Recycled fibers

Abstract

According to some embodiments of the present disclosure, a fiber may comprise a visbroken post-consumer recycled (PCR) ethylene-based polymer having a density of 0.925 g / cm3 to 0.970 g / cm3 and a melt index (I2) of at least 5 dg / 10 min., as determined by ASTM D1238 at 190 °C and 2.16 kg.

Description

RECYCLED FIBERSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 579,167 filed August 28, 2023, the contents of which are incorporated in their entirety herein.FIELD

[0002] The present disclosure relates to polymer fibers, and more specifically to polymer fibers comprising recycled polymeric material.BACKGROUND

[0003] Non-woven materials are an important application for recycled plastic packaging, such as post-consumer resins (PCR). Non-woven materials often are constructed from fibers. The PCRs available are often obtained from recycled blow molded milk jugs. These blow molded materials have a melt index of less than 1 g / 10 min while fiber spinning which is used to produce non-woven materials requires a significantly higher melt index.

[0004] Accordingly, methods of producing PCR based fibers are desired.SUMMARY

[0005] Embodiments of the present disclosure meet this need by providing a fiber comprising a visbroken PCR ethylene-based polymer having a density of 0.925 g / cm3to 0.970 g / cm3and a melt index (I2) of at least 5 dg / 10 min.

[0006] According to some embodiments of the present disclosure, a fiber may comprise: visbroken post-consumer recycled (PCR) ethylene-based polymer having a density of 0.925 g / cm3to 0.970 g / cm3and a melt index (I2) of at least 5 dg / 10 min., as determined by ASTM D1238 at 190 °C and 2.16 kg.

[0007] These and other embodiments are described in more detail in the Detailed Description. It is to be understood that both the foregoing general description and the following detailed description present embodiments of the presently disclosed technology and are intended to provide an overview or framework for understanding the nature and character of the technology as it is claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 illustrates a perspective view of a monocomponent fiber, in accordance with one or more embodiments described herein.

[0009] FIG. 2 illustrates a perspective view of a bi-component fiber, in accordance with one or more embodiments described herein.DETAILED DESCRIPTION

[0010] "Polymer" refers to a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The term polymer thus embraces the term homopolymer (employed to refer to polymers prepared from only one type of monomer, with the understanding that trace amounts of impurities can be incorporated into the polymer structure), and the term copolymer or interpolymer. Trace amounts of impurities (for example, catalyst residues) may be incorporated into and / or within the polymer. A polymer may be a single polymer or a polymer blend.

[0011] “Copolymer” refers to a polymer formed by the polymerization reaction of at least two structurally different monomers. The term “copolymer” is inclusive of terpolymers. For example, ethylene copolymers, such as ethylene-propylene copolymers, include at least two structurally different monomers (e.g., ethylene-propylene copolymer includes copolymerized units of at least ethylene monomer and propylene monomer) and can optionally include additional monomers or functional materials or modifiers, such as acid, acrylate, or anhydride functional groups. Put another way, the copolymers described herein comprise at least two structurally different monomers, and although the copolymers may consist of only two structurally different monomers, they do not necessarily consist of only two structurally different monomers and may include additional monomers or functional materials or modifiers.

[0012] "Ethylene-based polymer" (also referred to herein as “polyethylene” or "polyethylene-based polymers”) refers to polymers comprising greater than 50% by weight of units which have been derived from ethylene monomer. This includes polyethylene homopolymers or copolymers (meaning units derived from two or more comonomers). Common forms of polyethylene known in the art include Low Density Polyethylene (LDPE); Linear Low Density Polyethylene (LLDPE); Ultra Low Density Polyethylene (ULDPE); Very Low Density Polyethylene (VLDPE); single-site catalyzed Linear Low Density Polyethylene,including both linear and substantially linear low density resins (m-LLDPE); Medium Density Polyethylene (MDPE); and High Density Polyethylene (HDPE).

[0013] The term “LLDPE” includes resins made using the traditional Ziegler-Natta catalyst systems as well as single-site catalysts such as metallocenes (sometimes referred to as “m- LLDPE”). LLDPEs contain less long chain branching than LDPEs and include the substantially linear ethylene polymers which are further defined in U.S. Pat. No. 5,272,236, U.S. Pat. No. 5,278,272, U.S. Pat. No. 5,582,923 and U.S. Pat. No. 5,733,155; the homogeneously branched linear ethylene polymer compositions such as those in U.S. Pat. No. 3,645,992; the heterogeneously branched ethylene polymers such as those prepared according to the process disclosed in U.S. Pat. No. 4,076,698; and / or blends thereof (such as those disclosed in U.S. Pat. No. 3,914,342 or U.S. Pat. No. 5,854,045). The LLDPE can be made via gas-phase, solution-phase or slurry polymerization or any combination thereof, using any type of reactor or reactor configuration known in the art, including, but not limited to, gas and solution phase reactors.

[0014] “HDPE” generally refers to polyethylenes having densities greater than about 0.930 g / cm3and up to about 0.970 g / cm3, which are generally prepared with Ziegler-Natta catalysts, chrome catalysts or single-site catalysts including, but not limited to, substituted mono- or bis-cyclopentadienyl catalysts (typically referred to as metallocene), constrained geometry catalysts, phosphinimine catalysts & polyvalent aryloxyether catalysts (typically referred to as bisphenyl phenoxy).

[0015] The term “polypropylene,” as used herein, refers to a polymer that comprises, in polymerized form, greater than 50% by mole of units which have been derived from propylene monomer. This includes propylene homopolymer, random copolymer polypropylene, impact copolymer polypropylene, propylene / a-olefin copolymer, and propylene / a-olefin copolymer.

[0016] “Recycled resins” refers to resins, which were incorporated into products and subsequently re-melted to form a recycled resin. The term “recycled resins” refers to mechanically recycled resins, where the resin is melted and reincorporated into a new product. “Recycled resins” does not include chemically recycled resins, where the polymer is broken down into constituent monomers and incorporated into a new virgin polymer. The term “recycled resins” embraces both pre-consumer recycled polymer and post-consumer resin. Recycled resins are defined in ISO 14021 7.8.1.1.

[0017] The terms “pre-consumer recycled polymer” and “post-industrial recycled polymer” refer to polymers, including blends of polymers, recovered from pre-consumer material, as defined by ISO- 14021. The generic term pre-consumer recycled polymer thus includes blends of polymers recovered from materials diverted from the waste stream during a manufacturing process. The generic term pre-consumer recycled polymer excludes the reutilization of materials, such as rework, regrind, or scrap, generated in a process and capable of being reclaimed within the same process that generated it. Pre-consumer recycled polymer is defined in ISO 14021 7.8.1.1.

[0018] The term “post-consumer resin” (or “PCR”), as used herein, refers to a polymeric material that includes materials previously used in a consumer or industry application (i.e., pre-consumer recycled polymer and post-industrial recycled polymer). PCR is typically collected from recycling programs and recycling plants. The PCR may include one or more of an ethylene-based polymer, such as LDPE, LLDPE, HDPE, a polyethylene, a polypropylene, a polyester, a poly(vinyl chloride), a polystyrene, an acrylonitrile butadiene styrene, a polyamide, an ethylene vinyl alcohol, an ethylene vinyl acetate, or a poly-vinyl chloride. The PCR may include one or more contaminants. The contaminants may be the result of the polymeric material’s use prior to being repurposed for reuse. For example, contaminants may include paper, ink, food residue, or other recycled materials in addition to the polymer, which may result from the recycling process. PCR is distinct from virgin polymeric material. A virgin polymeric material (such as a virgin polyethylene resin) does not include materials previously used in a consumer or industry application. Virgin polymeric material has not undergone, or otherwise has not been subject to, a heat process or a molding process, after the initial polymer manufacturing process. The physical, chemical, and flow properties of PCR resins differ when compared to virgin polymeric resin, which in turn can present challenges to incorporating PCR into formulations for commercial use. Post-consumer resin is defined in ISO 14021 7.8.1.1.

[0019] As used herein, the term “devolatilization” refers to a process by which undesired volatile contaminants (e.g., dissolved gasses, solvent, unreacted monomer, etc.) are removed from a polymer melt or solution.

[0020] The term “dtex” refers to the unit of measuring fiber thickness. 1 dtex is 1 gram of polymer per 10,000 meters of fiber.

[0021] The term “bi-component fiber” as used in this disclosure means a fiber comprised of two polymers of different chemical and / or physical properties extruded from the same spinneret with both polymers being within the same filament. The two polymers may be arranged such that the properties of the bi-component fiber differ across a cross section of the bi-component fiber. The two polymers may be arranged in a sheath region / core region arrangement, such that a first region comprises the core of the fiber and a second region comprises the sheath of the fiber.

[0022] The term “monocomponent fiber” as used in this disclosure means a fiber comprised of a polymer extruded from a spinneret with the polymer making up a single filament. Where more than one polymer is present, the polymers are combined to form a homogenous blend such that the properties of the monocomponent fiber do not vary across the cross section of the fiber.

[0023] Referring now to FIGs. 1 and 2, a fiber 10 may comprise a visbroken post-consumer recycled (PCR) ethylene-based polymer. The fiber 10 may be a monocomponent fiber 100 or a bi-component fiber 200.

[0024] Referring now to FIG. 1, the fiber 10 may be a monocomponent fiber 100. In a monocomponent fiber 100, the properties of the polymers which make up the monocomponent fiber 100 may not vary across the cross section 102 of the fiber.

[0025] The monocomponent fiber 100 may comprise a visbroken PCR ethylene-based polymer, either alone or in a blend with a virgin ethylene-based polymer. The blend may comprise at least 5 wt. % of the visbroken PCR ethylene-based polymer, based on the total weight of the monocomponent fiber. In embodiments, the blend may comprise at least 10 wt. %, at least 20 wt. %, at least 40 wt. %, at least 60 wt. %, at least 80 wt. %, at least 90 wt. %, from 5 wt. % to 15 wt. %, from 80 wt. % to 100 wt. %, from 90 wt. % to 100 wt. %, from 95 wt. % to 100 wt. %, from 98 wt. % to 100 wt. %, from 99 wt. % to 100 wt. %, from 5 wt. % to 95 wt. %, from 10 wt. % to 90 wt. %, or any subset thereof of the visbroken PCR ethylenebased polymer, based on the total weight of the monocomponent fiber. At least 80 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of the weight of the blend may comprise the combination of the visbroken PCR ethylene-based polymers and the virgin ethylene-based polymer.

[0026] Referring now to FIG. 2, the fiber 10 may be a bi-component fiber 200. The properties of the bi-component fiber 200 may vary across the cross section 202 of the bicomponent fiber 200.

[0027] The bi-component fiber 200 may comprise a first region 206 (such as a core) and a second region 204 (such as a sheath), each with differing properties. In embodiments, the bi- component fiber 200 may have a first region 206, and a second region 204 which partially or totally surrounds the first region 206.

[0028] The bi-component fiber 200 may be prepared by processes well known in the art. One such suitable method of production includes a melt spinning process. In this process, each of the first region 206 and the second region 204 are separately fed into extruders. Once extruded, the product is spun, cooled, and taken up so as to produce continuous filaments. Then, the continuous filaments are stretched, oiled, crimped, and cooled to produce the bi- component fiber 200.

[0029] The first region 206 and the second region 204 may have a weight ratio of 80 / 20 to 20 / 80 , based on total weight of the bi-component fiber 200. Other suitable weight ratios of the first region 206 to the second region 204 include 75 / 25 to 25 / 75, 70 / 30 to 30 / 70, 65 / 35 to 35 / 65, 60 / 40 to 40 / 60 or a weight ratio of about 50 / 50.

[0030] The bi-component fiber 200 may comprise at least 80 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of the first region 206 and the second region 204, based on the total weight of the bi-component fiber 200.

[0031] The first region 206 (such as a sheath) may comprise a visbroken PCR ethylenebased polymer, a virgin ethylene-based polymer, or a blend of the visbroken PCR ethylenebased polymer and the virgin ethylene-based polymer.

[0032] In embodiments where the first region 206 comprises a blend of the visbroken PCR ethylene-based polymer and the virgin ethylene-based polymer, the blend may comprise at least 5 wt. % of the visbroken PCR ethylene-based polymer, based on the total weight of the first region 206. In embodiments, the blend may comprise at least 10 wt. %, at least 20 wt. %, at least 40 wt. %, at least 60 wt. %, at least 80 wt. %, at least 90 wt. %, from 5 wt. % to 15 wt. %, from 80 wt. % to 100 wt. %, from 90 wt. % to 100 wt. %, from 95 wt. % to 100 wt. %, from 98 wt. % to 100 wt. %, from 99 wt. % to 100 wt. %, from 5 wt. % to 95 wt. %, from 10 wt. % to 90 wt. %, or any subset thereof of the visbroken PCR ethylene-based polymer,based on the total weight of the first region 206. At least 80 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of the weight of the blend may comprise the combination of the weights of the visbroken PCR ethylene-based polymer and the virgin ethylene-based polymer.

[0033] At least 80 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or at least 99.9 wt. % of the weight of the first region 206 may be the weight of the blend.

[0034] At least 80 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or at least 99.9 wt. % of the weight of the first region 206 may be the visbroken PCR ethylene-based polymer.

[0035] The second region 204 (such as a core) may comprise a polypropylene, the visbroken PCR ethylene-based polymer, a virgin ethylene-based polymer, or a blend thereof. In embodiments, the polypropylene may be a visbroken polypropylene, a PCR polypropylene, or a visbroken PCR polypropylene.

[0036] The second region 204 may comprise at least 80 wt. %, such as at least 85 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of the polypropylene (such as a visbroken polypropylene, a PCR polypropylene, or a visbroken PCR polypropylene), based on the total weight of the second region 204.

[0037] Where the second region 204 is a blend of one or more of polypropylene, visbroken PCR ethylene-based polymer, and virgin ethylene-based polymer, the blend may comprise at least 5 wt. % of the visbroken PCR ethylene-based polymer, based on the total weight of the second region 204. In embodiments, the blend may comprise at least 10 wt. %, at least 20 wt. %, at least 40 wt. %, at least 60 wt. %, at least 80 wt. %, at least 90 wt. %, from 5 wt. % to 15 wt. %, from 80 wt. % to 100 wt. %, from 90 wt. % to 100 wt. %, from 95 wt. % to 100 wt. %, from 98 wt. % to 100 wt. %, from 99 wt. % to 100 wt. %, from 5 wt. % to 95 wt. %, from 10 wt. % to 90 wt. %, or any subset thereof of the visbroken PCR ethylene-based polymer, based on the total weight of the second region 204. At least 80 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of the weight of the blend may comprise the combination of the visbroken PCR ethylene-based polymers, the virgin ethylene-based polymer, and the polypropylene.

[0038] The second region 204 may comprise at least 80 wt. %, at least 90 wt. %, at least 95 wt. %, or at least 99 wt. % of the blend, on the basis of the total weight of the second region 204.

[0039] The second region 204 may comprise at least 80 wt. %, at least 90 wt. %, at least 95 wt. %, or at least 99 wt. % of the visbroken PCR ethylene-based polymer, on the basis of the total weight of the second region 204.

[0040] The visbroken PCR ethylene-based polymer may be formed from a base PCR ethylene-based polymer. Extrusion visbreaking is a thermal cracking process conducted in an extruder under shear to reduce the viscosity of a polymer resin.

[0041] The base PCR ethylene-based polymer may have been an HDPE, an LLDPE, or both.

[0042] The visbroken PCR ethylene-based polymer may have a density of 0.925 g / cm3to 0.970 g / cm3. In embodiments, the visbroken PCR ethylene-based polymer may have a density of 0.930 g / cm3to 0.970 g / cm3, 0.935 g / cm3to 0.970 g / cm3, 0.940 g / cm3to 0.970 g / cm3, 0.945 g / cm3to 0.970 g / cm3, 0.950 g / cm3to 0.970 g / cm3, 0.955 g / cm3to 0.970 g / cm3, 0.925 g / cm3to 0.965 g / cm3, 0.925 g / cm3to 0.960 g / cm3, 0.925 g / cm3to 0.955 g / cm3, 0.925 g / cm3to 0.950 g / cm3, 0.930 g / cm3to 0.965 g / cm3, 0.935 g / cm3to 0.960 g / cm3, 0.940 g / cm3to 0.955 g / cm3, or any subset thereof.

[0043] The visbroken PCR ethylene-based polymer may have an h at least 3 times greater than the I2 of the base PCR ethylene-based polymer resin. In embodiments, the visbroken PCR ethylene-based polymer may have an I2 at least 4 times greater, at least 5 times greater, at least 7 at least 8 times greater, at least 10 times greater, at least 12.5 times greater, at least 15 times greater, at least 17.5 times greater, at least 20 times greater, from 3 times to 50 times greater, from 5 times greater to 50 times greater, from 7 times greater to 50 times greater, from 10 times greater to 50 times greater, from 15 times greater to 50 times greater, from 18 times greater to 50 times greater, or any subset thereof greater than the I2 of the base PCR ethylene-based polymer resin.

[0044] The I2 of the visbroken PCR ethylene-based polymer may be at least 5 dg / min. In embodiments, the I2 of the visbroken PCR ethylene-based polymer may be at least 6 dg / min, at least 7 dg / min, at least 8 dg / min, at least 10 dg / min, from 5 dg / min to 50 dg / min, from 5 dg / min to 25 dg / min, from 5 dg / min to 15 dg / min, from 6 dg / min to 15 dg / min, from 8 dg / min to 15, from 10 dg / min to 20 dg / min, or any subset thereof.

[0045] The visbroken PCR ethylene-based polymer may have an Iio at least 5 times greater than the Iio of the base PCR ethylene-based polymer resin. In embodiments, the visbroken PCR ethylene-based polymer may have an Iio at least 6 times greater, at least 7 times greater, at least 8 times greater, at least 9 times greater, from 5 times greater to 20 times greater, from 8 times greater to 20 times greater, from 5 times greater to 15 times greater, from 8 times greater to 15 times greater, or any subset thereof greater than the Iio of the base PCR ethylenebased polymer resin.

[0046] The visbroken PCR ethylene-based polymer may have an Iio of at least 16 dg / min, such as at least 20 dg / min, at least 30 dg / min, at least 50 dg / min, at least 75 dg / min, at least 80 dg / min, at least 90 dg / min, at least 95 dg / min, at least 100 dg / min, from 20 dg / min to 200 dg / min, from 40 dg / min to 200 dg / min, from 80 dg / min to 200 dg / min, from 90 dg / min to 200 dg / min, from 40 dg / min to 160 dg / min, from 80 dg / min to 150 dg / min, from 90 dg / min to 120 dg / min, from 95 dg / min to 110 dg / min, or any subset thereof.

[0047] The visbroken PCR ethylene-based polymer may have a Yellowness index (YI) less than 4 times a YI of the at least one base PCR ethylene-based polymer resin. In embodiments, the YI of the visbroken PCR ethylene-based polymer may be less than 3 times, less than 2 times, less than 1.5 times, or even less than the YI of the at least one base PCR ethylene-based polymer resin.

[0048] The visbroken PCR ethylene-based polymer may have a YI of less than 50, such as less than 40, less than 30, less than 20, less than 15, or even less than 10.

[0049] The visbroken ethylene-based polymer may have a color coordinate (L) value of less than the L value of the at least one base PCR ethylene-based polymer resin, such as less than 100 %, less than 95 %, less than 90 %, less than 85 %, less than 80 %, or less than 75 % of the L value of the at least one base PCR ethylene-based polymer resin.

[0050] The visbroken PCR ethylene-based polymer may have a color coordinate (L) value of less than 100, such as less than 90, less than 80, less than 75, less than 70, less than 65, or less than 60.

[0051] The visbroken ethylene-based polymer may have an Mw / Mn, measured by GPC in the “Test Methods” section, of less than the Mw / Mn of the at least one base PCR ethylene-based polymer resin. Generally, visbreaking results in a decrease of the Mw / Mn of the polymer. In embodiments, the visbroken ethylene-based polymer may have an Mw / Mn of less 100 %, less than 97.5 %, less than 95 %, less than 90 %, less than 85 %, less than 80 %, less than 70 %, lessthan 60 %, or even less than 50 % of an Mw / Mn of the at least one base PCR ethylene-based polymer resin.

[0052] The visbroken PCR ethylene-based polymer may have an Mw / Mn, as measured by GPC in the “Test Methods” section, of less than 8, such as less than 6, less than 5, less than 4, less than 3, or less than 2.

[0053] Suitable visbroken PCR ethylene-based polymers, and their methods of making, are disclosed in U.S. Patent Appln. No. 63 / 579, 105, the entirety of which is incorporated herein by reference.

[0054] The visbroken PCR ethylene-based polymer may be produced by extrusion visbreaking the base PCR ethylene-based polymer resin in an extruder. The extruder may be a tandem system, a single screw extruder, a twin screw extruder, or the like. The extruder may be equipped with multilayer annular dies, flat film dies and feedblocks, multi-layer feedblocks, multi -vaned or multi-manifold dies such as a 3 -layer vane die. In embodiments, the extrusion visbreaking utilizes a twin screw extruder. The base PCR ethylene-based polymer resin may comprise at least 80 wt. % of polymers introduced into the extruder, such as at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or even at least 99.9 wt. %, on the basis of the total polymer weight introduced into the extruder. The base PCR ethylene-based polymer resin may comprise at least 80 wt. % of the material introduced into the extruder, such as at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, at least 99.9 wt. %, or even at least 99.99 wt. % of all material introduced into the extruder.

[0055] Without being limited by theory, the extrusion visbreaking process may introduce heat and mechanical energy (through the extruder) into the base PCR ethylene-based polymer resin. Generally, this energy may cause chain scission of the ethylene-based polymers in the base PCR ethylene-based polymer resin. It is believed that the chain scission may cause the melt index of the resin to increase and the molecular weights and Mw / Mn to decrease. The total mechanical energy input may be referred to as the specific energy input (SEI). SEI may be calculated from according to the equation SEIas unjts ofkW-hr / kg.

[0056] The specific energy input (SEI) may be from 0.4 kW-hr / kg polymer to 2.0 kW-hr / kg polymer. Without being limited by theory, it is believed that an SEI below this range may not cause sufficient chain scission to sufficiently increase the melt indices of the base ethylene-basedpolymer. Conversely, an SEI above this range may cause excessive chain scission and damage the mechanical properties of the base ethylene-based polymer. In embodiments, the SEI may be from 0.4 kW-hr / kg polymer to 1.8 kW-hr / kg polymer, from 0.4 kW-hr / kg polymer to 1.6 kW-hr / kg polymer, from 0.4 kW-hr / kg polymer to 1.4 kW-hr / kg polymer, from 0.4 kW-hr / kg polymer to 1.2 kW-hr / kg polymer, from 0.4 kW-hr / kg polymer to 1.0 kW-hr / kg polymer, from 0.4 kW-hr / kg polymer to 0.8 kW-hr / kg polymer, from 0.4 kW-hr / kg polymer to 0.6 kW-hr / kg polymer, from 0.6 kW-hr / kg polymer to 2.0 kW-hr / kg polymer, from 0.8 kW-hr / kg polymer to 2.0 kW-hr / kg polymer, from 1.0 kW-hr / kg polymer to 2.0 kW-hr / kg polymer, from 1.2 kW-hr / kg polymer to 2.0 kW-hr / kg polymer, from 1.4 kW-hr / kg polymer to 2.0 kW-hr / kg polymer, from 1.6 kW-hr / kg polymer to 2.0 kW-hr / kg polymer, from 1.8 kW-hr / kg polymer to 2.0 kW-hr / kg polymer, from 0.6 kW-hr / kg polymer to 1.8 kW-hr / kg polymer, from 0.8 kW-hr / kg polymer to 1.6 kW-hr / kg polymer, from 1.0 kW-hr / kg polymer to 1.4 kW-hr / kg polymer, or any subset thereof.

[0057] The extrusion visbreaking may occur at a temperature of at least 250 °C. Without being limited by theory, it is believed that if the visbreaking temperature is too low, such as less than 250 °C or less than 290 °C, it may be difficult for the extruder motor to add enough energy to the resin to accomplish the visbreaking. In embodiments, the extrusion visbreaking may occur at a temperature of at least 275 °C, at least 285 °C, at least 290 °C, at least 295 °C, from 250 °C to 350 °C, from 275 °C to 350 °C, from 285 °C to 350 °C, from 295 °C to 350 °C, from 275 °C to 325 °C, from 285 °C to 325 °C, from 295 °C to 325 °C, from 295 °C to 315 °C, from 295 °C to 305 °C, or any subset thereof.

[0058] The extrusion visbreaking may occur in an extruder, such as a twin screw extruder, at a screw speed of at least 350 revolutions per minute (RPM). Without being limited by theory, it is believed that a screw speed below this range may not introduce enough energy to cause sufficient chain scission to sufficiently increase the melt indices of the base ethylene-based polymer. The extrusion visbreaking may occur at a screw speed of at least 400 RPM, at least 500 RPM, at least 600 RPM, at least 700 RPM, at least 800 RPM, from 400 RPM to 1100 RPM, from 500 RPM to 1100 RPM, from 600 RPM to 1100 RPM, from 700 RPM to 1100 RPM, from 800 RPM to 1100 RPM, from 900 RPM to 1100 RPM, from 350 RPM to 1000 RPM, from 500 RPM to 1000 RPM, from 700 RPM to 1000 RPM from 800 RPM to 1000 RPM, or any subset thereof.

[0059] The extrusion visbreaking may have a residence time of from 30 seconds (sec) to 200 sec. Without being limited by theory, the amount of energy input into the resin is a function of the temperature, the extruder motor power (as is defined by screw speed), and theamount of time the resin is exposed to these conditions (the residence time). The extrusion visbreaking may have a residence time of from 30 sec to 180 sec, from 30 sec to 160 sec, from 30 sec to 140 sec, from 30 sec to 120 sec, from 30 sec to 100 sec, from 30 sec to 80 sec, from 30 sec to 60 sec, from 50 sec to 200 sec, from 70 sec to 200 sec, from 90 sec to 200 sec, from 110 sec to 200 sec, from 130 sec to 200 sec, from 150 sec to 200 sec, from 170 sec to 200 sec, from 50 sec to 180 sec, from 70 sec to 160 sec, from 90 sec to 140 sec, from 110 sec to 130 sec, or any subset thereof.

[0060] The extrusion visbreaking may occur in the absence of oxygen. Without being limited by theory, it is believed that extrusion visbreaking in the absence of oxygen results in a lower percentage of aldehydes in the visbroken PCR ethylene-based polymer than extrusion visbreaking in the presence of oxygen. Aldehydes are organoleptic and can cause taste and odor issues in many applications including food storage containers Accordingly, decreasing the production of aldehydes is a significant benefit. Generally, the concentration of oxygen may be reduced through the use of a vacuum or by replacing the oxygen with another gas, such an inert gas (e.g., nitrogen, helium, argon, krypton, neon, or xenon). The gas in the extruder may have an oxygen partial pressure of less than 3 psi, such as less than 2 psi, less than 1 psi, less than 0.5 psi, less than 0.1 psi, or even less than 0.01 psi. The gas in the extruder may be at least 80 mol. % of inert gas, such as at least 90 mol. %, at least 95 mol. %, at least 99 mol. %, at least 99.9 mol. %, at least 99.99 mol. %, or even at least 99.999 mol. % of inert gas, on the basis of the total moles of gas in the extruder.

[0061] In some embodiments, the visbreaking process may comprise a devolatization step. This devolatilization may be carried out using any conventional devolatilization means and methods, including, in non-limiting embodiments, use of extruder reactors and / or kneader reactors, and methods including, for example, direct separation, main evaporation bulk evaporation, steam stripping, and / or direct devolatilization. In embodiments, the devolatization step may occur in the extruder during the extrusion visbreaking step or after the extrusion visbreaking step in a separate extruder. In embodiments, the devolatization process is driven by superheating the volatile component of the polymer melt, then subsequently exposing the melt to a rapid decompression. Devolatization may be performed on screw extruders, including single-screw or multi-screw extruders. A typical devolatization zone in a screw extruder consists of a portion of a screw that is partially filled, isolated by two sections that are filled with melt / solution. A stripping agent may be used in the extruder.In aspects, the stripping agent used in the extruder may be selected from the group consisting of: water, carbon dioxide, nitrogen, and a hydrocarbon gas. The stripping agent used in the extruder may be selected from the group consisting of water and carbon dioxide. The stripping agent used in the extruder may be water.

[0062] Devolatilizing the visbroken PCR ethylene-based polymer may produce a devolatilized visbroken PCR ethylene-based polymer. The devolatilized visbroken PCR ethylene-based polymer may have a concentration of volatile organic compounds (VOCs) at least 50 % lower, such as at least 75 %, at least 80 %, at least 85 %, at least 90 %, at least 95 %, or even at least 99 % lower than the concentration of VOCs in the visbroken PCR ethylenebased polymer as the visbroken PCR ethylene-based polymer exits the extrusion visbreaking process. In embodiments, no properties of the visbroken PCR ethylene-based polymer, other than the VOC concentration, may change by more than 10 %, such as more than 5 %, more than 3 %, or more than 1 % during the devolatization process.

[0063] The extrusion visbreaking may occur without the presence of reaction aids (such as catalysts, peroxides, or radical initiators). The reaction aids may include metal salts, carboxylates (such as metal carboxylates, such as stearates), metal halides (such as chlorides), metal oxides and zeolites. Non-limiting examples include zinc, aluminum, manganese, cobalt, chromium, iron, calcium and magnesium, carboxylates thereof, chlorides thereof, and oxides thereof. The concentration of the reaction aids may be from 0 wt. % to 1 wt. %, from 0 wt. % to 0.5 wt. %, from 0 wt. % to 0.1 wt. %, from 0 wt. % to 0.01 wt. %, from 0 wt. % to 0.001 wt. %, from 0 wt. % to 0.0001 wt. %, from 0 wt. % to 0.000001 wt. %, or even from 0 wt. % to 0.0000000001 wt. % on the basis of the total polymer weight of the at least one base PCR ethylenebased polymer resin.

[0064] In addition to the visbroken polypropylene, the fiber 10 (such as in the blend) may further comprise a virgin ethylene-based polymer. In embodiments, the virgin ethylene-based polymer may be an HDPE or an LLDPE.

[0065] The virgin ethylene-based polymer may have a density of 0.900 g / cm3to 0.975 g / cm3, such as 0.905 g / cm3to 0.975 g / cm3, 0.910 g / cm3to 0.975 g / cm3, 0.915 g / cm3to 0.975 g / cm3, 0.920 g / cm3to 0.975 g / cm3, 0.925 g / cm3to 0.975 g / cm3, 0.930 g / cm3to 0.975 g / cm3, 0.935 g / cm3to 0.975 g / cm3, 0.940 g / cm3to 0.975 g / cm3, 0.945 g / cm3to 0.975 g / cm3, 0.950 g / cm3to 0.975 g / cm3, 0.955 g / cm3to 0.975 g / cm3, 0.960 g / cm3to 0.975 g / cm3, 0.900 g / cm3to 0.970 g / cm3, 0.900 g / cm3to 0.965 g / cm3, 0.900 g / cm3to 0.960 g / cm3, 0.900 g / cm3to 0.955g / cm3, 0.900 g / cm3to 0.950 g / cm3, 0.900 g / cm3to 0.945 g / cm3, 0.900 g / cm3to 0.940 g / cm3, 0.900 g / cm3to 0.935 g / cm3, 0.905 g / cm3to 0.970 g / cm3, 0.915 g / cm3to 0.960 g / cm3, 0.925 g / cm3to 0.950 g / cm3, or any subset thereof.

[0066] The virgin ethylene-based polymer may have a melt index (h) of at least 5 dg / 10 min, such as at least 6 dg / 10 min, at least 7 dg / 10 min, at least 8 dg / 10 min, at least 9 dg / 10 min, at least 10, from 5 dg / 10 min to 50 dg / 10 min, from 5 dg / 10 min to 40 dg / 10 min, from 5 dg / 10 min to 30 dg / 10 min, from 5 dg / 10 min to 20, from 8 dg / 10 min to 50 dg / 10 min, from 8 dg / 10 min to 30 dg / 10 min, from 8 dg / 10 min to 20 dg / 10 min, from 8 dg / 10 min to 15 dg / 10 min, or any subset thereof.

[0067] Referring again to FIG. 2, the first region 206, the second region 204, or both may include polypropylene. The polypropylene may be present alone in the first region 206 or the second region 204. In embodiments, the polypropylene may be blended with the visbroken PCR ethylene-based polymer, the virgin ethylene-based polymer, or both. The polypropylene may be a visbroken polypropylene (e.g., one which has been subjected to the extrusion visbreaking process described herein). The polypropylene, such as the visbroken polypropylene, may have a melting temperature of at least 150 °C, at least 160 °C, at least 170 °C, at least 180 °C, at least 190 °C, or at least 200 °C. The polypropylene, such as the visbroken polypropylene, may have a Melt Index (I2) from 10 g / 10 min. to 100 g / 10 min., from 15 g / 10 min. to 75 g / 10 min., from 20 g / 10 min. to 50 g / 10 min., or from 22 g / 10 min. to 28 g / 10 min., as determined by ASTM D1238 at 230 °C and 2.16 kg.

[0068] The polypropylene present in the first region 206 or the second region 204 may be a propylene homopolymer.

[0069] The monocomponent fiber 100, the first region 206 of the bi-component fiber 200, and / or the second region 204 of the bi-component fiber 200 can additionally include small amounts of additives including plasticizers, stabilizers including viscosity stabilizers, hydrolytic stabilizers, primary and secondary antioxidants, ultraviolet light absorbers, antistatic agents, dyes, pigments or other coloring agents, inorganic fillers, fire-retardants, lubricants, reinforcing agents such as glass fiber and flakes, foaming or blowing agents, processing aids, slip additives, antiblock agents such as silica or talc, release agents, tackifying resins, or combinations of two or more thereof. Inorganic fillers, such as calcium carbonate, and the like can also be incorporated into the monocomponent fiber 100, the firstregion 206 of the bi-component fiber 200, and / or the second region 204 of the bi-component fiber 200.

[0070] These additives may be present in the monocomponent fiber 100, the first region 206 of the bi-component fiber 200, and / or the second region 204 of the bi-component fiber 200 in quantities ranging from 0.001 wt.% to 5 wt.%, from 0.001 wt.% to 2.5 w.t%, from 0.001 wt.% to 1 wt.%, from 0.001 wt.% to 0.1 wt.%, or from 0.001 wt.% to 0.01 wt.%, on the basis of the total weight of the monocomponent fiber 100, the first region 206 of the bi-component fiber 200, and / or the second region 204 of the bi-component fiber 200. The incorporation of the additives can be carried out by any known process such as, for example, by dry blending, by extruding a mixture of the various constituents, by the conventional masterbatch technique, or the like.

[0071] The fiber 10 may have a thickness of from 1 dtex to 10 dtex, such as from 2 dtex to 10 dtex, from 4 dtex to 10 dtex, from 6 dtex to 10 dtex from 8 dtex to 10 dtex, from 1 dtex to 8 dtex, from 1 dtex to 6 dtex, from 1 dtex to 4 dtex, from 1 dtex to 2 dtex, from 2 dtex to 8 dtex, from 4 dtex to 6 dtex, or any subset thereof.

[0072] The fiber 10 may have a tenacity at break of at least 0.1 cN / dtex, such as at least 0.3 cN / dtex, at least 0.5 cN / dtex, at least 0.8 cN / dtex, at least 1 cN / dtex, from 0.1 cN / dtex to 5 cN / dtex, from 0.1 cN / dtex to 3 cN / dtex, from 0.1 cN / dtex to 2 cN / dtex, or any subset thereof.

[0073] The fiber 10 may have a strain at break of at least 200 %, such as at least 250 %, at least 300 %, at least 350 %, at least 400 %, at least 450 %, at least 500 %, from 200 % to 1000 %, from 250 % to 1000 %, or any subset thereof.

[0074] An article may comprise the fiber 10. In embodiments, the article may be a nonwoven fabric comprising the fiber 10.TEST METHODS

[0075] Melt Flow index

[0076] Melt Index (h) of polyethylenes is measured in accordance with ASTM D 1238-10 at 190 °C and 2.16 kg, Method B, and is expressed in grams eluted / 10 minutes (g / 10 min).

[0077] Melt Index (I2) of polypropylenes is measured in accordance with ASTM D 1238-10 at 230 °C and 2.16 kg, Method B, and is expressed in grams eluted / 10 minutes (g / 10 min).

[0078] Melt Flow index (I10)

[0079] Melt Index (Iio) of polyethylenes is measured in accordance with ASTM D 1238-10 at 190 °C and 10 kg, Method B, and is expressed in grams eluted / 10 minutes (g / 10 min).

[0080] Melt Index (Iio) of polypropylene is measured in accordance with ASTM D 1238-10 at 230 °C and 10 kg, Method B, and is expressed in grams eluted / 10 minutes (g / 10 min).

[0081] Density

[0082] Density is measured according to ASTM D792.

[0083] Dynamic Mechanical Spectroscopy (DMS)

[0084] Resins were compression-molded into “3 mm thick x 1 inch” circular plaques at 177°C, for five minutes, under 25,000 psi pressure, in air. The sample was then taken out of the press and placed on a counter to cool.

[0085] A constant temperature frequency sweep was performed using a TA Instruments “Advanced Rheometric Expansion System (ARES),” equipped with 25 mm (diameter) parallel plates, under a nitrogen purge. The sample was placed on the plate, and allowed to melt for five minutes at 190°C. The plates were then closed to a gap of “2 mm,” the sample trimmed (extra sample that extends beyond the circumference of the “25 mm diameter” plate was removed), and then the test was started. The method had an additional five minute delay built in, to allow for temperature equilibrium. The experiments were performed at 190 °C over a frequency range of 0.1 to 100 rad / s. The strain amplitude was constant at 10%. The complex viscosity q*, tan (5) or tan delta, viscosity at 0.1 rad / s (V0.1), the viscosity at 100 rad / s (V100), the viscosity ratio (V0.1 / V100), and the tan delta at 0.1 rad / s were calculated from these data.

[0086] Yell.owness lndgx

[0087] Yellowness Index (YI) values were determined on pellets using ASTM D6290-05 (Method Title: Standard Test Method for Color Determinations of Plastic Pellets). The yellowness index (YI) is an instrumental measurement, using a BYK-Gardner Model 9000 spectrophotometer with sample rotator of the degree of yellowness (or change of degree of yellowness) under daylight illumination of homogeneous, nonfluorescent, nearly-colorless transparent or nearly-white translucent or opaque plastics. The measurement was made on pellets (250 g), and based on values obtained with a colorimeter. The test method is applicable to the color analysis of plastic pellets. Color in the polymer was primarily due to organic impurities. Inorganic impurities may also affect the color.

[0088] Color Coordinate (L)

[0089] Color coordinate (L) values were determined on pellets using ASTM D6290-05 (Method Title: Standard Test Method for Color Determinations of Plastic Pellets).

[0090] Gel Permeation Chromatography

[0091] Details of the GPC method can be found in U.S. Patent Application Number 17 / 632598, which is incorporated by reference herein. The chromatographic system utilized a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph equipped with an internal IR5 infra-red detector (IR5). The autosampler oven compartment was set at 160° Celsius and the column compartment was set at 150° Celsius. The columns used were 4 Agilent “Mixed A” 30cm 20-micron linear mixed-bed columns. The chromatographic solvent used was 1,2,4 tri chlorobenzene and contained 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters and the flow rate was 1.0 milliliters / minute.

[0092] Calibration of the GPC column set was performed with 21 narrow molecular weight distribution polystyrene standards with molecular weights ranging from 580 to 8,400,000 and were arranged in 6 “cocktail” mixtures with at least a decade of separation between individual molecular weights. The standards were purchased from Agilent Technologies. The polystyrene standards were prepared at 0.025 grams in 50 milliliters of solvent for molecular weights equal to or greater than 1,000,000, and 0.05 grams in 50 milliliters of solvent for molecular weights less than 1,000,000. The polystyrene standards were pre-dissolved at 80 °C with gentle agitation for 30 minutes then cooled and the room temperature solution is transferred cooled into the autosampler dissolution oven at 160°C for 30 minutes. The polystyrene standard peak molecular weights were converted to polyethylene molecular weights using Equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)).:

[0093] ^polyethylene A X Mpolystyrene)' (EQI)

[0094] where M is the molecular weight, A has a value of 0.4049 and B is equal to 1.0.

[0095] A fifth order polynomial was used to fit the respective polyethylene-equivalent calibration points.

[0096] The total plate count of the GPC column set was performed with decane which was introduced into blank sample via a micropump controlled with the PolymerChar GPC-IRsystem. The plate count for the chromatographic system should be greater than 18,000 for the 4 Agilent “Mixed A” 30cm 20-micron linear mixed-bed columns.

[0097] Samples were prepared in a semi-automatic manner with the PolymerChar “Instrument Control” Software, wherein the samples were weight-targeted at 2 mg / ml, and the solvent (contained 200ppm BHT) was added to a pre nitrogen-sparged septa-capped vial, via the PolymerChar high temperature autosampler. The samples were dissolved for 2 hours at 160° Celsius under “low speed” shaking.

[0098] The calculations of Mn, Mw, and Mz were based on GPC results using the internalIR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph according to Equations 2-4, using PolymerChar GPCOne™ software, the baseline-subtracted IR chromatogram at each equally-spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve for the point(i) from Equation 1.

[0102] In order to monitor the deviations over time, a flowrate marker (decane) was introduced into each sample via a micropump controlled with the PolymerChar GPC-IR system. This flowrate marker (FM) was used to linearly correct the pump flowrate (Flowrate(nominal)) for each sample by RV alignment of the respective decane peak within the sample (RV(FM Sample)) to that of the decane peak within the narrow standards calibration (RV(FM Calibrated)). Any changes in the time of the decane marker peak are then assumed to be related to a linear-shift in flowrate (Flowrate(effective)) for the entire run. After calibrating the system based on a flow marker peak, the effective flowrate (with respect to the narrow standards calibration) is calculated as Equation 5. Processing of the flow marker peak was done via the PolymerChar GPCOne™ Software. Acceptable flowrate correction is such that the effective flowrate should be within + / -0.5% of the nominal flowrate.

[0103] Flowrate(effective) = Flowrate(nominal) * (RV(FM Calibrated) / RV(FM Sample)) (EQ 5)

[0104] Tenacity at Break and Strain at Break

[0105] The tenacity at break and strain at break of the fiber yarns are tested by an Instron tensile machine. The fiber yarns are stretched by the Instron tensile machine and force vs. strain curve is recorded. The strain is calculated as displacement / initial gauge length. The initial gauge length is set at 10 cm and the tensile speed is 24 cm / min. The peak force (maximum force) from the force vs. strain curve is used to calculate the tenacity at break (tenacity at break = peak force / fiber yarn thickness). The strain at the peak force on the curve is reported as the strain at break. The unit of peak force is centi Newton (cN) and the unit of fiber yarn thickness is dtex. The fiber yarn thickness is measured by weighing 10-cm long unstretched fiber yarn and calculated as fiber yarn thickness = grams of 10-cm long unstretched fiber yarn x 100000. Single fiber thickness can be calculated as fiber yarn thickness / the number of fibers of the fiber yarn.EXAMPLES

[0106] Materials:

[0107] The following materials were used in the examples. Rheology for each of the materials is shown in Table 1.

[0108] KWR101-150 (referred to as “KWR”) is a recycled HDPE resin with a density of 0.960 g / cc and a melt index (h) of 0.6 g / 10 minutes, commercially available from KW Plastics, Troy, AL.

[0109] Envision Ecoprime™ (referred to as “EE”) is a food safe, recycled resin with a density of 0.961 g / cc and a melt index (I2) of 0.6, commercially available from Envision Plastics.

[0110] The visbroken resins were subjected to extrusion visbreaking in a twin screw extruder at 300 °C, 900 RPM, 10 pph feed, an average residence time of 81s, and an average specific energy input (SEI) of 1.72. The visbroken form of each resin is referred to in the tables as V-resin name, for example visbroken EE is referred to as “V-EE”)

[0111] PP is a polypropylene (ExxonMobil™ PP3155E5) manufactured by ExxonMobil.

[0112] ASPUN™ 6850A (referred to as “6850A”) is a polyethylene resin with a density of 0.955 g / cc and melt index (I2) of 30 g / 10 min, commercially available from Dow Inc., Midland MI.

[0113] ASPUN™ AT 2135 (referred to as “2135”) is a polyethylene resin with a density of 0.935 g / cc and melt index (I2) of 21 g / 10 min, commercially available from Dow Inc., Midland MI.Table 1

[0114] Formation of Fibers

[0115] Fibers were spun on a Hills Bicomponent Continuous Filament Fiber Spinning Line. Extruder profiles were adjusted to achieve a melt temperature of 230°C. The throughput rate of each hole was 0.6 ghm (grams per hole per minute). A Hills Bi-component die was used and operated at a 50 / 50 core / sheath ratio (in weight) with the first region (core) comprising a polymer in one extruder and second region (sheath) comprising another polymer in the other extruder. The bi-component fibers were obtained by feeding the polypropylene (such as ExxonMobil PP 3155E5) in the core extruder and polyethylene (such as the visbroken PCR ethylene-based polymer, the virgin ethylene-based polymer, or the blend of the visbroken PCR ethylene-based polymer and the virgin ethylene-based polymer) in the sheath extruder. The mono-component fibers were obtained by feeding the same material (such as the visbroken PCR ethylene-based polymer, the virgin ethylene-based polymer, or the blend of the visbroken PCR ethylene-based polymer and the virgin ethylene-based polymer) in both extruders. The die had 144 holes, with each hole having a diameter of 0.6 mm and a length / diameter (L / D) of 4 / 1. Quench air temperature and flow rate were set at 15-18 °C, and 520 cfm (cubic feet per minute), respectively.

[0116] After the quenching zone, the 144 filaments were stretched into thin fibers in either a pneumatic stretching process or a mechanical stretching process.

[0117] In the pneumatic stretching process, a draw tension was applied on the 144 filaments by pneumatically entraining the filaments in a slot unit with an air stream. The velocity of the air stream was controlled by the slot aspirator pressure. For each example, a higher velocity of the air stream can be achieved by using a higher slot aspirator pressure. A higher velocity of the air stream also results in thinner fibers. However, too high of a velocity of the air stream (or too high slot pressure) will break the fibers. The fibers were collected at the maximum slot pressure before the fiber break was seen.

[0118] In the mechanical stretching process, the 144 filaments were guided into and stretched between a set of rotating godets (denier roll, feed roll, draw roll) having different rotating speeds. The fibers were stretched between the denier roll, feed roll and draw roll, before being collected on a bobbin with a winder.

[0119] Pneumatically Drawn Monocomponent fibers

[0120] Details of each of the monocomponent, pneumatically stretched fibers are given in Table 2.Table 2

[0121] As can be seen in Table 2, fibers were successfully produced from visbroken PCR ethylene-based polymers.

[0122] Mechanically Drawn Monocomponent Fibers

[0123] Monocomponent fibers were also fabricated through a mechanical drawing process using godets, as described above. The production conditions are given in Table 3 and the properties of the resulting fibers are given in Table 4.Table 3Table 4 j

[0124] Pneumatic Bi-component Fiber

[0125] Bi-component fibers were produced by a pneumatic drawing process as described above. These fibers are described in Table 5.Table 5

[0126] Mechanically .Drawn Bi-component

[0127] Bi-component fibers were also fabricated through a mechanical drawing process using godets as described above. The production details are given in Table 6 and the properties of the resulting fibers are given in Table 7.Table 6Table 7

Claims

CLAIMS1. A fiber comprising: visbroken post-consumer recycled (PCR) ethylene-based polymer having a density of 0.925 g / cm3to 0.970 g / cm3and a melt index (h) of at least 5 dg / 10 min., as determined by ASTM D1238 at 190 °C and 2.16 kg.

2. The fiber of claim 1, wherein the fiber comprises a blend, the blend comprising the visbroken PCR ethylene-based polymer and a virgin ethylene-based polymer having a density of 0.900 g / cm3to 0.975 g / cm3and a melt index (I2) of at least 5 dg / 10 min., as determined by ASTM D1238 at 190 °C and 2.16 kg.

3. The fiber of any preceding claim, wherein the fiber has a thickness of from 1 to 10 dtex.

4. The fiber of any preceding claim, wherein the fiber is a bi-component fiber comprising a core and a sheath, wherein the sheath comprises at least 5 wt. % of the visbroken PCR ethylene-based polymer, based on the total weight of the sheath.

5. The fiber of claim 4, wherein the sheath comprises at least 90 wt. % of the visbroken resin, based on the total weight of the sheath.

6. The fiber of claim 4 or claim 5, wherein the core comprises polypropylene.

7. The fiber of any of claim 1 to claim 3, wherein the fiber is a monocomponent fiber and the monocomponent fiber comprises at least 5 wt. % of the visbroken PCR ethylene-based polymer, based on the total weight of the monocomponent fiber.

8. The fiber of claim 7, wherein the monocomponent fiber comprises at least 90 wt. % of the visbroken PCR ethylene-based polymer, based on the total weight of the monocomponent fiber.

9. The fiber of any preceding claim, wherein the visbroken PCR ethylene-based polymer has a Mw / Mn, as measured by GPC, of less than 6.

10. An article comprising the fiber of any preceding claim.

11. The article of claim 10, wherein the article is a non-woven fabric.

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