Bicomponent fiber with component

Abstract

The present disclosure provides a fiber. In an embodiment a fiber is provided and includes a first region and a second region. A component is present in at least one of the first region and the second region. The component is composed of (i) a post-industrial resin (FIR) and (ii) a low density polyethylene (LDPE).

Description

BICOMPONENT FIBER WITH COMPONENTBACKGROUND

[0001] Polyethylene fiber grade resins are designed for the fiber spinning process in order to enable excellent spinnability. Polyethylene fiber is used in making nonwoven fabrics through the spunbond process. In general, polyethylene (PE) is spun with polypropylene (PP) in a bicomponent fiber configuration with PP being the core and PE being the sheath. Edges of the nonwoven web (typically 10-15 wt% of the production) need to be trimmed off due to poor fiber laydown quality and the trimmed edges are usually scrapped. Recycling the trimmed edges into the spunbond production is desired by the spunbond converters. Currently, only low levels of the trimmed edges (also known as regrind) (4 wt% or less) can be incorporated back on commercial fiber spinning production lines without sacrificing the spinning process, due to significant fiber breaks. Also, it is not possible currently to recover core material and sheath material separately for recycling.

[0002] Hence, a need exists for increasing the amount of fiber regrind (and PE / PP fiber regrind in particular) back into a fiber without causing fiber breaks during spinning.SUMMARY

[0003] The present disclosure provides a fiber. In an embodiment, a fiber is provided and the fiber includes a first region and a second region. A component is present in at least one of the first region and the second region. The component includes (i) a post-industrial resin (PIR) and (ii) a low density polyethylene (LDPE).BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a schematic representation of a fiber spinning process.DEFINITIONS

[0005] Any reference to the Periodic Table of Elements is that as published by CRC Press, Inc., 1990-1991. Reference to a group of elements in this table is by the new notation for numberinggroups.

[0006] For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent US version is so incorporated by reference) especially with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure) and general knowledge in the art.

[0007] The numerical ranges disclosed herein include all values from, and including, the lower and upper value. For ranges containing explicit values (e.g., a range from 1, or 2, or 3 to 5, or 6, or 7), any subrange between any two explicit values is included (e.g., the range 1-7 above includes subranges 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6; etc.).

[0008] Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight and all test methods are current as of the filing date of this disclosure.

[0009] The terms "comprising", "including", "having" and their derivatives do not exclude the presence of any additional component or procedure. The term, "consisting essentially of" excludes any other component or procedure, except those essential to operability. The term "consisting of" excludes any component or procedure not specifically stated.

[0010] Decitex (or dtex) is the fiber weight in grams of 10,000 meters (m) fiber length.

[0011] The term "denier" is the linear mass density of a fiber. Denier is defined as the grams of the fiber per 9000 meters of the fiber length.

[0012] An "ethylene-based polymer" is a polymer that contains more than 50 mole percent (wt%) polymerized ethylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer. Ethylene-based polymer includes ethylene homopolymer, and ethylene copolymer (meaning units derived from ethylene and one or more comonomer). The terms "ethylene-based polymer" and "polyethylene" may be used interchangeably. Nonlimiting examples of ethylene-based polymer (polyethylene) include low density polyethylene (LDPE) and linear polyethylene. Nonlimiting examples of linear polyethylene include linear low density polyethylene (LLDPE), ultra low density polyethylene (ULDPE), very low density polyethylene (VLDPE), multi-component ethylene-based copolymer(EPE), ethylene / a-olefin multi-block copolymers (also known as olefin block copolymer (OBC)), substantially linear, or linear, plastomers / elastomers, and high density polyethylene (HDPE). Generally, polyethylene may be produced in gas-phase, fluidized bed reactors, liquid phase slurry process reactors, or liquid phase solution process reactors, using a heterogeneous catalyst system, such as Ziegler-Natta catalyst, a homogeneous catalyst system, comprising Group 4 transition metals and ligand structures such as metallocene, non-metallocene metalcentered, heteroaryl, heterovalent aryloxyether, phosphinimine, and others. Combinations of heterogeneous and / or homogeneous catalysts also may be used in either single reactor or dual reactor configurations.

[0013] High density polyethylene (or "HDPE") is an ethylene homopolymer or an ethylene / a-olefin copolymer with at least one C4-C10a-olefin comonomer, or C4-C8a-olefin comonomer and a density from 0.940 g / cc, or 0.945 g / cc, or 0.950 g / cc, 0.953 g / cc to 0.955 g / cc, or 0.960 g / cc, or 0.965 g / cc, or 0.970 g / cc, or 0.975 g / cc, or 0.980 g / cc. The HDPE can be a monomodal copolymer or a multimodal copolymer. A "monomodal ethylene copolymer" is an ethylene / C4-C10a-olefin copolymer that has one distinct peak in a gel permeation chromatography (GPC) showing the molecular weight distribution. A "multimodal ethylene copolymer" is an ethylene / C4-C10a-olefin copolymer that has at least two distinct peaks in a GPC showing the molecular weight distribution. Multimodal includes copolymer having two peaks (bimodal) as well as copolymer having more than two peaks. Nonlimiting examples of HDPE include DOW™ High Density Polyethylene (HDPE) Resins (available from The Dow Chemical Company), CONTINUUM™ Bimodal Polyethylene Resins (available from The Dow Chemical Company), LUPOLEN™ (available from LyondellBasell), as well as HDPE products from Borealis, Ineos, and ExxonMobil.

[0014] "Low density polyethylene" (or "LDPE") may also be referred to as "high pressure ethylene polymer" or "highly branched polyethylene" and consists of ethylene homopolymer, or ethylene / a-olefin copolymer comprising at least one C3-C10a-olefin that has a density from 0.915 g / cc to less than 0.935g / cc and contains long chain branching. LDPE is typically produced by high pressure free radical polymerization (tubular reactor or autoclave reactor with free radical initiator). LDPE resins typically have a density in the range from 0.915 g / cc to 0.935g / cc. Nonlimiting examples of LDPE include Marlex™ (Chevron Phillips), LUPOLEN™ (LyondellBasell), as well as LDPE products from Dow, Borealis, Ineos, ExxonMobil, and others. Low density polyethylene (LDPE), is distinct from, and excludes, linear low density polyethylene.

[0015] "Linear low density polyethylene" (or "LLDPE") is a linear ethylene / a-olefin copolymer containing heterogeneous short-chain branching distribution comprising units derived from ethylene and units derived from at least one C3-C10a-olefin comonomer. LLDPE is characterized by little, if any, long chain branching, in contrast to conventional LDPE. LLDPE has a density from 0.910 g / cc to less than 0.940 g / cc. Nonlimiting examples of LLDPE include TUFLIN™ linear low density polyethylene resins (available from The Dow Chemical Company), DOWLEX™ polyethylene resins (available from the Dow Chemical Company), FINGERPRINT™ polyethylene resins (available from the Dow Chemical Company), and MARLEX™ polyethylene (available from Chevron Phillips). LLDPE is distinct from and excludes LDPE.

[0016] The term "meltblown" refers to the fabrication of nonwoven fabrics via a process which generally includes the following steps: (a) extruding molten thermoplastic strands from a spinneret; (b) simultaneously quenching and attenuating the polymer stream immediately below the spinneret using streams of high velocity heated air; (c) collecting the drawn strands into a web on a collecting surface. Meltblown webs can be bonded by a variety of means including, but not limited to, autogeneous bonding, i.e., self bonding without further treatment, thermo-calendaring process, adhesive bonding process, hot air bonding process, needle punch process, hydroentangling process, and combinations thereof.

[0017] The terms "nonwoven," "nonwoven web," and "nonwoven fabric" are used herein interchangeably. "Nonwoven" refers to a web or fabric having a structure of individual fibers or threads which are randomly interlaid, but not in an identifiable manner as is the case for a knitted fabric.

[0018] An "olefin-based polymer" is a polymer that contains a majority mole percent polymerized olefin monomer (based on total amount of polymerizable monomers), and optionally, may contain at least one comonomer. Nonlimiting examples of olefin-based polymers include ethylene-based polymer and propylene-based polymer.

[0019] The term "polymer" is a macromolecular compound prepared by polymerizing monomers of the same or different type. "Polymer" includes homopolymers, copolymers, terpolymers, interpolymers, and so on. The term "interpolymer" is a polymer prepared by the polymerization of at least two types of monomers or comonomers. It includes, but is not limited to, copolymers (which usually refers to polymers prepared from two different types of monomers or comonomers, terpolymers (which usually refers to polymers prepared from three different types of monomers or comonomers), tetrapolymers (which usually refers to polymers prepared from four different types of monomers or comonomers), and the like.

[0020] A "propylene-based polymer" is a polymer that contains a majority amount of polymerized propylene based on the weight of the polymer and, optionally, may comprise at least one comonomer. Propylene-based polymers typically comprise at least 50 mole percent (mol%) units derived from propylene (based on the total amount of polymerizable monomers.

[0021] The term "spunbond" refers to the fabrication of nonwoven fabric including the following steps: (a) extruding molten thermoplastic strands from a plurality of fine capillaries called a spinneret; (b) quenching the strands with a flow of air which is generally cooled in order to hasten the solidification of the molten strands; (c) attenuating the strands by advancing them through the quench zone with a draw tension that can be applied by either pneumatically entraining the strands in an air stream or by winding them around mechanical draw rolls of the type commonly used in the textile fibers industry; (d) collecting the drawn strands into a web on a foraminous surface (e.g., moving screen or porous belt); and (e) bonding the web of loose strands into a nonwoven fabric. Bonding can be achieved by a variety of means including, but not limited to, thermo-calendaring process, adhesive bonding process, hot air bonding process, needle punch process, hydroentangling process, and combinations thereof.TEST METHODS

[0022] Density. Density was measured by the displacement (Archimedes) method, ASTM method D792 Method B. A sample was weighed in air (dry weight) and immersed in a fluid (wet weight). Knowing the density of the immersion fluid, the loss in weight of the sample onimmersion allows the sample density to be calculated. A sheet of material is molded under per ASTM D4703 per Annex A.l Procedure C (15°C cooling). On removal from the press, 3 (three) coupons (~1.5" x ~0.5" x ~0.125") were cut from the sheet and density is measured. For Method B, the samples were weighed in air and then immersed in the fluid. The fluid (IPA, isopropyl alcohol) was contained in a double walled vessel and the temperature was controlled to 23°C + / - 0.1°C. The samples were allowed to soak in the fluid for 8 minutes to ensure the samples had equilibrated to the bath temperature. The samples were then weighed while still immersed in the fluid. A glass sinker of known dry weight and volume was then weighed while immersed in the fluid. The density of the immersion fluid was calculated from the known and measured values for the glass sinker (this corrects for any small deviations in the fluid density in the allowable temperature range). The non-annealed density of the samples may then be calculated from the known fluid density and the measured wet and dry sample weights.

[0023] Differential Scanning Calorimetry (DSC). Differential scanning calorimetry is a common technique that can be used to examine the melting and crystallization of semicrystalline polymers. General principles of DSC measurements and applications of DSC to studying semi-crystalline polymers are described in standard texts (e.g., E. A. Turi, ed., Thermal Characterization of Polymeric Materials, Academic Press, 1981).

[0024] DSC analysis was determined using DSC from TA Instruments, Inc (or other suppliers). Calibration of the DSC is done as follows. First, instrument baseline needed to be calibrated using standard procedure for the DSC. Then about 5-7 milligrams of a fresh indium sample were analyzed by heating the sample to 180°C, cooling the sample to 140°C at a cooling rate of 10°C / min followed by keeping the sample isothermally at 140°C for 1 minute, followed by heating the sample from 140°C to 180°C at a heating rate of 10°C / min. The heat of fusion and the onset of melting of the indium sample were determined and checked to be within 0.5°C from 156.6°C for the onset of melting and within 0.5 J / g from 28.57 J / g for the heat of fusion. The polyethylene samples were pressed into a thin film at a temperature of 190°C. About 5 to 8 mg of sample was weighed out and placed in the DSC pan. The lid was crimped on the pan to ensure a closed atmosphere. In reference to ASTM standard D3418, the DSC test was conducted using a heat-cool-heat cycle. First the sample was heated to 230°C with at a rate of10°C / min and held isothermally for 5 minutes to remove thermal and process history. The sample was then quenched to -40°C at a rate of 10°C / minute and held isothermally once again for 5 minutes. Lastly, the sample was heated at a rate of 10°C / min. to 230°C for the second heating cycle. The resulting enthalpy curves were analyzed for peak melt temperature, onset and peak crystallization temperatures, and the total heat of fusion (also known as heat of melting), AHf. The total heat of fusion, in Joules / gram, was measured by integrating the area under the melting endotherm (second heat) from -20°C to the end of melting by using a linear baseline. Heat of fusion of 100% crystalline polyethylene was taken to be 292 Joules / gram to calculate wt% crystallinity. The DSC tests were performed using the TA Instruments Discovery DSC, and data analyses were conducted via TA Instruments Universal Analysis and TRIOS software packages.

[0025] Fiber Spinning. Fibers were spun on a Hills Bicomponent Continuous Filament Fiber Spinning Line at a throughput rate of 0.6 ghm (grams per hole per minute). A Hills Bicomponent die was used to operate at a 70 / 30 core / sheath ratio. Extruder profiles were adjusted to achieve a melt temperature of 230 °C for sheath and 250 °C for core material. The die configuration consisted of 144 holes, with a hole diameter of 0.6 mm. The hole has a 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. After the quenching zone, a draw tension was applied on the 144 filaments by pneumatically entraining the filaments in a slot unit with an air stream. Velocity of the air stream was controlled by the slot aspirator pressure. The distance between the die and aspirator slot unit is 64 inches. The fibers were drawn vertically down from the die, using a slot pressure that starts with an initial value of 5 pounds per square inch (psi) or 10 psi, and then is incrementally increased to the maximum slot pressure while maintaining stable fiber spinning. Stable fiber spinning is defined as no fiber breaks at die. Fiber spinnability, was reported as the highest slot aspirator pressure with no fiber breaks at the die, for at least 5 minutes of fiber spinning. Figure 1 depicts the experimental set up, as described above.

[0026] Fiber Tensile Testing: The test is conducted according to ISO 2062. Spun yarns are tested at 23 °C. The tensile properties are determined on a Zwick tensile tester using a gauge length of 200 mm and a rate of elongation of 200 mm / min. Tenacity is determined at maximum(break) force. Results were reported in centi-Newtons per decitex, cN / dtex.

[0027] Fiber size measurement. Fiber diameter is measured via optical microscopy, Olympus SZX16. Results are reported in microns.

[0028] Melt Index. Melt index (Ml) or 12, was measured in accordance with ASTM D 1238-10, Condition 190°C / 2.16 kg, Method B, and was reported in grams eluted per 10 minutes.

[0029] Melt Flow Rate. Melt flow rate (MFR) (for propylene-based polymer) was measured in accordance with ASTM D 1238-10, Condition 230 °C / 2.16 kg, Method B, and was reported in grams eluted per 10 minutes.

[0030] Melt strength. Melt strength measurements were conducted on a Gottfert Rheotens 71.97 (Gottfert Inc.; Rock Hill, SC), attached to a Gottfert Rheotester 2000 capillary rheometer. The melted sample (about 25 to 30 grams) was fed with a Gbettfert Rheotester 2000 capillary rheometer, equipped with a flat entrance angle (180 degrees) of length of 30 mm, diameter of 2.0 mm, and an aspect ratio (length / diameter) of 15. After equilibrating the samples at 190 °C for 10 minutes, the piston was run at a constant piston speed of 0.265 mm / second. The standard test temperature was 190°C. The sample was drawn uniaxially to a set of accelerating nips, located 100 mm below the die, with an acceleration of 2.4 mm / s2. The tensile force was recorded as a function of the take-up speed of the nip rolls. The following conditions were used in the melt strength measurements: plunger speed - 0.265 mm / second; wheel acceleration = 2.4 mm / s2; capillary diameter = 2.0 mm; capillary length = 30 mm; and barrel diameter = 12 mm. Melt strength results were reported as the average plateau force in centi-Newtons (cN) before the strand broke.DETAILED DESCRIPTION

[0031] The present disclosure provides a fiber. The fiber includes a first region and a second region. The fiber also includes a component present in at least one of the first region and the second region. The component is composed of (i) a post-industrial resin ( PI R) and (ii) a low density polyethylene (LDPE).

[0032] A "fiber," as used herein, is an elongated strand of material in which the length to diameter ratio is greater than 10. A fiber typically has a round, or substantially round, cross section. Other cross-sectional shapes for the fiber include a trilobal shape, or a flat ( / .e., "ribbon" like) shape. A fiber excludes a film which has opposing parallel, or substantially parallel, sides.1. First region

[0033] The fiber includes the first region. The first region is an olefin-based polymer and is selected from a propylene-based polymer, an ethylene-based polymer, and combinations thereof.

[0034] In an embodiment, the first region is a propylene-based polymer. The propylene- based polymer can be a propylene homopolymer, a propylene / a-olefin interpolymer, or a combination thereof. In a further embodiment, the propylene-based polymer is a propylene homopolymer. The propylene homopolymer has a density from 0.88 g / cc to 0.92 g / cc, or 0.90 g / cc. The propylene homopolymer has a melt flow rate (MFR) from 1.0 g / 10 min to 50 g / 10 min, or from 10 g / 10 min to 40 g / 10 min, or from 30 g / 10 min to 40 g / 10 min.

[0035] In an embodiment, the propylene-based polymer is a propylene / a-olefin copolymer with a C2(ethylene) comonomer or a C4-C20a-olefin comonomer, or a C4-C8a-olefin comonomer. The propylene / a-olefin copolymer has a density from 0.87 g / cc to 0.92 g / cc, or 0.90 g / cc. The propylene / a-olefin copolymer has a MFR from 1.0 g / 10 min to 50 g / 10 min, or from 10 g / 10 min to 40 g / 10 min, or from 30 g / 10 min to 40 g / 10 min. Nonlimiting examples of suitable propylene / a-olefin copolymer include propylene / ethylene copolymer, propylene / 1- butene copolymer, propylene / l-hexene copolymer, propylene / 4-methyl-l-pentene copolymer, propylene / l-octene copolymer, and combinations thereof.

[0036] In an embodiment, the first region is an ethylene-based polymer. The ethylenebased polymer can be an ethylene homopolymer, an ethylene / C3-C10a-olefin copolymer, or an ethylene C4-C8a-olefin copolymer. The ethylene-based polymer has a density from 0.930 g / cc to 0.960 g / cc and a melt index (Ml) from 1 g / 10 min to 50 g / 10 min, or from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 40 g / 10 min. Nonlimiting examples of suitable ethylenebased polymer include ethylene plastomer / elastomer, high density polyethylene (HDPE), linear low density polyethylene (LLDPE), ethylene / a-olefin multi-block copolymer, and combinations thereof.

[0037] In an embodiment, the ethylene-based polymer is HDPE, and the HDPE is an ethylene / octene copolymer with one, some, or all of the following properties:(i) a density from 0.950 g / cc to 0.960 g / cc, or 0.955 g / cc; and / or(ii) an l2from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 30 g / 10 min, or 30 g / 10 min.2. Second region

[0038] The present fiber includes the second region. The second region is an olefin-based polymer and is selected from a propylene-based polymer, an ethylene-based polymer, and combinations thereof.

[0039] The olefin-based polymer of the second region can be a propylene-based polymer or an ethylene-based polymer. The propylene-based polymer and the ethylene-based polymer for the second region can be any propylene-based polymer or any ethylene-based polymer as for the first region as disclosed above. In an embodiment, when the first region is a propylene- based polymer, the olefin-based polymer for the second region is an ethylene-based polymer. Alternatively, when the first region is an ethylene-based polymer, the olefin-based polymer for the second region is a propylene-based polymer.3. Component

[0040] The fiber includes the component (interchangeably referred to as "recycled component"). The recycled component includes the post-industrial resin. The term "postindustrial resin" (or "PIR") is a polymeric material that has been recovered from an industrialprocess and / or a manufacturing process which has subjected the polymeric resin to one or more heating and / or molding processes. PIR is distinct from a post-consumer resin (or "PCR") as PIR has not yet been in the hands of a consumer. PIR is typically collected from a manufacturing plant or an industrial site and is not collected from a recycling program or a recycling plant. Where PCR typically requires additional cleaning and processing before it can be re-introduced into a manufacturing line, PIR typically does not need additional cleaning and / or processing before it can be re-introduced in a manufacturing line.

[0041] PIR (and PCR) is distinct from virgin polymeric material. Since PIR has gone through an initial heat and molding process; PIR is not "virgin" polymeric material. A "virgin polymeric material" is a polymeric material that has not undergone, or otherwise has not been subject to, one or more heat process(es) and / or one or more molding process(es). The physical, chemical and flow properties of PIR resin differ when compared to virgin polymeric resin.

[0042] In an embodiment, the PIR is trim (or regrind) from a bicomponent fiber manufacturing line. The PIR includes from 20 wt% to 60 wt% of an ethylene-based polymer and from 80 wt% to 40 wt% of a propylene-based polymer, based on total weight of the PIR. The ethylene-based polymer may be any ethylene-based polymer as previously disclosed herein. The propylene-based polymer may be any propylene-based polymer as previously disclosed herein.

[0043] In an embodiment, the PIR contains(A) from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 25 wt% to 35 wt%, or 30 wt% of an ethylene-based polymer having density from 0.930 g / cc to 0.96 g / cc, or from 0.95 g / cc to 0.96 g / cc, and an Ml from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 30 g / 10 min; and(B) from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 75 wt% to 65 wt%, or 70 wt% of a propylene-based polymer that is a propylene homopolymer having a density from 0.89 g / cc to 0.91 g / cc, or 0.90 g / cc and an MFR from 20 g / 10 min to 50 g / 10 min, or from 30 g / 10 min to 40 g / 10 min, and weight percent is based on total weight of the PIR, and weight percent is based on total weight of the PIR.

[0044] The recycled component includes a low density polyethylene (LDPE) in addition to the PIR. The LDPE is an ethylene homopolymer and has(i) a density from 0.915 g / cc to 0.930 g / cc, or from 0.915 g / cc to 0.925 g / cc, and / or(ii) a melt index (Ml) from 2 g / 10 min to 8 g / 10 min or from 4 g / 10 min to 8 g / 10 min, and / or(iii) a melt strength greater than or equal to 5.0 cN, or from 5.0 cN to 9.0 cN; and / or(iv) a melt temperature, Tm, from 105°C to 118°C, or from 107°C to 112°C. In an embodiment, the LDPE is virgin LDPE that is virgin ethylene homopolymer having the foregoing properties (i)-(iv).

[0045] In an embodiment, the recycled component is void of, or otherwise excludes, a compatibilizer. Nonlimiting examples of compatibilizer void from the recycled component include acrylate-based compatibilizer (polymer containing an acrylate monomer), ethylene / a- olefin random copolymer, ethylene / a-olefin multi-block copolymer, ethylene / propylene random copolymer, ethylene / propylene block copolymer, and styrenic-based polymer (such as styrene / ethylene / butylene / styrene polymer).

[0046] In an embodiment, the recycled component consists of the PIR and the LDPE.

[0047] The recycled component includes from 99 wt% to 80 wt% of the PIR and from 1 wt% to 20 wt% of the LDPE, or from 99 wt% to 90 wt% of the PIR and from 1 wt% to 10 wt% of the LDPE, or from 99 wt% to 95 wt% of the PIR and from 1 wt% to 5 wt% of the LDPE, based on total weight of the recycled component.

[0048] In an embodiment, the recycled component includes from 99 wt% to 95 wt% of the PIR and from 1 wt% to 5 wt% of the LDPE, based on the total weight of the recycled component, the PIR includes(A) from 20 wt% to 60 wt%, or from 20 wt % to 50 wt%, or from 25 wt% to 35 wt%, or 30 wt% of an ethylene-based polymer that is an HDPE having density from 0.95 g / cc to 0.96 g / cc and an Ml from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 30 g / 10 min (based on total weight of the PIR); and(B) from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 75 wt% to 65 wt%, or 70 wt% of a propylene-based polymer that is a propylene homopolymer having a density from 0.89 g / cc to 0.91 g / cc, or 0.90 g / cc and an MFR from 20 g / 10 min to 50 g / 10 min, or from 30 g / 10 min to 40 g / 10 min (based on total weight of the PIR); and(C) the LDPE is a virgin LDPE that is an ethylene homopolymer and has(i) a density from 0.915 g / cc to 0.930 g / cc or from 0.915 g / cc to 0.925 g / cc, and / or(ii) a melt index (Ml) from 2 g / 10 min to 8 g / 10 min or from 4 g / 10 min to 8 g / 10 min, and / or(iii) a melt strength greater than or equal to 5.0 cN, or from 5.0 cN to 9.0 cN; and / or(iv) a melt temperature, Tm, from 105°C to 118°C, or from 107°C to 112°C.

[0049] The fiber may further include additional optional components such as one or more additives. Such additives include, but are not limited to, antistatic agents, color enhancers, dyes, lubricants, fillers, pigments, primary antioxidants, secondary antioxidants, processing aids, UV stabilizers, anti-blocks, slip agents, tackifiers, fire retardants, anti-microbial agents, odor reducer agents, anti-fungal agents, and combinations thereof. The additive(s) may be present in the fiber in an amount from 0 wt%, or from 0.1 wt% to 10 wt%, or from 0.1 wt% to 5 wt%, or from 0.1 wt% to 1.0 wt%, based on total weight of the fiber.4. Fiber

[0050] The present fiber is a bicomponent fiber. A "bicomponent fiber" (or "BICO fiber" or "BICO") is a fiber that has two or more, or two, distinct polymer regions or domains. Bicomponent fibers are also known as conjugated fibers or multicomponent fibers. The polymers are usually different from each other although two or more regions may contain the same polymer. The polymers are arranged in substantially distinct regions, or zones, across the cross-section of the bicomponent fiber, and usually extend continuously along the length of the bicomponent fiber. The configuration of a bicomponent fiber can be, for example, a sheath / core arrangement (in which one polymer (the "core") is surrounded by another polymer (the "sheath"), a side by side arrangement, a pie arrangement or an "islands-in-the sea" arrangement.

[0051] In an embodiment, the fiber is a bicomponent fiber with a sheath / core configuration. The sheath is from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 20 wt% to 40 wt%, or 30 wt% of the fiber and the core is from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 80 wt% to 60 wt%, or 70 wt% of the fiber (based on total weight of the fiber). The fiber includes(1) a first region that is the sheath and is a propylene-based polymer;(2) a second region that is the core, the core composed of(A) from 65 wt% to 98 wt%, or 67 wt% of a propylene-based polymer (based on total weight of the core), and(B) from 35 wt% to 2 wt%, or from 33 wt% to 2 wt%, or from 20 wt% to 2 wt%, or 33 wt% of the recycled component (based on total weight of fiber), the recycled component is from 99 wt% to 80 wt% of the PIR and from 1 wt% to 20 wt%, or from 1 wt% to 10 wt% or from 1 wt% to 5 wt% of the LDPE (based on total weight of the recycled component), the PIR includes(i) from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 25 wt% to 35 wt%, or 30 wt% of an ethylene-based polymer having density from 0.930 g / cc to 0.96 g / cc, or from 0.95 g / cc to 0.96 g / cc and an Ml from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 30 g / 10 min (based on total weight of the PIR); and(ii) from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 75 wt% to 65 wt%, or 70 wt% of a propylene-based polymer that is a propylene homopolymer having a density from 0.89 g / cc to 0.91 g / cc, or 0.9 g / cc and an MFR from 20 g / 10 min to 50 g / 10 min, or from 30 g / 10 min to 40 g / 10 min (based on total weight of the PIR); and the LDPE that is an ethylene homopolymer and has(i) a density from 0.915 g / cc to 0.930 g / cc or from 0.915 g / cc to 0.925 g / cc, and / or(ii) a melt index (Ml) from 2 g / 10 min to 8 g / 10 min or from 4 g / 10 min to 8 g / 10 min, and / or(iii) a melt strength greater than or equal to 5.0 cN, or from 5.0 cN to 9.0 cN; and / or(iv) a melt temperature, Tm, from 105°C to 118°C, or from 107°C to 112°C.

[0052] In an embodiment, the fiber is a bicomponent fiber with a sheath / core configuration. The sheath is from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 20 wt% to 40 wt%, or 30 wt% of the fiber and the core is from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 80 wt% to 60 wt%, or 70 wt% of the fiber (based on total weight of the fiber). The fiber includes(1) a first region that is the sheath and is an ethylene-based polymer;(2) a second region that is the core, the core composed of(A) from 65 wt% to 98 wt%, or 67 wt% of a propylene-based polymer (based on total weight of the core), and(B) from 35 wt% to 2 wt%, or from 33 wt% to 2 wt%, or from 20 wt% to 2 wt%, or 33 wt% of the recycled component (based on total weight of the core), the recycled component is from 99 wt% to 85 wt% of the PIR and from 1 wt% to 15 wt%, or from 1 wt% to 10 wt%, or from 1 wt% to 5 wt% of the LDPE (based on total weight of the recycled component), the PIR includes(i) from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 25 wt% to 35 wt%, or 30 wt% of an ethylene-based polymer having density from 0.930 g / cc to 0.96 g / cc, or from 0.95 g / cc to 0.96 g / cc and an Ml from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 30 g / 10 min (based on total weight of the PIR); and(ii) from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 75 wt% to 65 wt%, or 70 wt% of a propylene-based polymer that is a propylene homopolymer having a density from 0.89 g / cc to 0.91 g / cc, or 0.9 g / cc and an MFR from 20 g / 10 min to 50 g / 10 min, or from 30 g / 10 min to 40 g / 10 min (based on total weight of the PIR); and the LDPE that is an ethylene homopolymer and has(i) a density from 0.915 g / cc to 0.930 g / cc or from 0.915 g / cc to 0.925 g / cc, and / or(ii) a melt index (Ml) from 2 g / 10 min to 8 g / 10 min or from 4 g / 10 min to 8 g / 10 min, and / or(iii) a melt strength greater than or equal to 5.0 cN, or from 5.0 cN to 9.0 cN; and / or(iv) a melt temperature, Tm, from 105°C to 118°C, or from 107°C to 112°C.

[0053] In an embodiment, the fiber is a bicomponent fiber with a sheath / core configuration. The sheath is from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 20 wt% to 40 wt%, or 30 wt% of the fiber and the core is from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 80 wt% to 60 wt%, or 70 wt% of the fiber (based on total weight of the fiber). The fiber includes(1) a first region that is the sheath, the sheath composed of(A) from 65 wt% to 98 wt%, or 83 wt% of an ethylene-based polymer (based on total weight of the sheath), and(B) from 35 wt% to 2 wt%, or from 33 wt% to 2 wt%, or from 20 wt% to 2 wt%, or 17 wt% of the recycled component (based on total weight of the sheath), the recycled component is from 99 wt% to 85 wt% of the PIR and from 1 wt% to 15 wt%, or from 1 wt% to 10 wt%, or from 1 wt% to 5 wt% of the LDPE (based on total weight of the recycled component), the PIR includes(i) from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 25 wt% to 35 wt%, or 30 wt% of an ethylene-based polymer having density from 0.930 g / cc to 0.960 g / cc, or from 0.95 g / cc to 0.96 g / cc and an Ml from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 30 g / 10 min (based on total weight of the PIR); and(ii) from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 75 wt% to 65 wt%, or 70 wt% of a propylene-based polymer that is a propylene homopolymer having a density from 0.89 g / cc to 0.91 g / cc, or 0.9 g / cc and an MFR from 20 g / 10 min to 50 g / 10 min, or from 30 g / 10 min to 40 g / 10 min (based on total weight of the PIR); and the LDPE that is an ethylene homopolymer and has(1) a density from 0.915 g / cc to 0.930 g / cc or from 0.915 g / cc to 0.925 g / cc, and / or(ii) a melt index (Ml) from 2 g / 10 min to 8 g / 10 min, or from 4 g / 10 min to 8 g / 10 min, and / or(iii) a melt strength greater than or equal to 5.0 cN, or from 5.0 cN to 9.0 cN; and / or(iv) a melt temperature, Tm, from 105°C to 118°C, or from 107°C to 112°C; and(2) a second region that is the core, the core composed of a propylene-based polymer.

[0054] The fiber may be a melt-spun fiber or a meltblown fiber. In an embodiment, the fiber is a melt-spun fiber. A "melt-spun fiber," as used herein, is a fiber produced by a meltspinning process. Melt-spinning is a process whereby a polymer melt is extruded through a plurality of fine die capillaries (such as a spinneret, for example) as molten filaments while simultaneously applying an extensional force which reduces the density of the molten filaments. The molten filaments solidify upon cooling below their melt temperature to form fibers. The term "melt spinning" encompasses stable fiber spinning (including short spinning and long spinning) and bulk continuous filament fiber. Melt spun fibers may be cold-drawn.

[0055] In an embodiment, the fiber is a meltblown fiber. A "meltblown fiber" is a fiber formed by extruding a molten thermoplastic polymer composition through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity gas streams (e.g. air) which function to attenuate the threads or filaments to reduced density. The filaments or threads are carried by the high velocity gas streams and deposited on a collecting surface to form a web of randomly dispersed fibers with average density generally smaller than 10 microns.

[0056] In an embodiment, the fiber has a density from 1 denier to 10 denier, or from 1 denier to 5 denier, or from 1 denier to 3 denier, or from 1 denier to 2 denier.

[0057] In an embodiment, the fiber has a tenacity from 1.3 cN / dtex to 1.4 cN / dtex.

[0058] In an embodiment, the fiber contains from 2 wt% to 35 wt%, or from 10 wt% to 33 wt% of the recycled component based on total weight of the fiber.

[0059] In an embodiment, the fiber is a bicomponent fiber with a sheath / core configuration. The sheath is from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 20 wt% to 40 wt%, or 30 wt% of the fiber and the core is from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 80 wt% to 60 wt%, or 70 wt% of the fiber (based on total weight of the fiber). The fiber includes(1) a first region that is the sheath and is an ethylene-based polymer;(2) a second region that is the core, the core composed of(A) from 65 wt% to 98 wt%, or 67 wt% of a propylene-based polymer (based on total weight of the core), and(B) from 35 wt% to 2 wt%, or from 33 wt% to 2 wt%, or from 20 wt% to 2 wt%, or 33 wt% of the recycled component (based on total weight of the core), the recycled component is from 99 wt% to 85 wt% of the PIR and from 1 wt% to 15 wt%, or from 1 wt% to 10 wt%, or from 1 wt% to 5 wt% of the LDPE (based on total weight of the recycled component), the PIR includes(i) from 20 wt% to 60 wt%, or from 20 wt% to 50 wt%, or from 25 wt% to 35 wt%, or 30 wt% of an ethylene-based polymer having density from 0.930 g / cc to 0.96 g / cc, or from 0.95 g / cc to 0.96 g / cc and an Ml from 10 g / 10 min to 40 g / 10 min, or from 20 g / 10 min to 30 g / 10 min (based on total weight of the PIR); and(ii) from 80 wt% to 40 wt%, or from 80 wt% to 50 wt%, or from 75 wt% to 65 wt%, or 70 wt% of a propylene-based polymer that is a propylene homopolymer having a density from 0.89 g / cc to 0.91 g / cc, or 0.9 g / cc and an MFR from 20 g / 10 min to 50 g / 10 min, or from 30 g / 10 min to 40 g / 10 min (based on total weight of the PIR); and the LDPE that is an ethylene homopolymer and has(i) a density from 0.915 g / cc to 0.930 g / cc or from 0.915 g / cc to 0.925 g / cc, and / or(ii) a melt index (Ml) from 2 g / 10 min to 8 g / 10 min or from 4 g / 10 min to 8 g / 10 min, and / or(iii) a melt strength greater than or equal to 5.0 cN, or from 5.0 cN to 9.0 cN; and / or(iv) a melt temperature, Tm, from 105°C to 118°C, or from 107°C to 112°C; and the fiber has a density from 1 denier to 10 denier, or from 1 denier to 5 denier, or from 1 denier to 3 denier, or from 1 denier to 2 denier. The present fiber may comprise two or more embodiments disclosed herein.5. Fabrics

[0060] The present fiber can be used to make fabric spunbond nonwoven fabrics, bonded carded webs, woven fabrics, knitted fabrics, woven tapes, and artificial turf.

[0061] In an embodiment, the present fiber is used to make a non-woven fabric. As used herein a "non-woven" or a "non-woven fabric" or "non-woven material" is an assembly offibers (for example, core / sheath, islands in the sea, side by side, segmented pie etc.) held together in a random web such as by mechanical interlocking or by fusing at least a portion of the fibers. The non-woven fabrics according to the present disclosure may be fabricated via different techniques. Such methods include, but are not limited to, spunbond process, carded web process, air laid process, thermo-calendaring process, adhesive bonding process, hot air bonding process, needle punch process, hydroentangling process, electrospinning process, and combinations thereof.

[0062] In an embodiment, the present fiber is produced by way of a spunbond process. In a spunbond process, the fabrication of non-woven fabric includes the following steps: (a) extruding strands of the BICO fiber from a spinneret; (b) quenching the strands of the blend with a flow of air which is generally cooled in order to hasten the solidification of the molten strands of the blend; (c) attenuating the filaments by advancing them through the quench zone with a draw tension that can be applied by either pneumatically entraining the filaments in an air stream or by winding them around mechanical draw rolls of the type commonly used in the textile fibers industry; (d) collecting the drawn strands into a web on a foraminous surface, e.g. moving screen or porous belt; and (e) bonding the web of loose strands into the non-woven fabric. Bonding can be achieved by a variety of means including, but not limited to, thermocalendaring process, adhesive bonding process, hot air bonding process, needle punch process, hydroentangling process, and combinations thereof.

[0063] In the case of the staple or binder fibers, the fibers can be mixed with a variety of other fibers including synthetic fibers such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or natural fibers such as cellulose, rayon, or cotton. These fibers can be wet laid, air laid or carded into a non-woven web. The non-woven web can then be laminated to other materials.

[0064] The spunbond non-woven fabric can be used in various end-use applications including, but not limited to, hygiene absorbent products such diapers, feminine hygiene articles, adult incontinence products, wipes, bandages and wound dressings, and disposable slippers and footwear, medical application such isolation gowns, surgical gowns, surgical drapes and covers, surgical scrub suits, caps, masks, and medical packaging.

[0065] In an embodiment, the present fiber can be used with a carding line to produce fabric.

[0066] In an embodiment, the present fiber can be used to make carpeting, woven textiles, artificial turf, or other fiber-containing articles.

[0067] By way of example, and not limitation, examples of the present disclosure will now be described in detail in the following examples.EXAMPLES1. Materials

[0068] Materials for the inventive examples ("IE") and comparative samples ("CS") are listed in Tables 1A and IB below.

[0069] Table 1A*MFR (230°C / 2.16Kg), not l22. Preparation of recycled component

[0070] Recycled component (Table 2B below) was made by melt blending and extruding (i) PP3155 (hPP) and ASPUN 6850A (HDPE) (replicating PIR) with (ii) LDPE on a Coperion 26 Mcl8 twin screw extruder. The melt blending on the Coperion 26 Mcl8 twin screw extruder replicates at least one thermal history for regrind (or trim) generated on a commercial bicomponent fiber production line. The melt blending and extrusion conditions for the preparation of the recycled component / comparative recycled component are provided in Table 2A below. Properties for the recycled component are provided in Table 2B below. In Table 2B (recycled component), the weight percent for each individual material is shown in closed parentheses, wherein weight percent is based on the total weight of the recycled component.

[0071] Table 2A— extrusion conditions

[0072] Table 2B— (recycled) component (PIR + LDPE)*Not a recycled component3. Preparation of bicomponent fiber

[0073] A Fiber Hills line was used to produce BICO fibers. All fibers had a sheath / core configuration, with 30 wt% is sheath, and 70 wt% is core, and wt% is based on total weight of the fiber. Two different types of bicomponent fibers were prepared as shown in Table A. The production conditions for the Fiber Hills line are provided in Table 2C below.

[0074] Table A

[0075] Table 2C -BICO fiber process conditions

[0076] Fibers were spun on a Hills Bicomponent Continuous Filament Fiber Spinning Line at a throughput rate of 0.6 ghm (grams per hole per minute). A Hills Bicomponent die was used to operate at a 70 / 30 core / sheath ratio. Extruder profiles were adjusted to achieve a melt temperature of 230 °C for sheath and 250 °C for core material. The die configuration consisted of 144 holes, with a hole diameter of 0.6 mm. The hole has a 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. After the quenching zone, a draw tension is applied on the 144 filaments by pneumatically entraining the filaments in a slot unit with an air stream. Velocity of the air stream was controlled by the slot aspirator pressure. The distance between the die and slot unit is 64 inches. The fibers were drawn vertically down from the die, using a slot pressure that starts with an initial value of 5 pounds per square inch (psi) or 10 psi, and then was incrementally increased to the maximum slot pressure while maintaining stable fiber spinning. Stable fiber spinning is defined as no fiber breaks at die. Fiber spinnability, was reported as the highest slot aspirator pressure with no fiber breaks at the die, for at least 5 minutes of fiber spinning. Figure 1 depicts the experimental set up, as described above.

[0077] BICO fiber properties, maximum aspirator slot pressure without fiber break, and tenacity values are provided in Table 3 below. Each BICO fiber sample in Table 3 has a 30 wt% sheath / 70 wt% core configuration. The sheath for each fiber in Table 3 is Aspun 6850A HDPE. The fiber core composition varies as is shown in Table 3.

[0078] Table 3 - BICO Fiber Properties

[0079] CS1 shows that without a recycled component, BICO fiber can be melt spun to a maximum aspirator pressure of 55 psi (CS1). However, with incorporation of 33 wt% of PIR and no LDPE in the PP core, BICO fiber breaks occur at a maximum aspirator pressure of 5 psi, as seen in CS2.

[0080] IE1 and IE2 each contain 33 wt% of recycled component (PIR and LDPE). The recycled component in IE1 and IE2 each contains an LDPE having a melt strength greater than 5.0 cN, or from 5.0 cN to 9.0 cN. Each of IE1 and IE2 unexpectedly exhibits the ability to melt spin BICO fiber to a maximum aspirator pressure from 25 psi to 30 psi, compared to a maximum aspirator pressure of 5 psi shown by CS3, CS3's recycled component containing LDPE having a melt strength less than 5.0 cN, or from 1.0 cN to less than 3.0 cN (2.0 cN).

[0081] Bounded by no particular theory, it is believed that incorporation of LDPE with long chain branching, as evidenced by LDPE with melt strength from 5.0 cN to 9.0 cN, improves drawability of the fibers, and thus prevents fiber breaks, when the LDPE is blended with PIR and added to the fiber core. Low elongational viscosity at high extension rates contributes to stable spinning. Applicant discovered that incorporating LDPE having a melt strength from 5.0 cN to 9.0 cN blended with PIR to form the recycled component unexpectedly improves fiber drawability values (maximum aspirator slot pressure 25-30 psi), and thus improves spinnability by increasing maximum aspirator slot pressure without fiber break.

[0082] It is specifically intended that the present disclosure not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.

Claims

CLAIMS1. A fiber comprising: a first region; a second region; and a component present in at least one of the first region and the second region, the component comprising (i) a post-industrial resin (PI R) and (ii) a low density polyethylene (LDPE).

2. The fiber of claim 1 wherein the first region is a polymer selected from the group consisting of a propylene-based polymer, an ethylene-based polymer, and combinations thereof.

3. The fiber of any of claims 1-2 wherein the second region is a polymer selected from the group consisting of a propylene-based polymer, an ethylene-based polymer, and combinations thereof.

4. The fiber of any of claims 1-3 wherein the PIR comprises from 20 wt% to 60 wt% of an ethylene-based polymer and from 80 wt% to 40 wt% of a propylene-based polymer, based on total weight of the PIR.

5. The fiber of any of claims 1-4 wherein the LDPE has(i) a density from 0.915 g / cc to 0.930 g / cc,(ii) a melt index (Ml) from 2 g / 10 min to 8 g / 10 min, and(iii) a melt strength from 5.0 cN to 9.0 cN.

6. The fiber of any of claims 1-5 wherein the component comprises from 99 wt% to 85 wt% of the PIR and from 1 wt% to 15 wt% of the LDPE, based on total weight of the component.

7. The fiber of any of claims 1-6 wherein the first region and the second region are arranged in a configuration selected from the group consisting of a core-sheath configuration, a side-by-side configuration, and an island-in-the-sea configuration.

8. The fiber of claim 7 wherein the first region and the second region are arranged in the core-sheath configuration; the first region is the sheath and is composed of a propylene-based polymer; and the second region is the core and is composed of(A) a propylene-based polymer; and(B) the component.

9. The fiber of claim 7 wherein the first region and the second region are arranged in the core-sheath configuration; the first region is the sheath and is composed of an ethylene-based polymer; and the second region is the core and is composed of(A) a propylene-based polymer; and(B) the component.

10. The fiber of claim 7 wherein the first region and the second region are arranged in the core-sheath configuration; the first region is the sheath composed of(A) an ethylene-based polymer, and(B) the component; and the second region is the core composed of a propylene-based polymer.

11. The fiber of any of claims 1-10 wherein the fiber comprises from 2 wt% to 35 wt% of the component based on total weight of the fiber.

12. The fiber of any of claims 1-11 having a denier from 1 denier to 10 denier.

13. The fiber of claim 12 wherein the first region comprises a propylene-based polymer; and the second region comprises the same propylene-based polymer that is present in the first region.

14. The fiber of claim 13 wherein the first region comprises ethylene-based polymer; and the second region comprises the same ethylene-based polymer present in the first region.

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