The polymer of the melt-spun fibers 10, 30, and 45 shown is PET, and the PET is spun through spinneret 200 with a yarn denier of 1350 and a yarn filament count of 150, for example producing fibers with a 9 DPF. In other embodiments, the yarn can be produced by one or more spinnerets. Furthermore, by changing the yarn denier and / or the number of yarn filaments, spinneret 200 can produce multiple melt-spun fibers with different shapes. For example, Figure 12 The rightmost photograph shows melt-spun filaments 90, each having an oval outer surface when viewed in a plane perpendicular to the central axis of the melt-spun filament. Each filament also defines an axial gap. Figure 12 The polymer of the melt-spun fiber 90 shown is PET, and the PET is spun through a spinneret 200 with a yarn denier of 1100 and a yarn filament count of 300, producing a fiber with a DPF of 3.6. Furthermore, as... Figure 12 As shown, melt-spun fibers 10, 30, and 45 have a hand feel similar to untreated cotton fibers. Furthermore, melt-spun fiber 90 has a hand feel similar to mercerized cotton (which is silkier / softer than untreated cotton). Figure 13 It is natural, untreated cotton fiber and Figure 3 The photographs show the end view and axial view of the melt-spun fiber.

[0076] Figures 4A-4C A spinneret 400 for spinning molten thermoplastic material into filaments, according to another embodiment, is shown. Spinneret 400 is similar to spinneret 200. Similar to spinneret 200, spinneret 400 defines one or more capillaries 402, and each capillary 402 defines a pair of outlet openings 404, 406. However, the radius of curvature of the arc B extending through the intermediate portions 412, 414 of the openings 404, 406 is greater than that of the spinneret 200. Figure 2CThe radius of curvature of arc A is shown. Additionally, the central angle of arc B is smaller than the central angle of arc A, the width of arc B is smaller than the width of arc A, and the radial widths of openings 404 and 406 are the same as the radial widths of openings 204 and 206. Figure 5 Multiple melt-spun filaments 50 and 60 produced by spinneret 400 are shown. Melt-spun filaments 50 and 60 are similar to filaments 10 and 30, respectively.

[0077] Figures 6A-6C A spinneret 600 according to another embodiment is shown. The spinneret 600 is similar to the spinneret 200. Similar to the spinneret 200, the spinneret 600 defines one or more capillaries 602, and each capillary 602 defines a pair of outlet openings 604, 606. However, the radius of curvature of the arc C extending through the intermediate portions 612, 614 of the openings 604, 606 is smaller than that of the spinneret 200. Figure 2C The radius of curvature of arc A is shown. Furthermore, the central angle of arc C is the same as that of arc A, the width of arc C is greater than the width of arc A, and the radial widths of openings 604 and 606 are less than the radial widths of openings 204 and 206. Figure 7 Multiple melt-spun filaments 70 and 80 produced by spinneret 600 are shown. Melt-spun filaments 70 and 80 are similar to filaments 10 and 30, respectively.

[0078] Figure 8 Provided Figure 2C , Figure 4C and Figure 6C Comparison of the end views of the capillary shown and Figure 3 , Figure 5 and Figure 7 The photograph shows an end view of the melt-spun fiber.

[0079] Figures 9-11 It shows the results from... Figures 2A-2C , Figures 4A-4C and Figures 6A-6C Various photographs of melt-spun fibers produced by a spinneret. In each Figures 9-11 The image shows a view of the ends of the fibers and an axial view of the fibers twisted around the central axis of each fiber.

[0080] Figure 14 End views are shown of various melt-spun fibers 10 and 30 produced by spinneret 200, various melt-spun fibers 50 and 60 produced by spinneret 400, and various melt-spun fibers 70 and 80 produced by spinneret 600.

[0081] In other embodiments, melt-spun fibers (such as melt-spun fibers 10, 30, 45, 50, 60, 70, 80) are converted into multiple short fibers. Short fibers have a shorter length, such as 2 to 3 inches, compared to fibers with a longer continuous length. For example, melt-spun fibers can be converted into multiple short fibers by stretching, breaking, or shredding one or more such melt-spun fibers. Furthermore, in some embodiments, multiple short fibers can be bundled together.

[0082] According to some embodiments, the above-mentioned melt-spun fibers are manufactured by: (1) providing a spinneret comprising one or more capillaries, each capillary defining a pair of outlet openings, wherein each opening has a C-shaped cross-section, wherein each pair of C-shaped openings is arranged relative to each other such that the ends of the C-shaped openings face each other and are spaced apart, and the distance between the middle portions of the openings is greater than the distance between the ends of the openings; and (2) feeding at least one molten thermoplastic polymer through the capillaries. For example, the spinneret may be one of the above-mentioned spinnerets 200, 400, and 600.

[0083] Various factors influence the shape and denier of the filaments, including the type of polymer, its melt temperature, the polymer temperature during spinning, the speed of the pump connected to the extruder, the draw ratio, and the rate of filament cooling. Changing one or more of these factors can provide the desired shape. For example, if the pump speed is increased while all other factors remain constant, the denier of the filaments increases. If the draw ratio is increased while all other factors remain constant, the denier of the filaments decreases. As another example, if the cooling rate is increased while all other factors remain constant, the cross-sectional shape of the filaments becomes more defined. Furthermore, depending on the properties of the polymer being spun, the shape and / or size of the capillary and / or the capillary outlet opening of the spinneret can differ from those described above. For example, lower viscosity PET can be spun using capillary sizes different from those used for higher viscosity PET.

[0084] Various embodiments have been described. However, it should be understood that various modifications may be made without departing from the spirit and scope of this specification. Therefore, other embodiments are within the scope of the appended claims.

[0085] What is disclosed are materials, systems, apparatuses, methods, compositions, and components that can be used, combined, or used in the preparation of a disclosed method, system, or apparatus. These and other components are disclosed herein, and it should be understood that when combinations, subsets, interactions, groups, etc., of these components are disclosed, while specific references to every various individual and collective combination and arrangement of these components may not be explicitly disclosed, each is specifically considered and described herein. For example, if an apparatus is disclosed and discussed, every combination and arrangement of that apparatus, as well as possible modifications, is specifically considered unless specifically stated to the contrary. Similarly, any subset or combination of these is also specifically considered and disclosed. This concept applies to all aspects of this disclosure, including but not limited to steps in methods using the disclosed system or apparatus. Therefore, if multiple additional steps are available, it should be understood that each of these additional steps may be performed with any particular method step or combination of method steps of the disclosed method, and each such combination or subset of combination is specifically considered and should be considered disclosed.

Claims

1. A melt-spun fiber having an outer surface and a central axis, wherein, The outer surface has a cross-section with a first peripheral section, a second peripheral section, a third peripheral section, and a fourth peripheral section, wherein the first peripheral section and the third peripheral section are spaced apart from each other, and the second peripheral section and the fourth peripheral section extend between the first peripheral section and the third peripheral section and are spaced apart from each other, wherein the first peripheral section, the second peripheral section, and the third peripheral section are arc-shaped and are convex when viewed from the outside of each respective peripheral section, the fourth peripheral section is arc-shaped and is concave when viewed from the outside of the fourth peripheral section, the arc length of the second peripheral section is greater than the arc length of the fourth peripheral section, and the average radial thickness of each peripheral section is the same.

2. The melt-spun fiber according to claim 1, wherein, The radii of curvature of the first peripheral section and the third peripheral section are smaller than the radius of curvature of the second peripheral section.

3. The melt-spun fiber according to claim 1 or 2, wherein, The radius of curvature of the fourth peripheral section is smaller than that of the second peripheral section.

4. The melt-spun fiber according to claim 1 or 2, wherein, The radius of curvature of the fourth peripheral section is greater than that of the second peripheral section.

5. The melt-spun fiber according to claim 1 or 2, wherein, The filament defines at least one axial gap.

6. The melt-spun fiber according to claim 5, wherein, The at least one axial gap has a cross-sectional shape corresponding to the outer surface of the filament.

7. The melt-spun fiber according to claim 5, wherein, The filament also includes a bridging section extending between the second peripheral section and the fourth peripheral section adjacent to the central axis of the filament, wherein the bridging section, together with the first peripheral section, the second peripheral section and the fourth peripheral section, defines a first gap, and the bridging section, together with the second peripheral section, the third peripheral section and the fourth peripheral section, defines a second gap.

8. The melt-spun fiber according to claim 1 or 2, wherein, The filaments contain at least one thermoplastic material.

9. The melt-spun fiber according to claim 8, wherein, The thermoplastic material is selected from the group consisting of one or more polyesters, one or more polyamides, one or more polyolefins, and combinations thereof.

10. The melt-spun fiber according to claim 1 or 2, wherein, The denier of the monofilament is between 2 and 35.

11. The melt-spun fiber according to claim 1 or 2, wherein, The melt-spun fibers are converted into multiple short fibers.

12. A fiber bundle comprising a plurality of melt-spun fibers according to any one of claims 1 to 11.

13. A yarn comprising a bundle of filaments as claimed in claim 12.

14. The yarn according to claim 13, wherein, The yarn is a bulked continuous filament yarn.

15. A spun yarn comprising the short fibers of claim 11.

16. A carpet comprising a pile made of yarn according to any one of claims 13 to 15.

17. Garment comprising the yarn of any one of claims 13 to 15.

18. A spinneret for producing melt-spun fibers according to claim 1, the spinneret comprising one or more capillaries, each capillary defining a pair of outlet openings, wherein, Each opening has a C-shaped cross-section, wherein each pair of C-shaped openings is arranged relative to each other such that the ends of the C-shaped openings face each other and are spaced apart, and the distance between the middle portions of the openings is greater than the distance between the ends of the openings.

19. The spinneret according to claim 18, wherein, The arc extends between the ends of each opening, spaced apart from the ends of each opening, and bisects the middle portion of each pair of C-shaped openings.

20. The spinneret according to claim 19, wherein, The radius of the arc is in the range of 0.04 to 0.09 inches, the central angle of the arc is in the range of 40 to 80 degrees, and the width of the arc, measured along a chord extending between the ends of the arc, is in the range of 0.06 to 0.2 inches.

21. The spinneret according to any one of claims 18 to 20, wherein, Each pair of C-shaped openings has a radial width, and the radial width is in the range of 0.004 to 0.03 inches.

22. A method for manufacturing melt-spun fibers according to claim 1, comprising: A spinneret is provided, the spinneret comprising one or more capillaries, each capillary defining a pair of outlet openings, wherein each opening has a C-shaped cross-section, wherein each pair of C-shaped openings is arranged relative to each other such that the ends of the C-shaped openings face each other and are spaced apart, and the distance between the middle portions of the openings is greater than the distance between the ends of the openings; and At least one molten thermoplastic polymer is fed through the capillary.

23. The method according to claim 22, wherein, The arc extends between the ends of each opening, spaced apart from the ends of each opening, and bisects the middle portion of each pair of C-shaped openings.

24. The method according to claim 23, wherein, The radius of the arc is in the range of 0.04 to 0.09 inches, the central angle of the arc is in the range of 40 to 80 degrees, and the width of the arc, measured along a chord extending between the ends of the arc, is in the range of 0.06 to 0.2 inches.

25. The method according to any one of claims 22 to 24, wherein, Each pair of C-shaped openings has a radial width, and the radial width is in the range of 0.004 to 0.03 inches.

26. A yarn comprising: At least one first melt-spun fiber, the first melt-spun fiber having an outer surface and a central axis, wherein the cross-sectional shape of the outer surface is figure-eight shaped, wherein the first melt-spun fiber defines a first gap and a second gap extending axially through the first melt-spun fiber, wherein the first gap is on one side of the central axis and the second gap is on the other side of the central axis; and At least one second melt-spun fiber has an outer surface and a central axis. The outer surface has a cross-section having a first peripheral section, a second peripheral section, a third peripheral section, and a fourth peripheral section. The first and third peripheral sections are spaced apart from each other, and the second and fourth peripheral sections extend between the first and third peripheral sections and are spaced apart from each other. The first, second, and third peripheral sections are arc-shaped and are convex when viewed from the outside of each corresponding peripheral section. The fourth peripheral section is arc-shaped and is concave when viewed from the outside of the fourth peripheral section. The arc length of the second peripheral section is greater than the arc length of the fourth peripheral section, and the average radial thickness of each peripheral section is the same.

Images