RELATED APPLICATIONS

[0001] This application claims the priority benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application Serial No. 62,729,200 entitled“WOOL-LIKE SYNTHETIC MULTIFILAMENT YARNS,” filed September 10, 2018, the entire disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field of the Invention

[0002] The present invention relates to multifilament yarns that exhibit wool-like characteristics and methods for manufacturing such yams. More particularly, the present invention generally relates to wool-like multifilament yarns for floorcovering applications.

2. Description of the Related Art

[0003] Natural fibers, particularly wool obtained from sheep, goats, alpacas, etc., have been known and exploited by humans since pre-historic times. Besides the control of fire, and the use of wood, bone, and stone to make tools, one of the earliest technological breakthroughs by humans was the discovery that the short fibers of wool could be spun together to form continuous threads or yams, which themselves could be woven into cloth. Such cloth found extensive use in the form of blankets, clothing, wall hangings, and woven or tufted floorcoverings, such as mgs and carpets. The appearance, or aesthetics, and the tactile feel, or hand, of such textiles has, throughout the years, constituted something of a“gold standard” for textiles in general.

[0004] With the development of melt-spun man-made fibers, especially polyamides, in the mid-twentieth century, potential replacements for wool seemed to be available. However, simple melt-spinning of the polyamide produces very straight and rather harsh yarns which, when used in floorcovering face yarns, give neither satisfactory aesthetics nor desirable hand.

[0005] Reasons for the good aesthetics and hand of wool, at least from a human perspective, lie in the rather complex nature of wool fibers and yarns made therefrom. Wool fibers generally consist of a central core, which itself consists of a side-by-side arrangement of materials of differing structure, and an outer layer, or cuticle, of a third structure, the last featuring a roughened surface. For these reasons, wool naturally has fibers featuring spiral and lopped sections along its length, and the surface roughness aids in keeping the spun short fibers together in the yam, and in producing a useful degree of elasticity. Additionally, the yarn comprises short fibers whose ends can protrude from the yarn surface, which may also enhance the inherent appearance and tactile comfort of textiles made from the yarns.

[0006] A number of different approaches have been tried in order to produce wool-like yarns from melt-spun polyamides.

[0007] One approach involved chopping the continuous melt-spun fibers into shorter fibers, usually referred to as staple fibers, and spinning the staple fibers into a yarn. However, such a process involved a number of additional steps in the yam making process, thereby adding to manufacturing complexity and costs. Furthermore, the smooth nature of the polyamide fiber surface makes it difficult to produce a yarn with suitable properties.

[0008] Various alternative methods were used to impart some form of shape to the polyamide fibers, such as imposition of a permanent spiral form, loops, etc., a process often referred to as crimping. Application of physical forces, in the form of tensioning, mechanically bending, and fluid jet bending, were developed to produce the product known as Bulked Continuous Filament (BCF) yam. While such processes have produced useful commercial products, with some degree of resemblance to wool, BCF processes still exhibit a number of deficiencies.

[0009] At a later stage, attempts were made to reproduce the asymmetric structure of wool fibers by melt-spinning bicomponent polyamide fibers, i.e., spinning two melt components together in a set configuration to provide a“built-in” spiral or looped shape in the final product. Side-by-side and eccentric core-sheath configurations are well known, but are complex and costly to produce, and still do not provide a yam with the required aesthetics and hand.

[0010] Accordingly, there still exists a need for polyamide-based yarns, which provide an initial and long-lived appearance and feel of wool-based yarns.

SUMMARY

[0011] One or more embodiments of the present invention generally concern a wool-like multifilament yam comprising: (a) a plurality of texturized primary yarns formed from a first fiber-forming synthetic polymer, wherein the texturized primary yarns exhibit a residual elongation to break in the range of 50 to 700 percent as measured according to ISO 2062; and (b) at least one texturized secondary yarn formed from a second fiber-forming synthetic polymer, wherein the texturized secondary yarn exhibits a residual elongation to break in the range of 50 to 700 percent as measured according to ISO 2062. Generally, the denier of the texturized primary yams is greater than the denier of the texturized secondary yarn.

[0012] One or more embodiments of the present invention also concern a process for manufacturing a multifilament yarn. Generally, the process comprises: (1) melt-spinning the primary yams and the secondary yarn; (2) drawing and texturizing the primary yarns and the secondary yams; (3) entangling the texturized primary yarns and the texturized secondary yarn to form the inventive yam; (4) optionally subjecting the inventive yarn to heat-setting or heat annealing; and (5) winding the yam onto a package for distribution.

[0013] One or more embodiments of the present invention also concern a floorcovering yarn comprising a wool-like multifilament yarn that comprises: (a) a plurality of texturized primary yarns formed from a first fiber-forming synthetic polymer, wherein the texturized primary yarns exhibit a residual elongation to break in the range of 50 to 700 percent as measured according to ISO 2062; and (b) at least one texturized secondary yarn formed from a second fiber-forming synthetic polymer, wherein the texturized secondary yam exhibits a residual elongation to break of in the range of 50 to 700 percent as measured according to ISO 2062. Generally, the denier of the texturized primary yarns is greater than the denier of the texturized secondary yam.

DETAILED DESCRIPTION

[0014] The present invention generally relates to the manufacture of floorcovering face yarns formed from melt-spun synthetic fibers, such as melt-spun polyamide fibers. The inventive yarns closely resemble wool-based yarns in terms of aesthetics and hand. As discussed below in greater detail, the wool-like yarns of the present invention may be produced by combining a plurality of melt-spun, multifilament yarns, i.e., the“primary yams,” with a second single yarn, i.e., the“secondary yarn.” As discussed below, the primary yarns and secondary yarns differ from each other in various ways, such as fiber bundle size. In various embodiments, the primary yams and the secondary yarns are continuous multifilament yams that may be melt- spun from various fiber-forming synthetic polymers, such as polyamides. The inventive, wool- like multifilament yarns of the present invention may be used in various applications, such as floorcoverings, due to the yam’s improved aesthetics and hand.

[0015] As discussed below in greater detail, the wool-like multifilament yams of the present invention may be produced by: (1) melt-spinning the primary yarns and the secondary yarn; (2) drawing and texturizing the primary yams and the secondary yarns; (3) entangling the texturized primary yarns and the texturized secondary yam to form the inventive yarn; (4) optionally subjecting the inventive yarn to heat-setting or heat annealing; and (5) winding the yarn onto a package for distribution.

The Primary Yarns and Secondary Yarns

[0016] The starting materials for use in the inventive process include continuous filament singles yams divided into two types - a plurality of primary yarns and at least one secondary yarn. In one or more embodiments, the inventive yams can comprise, consist essentially of, or consist of a plurality of the primary yarns and at least one secondary yarn.

[0017] The inventive yams may be formed from one or more primary yarns. In various embodiments, the inventive yarns can comprise at least 2, 3, 4, or 5 and/or less than 20, 15, 10, 8, or 6 primary yams.

[0018] The primary yams may be oriented to such a degree so as to possess a residual elongation to break of at least 50, 100, 150, 200, 250, 300, 350, or 400 percent and/or less than 700, 650, 600, 550, or 500 percent as measured according to ISO 2062.

[0019] In various embodiments, the primary yarns may comprise or consist of filaments that are not substantially interlaced. For example, the primary yarns may comprise less than 200, 150, 100, 75, 50, or 35 tack points per meter of yarn.

[0020] The starting secondary yam may be oriented to such a degree so as to possess a residual elongation to break of at least 50, 100, 150, 200, 250, 300, 350, or 400 percent and/or less than 700, 650, 600, 550, or 500 percent as measured according to ISO 2062.

[0021] In various embodiments, the denier of the primary yarns is greater than that of the secondary yarn. In one or more embodiments, the primary yarns may have a denier of at least 100, 200, 300, 400, or 500 and/or less than 2,000, 1,500, 1,000, or 750. Additionally or alternatively, the primary yams may have a denier per filament of at least 2, 3, 4, 5, 6, or 7 and/or less than 50, 40, 30, 25, 20, or 15. [0022] In various embodiments, the secondary yarn has a denier of at least 50, 100, 150, 200, or 225 and/or less than 1,000, 750, 500, 400, 350, or 300. Additionally or alternatively, the secondary yarn may have a denier per filament of at least 2, 4, 5, 6, 7, 8, 9, or 10 and/or less than 50, 40, 30, 25, 20, or 15.

[0023] In various embodiments, the primary yarns and/or the secondary yam may comprise or consist of filaments with the same or different cross-sectional shapes. Exemplary cross-sectional shapes include, but are not limited to, round, oval, triangular, square, multilobal, irregular, and/or hollow. In one or more embodiments, the primary yarns and the secondary yarns comprise or consist of filaments having different cross-sectional shapes. In certain embodiments, the primary yarns comprise or consist of filaments with a round cross-sectional shape and the secondary yam comprises or consists of fibers with a multilobal cross-sectional shape, such as a trilobal shape.

[0024] In various embodiments, the primary yams and/or the secondary yarn may be low-oriented yarns (“LOY”). More specifically, in various embodiments, the primary yarns and/or the secondary yarn may be subjected to little or no drawing when created during the melt- spinning steps. In such embodiments, the primary yarns and/or the secondary yarn may be immediately transferred to the texturizing (i.e., crimping) device from the melt-spinning device without being subjected to any orientation (i.e., drawing).

[0025] Both the primary yams and the secondary yam can be continuous filament, melt- spun yarns, which may be melt-spun utilizing standard melt-spinning equipment and methods known to those skilled in the art.

[0026] The primary yarns and secondary yarn may be melt-spun from any suitable fiber forming synthetic polymer known in the art including, for example, polyamides, polyesters, or polyolefins. In various embodiments, the primary yarns and secondary yarn may be melt-spun from a polyamide, with the primary yarns and the secondary yarns being formed from the same or different polyamides. Exemplary fiber-forming polyamides include, but are not limited to, Nylon 6, Nylon 11, Nylon 12, Nylon 5,6, Nylon 6,6, Nylon 6,10, Nylon 6,12, copolymers thereof, and blends thereof. In certain embodiments, both the primary yarns and the secondary yarn are melt-spun from Nylon 6,6. In other embodiments, both the primary yarns and the secondary yam are melt-spun from a Nylon 6,6 copolymer containing one or more sulfonated co monomers. [0027] The primary yarns and/or the secondary yarn may contain colorant species, preferably pigments incorporated at the melt-spinning stage. The primary yams and the secondary yam may contain the same or different colorants.

[0028] The primary yams and/or the secondary yarn may contain one or more active additives incorporated into the polyamide at the melt-spinning stage. Such additives include, but are not limited to, antioxidants, UV stabilizers, metal deactivators, processing aids, nucleating agents, antimicrobials, flame retardants, and antistatic agents.

[0029] In various embodiments, the primary yams and/or the secondary yarn may have been exhibited to little or no shrinkage during the melt-spinning process.

[0030] As discussed below, the melt-spinning and drawing processes may be carried out utilizing separate melt-spinning and drawing sequences. Alternatively, in certain embodiments, the melt-spinning and drawing processes may be a combined spin-draw process. In one or more embodiments, the primary yarns and the secondary yarn may be melt-spun and drawn using the same or different methods.

The Method of Producing the Inventive Yarns

[0031] The wool-like multifilament yarns of the present invention may be produced by: (1) melt-spinning the primary yarns and the secondary yarn; (2) drawing and texturizing the primary yarns and the secondary yarns; (3) entangling the texturized primary yams and the texturized secondary yarn to form the inventive yarn; (4) optionally subjecting the inventive yarn to heat-setting or heat annealing; and (5) winding the yam onto a package for distribution.

[0032] As noted above, the primary yarns and the secondary yarns may be produced using any melt-spinning technique known in the art. In various embodiments, the melt-spinning process may occur at a rate of at least 100, 200, 300, 400, or 500 and/or less than 2,500, 1,500, 1,000, 750, or 600 meters per minute (“MPM”). Furthermore, in various embodiments, the melt- spinning may occur at a temperature in the range of 250 to 350 °F.

[0033] The primary yams may be texturized using any suitable method known in the art. Likewise, the secondary yarn may also be texturized using the same method as the primary yams or, alternatively, may be texturized using a different method.

[0034] In various embodiments, the primary yarns are simultaneously and separately texturized, with the texturizing being carried out using any suitable method including, but not limited to, false-twist texturing, mechanical crimping, friction texturing, and stuffer box crimping. In a preferred embodiment, the texturizing process is carried out using stuffer box crimping. In certain embodiments, the texturizing process does not involve false-twist texturizing or friction texturizing. In one or more embodiments, the secondary yarn may also be subjected to a texturizing process, using the same or different process as applied to the primary yarns. In a preferred embodiment, the secondary yarn is texturized.

[0035] During the texturizing step, the secondary yarn may be intermingled with the primary yams, thereby giving the yam a“speckled” appearance.

[0036] As noted above, the primary yams and/or the secondary yarn can be low orientation yarns when introduced into the texturizing step. The separation of the melt-spinning and texturizing steps allows the combination of yams having low deniers and/or the combination of yams having different deniers. Another benefit of using low orientation yams during the texturizing step is that it allows the melt-spinning step to occur at a higher machine output, which reduces the costs of the preceding melt-spinning step. The denier of the resulting melt- spun yarn can be modified as necessary during the texturizing/drawing step.

[0037] Additionally, in various embodiments, the primary yams and/or the secondary yarn may also be subjected to drawing during the texturizing steps. In certain embodiments, this drawing occurs at elevated temperatures above room temperature. Alternatively, the drawing may be carried out at room temperature.

[0038] In various embodiments, the texturizing/drawing step mitigates any formation of interlacing within the primary yams. This can be accomplished by not using an air tack jet during the texturizing step. Consequently, in various embodiments, the texturized primary yarns after the texturizing/drawing step may comprise or consist of filaments that are not substantially interlaced. For example, the texturized primary yams may comprise less than 200, 150, 100, 75, 50, or 35 tack points per meter of yarn.

[0039] The texturized primary yarns may be produced in such a manner as to possess a residual elongation to break of at least 50, 100, 150, 200, 250, 300, 350, or 400 percent and/or less than 700, 650, 600, 550, or 500 percent as measured according to ISO 2062.

[0040] The texturized secondary yarn may be produced in such a manner as to possess a residual elongation to break of at least 50, 100, 150, 200, 250, 300, 350, or 400 percent and/or less than 700, 650, 600, 550, or 500 percent as measured according to ISO 2062. [0041] In one or more embodiments, the texturized primary yams may have a denier of at least 100, 200, 300, 400, or 500 and/or less than 2,000. Additionally or alternatively, the texturized primary yarns may have a denier per filament of at least 2, 3, 4, 5, 6, or 7 and/or less than 50, 40, 30, 25, 20, or 15.

[0042] In various embodiments, the texturized secondary yarn has a denier of at least 50, 100, 150, 200, or 225 and/or less than 1,000, 750, 500, 400, 350, or 300. Additionally or alternatively, the texturized secondary yarn may have a denier per filament of at least 2, 4, 5, 6, 7, 8, 9, or 10 and/or less than 50, 40, 30, 25, 20, or 15.

[0043] In certain embodiments, the texturizing step does not involve any air bulking steps.

[0044] Next, in various embodiments, the texturized primary yarns and the secondary yarn may be combined together in an entangling device and entangled together to form the face yarn. The entangling device may be any such device known to those skilled in the art including, but not limited to, a cable twisting device or a fluid jet entangling device. In a preferred embodiment, the entangling process is carried out using a Gilbos air twist device. While in the entanglement device, the primary yams and the secondary yam may be entangled to form a face yarn, which may be wound up into a suitable package.

[0045] In various embodiments, the texturized primary yarns and the single secondary yarn may be wound together onto a suitable package after being introduced into an entanglement device.

[0046] In an optional step, the resulting face yarn may be heat-set or annealed by any suitable method prior to being re-wound into a package. In such embodiments, the face yarn may be annealed or heat-set using any suitable device and method known to those skilled in the art. In one or more embodiments, the yam may be heat-set using a Superba or Suessen heat setting method.

[0047] Lastly, the resulting yarn may be wound onto a package for subsequent distribution.

[0048] The inventive yams of the present invention can exhibit aesthetic features that are very similar to wool-based yams. For example, the inventive yarns may look like wool and have a soft hand. [0049] The inventive yarns of the present invention may be used to produce various articles including floorcovering (e.g., rugs and carpets), textiles, and clothing. In certain embodiments, the inventive yarns are used to manufacture floorcoverings.

DEFINITIONS

[0050] It should be understood that the following is not intended to be an exclusive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, when accompanying the use of a defined term in context.

[0051] As used herein, the terms“a,”“an,” and“the” mean one or more.

[0052] As used herein, the term“and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.

[0053] As used herein, the terms“comprising,”“comprises,” and“comprise” are open- ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.

[0054] As used herein, the terms“having,”“has,” and“have” have the same open-ended meaning as“comprising,”“comprises,” and“comprise” provided above.

[0055] As used herein, the terms“including,”“include,” and“included” have the same open-ended meaning as“comprising,”“comprises,” and“comprise” provided above.

NUMERICAL RANGES

[0056] The present description uses numerical ranges to quantify certain parameters relating to the invention. It should be understood that when numerical ranges are provided, such ranges are to be construed as providing literal support for claim limitations that only recite the lower value of the range as well as claim limitations that only recite the upper value of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for a claim reciting“greater than 10” (with no upper bounds) and a claim reciting“less than 100” (with no lower bounds).

CLAIMS NOT LIMITED TO DISCLOSED EMBODIMENTS

[0057] The preferred forms of the invention described above are to be used as illustration only, and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention.

[0058] The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.