Recycled polypropylene filament for raised yarn

Abstract

The raised yarns are filaments. The filament is a multi-component filament comprising a core (10), at least a first sheath (20) and optionally a second sheath (30), the first sheath (20) at least partially surrounding the core (10), and the second sheath (30) at least partially surrounding the first sheath (20). The core (10) comprises recycled polypropylene, and the first sheath (20) comprises polypropylene and a particulate opaque additive.

Description

Technical Field

[0001] The present invention relates to filaments of recycled polymers such as polypropylene. Such filaments can be used in carpets such as carpet yarns comprising a pile fabric backing and a pile comprising tufts of pile yarn extending from the pile fabric backing. Background Art

[0002] Carpets and pile twills have long been used as textile floor coverings to provide comfort, durability, safety and decoration. The terms carpet and pile twills are used interchangeably in the art. They can be used to cover the entire floor in a room and are fixed to the floor. Sometimes, the term carpet is used to refer to such floor coverings. However, the term carpet can also be used to refer to textile floor coverings that are not fixed and do not usually cover the entire floor, in the same way as the term pile twills are used.

[0003] Various yarns are used in the production of carpets and pile tweeds. Synthetic fibers as well as natural fibers are used in such yarns. Synthetic fibers used for yarns for carpets and pile tweeds include, in particular, polyethylene terephthalate (PET) fibers and polypropylene (PP) fibers.

[0004] Although the use of recycled PET (e.g. recycled PET from PET bottles) has become widespread, the recycling of PP has become more challenging. Recycled polyethylene terephthalate is generally transparent and does not discolor strongly, so in principle it can be colored by adding pigments as desired. However, from a cost perspective, PET is a more expensive material than PP. This also applies to other polyesters such as polylactic acid (PLA). In addition, the lower density of PP compared to PET means that more PET is needed to obtain the same yarn specifications as PP. Therefore, one of the most commonly used materials in carpets is PP. Therefore, in order to provide a more sustainable yarn at a low cost, the use of recycled PP would be highly desirable.

[0005] However, standard recycled PP is usually very dark, close to black. Although there are available recycled PP qualities that are not so dark, these are usually more expensive, making them less attractive from an economic point of view. In addition, methods for purifying (i.e. decolorizing) recycled PP are known in the art. Since purification will increase the costs, it is less attractive from an economic point of view. The dark color of recycled PP hinders its use in providing yarns for textile applications (such as carpets and fleece tweed). By adding pigments to the recycled PP, the color can be slightly affected. However, the initial dark color still significantly limits the colors that can be obtained. In particular, lighter colors may not be obtainable in principle. In further applications, it would be interesting to replace virgin PP with recycled PP.

[0006] DE202008016836U1 discloses a nonwoven carpet pile fabric backing containing bicomponent binder fibers with a core / sheath structure. The core polymer is PET and the sheath polymer is polyamide 6. By coloring the PET core polymer, the use of the core polymer is no longer limited to raw materials with constant coloring. However, in contrast to recycled PET, dark constant colors have been achieved for recycled PP. Furthermore, in carpet pile fabric backings, dark materials are generally acceptable.

[0007] To promote the recycling of PP in filaments for use in yarns such as carpets, it would be desirable to provide for the use of dark-colored recycled PP in various colored filaments, so as to provide flexibility. Summary of the invention

[0008] Therefore, according to a first aspect, a filament for pile yarn is provided. The filament is a multi-component filament comprising a core and at least a first sheath. The first sheath at least partially surrounds the core. The core comprises recycled polypropylene, and the first sheath comprises polypropylene. In addition, the first sheath comprises a granular opaque additive. By covering a core of recycled polypropylene of a dark color (the dark color further varies between different batches) with a sheath comprising a granular opaque additive, the color of the core can be concealed. In addition, in addition to the granular opaque additive, at least the first sheath can also comprise a pigment to provide a colored filament. Therefore, the use of dark recycled polypropylene in filaments of various colors is provided.

[0009] Add a granular opaque additive to cover the color of the core of the bottom layer. Therefore, if the granular additive is opaque, it is preferred. In addition, the granular opaque additive is preferably white or at least bright to provide flexibility in the color of the filament. The granular opaque additive can be an inorganic additive, such as titanium dioxide or calcium carbonate. According to one embodiment, the granular opaque additive is titanium dioxide. The content of the granular opaque additive can vary. On the one hand, a high content can improve the masking effect and provide brighter filaments, on the other hand, too high a content may adversely affect the mechanical properties of the filament and the combination between the filament and the core. The first sheath can generally include 5% to 40% by weight of a granular opaque additive. Therefore, it can include 5% to 30% by weight or 10% to 20% by weight of a granular opaque additive. According to some embodiments, for example, where a lighter color is desired, the first sheath can include at least 10% by weight of a granular opaque additive.

[0010] Since the first sheath is used to cover the core, it can constitute 5% to 30% by weight of the filament. According to some embodiments, it constitutes 10% to 25% by weight of the filament. The more it constitutes, the better the masking effect. However, since one purpose is to provide the use of recycled polypropylene, it is preferred if the first sheath is a minor component (i.e., less than 50% by weight of the filament). In addition, the thickness of the first sheath can vary on its periphery; especially if the cross section of the filament is multi-lobed. In order to cover the core, the first sheath can be at least 0.2 μm thick, for example, at least 1.0 μm thick. According to one embodiment, the first sheath is 1.0 μm to 10.0 μm thick, for example, 1.0 μm to 4.0 μm thick.

[0011] Typically, the first sheath completely surrounds the core. However, in some embodiments, it may be of interest to only partially cover the periphery of the core, thereby providing filaments with a melange effect (also referred to in the art as a heathered effect of fiber dyeing). Thus, the first sheath may surround at least 80% of the periphery of the core, such as at least 90% or 95%. In addition, the first sheath may surround 80% to 99%, such as 90% or 97%, of the periphery of the core.

[0012] In addition to particulate opaque additives (such as titanium dioxide), the first sheath can also include pigments in addition to particulate opaque additives. This pigment is usually not white. By adding pigments, filaments of different colors can be provided. Particulate opaque additives are usually white. By applying the first sheath to the core, multi-component filaments are provided, and particulate opaque additives and optional pigments can be positioned to the surface of the filaments. This means that in order to affect the color of the filaments, less additives must be used. In fact, it is difficult to provide a color corresponding to the multi-component filaments of the present invention in recycled polypropylene monocomponent filaments, because too much additive may adversely affect mechanical properties.

[0013] However, according to some embodiments, the core may contain inorganic particulate opaque additives, such as titanium dioxide or calcium carbonate. The core may contain up to 5% by weight of inorganic particulate opaque additives. As already described, too high a content of inorganic particulate opaque additives may adversely affect the mechanical properties of the filaments. In addition, in order to compensate for slight color variations between different batches and provide a uniformly colored core, the core may contain dark pigments such as carbon black.

[0014] The first sheath comprises polypropylene. This polypropylene can be virgin polypropylene. The virgin polypropylene has not been subjected to discoloration. In addition, the polypropylene in the first sheath can be recycled polypropylene. If recycled polypropylene is used in the first sheath, it is preferred if the recycled polypropylene in the first sheath is lighter in color than the recycled polypropylene in the core. At least for some applications, such as some applications in dark filaments, recycled polypropylene can be used in the first sheath. The discoloration of recycled polypropylene is different, and lighter qualities can be obtained, but slightly more expensive. Therefore, the use of recycled polypropylene in carpet filaments can be provided by using a first sheath comprising virgin polypropylene or by using a first sheath comprising recycled polypropylene whose color is lighter than the recycled polypropylene in the core.

[0015] The multi-component filaments of the present invention allow the use of dark colored recycled polypropylene. It is desirable to use as much recycled material as possible in the filaments. The core may constitute at least 40% by weight of the filaments. According to one embodiment, the core constitutes 50% to 85% by weight of the filaments.

[0016] According to one embodiment, the multi-component filament further comprises a second sheath at least partially surrounding the first sheath. The second sheath comprises a polymer. With the aid of a multi-component filament having a first sheath and a second sheath, the color of the filament can be even further changed and adjusted. In addition, the use of a first sheath that masks the core color and a second sheath that colors the filament helps to provide a filament with a lighter color. In addition, concentrating the pigment to the outermost layer means that less pigment is needed to provide the same color. According to one embodiment, the first sheath comprises a first pigment, and the second sheath comprises a second pigment different from the first pigment. By having a first pigment in the first sheath and a second pigment different from the first pigment in the second sheath, the color of the filament can be changed and adjusted. If two pigments are present in the same sheath, the apparent color of the filament may not be the same. In addition, the color may be different depending on the pigment present in the outer sheath.

[0017] The polymer in the second sheath can be polypropylene. The polypropylene in the second sheath is typically virgin polypropylene. However, in some alternative embodiments, the polypropylene in the second sheath can be recycled polypropylene or at least comprise recycled polypropylene. Similar to the first sheath, it is preferred if the recycled polypropylene used for the second sheath is lighter in color than the recycled polypropylene in the core.

[0018] According to one embodiment, the second sheath comprises polypropylene. However, although the polymer in the second sheath is generally polypropylene, it can also be another type of polymer, such as polyester, for example, semi-aromatic polyester (e.g., polyethylene terephthalate) or aliphatic polyamide (e.g., polyamide 6 or polyamide 66). According to one embodiment, the second sheath comprises polyester (e.g., semi-aromatic polyester (e.g., polyethylene terephthalate)) and / or aliphatic polyamide (e.g., polyamide 6 or polyamide 66). An outer sheath comprising polyester such as semi-aromatic polyester (e.g., polyethylene terephthalate) and / or aliphatic polyamide (e.g., polyamide 6 or polyamide 66) can provide improved moisture management for the multi-component filaments.

[0019] Typically, the second sheath contains a pigment. Unless a slightly whitish fiber is desired, the pigment is generally not white. The second sheath may contain 1% to 20% by weight of the pigment. In addition, the second sheath may optionally or alternatively contain a particulate opaque additive. Particulate opaque additives are generally white and can therefore also be used as white pigments. According to one embodiment, the second sheath contains a particulate opaque additive such as titanium dioxide, and a pigment in addition to the particulate opaque additive. The particulate opaque additive may be an inorganic particulate opaque additive, such as titanium dioxide or calcium carbonate. According to one embodiment, the particulate opaque additive is titanium dioxide. The second sheath may contain 5% to 40% by weight, such as 5% to 30% or 10% to 20% by weight of the particulate opaque additive. According to some embodiments, where a lighter color is desired, the second sheath may contain at least 10% by weight of the particulate opaque additive.

[0020] Since the second sheath is used to color the filament, it can constitute 5% to 30% by weight of the filament. According to some embodiments, it constitutes 10% to 25% by weight of the filament. The more it constitutes, the stronger the coloring effect. However, since one purpose is to provide the use of recycled polypropylene, it is preferred if the second sheath is a minor component (i.e., less than 50% by weight of the filament). In addition, the thickness of the second sheath can vary on its periphery; especially if the cross section of the filament is multi-lobed. In order to color the filament, the second sheath can be at least 0.2 μm thick, for example, at least 1.0 μm thick. According to one embodiment, the second sheath is 1.0 μm to 10.0 μm thick, for example, 1.0 μm to 4.0 μm thick.

[0021] In addition, the first sheath and the second sheath both affect the color of the resulting long filament. In some embodiments, the first sheath constitutes a greater proportion of the long filament than the second sheath. According to such an embodiment, the first sheath can constitute 10% to 30% by weight of the long filament, and the second sheath can constitute 5% to 20% by weight of the long filament. If the first sheath fully covers the core, the second sheath can be slightly thinner, thereby still providing the desired color.

[0022] Typically, the second sheath completely surrounds the first sheath. However, in some embodiments, it may be of interest to only partially cover the periphery of the first sheath, thereby providing a filament with a mixed color effect. Thus, the second sheath may surround at least 80% of the periphery of the first sheath, such as at least 90% or 95%. In addition, the second sheath may surround 80% to 99%, such as 90% or 97%, of the periphery of the first sheath.

[0023] In addition, although the polymer in the core is usually recycled polypropylene, the concept of using the first sheath and the second sheath can also be applied in providing filaments of various colors, wherein the core contains other types of recycled polymers except polypropylene, such as polyester, such as semi-aromatic polyester (such as polyethylene terephthalate) or aliphatic polyamide (such as polyamide 6 or polyamide 66). According to the second aspect, a multi-component filament for pile yarn is therefore provided. The multi-component filament comprises a core, at least a first sheath and a second sheath, wherein the first sheath at least partially surrounds the core, and the second sheath at least partially comprises the first sheath. The core contains a polymer, which is usually a recycled polymer. The polymer can be a polyolefin (such as polypropylene), a polyester such as a semi-aromatic polyester (such as polyethylene terephthalate) or an aliphatic polyamide (such as polyamide 6 or polyamide 66). Similarly, the first sheath contains a polymer. Therefore, the first sheath can contain a polyolefin (such as polypropylene), an aliphatic polyamide (such as polyamide 6 or polyamide 66) or a polyester such as a semi-aromatic polyester (such as polyethylene terephthalate). As already outlined above, the polymer used in the first sheath is generally a virgin polymer. However, it can also be a recycled polymer. If a recycled polymer is used in the first sheath, it is preferred if such a recycled polymer is lighter in color than the recycled polymer in the core. In addition, the second sheath also comprises a polymer. Therefore, the second sheath can comprise a polyolefin (e.g. polypropylene), an aliphatic polyamide (e.g. polyamide 6 or polyamide 66) or a polyester such as a semi-aromatic polyester (e.g. polyethylene terephthalate). As already outlined above, the polymer used in the second sheath is generally a virgin polymer. However, it can also be a recycled polymer. If a recycled polymer is used in the second sheath, it is preferred if such a recycled polymer is lighter in color than the recycled polymer in the core. In addition, similar to what has been described, the first sheath comprises a first granular opaque additive. The first granular opaque additive can be an inorganic additive, such as titanium dioxide or calcium carbonate. Preferably, the first granular opaque additive is titanium dioxide. In a corresponding manner, the second sheath does optionally comprise a pigment and / or a second granular opaque additive. The second particulate opacifying additive, if present, may be an inorganic additive, such as titanium dioxide or calcium carbonate. Preferably, the second particulate opacifying additive is titanium dioxide.

[0024] With the aid of a multi-component filament having a first sheath and a second sheath, the color of the filament can be even further varied and adjusted. In addition, the use of a first sheath that masks the core color and a second sheath that colors the filament helps to provide a filament with a lighter color. In addition, concentrating the pigment to the outermost layer means that less pigment is needed to provide the same color. According to one embodiment, the first sheath contains a first pigment, and the second sheath contains a second pigment different from the first pigment. By having a first pigment in the first sheath and a second pigment different from the first pigment in the second sheath, the color of the filament can be varied and adjusted. If the two pigments are contained in the same sheath, the apparent color of the filament may not be the same. In addition, the color can be different depending on the pigment present in the outer sheath.

[0025] Preferred embodiments of the first aspect of the present invention and the second aspect are closely related to each other.Therefore, the first sheath can comprise 5 % by weight to 40 % by weight, for example 5 % by weight to 30 % by weight or 10 % by weight to 20 % by weight of granular opaque additives.In addition, the second sheath can comprise 1 % by weight to 20 % by weight of pigment and / or 5 % by weight to 30 % by weight, for example 5 % by weight to 30 % by weight or 10 % by weight to 20 % by weight of granular opaque additives.In addition, the core can constitute at least 40 % by weight of long filament, for example 50 % by weight to 85 % by weight.The first sheath can constitute 5 % by weight to 30 % by weight of long filament, for example 10 % by weight to 25 % by weight.The second sheath can constitute 5 % by weight to 30 % by weight of long filament, for example 10 % by weight to 25 % by weight.

[0026] In a corresponding manner as described for the first aspect, in an embodiment according to the second aspect, the thickness of the first sheath may vary over its periphery; in particular if the cross section of the filament is multilobal. In order to conceal the core, the first sheath may be at least 0.2 μm thick, for example at least 1.0 μm thick. According to one embodiment, the first sheath is 1.0 μm to 10.0 μm thick, for example 1.0 μm to 4.0 μm thick. In addition, the first sheath generally completely surrounds the core. However, in some embodiments, it may be of interest to only partially cover the periphery of the core, thereby providing a filament with a mixed color effect. Therefore, the first sheath may surround at least 80% of the periphery of the core, for example at least 90% or 95%. In addition, the first sheath may surround 80% to 99%, for example 90% or 97%, of the periphery of the core. Similarly, the second sheath may be at least 0.2 μm thick, for example at least 1.0 μm thick. According to one embodiment, the second sheath is 1.0 μm to 10.0 μm thick, for example 1.0 μm to 4.0 μm thick. In addition, the second sheath generally completely surrounds the first sheath. However, in some embodiments, it may be of interest to only partially cover the periphery of the first sheath, thereby providing a filament with a mixed color effect. Thus, the second sheath may surround at least 80% of the periphery of the first sheath, such as at least 90% or 95%. In addition, the second sheath may surround 80% to 99%, such as 90% or 97%, of the periphery of the first sheath.

[0027] Turning to the preferred features of both aspects of the invention as outlined above, it should be noted that the cross-section of the multicomponent filament may have at least two lobes. Thus, the cross-section of the multicomponent filament may be bilobal, trilobal or quadrilobal. The cross-section of the filament does not only directly affect the mechanical properties. In particular, when used for carpets, other properties such as feel and touch are also affected and are generally improved, as described in WO 2022 / 005383. For filaments with a bilobal cross-section, it is preferred if the waist is concave. For filaments with a trilobal or quadrilobal cross-section, it is preferred if the side is concave. The present invention is not limited to a given size or diameter. The linear mass density of the filament may be in the range of 1 dtex to 20 dtex.

[0028] Furthermore, additional additives may be present in the first sheath and / or the second sheath. According to one embodiment, reflective additives such as glass beads, glitter or crystals are present in the first sheath and / or the second sheath. The reflective additive may be a retro-reflective additive such as glass beads. Furthermore, additives may be added that cause the filaments or the pile yarns comprising the filaments to change color in response to different light sources. According to one embodiment, the additive is a photochromic material. Photochromic materials change color when exposed to, for example, UV light. The photochromic materials used are generally reversible. Some common examples of photochromic materials include silver halides, spirocyanates, In some embodiments, a reflective additive or photochromic material is used instead of the pigment in the second sheath.

[0029] According to a third aspect, a multi-component filament for pile yarn is provided. The multi-component filament comprises a core, at least a first sheath and a second sheath, wherein the first sheath at least partially surrounds the core, and the second sheath at least partially surrounds the first sheath. The core comprises a polymer, typically a recycled polymer. The polymer can be a polyolefin (e.g., polypropylene), a polyester such as a semi-aromatic polyester (e.g., polyethylene terephthalate) or an aliphatic polyamide (e.g., polyamide 6 or polyamide 66). Similarly, the first sheath comprises a polymer. Therefore, the first sheath can comprise a polyolefin (e.g., polypropylene), an aliphatic polyamide (e.g., polyamide 6 or polyamide 66) or a polyester such as a semi-aromatic polyester (e.g., polyethylene terephthalate). As already outlined above, the polymer used in the first sheath is typically a virgin polymer. However, it can also be a recycled polymer. If a recycled polymer is used in the first sheath, it is preferred if such a recycled polymer is lighter than the polymer color in the core. In addition, the second sheath also comprises a polymer. Therefore, the second sheath can comprise polyolefins (e.g. polypropylene), aliphatic polyamides (e.g. polyamide 6 or polyamide 66), or polyesters such as semi-aromatic polyesters (e.g. polyethylene terephthalate). As already outlined above, the polymer used in the second sheath is typically a virgin polymer. However, it can also be a recycled polymer. If a recycled polymer is used in the second sheath, it is preferred if such a recycled polymer is lighter in color than the polymer in the core. In addition, the first sheath optionally comprises a first additive. The second sheath comprises a second additive. The second additive (if present) is different from the first additive. By having different additives in different sheaths, the properties of the filament can be improved and adjusted. In addition, the presence of the first sheath will separate the additive in the second sheath from the core. It will be understood that each sheath can comprise several additives, and if one of these additives is different between the first sheath and the second sheath, it is sufficient.

[0030] The preferred embodiments of the second and third aspects of the present invention are closely related to each other. Therefore, the core of the filament can constitute at least 40% by weight of the filament, such as 50% to 85% by weight. In addition, the first sheath can constitute 5% to 30% by weight of the filament, such as 10% to 25% by weight. In addition, the second sheath can constitute 5% to 30% by weight of the filament, such as 10% to 25% by weight. The first sheath can be at least 0.2 μm thick, such as at least 1.0 μm thick. The first sheath can surround at least 80% of the periphery of the core, such as at least 90% or 95%. According to one embodiment, the first sheath completely surrounds the core. The second sheath can be at least 0.2 μm thick, such as at least 1.0 μm thick. The second sheath can surround at least 80% of the periphery of the first sheath, such as at least 90% or 95%. According to one embodiment, the second sheath completely surrounds the first sheath.

[0031] As already outlined, a variety of polymers can be used in the filaments. In addition, various combinations of polymers are used. According to one embodiment, the polymer in the first sheath is different from the polymer in the second sheath. According to another embodiment, the polymer in the first sheath is the same type of polymer as the polymer in the second sheath. In addition, according to one embodiment, the polymer in the core can be different from the polymer in the first sheath. Alternatively, the polymer in the core can be the same type of polymer as the polymer in the first sheath.

[0032] The cross section of the multicomponent filament has at least two lobes. According to one embodiment, its cross section is bilobal, trilobal or quadrilobal. According to one embodiment, the waist of the bilobal cross section is concave, and the sides of the trilobal and / or quadrilobal cross sections are concave.

[0033] The linear mass density of the filaments may be from 1 dtex to 20 dtex.

[0034] According to a fourth aspect, a yarn is provided, such as a pile yarn. The yarn comprises at least two filaments, but there are usually additional filaments of the type described above. In addition, the yarn can be drawn and deformed to form a bulked continuous fiber (BCF) yarn. Therefore, the yarn can be a bulked continuous fiber (BCF) yarn. The manufacture of bicomponent textured filaments with a sheath-core arrangement for, for example, bulked continuous filaments (BCF) fibers and floor coverings (e.g., mats, pile tweed, and carpets) is known in the art (see, for example, US2018282908A1).

[0035] According to a fifth aspect, short fibers are provided. The short fibers may be obtained by cutting filaments of the type described above into short fibers. The short fibers may be 20 mm to 100 mm long, for example 30 mm to 70 mm long.

[0036] According to a sixth aspect, a carpet or a pile tweed is provided. The carpet or the pile tweed comprises the yarn described above or the staple fiber described above.

[0037] According to a seventh aspect, there is provided a method for producing a filament according to the first or second aspect of the invention as disclosed above. The method comprises the following steps:

[0038] - extruding a first melt comprising a recycled polymer, such as polypropylene, to form a core, extruding a second melt comprising a polymer, such as polypropylene and a particulate opaque additive to form a sheath at least partially surrounding the core, and optionally extruding a third melt comprising a polymer, preferably polypropylene, to form a second sheath at least partially surrounding the first sheath;

[0039] - drawing and solidifying the filaments; and

[0040] - Optionally texturing and / or stretching the filaments.

[0041] Further aspects of such embodiments are disclosed in particular in WO 2022 / 005383.

[0042] Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific forms set forth herein. Instead, the present invention is limited only by the appended claims, and other embodiments besides the specific embodiments described above are equally possible within the scope of these appended claims.

[0043] In the claims, the term "comprises / comprising" does not exclude the presence of other elements or steps. Furthermore, although individual features may be included in different claims, these may possibly be advantageously combined, and the inclusion in different claims does not imply that a combination of features is not feasible and / or advantageous.

[0044] In addition, singular references do not exclude a plurality. Nouns without quantifiers, the terms "first", "second" etc. do not exclude a plurality. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] These and other aspects, features and advantages that can be achieved by the present invention will become apparent and elucidated from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

[0046] Figure 1a shows a cross section of a filament having a first sheath according to one embodiment;

[0047] Figure 1b Shown is a cross section of a filament having a first sheath and a second sheath according to one embodiment. DETAILED DESCRIPTION

[0048] exist Figure 1a , a cross section of a plurality of filaments according to one embodiment is shown. The filament is a bicomponent filament having a first sheath 20 surrounding a core 10. The cross section of the filament is trilobal. As can be seen, the thickness of the first sheath 20 varies slightly on the periphery of the filament.

[0049] exist Figure 1b , a plurality of cross sections of filaments according to one embodiment are shown. The filament is a three-component filament having a first sheath 20 surrounding a core 10 and a second sheath 30 surrounding the first sheath 20. The cross section of the filament is trilobal. As can be seen, the thickness of the first sheath 20 and the second sheath 30 respectively vary slightly on the periphery of the filament.

[0050] experiment

[0051] Filament spinning and yarn drawing

[0052] Conventional fiber forming equipment can be used to spin sheath-core fiber of the present invention.Therefore, for example, the independent melt stream of virgin sheath polypropylene and recovery core polypropylene can be fed to conventional sheath-core spinneret assembly (example is particularly provided in US 5,162,074, US 5,125,818, US 5,344,297 and 5,445,884), in which melt stream is merged to form extrusion multilobal (for example trilobal, quadrilobal, pentalobal or hexalobal) filament with sheath and core structure.In the embodiment comprising two sheaths, other melt stream is fed to spinneret assembly.

[0053] After extrusion, the extruded filaments are subjected to airflow cooling, for example, airflow cooling with air to solidify the filaments. The filaments can then be treated with a finishing agent comprising a lubricating oil or a mixture of oil and an antistatic agent. The filaments thus formed are then combined to form a yarn bundle.

[0054] In subsequent steps, the yarn can be drawn and textured to form a bulked textured fiber (BCF) yarn suitable for tufting into carpet, for example. In addition, spinning and drawing can be combined into a single process. The one-step method of making BCF is generally referred to in the art as spin-draw-texturing (SDT).

[0055] Example 1

[0056] A first flat filament yarn having core-sheath-core filaments of recycled polypropylene in the core 10 was provided having the following specifications (see Figure 1a ):

[0057] Weight ratio core / sheath : 60 / 40

[0058] Polymer in core 10 : Recycled polypropylene from ADCompound Spa (MFI at 230°C / 2.16 kg according to ISO 1133: 26.4 g / 10 min; density at 23°C: 0.964 g / cm 3 )

[0059] Additives in core 10 : TiO2 (5 wt%) and carbon black (3 wt%)

[0060] Polymer in sheath 20 : Virgin polypropylene (Metocene MF650Y) from LyondellBasell (MFI at 230°C / 2.16 kg according to ISO 1133: 18 g / 10 min)

[0061] Additives in Sheath 20 : TiO2 (35 wt%) and red pigment (2 wt%)

[0062] Linear density filament :12 denier per filament (dpf)

[0063] Linear density yarn :1700 dtex

[0064] The yarn is reddish brown in color, has a tenacity of 2.16 and an elongation of 106%.

[0065] Example 2

[0066] A second flat filament yarn having sheath-sheath-core filaments of recycled polypropylene in the core 10 was provided having the following specifications (see Figure 1b ):

[0067] Weight ratio core / sheath / sheath : 60 / 30 / 10

[0068] Polymer in core 10 : MFI of recycled polypropylene at 230°C / 2.16kg according to ISO 1133: 26.4 g / 10 min; density at 23°C: 0.964 g / cm 3 )

[0069] Additives in core 10 : Carbon black (3 wt%)

[0070] The polymer in the first sheath 20: Virgin polypropylene (Metocene MF650Y) from LyondellBasell (MFI at 230°C / 2.16 kg according to ISO 1133: 18 g / 10 min)

[0071] Additives in the First Sheath 20 :TiO2(15wt%)

[0072] The polymer in the second sheath 30 : Virgin polypropylene (Metocene MF650Y) from LyondellBasell (MFI at 230°C / 2.16 kg according to ISO 1133: 18 g / 10 min)

[0073] Additives in the Second Sheath 30 : TiO2 (10 wt%) and yellow pigment (2 wt%)

[0074] Linear density filament :12 denier / filament (dpf)

[0075] Linear density yarn :1800 dtex

[0076] The yarn is light green in color and has a tenacity of 2.08 and an elongation of 98%.

Claims

1. A filament for pile yarn, wherein the filament is a multicomponent filament comprising a core (10) and at least a first sheath (20), wherein the first sheath (20) at least partially surrounds the core (10), the core (10) comprising recycled polypropylene, wherein the first sheath (20) comprises polypropylene and a particulate opaque additive.

2. The filament according to claim 1, wherein the particulate opaque additive is an inorganic additive, such as titanium dioxide or calcium carbonate; preferably, the particulate opaque additive is titanium dioxide.

3. The filament according to claim 1 or 2, wherein the first sheath (20) comprises 5 to 40 wt. %, for example 5 to 30 wt. % or 10 to 20 wt. % of the particulate opaque additive.

4. The filament according to any one of claims 1 to 3, wherein In addition to the particulate opaque additive, the first sheath (20) further comprises a pigment; and / or The core (10) comprises up to 5% by weight of a particulate opacifying additive, preferably an inorganic particulate opacifying additive, such as titanium dioxide or calcium carbonate, and / or the core (10) comprises a pigment, such as carbon black.

5. The filament according to any one of claims 1 to 4, wherein the core (10) constitutes at least 40% by weight of the filament, such as 50% to 85% by weight.

6. The filament according to any one of claims 1 to 5, wherein the multi-component filament further comprises a second sheath (30) at least partially surrounding the first sheath (20), the second sheath (30) comprising a polymer, preferably, the polymer is polypropylene.

7. The filament according to claim 6, wherein the second sheath (30) comprises pigments and / or particulate opacifying additives, preferably inorganic particulate opacifying additives, such as titanium dioxide or calcium carbonate.

8. The filament according to claim 7, wherein the second sheath (30) comprises 1 to 20 wt. % of the pigment and / or 5 to 40 wt. %, for example 5 to 30 wt. % or 10 to 20 wt. % of the particulate opaque additive.

9. The filament according to any one of claims 1 to 8, wherein: - the first sheath (20) constitutes 5% to 30% by weight of the filaments, for example 10% to 25% by weight; and / or - the first sheath (20) is at least 0.2 μm thick, such as at least 1.0 μm thick; and / or - the first sheath (20) surrounds at least 80%, such as at least 90% or 95%, of the circumference of the core (10); preferably, the first sheath (20) completely surrounds the core (10); and / or - if present, the second sheath (30) constitutes 5 to 30 wt. %, such as 10 to 25 wt. % of the filament; and / or - if present, the second sheath (30) is at least 0.2 μm thick, such as at least 1.0 μm thick; and / or If present, the second sheath (30) surrounds at least 80%, such as at least 90% or 95%, of the circumference of the first sheath (20); preferably, the second sheath (30) completely surrounds the first sheath (20).

10. The filament according to any one of claims 1 to 9, wherein the first sheath (20) comprises virgin polypropylene, or wherein the first sheath (20) comprises recycled polypropylene; preferably, the recycled polypropylene in the first sheath (20) is lighter in color than the recycled polypropylene in the core (10); and / or Wherein if the second sheath (30) is present, the second sheath (30) comprises virgin polypropylene, or wherein the second sheath (30) comprises recycled polypropylene; preferably, the recycled polypropylene in the second sheath (30) is lighter in color than the recycled polypropylene in the core (10).

11. A filament for pile yarn, wherein the filament is a multicomponent filament comprising a core (10), at least a first sheath (20) and a second sheath (30), the core (10) comprising a polymer, the first sheath (20) at least partially surrounding the core (10), the second sheath (30) at least partially surrounding the first sheath (20), wherein the first sheath (20) comprises a polymer and a first particulate opaque additive, and wherein the second sheath (30) optionally comprises a polymer, a pigment and / or a second particulate opaque additive.

12. The filament according to claim 11, wherein the first particulate opaque additive is an inorganic additive, such as titanium dioxide or calcium carbonate; preferably, the additive is titanium dioxide; and If the second particulate opaque additive is present, the second particulate opaque additive is an inorganic additive, such as titanium dioxide or calcium carbonate; preferably, the additive is titanium dioxide.

13. The filament according to claim 11 or 12, wherein: - the first sheath (20) comprises 5 to 40 wt. %, for example 5 to 30 wt. % or 10 to 20 wt. % of the particulate opaque additive; and / or The second sheath (30) contains 1 to 20% by weight of the pigment and / or 5 to 30% by weight, for example 5 to 30% by weight or 10 to 20% by weight, of the particulate opacifying additive.

14. The filament according to any one of claims 11 to 13, wherein: - the core (10) constitutes at least 40% by weight of the filaments, for example 50% to 85% by weight; and / or - the first sheath (20) constitutes 5% to 30% by weight of the filaments, for example 10% to 25% by weight; and / or The second sheath (30) constitutes 5 to 30 wt. %, such as 10 to 25 wt. % of the filaments.

15. The filament according to any one of claims 11 to 14, wherein: - the first sheath (20) is at least 0.2 μm thick, such as at least 1.0 μm thick; and / or - the first sheath (20) surrounds at least 80%, such as at least 90% or 95%, of the circumference of the core (10); preferably, the first sheath (20) completely surrounds the core (10); and / or - the second sheath (30) is at least 0.2 μm thick, such as at least 1.0 μm thick; and / or The second sheath (30) surrounds at least 80%, such as at least 90% or 95%, of the circumference of the first sheath (20); preferably, the second sheath (30) completely surrounds the first sheath (20).

16. The filament according to any one of claims 11 to 15, wherein: - the polymer in the core (10) is recycled polyolefin, recycled aliphatic polyamide, or recycled polyester such as recycled semi-aromatic polyester; preferably, the polymer in the core (10) is recycled polypropylene; and / or - the polymer in the first sheath (20) is a polyolefin, an aliphatic polyamide, or a polyester such as a semi-aromatic polyester; preferably, the polymer in the first sheath (20) is polypropylene; and / or - The polymer in the second sheath (30) is a polyolefin, an aliphatic polyamide, or a polyester such as a semi-aromatic polyester; preferably, the polymer in the second sheath (30) is polypropylene.

17. A filament according to any one of claims 1 to 16, wherein the cross-section of the multi-component filament has at least two lobes, preferably, the cross-section is bilobal, trilobal or quadrilobal; more preferably, the waist of the bilobal cross-section is concave, and the sides of the trilobal cross-section and / or the quadrilobal cross-section are concave.

18. The filament according to any one of claims 1 to 16, wherein the filament has a linear mass density of 1 to 20 dtex.

19. A filament for pile yarn, wherein the filament is a multicomponent filament comprising a core (10), at least a first sheath (20) and a second sheath (30), the core (10) comprising a polymer, the first sheath (20) at least partially surrounding the core (10), the second sheath (30) at least partially surrounding the first sheath (20), wherein the first sheath (20) comprises a polymer and an optional first additive, and wherein the second sheath (30) comprises a polymer and a second additive, the second additive being different from the first additive.

20. The filament according to claim 19, wherein the polymer in the core (10) is a recycled polymer.

21. The filament according to any one of claims 19 to 20, wherein: - the core (10) constitutes at least 40% by weight of the filaments, for example 50% to 85% by weight; and / or - the first sheath (20) constitutes 5% to 30% by weight of the filaments, for example 10% to 25% by weight; and / or The second sheath (30) constitutes 5 to 30 wt. %, such as 10 to 25 wt. % of the filaments.

22. The filament according to any one of claims 19 to 21, wherein: - the first sheath (20) is at least 0.2 μm thick, such as at least 1.0 μm thick; and / or - the first sheath (20) surrounds at least 80%, such as at least 90% or 95%, of the circumference of the core (10); preferably, the first sheath (20) completely surrounds the core (10); and / or - the second sheath (30) is at least 0.2 μm thick, such as at least 1.0 μm thick; and / or The second sheath (30) surrounds at least 80%, such as at least 90% or 95%, of the circumference of the first sheath (20); preferably, the second sheath (30) completely surrounds the first sheath (20).

23. The filament according to any one of claims 19 to 22, wherein: - the polymer in the core (10) is recycled polyolefin, recycled aliphatic polyamide, or recycled polyester such as semi-aromatic polyester; preferably, the polymer in the core (10) is recycled polypropylene; and / or - the polymer in the first sheath (20) is a polyolefin, an aliphatic polyamide, or a polyester such as a semi-aromatic polyester; and / or - The polymer in the second sheath (30) is a polyolefin, an aliphatic polyamide, or a polyester such as a semi-aromatic polyester.

24. The filament according to any one of claims 19 to 23, wherein the polymer in the first sheath (20) is different from the polymer in the second sheath (30).

25. The filament according to any one of claims 19 to 23, wherein the polymer in the first sheath (20) is the same type of polymer as the polymer in the second sheath (30).

26. The filament according to any one of claims 19 to 25, wherein the polymer in the core (10) is different from the polymer in the first sheath (20).

27. The filament according to any one of claims 19 to 25, wherein the polymer in the core (10) is the same type of polymer as the polymer in the first sheath (20).

28. A filament according to any one of claims 19 to 27, wherein the cross-section of the multi-component filament has at least two lobes, preferably, the cross-section is bilobal, trilobal or quadrilobal; more preferably, the waist of the bilobal cross-section is concave, and the sides of the trilobal cross-section and / or the quadrilobal cross-section are concave.

29. The filament according to any one of claims 19 to 28, wherein the filament has a linear mass density of 1 to 20 dtex.

30. A yarn comprising at least two filaments according to any one of claims 1 to 29.

31. A staple fiber, wherein the staple fiber is obtainable by cutting the filament according to any one of claims 1 to 29 into staple fibers; preferably, the staple fiber is 20 mm to 100 mm long, such as 30 mm to 70 mm long.

32. A carpet or pile tweed comprising the yarn according to claim 30 or the staple fiber according to claim 31.

33. A method for producing a filament according to any one of claims 1 to 29, wherein the method comprises the following steps: - extruding a first melt comprising recycled polypropylene to form a core (10), extruding a second melt comprising polypropylene and optionally a particulate opaque additive to form a sheath (20) at least partially surrounding said core (10), and optionally extruding a third melt comprising a polymer, preferably polypropylene, to form a second sheath (30) at least partially surrounding said first sheath (20); - drawing and solidifying the filaments; as well as - optionally texturing and / or stretching the filaments.

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