Compatible plastic straps and methods thereof

Abstract

In some embodiments, a method of making a formed polyolefin strip includes blending a first polymer component with, optionally, a second polymer component to form a polyolefin resin. The polyolefin resin has a density (as determined by ASTM D1505) of about 0.89 g / cm3 to about 0.965 g / cm3 and a melt index (as determined by ASTM D-1238; 190 °C with a 2.16 kg load) of about 0.25 g / 10 min to about 2.5 g / 10 min. The method further includes extruding the polyolefin resin to form a polyolefin strip. The method further includes forming the polyolefin strip via a pair of opposed forming rolls to produce a formed polyolefin strip. The method further includes collecting the formed polyolefin strip via winding, spooling, or a combination thereof.

Description

COMPATIBLE PLASTIC STRAPS AND METHODS THEREOFFIELD OF THE INVENTION

[0001] The present disclosure relates to polyolefin resin compositions and articles made therefrom.BACKGROUND OF THE INVENTION

[0002] Processes for recycling plastic waste commonly include intake of a plastic waste bale, sortation of plastics based on size and content, washing the plastic waste, reducing the size of the plastic waste via grinding, and melt blending the plastic waste into a resin, and manufacturing a new plastic product via any one or more processing methods. Of the materials to be recycled, polyolefins are of interest as polyolefin products are globally produced and subsequently discarded, leading to a large waste feedstock of such materials.

[0003] Plastic waste bales are a common method for storage and transport of large amounts of waste products to and from collecting at recycling facilities. Depending on the location in which the plastic waste is collected, the plastic waste bales produced therefrom can contain various types of plastic materials. However, it is difficult to recycle plastic waste streams having different polymeric compositions. For instance, nylons are a genuine source of contamination is polyolefin recyclate, as gelation of such materials can become problematic during processing. Unfortunately, nylon straps are used to retain the contents of plastic waste bales, and thus polyolefin recycling processes involve cost and time intensive sorting methods prior to recycling procedures.

[0004] There is a need for strap materials which are compatible with the contents of the plastic waste bales during recycling processes. In particular, there is a need to develop new strap compositions which are compatible with recycled polyolefin-containing plastic waste bales.SUMMARY OF THE INVENTION

[0005] The present disclosure relates to polyolefin resin compositions and articles made therefrom.

[0006] In some embodiments, a method of making a formed polyolefin strip includes blending a first polymer component with, optionally a second polymer component to form a polyolefin resin. The polyolefin resin has a density (as determined by ASTM D1505) of about 0.89 g / cm3to about 0.965 g / cm3and a melt index (as determined by ASTM D-1238; 190 °C with a 2.16 kg load) of about 0.25 g / 10 min to about 2.5 g / 10 min. The method further includes extruding the polyolefin resin to form a polyolefin strip. The method further includes forming the polyolefin strip via a pair of opposed forming rolls to produce a formed polyolefin strip. The method further includes collecting the formed polyolefin strip via winding, spooling, or a combination thereof.

[0007] In some embodiments, a method of making a formed polyolefin strip includes blending a first polymer component with, optionally a second polymer component to form a polyolefin resin. The polyolefin resin has a density (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3and a melt index (as determined by ASTM D-1238; 230 °C with a 2.16 kg load) of about 0.5 g / 10 min to about 5 g / 10 min. The method further includes extruding the polyolefin resin to form a polyolefin strip. The method further includes forming the polyolefin strip via a pair of opposed forming rolls to produce a formed polyolefin strip. The method further includes collecting the formed polyolefin strip via winding, spooling, or a combination thereof.DETAILED DESCRIPTION OF THE INVENTION

[0008] Resins of the current disclosure include one or more polymeric components that are compatible with polyolefin containing plastic waste bales. In some embodiments, the resin is a polyolefin resin comprising polyethylene and / or polypropylene. In some embodiments, the polyolefin resin is a blend of an unprocessed resin and, optionally a post-consumer resin (PCR). In one or more embodiments, the polyolefin resin is selected from a blend of an unprocessed high density polyethylene (HDPE) resin and a HDPE copolymer PCR, a blend of an unprocessed HDPE resin and a polypropylene copolymer PCR, a blend of an unprocessed polypropylene resin and a HDPE copolymer PCR, or a blend of an unprocessed polypropylene resin and a polypropylene copolymer PCR. Resins of the present disclosure are useful in manufacturing mono-oriented and bi-oriented films, straps, and nets for use in producing waste plastic bales and containment thereof. Polyolefin resins

[0009] Polyolefin resins described herein can be used as straps for plastic waste bales. Polyolefin resins described herein can be included as at least a portion of the content of the plastic waste bale to be strapped. Processes disclosed herein provide a method by which polyolefin straps can be produced from polyolefin resins for use in applications such as agricultural and waste baling applications. Such polyolefin resins can include at least one polymeric component, where at least one of the polymeric components includes one or more olefinic units.

[0010] In some embodiments, the polyolefin resin includes one or more polymers selected from polyethylene, polypropylene, poly- 1 -butene, poly-1 -hexene, poly- 1 -octene, poly-4- methylpentene-1, or other homopolymers or copolymers of similar mono- 1 -olefins containing up to 8 carbon atoms per molecule. In at least one embodiment, the polyolefin resin is selected from polyethylene, polypropylene, or a combination thereof.Polyethylene resins:

[0011] In some embodiments, the polyolefin resin used to produce straps and / or as one or more components of the bale can include polyethylene resin wherein the polyethylene resin is acommercially available unprocessed polyethylene resin, a commercially available polyethylene post-consumer resin (PCR), or a combination thereof. In one or more embodiments, the polyethylene resin is selected from ultra-high molecular weight polyethylene (UHMWPE), ultralow molecular weight polyethylene (ULMWPE), high molecular weight polyethylene (HMWPE), high density polyethylene (HDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), very-low density polyethylene (VLDPE), and combinations thereof.

[0012] In some embodiments, the polyethylene resin is an unprocessed HDPE resin and has a weight average molecular weight (Mw), as determined by gel permeation chromatography (GPC), of about 100,000 g / mol to about 225,000 g / mol, such as about 150,000 g / mol to about 185,000 g / mol, such as about 160,000 g / mol to about 170,000 g / mol. In some embodiments, the unprocessed HDPE resin has a density, as determined by (as determined by ASTM DI 505) of 0.940 g / cm3to about 0.975 g / cm3, such as about 0.940 g / cm3to about 0.970 g / cm3. such as about 0.940 g / cm3to about 0.965 g / cm3, such as about 0.945 g / cm3. In at least one embodiment, the unprocessed HDPE or HDPE PCR resin has a melt index (as determined by ASTM D-1238, 190°C with a 2.16 kg load) of about 0.1 g / 10 min to about 10 g / 10 min, such as about 0.3 g / 10 min to about 5 g / 10 min, such as about 0.3 g / 10 min to about 1 g / 10 min.. In at least one embodiment, the unprocessed HDPE resin has a tensile strength at yield (as determined by ASTM D882) of about 2,000 psi to about 10,000 psi, such as about 2,000 psi to about 5,000 psi, such as about 2,000 psi to about 4,000. In at least one embodiment, the unprocessed HDPE resin has a secant modulus (as determined by ASTM D882) of about 50,000 psi to about 200,000 psi, such as about 75,000 psi to about 175,000 psi, such as about 100,000 psi to about 150,000 psi.

[0013] In some embodiments, the polyethylene resin is a HDPE PCR resin and has a Mw, as determined by GPC, of about 100,000 g / mol to about 225,000 g / mol, such as about 150,000 g / mol to about 185,000 g / mol, such as about 160,000 g / mol to about 170,000 g / mol. In some embodiments, the HDPE has a density, as determined by (as determined by ASTM D1505) of about 0.910 g / cm3to about 0.970 g / cm3. such as about 0.940 g / cm3to about 0.970 g / cm3, such as about 0.940 g / cm3to about 0.965 g / cm3, such as about 0.945 g / cm3. In at least one embodiment, the HDPE PCR has a melt index (as determined by ASTM D-1238, 190°C with a 2.16 kg load) of about 0. 1 g / 10 min to about 10 g / 10 min, such as about 0.3 g / 10 min to about 10 g / 10 min, such as about 0.3 g / 10 min to about 5 g / 10 min such as about 0.3 g / 10 min to about 1 g / 10 min.. In at least one embodiment, the HDPE PCR has a tensile strength at yield (as determined by ASTM D882) of about 2,000 psi to about 10,000 psi, such as about 2,000 psi to about 5,000 psi, such as about 2,000 psi to about 4,000 psi. In at least one embodiment, the HDPE PCR has a secant modulus(as determined by ASTM D882) of about 50,000 psi to about 200,000 psi, such as about 75,000 psi to about 175,000 psi, such as about 100,000 psi to about 150,000 psi.

[0014] In some embodiments, the HDPE PCR is a copolymer of ethylene and any one or more comonomers selected from propylene, 1 -butene, 1 -hexene, 1 -octene, 4-methyl-l -pentene, and any combination thereof. In some embodiments, the HDPE copolymer PCR includes about 90. 1 mol % to about 99.9 mol % of ethylene units, such as about 91 mol % to about 99 mol %, such as about 92 mol % to about 98 mol %, such as about 93 mol % to about 97 mol %, such as about 94 mol % to about 96 mol %. The remaining mol % corresponds to the comonomer(s) content, wherein the combination of the ethylene units and the comonomer units totals 100 mol%.

[0015] In some embodiments, the HDPE copolymer PCR has a backbone architecture of at least one of a random copolymer, a block copolymer, an alternating copolymer, or a gradient copolymer. In one or more embodiments, the HDPE copolymer PCR is a random copolymer. In one or more embodiments, the HDPE copolymer PCR includes a molar ratio of ethylene repeat units to any one or more comonomer repeat units of about 99: 1 to about 60:40, such as about 95:5 to about 60:40, such as about 90: 10 to about 60:40.

[0016] In some embodiments, the HDPE copolymer PCR has a Mw, as determined by GPC, of about 100,000 g / mol to about 225,000 g / mol, such as about 150,000 g / mol to about 185,000 g / mol, such as about 160,000 g / mol to about 170,000 g / mol. In some embodiments, the HDPE copolymer PCR has a density, as determined by (as determined by ASTM D1505) of about 0.940 g / cm3to about 0.970 g / cm3, such as about 0.940 g / cm3to about 0.965 g / cm3, , such as about 0.945 g / cm3. In at least one embodiment, the HDPE copolymer PCR has a melt index (as determined by ASTM D-1238, 190°C with a 2. 16 kg load) of about 0.1 g / 10 min to about 10 g / 10 min, such as about 0.3 g / 10 min to about 10 g / 10 min, such as about 0.3 g / 10 min to about 5 g / 10 min such as about 0.3 g / 10 min to about 1 g / 10 min.. In at least one embodiment, the HDPE copolymer PCR has a tensile strength at yield (as determined by ASTM D882) of about 2,000 psi to about 10,000 psi, such as about 2,000 psi to about 5,000 psi, such as about 2,000 psi to about 4,000 psi. In at least one embodiment, the HDPE copolymer PCR has a secant modulus (as determined by ASTM D882) of about 50,000 psi to about 200,000 psi, such as about 75,000 psi to about 175,000 psi, such as about 100,000 psi to about 150,000 psi.

[0017] In some embodiments, the HDPE copolymer PCR further includes one or more additional polymers selected from the group consisting of low density polyethylene (LDPE), medium density polyethylene (MDPE), polypropylene, polyester, acrylic resin, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, polyvinyl ether, ethylene-vinyl acetate copolymers (EVA), ethylenevinyl alcohol copolymers (EV OH), ethylene-acrylic acid copolymers, any one or morenylons, and the like, and mixtures thereof. In at least one embodiment, the one or more additional polymers includes less than 15 wt% of the HDPE copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.

[0018] In some embodiments, the HDPE copolymer PCR further includes one or more compatiblizers, such as grafted copolymers of maleic anhydride with HDPE, LLDPE, and / or LDPE. In at least one embodiment, the one or more compatibilizers includes less than 15 wt% of the HDPE copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.

[0019] In some embodiments, the HDPE copolymer PCR further includes one or more tie layer material. A tie layer is commonly used in multi-layered film applications as an adhesive applied to prevent film delamination. A tie layer material typically includes a polyolefin base resin as the predominant component and one or more grafted polyolefins. In at least one embodiment, the one or more tie layer materials includes less than 15 wt% of the HDPE copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.

[0020] In one or more embodiments, the compositional summation of the one or more additional polymers, one or more compatibilizers, and one or more tie layer materials of the HDPE copolymer PCR includes less than 15 wt% of the HDPE copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.Polypropylene resins:

[0021] In some embodiments, the polyolefin resin can include a polypropylene resin wherein the polypropylene resin a commercially available unprocessed polypropylene resin, a commercially available polypropylene PCR, or a combination thereof. In one or more embodiments, the polypropylene resin is selected from the group consisting of an atactic polypropylene, an isotactic polypropylene, a syndiotactic polypropylene, or a combination thereof.

[0022] In some embodiments, the polypropylene resin is an unprocessed polypropylene resin and has a Mw, as determined by GPC, of about 380,000 g / mol to about 480,000 g / mol, such as about 415,000 g / mol to about 445,000 g / mol, such as about 420,000 g / mol to about 440.000 g / mol. In some embodiments, the unprocessed polypropylene resin has a density, as determined by (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3, such as about 0.89 g / cm3to about 0.92 g / cm3, such as about 0.89 g / cm3to about 0.91 g / cm3, such as about 0.9 g / cm3. In atleast one embodiment, the unprocessed polypropylene resin has a melt index (as determined by ASTM D-1238, 190°C with a 2.16 kg load) of about 0.1 g / 10 min to about 20 g / 10 min, such as about 0.5 g / 10 min to about 5 g / 10 min, such as about 1 g / 10 min to about 2 g / 10 min, such as about 1.5 g / 10 min. In at least one embodiment, the unprocessed polypropylene resinhas a tensile strength at yield (as determined by ASTM D256) of about 2,000 psi to about 10.000 psi, such as about 4,000 psi to about 8,000 psi, such as about 4,000 psi to about 6,000 psi. In at least one embodiment, the unprocessed polypropylene resin has a secant modulus (as determined by ASTM D882; 1% Secant) of about 150,000 psi to about 300,000 psi, such as about 175,000 psi to about 250,000 psi, such as about 200,000 psi to about 250,000 psi.

[0023] In some embodiments, the polypropylene resin is a polypropylene PCR and has a Mw, as determined by GPC, of about 380,000 g / mol to about 480,000 g / mol, such as about 415,000 g / mol to about 445,000 g / mol, such as about 420,000 g / mol to about 440,000 g / mol. In some embodiments, the polypropylene PCR has a density, as determined by (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3, such as about 0.89 g / cm3to about 0.92 g / cm3, such as about 0.89 g / cm3to about 0.91 g / cm3, such as about 0.9 g / cm3. In at least one embodiment, the polypropylene PCR has a melt index (as determined by ASTM D-1238, 190°C with a 2.16 kg load) of about 0.1 g / 10 min to about 20 g / 10 min, such as about 0.5 g / 10 min to about 5 g / 10 min, such as about 1 g / 10 min to about 2 g / 10 min, such as about 1.5 g / 10 min. In at least one embodiment, the polypropylene PCR has a tensile strength at yield (as determined by ASTM D256) of about 2,000 psi to about 10,000 psi, such as about 4,000 psi to about 8,000 psi, such as about 4,000 psi to about 6,000 psi. In at least one embodiment, the polypropylene PCR has a secant modulus (as determined by ASTM D882; 1% Secant) of about 150,000 psi to about 300,000 psi, such as about 175,000 psi to about 250,000 psi, such as about 200,000 psi to about 250,000 psi.

[0024] In some embodiments, the polypropylene PCR is a copolymer of propylene and any one or more comonomers selected from ethylene, 1-butene, 1-hexene, 1-octene, 4-methy 1-1 -pentene, and any combination thereof. In some embodiments, the polypropylene copolymer PCR includes about 90. 1 mol % to about 99.9 mol % of propylene repeat units, such as about 91 mol % to about 99 mol %, such as about 92 mol % to about 98 mol %, such as about 93 mol % to about 97 mol %, such as about 94 mol % to about 96 mol %.

[0025] In some embodiments, the polypropylene copolymer PCR has a backbone architecture of at least one of a random copolymer, a block copolymer, an alternating copolymer, or a gradient copolymer. In one or more embodiments, the polypropylene copolymer PCR is a random copolymer. In one or more embodiments, the polypropylene copolymer PCR includes a molarratio of ethylene repeat units to any one or more comonomer repeat units of about 99: 1 to about 60:40, such as about 95:5 to about 60:40, such as about 90: 10 to about 60:40.

[0026] In some embodiments, the polypropylene copolymer PCR has a Mw, as determined by GPC, of about 380,000 g / mol to about 480,000 g / mol, such as about 415.000 g / mol to about 445,000 g / mol. such as about 420.000 g / mol to about 440,000 g / mol. In some embodiments, the polypropylene copolymer PCR has a density, as determined by (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3, such as about 0.89 g / cm3to about 0.92 g / cm3, such as about 0.89 g / cm3to about 0.91 g / cm3, such as about 0.9 g / cm3. In at least one embodiment, the polypropylene copolymer PCR has a melt index (as determined by ASTM D-1238, 190°C with a 2.16 kg load) of about 0.1 g / 10 min to about 20 g / 10 min, such as about 0.5 g / 10 min to about 5 g / 10 min, such as about 1 g / 10 min to about 2 g / 10 min, such as about 1.5 g / 10 min. In at least one embodiment, the polypropylene copolymer PCR has a tensile strength at yield (as determined by ASTM D256) of about 2.000 psi to about 10,000 psi, such as about 4,000 psi to about 8,000 psi. such as about 4.000 psi to about 6.000 psi. In at least one embodiment, the polypropylene copolymer PCR has a secant modulus (as determined by ASTM D882; 1 % Secant) of about 150,000 psi to about 300,000 psi, such as about 175,000 psi to about 250,000 psi, such as about 200,000 psi to about 250,000 psi.

[0027] In some embodiments, the polypropylene copolymer PCR further includes one or more additional polymers selected from the group consisting of HDPE, LDPE, MDPE, polypropylene, polyester, acrylic resin, polyvinyl alcohol, polyvinyl chloride, polyvinyl acetate, polyvinyl ether, EVA, EVOH, ethylene-acrylic acid copolymers, any one or more nylons, and the like, and mixtures thereof. In at least one embodiment, the one or more additional polymers includes less than 15 wt% of the polypropylene copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.

[0028] In some embodiments, the polypropylene copolymer PCR further includes one or more compatiblizers. such as grafted copolymers of maleic anhydride with HDPE, LLDPE, and / or LDPE. In at least one embodiment, the one or more compatibilizers includes less than 15 wt% of the polypropylene copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.

[0029] In some embodiments, the polypropylene copolymer PCR further includes one or more tie layer material. A tie layer is commonly used in multi-layered film applications as an adhesive applied to prevent film delamination. A tie layer material typically includes a polyolefin base resinas the predominant component and one or more grafted polyolefins. In at least one embodiment, the one or more tie layer materials includes less than 15 wt% of the polypropylene copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.

[0030] In one or more embodiments, the compositional summation of the one or more additional polymers, one or more compatibilizers, and one or more tie layer materials of the polypropylene copolymer PCR includes less than 15 wt% of the polypropylene copolymer PCR, such as about 0.01 wt% to about 15 wt%, such as about 0.01 wt% to about 10 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 1 wt%.Polyolefin resin blends:

[0031] In some embodiments, the polyolefin resin is a blend of any one or more polymeric resins described above. In one or more embodiments, the one or more polymeric resins of the polyolefin resin can be blended via any one or more suitable methods known to one of ordinary skill in the art. Such blending methods can include, solution processing, thermal processing, and / or mechanical processing. In some embodiments, melt screw extrusion is implemented to form the polyolefin resin extrudate, which can then be further processed via pelletization to form a pelletized polyolefin resin. Melt blending is one suitable method for preparing the final polymer blend of the present disclosure, although any suitable polymer blending techniques available to those of ordinary skill in the art may be used. Techniques for melt blending of a polymer with additives of all types are known to those of ordinary skill the art and can typically be used with the present disclosure. In one type of melt blending operation useful with the present disclosure, the individual components of the blend are combined in a mechanical extruder or mixer, and then heated to a temperature sufficient to form a polymer melt.

[0032] The mechanical mixer can be a continuous or batch mixer. Examples of suitable continuous mixers include single screw extruders, intermeshing co-rotating twin screw extruders such as Wemer & PfleidererZSK™ extruders, counter-rotating twin screw extruders such as those manufactured by Leistritz™, and reciprocating single screw kneaders such as Buss™ co-kneaders. Examples of suitable batch mixers are lateral 2-roll mixers such as Banbury™ or Boling™ mixers. The temperature of the melt, residence time of the melt within the mixer, and the mechanical design of the mixer are several well-known variables that control the amount of shear to be applied to the composition during mixing, and can be readily selected by one of ordinary skill in the art based on the disclosure of the disclosure herein.

[0033] In some embodiments, the polyolefin resin is a blend of an unprocessed resin and, optionally a PCR. In one or more embodiments, the polyolefin resin is selected from a blend of an unprocessed HDPE resin and a HDPE copolymer PCR, a blend of an unprocessed HDPE resin and a polypropylene copolymer PCR, a blend of an unprocessed polypropylene resin and a HDPE copolymer PCR, or a blend of an unprocessed polypropylene resin and a polypropylene copolymer PCR.

[0034] In at least one embodiment, the polyolefin resin is a blend of an unprocessed HDPE resin and a HDPE copolymer PCR (hereinafter referred to as a ‘‘blended polyethylene resin”). In some embodiments, the blended polyethylene resin includes about 0.1 wt% to about 99.9 wt% of unprocessed HDPE resin, such as about 10 wt% to about 90 wt%, such as about 25 wt% to about 75 wt%. In at least one alternative embodiment, the blended polyethylene resin includes about 25 wt% to about 100 wt% of unprocessed HDPE resin. In some embodiments, the blended polyethylene resin includes about 0.1 wt% to about 99.9 wt% of HDPE copolymer PCR, such as about 10 wt% to about 90 wt%, such as about 25 wt% to about 75 wt%. In at least one alternative embodiment, the blended polyethylene resin includes about 0 wt% to about 75 wt% of HDPE copolymer PCR.

[0035] In some embodiments, the blended polyethylene resin has a density, as determined by (as determined by ASTM D1505) of about 0.89 g / cm3to about 0.965 g / cm3, such as about 0.94 g / cm3to about 0.96 g / cm3, such as about 0.945 g / cm3to about 0.957 g / cm3. In at least one embodiment, the blended polyethylene resin has a melt index (as determined by ASTM D-1238, 190°C with a 2.16 kg load) of about 0.1 g / 10 min to about 20 g / 10 min, such as about 0.25 g / 10 min to about 2.5 g / 10 min. such as about 0.43 g / 10 min to about 0.45 g / 10 min. In at least one embodiment, the blended polyethylene resin has a tensile strength at yield (as determined by ASTM D882) of about 2,000 psi to about 10,000 psi, such as about 3,000 psi to about 7,000 psi, such as about 3,000 psi to about 6,000 psi. In at least one embodiment, the blended polyethylene resin has a secant modulus (as determined by ASTM D882; machine direction) of about 50,000 psi to about 200,000 psi. such as about 75.000 psi to about 175,000 psi, such as about 100,000 psi to about 150,000 psi.

[0036] In at least one embodiment, the polyolefin resin is a blend of an unprocessed polypropylene resin and a polypropylene copolymer PCR (hereinafter referred to as a “blended polypropylene resin”). In some embodiments, the blended polypropylene resin includes about 0. 1 wt% to about 99.9 wt% of unprocessed polypropylene resin, such as about 10 wt% to about 90 wt%, such as about 25 wt% to about 75 wt%. In at least one alternative embodiment, the blended polypropylene resin includes about 25 wt% to about 100 wt% of unprocessed polypropylene resin. In some embodiments, the blended polyethylene resin includes about 0.1 wt% to about 99 wt% ofpolypropylene copolymer PCR, such as about 10 wt% to about 90 wt%, such as about 25 wt% to about 75 wt%. In at least one alternative embodiment, the blended propylene resin includes about 0 wt% to about 75 wt% of propylene copolymer PCR.

[0037] In some embodiments, the blended polypropylene resin has a density, as determined by (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3, such as about 0.89 g / cm3to about 0.92 g / cm3, such as about 0.89 g / cm3to about 0.91 g / cm3, such as about 0.9 g / cm3. In at least one embodiment, the blended polypropylene resin has a melt index (as determined by ASTM D-1238, 230°C with a 2.16 kg load) of about 0.1 g / 10 min to about 20 g / 10 min, such as about 0.5 g / 10 min to about 5 g / 10 min, such as about 1 g / 10 min to about 2 g / 10 min, such as about 1.5 g / 10 min. In at least one embodiment, the blended polypropylene resin has a tensile strength at yield (as determined by ASTM D256) of about 2,000 psi to about 10,000 psi, such as about 4,000 psi to about 8,000 psi, such as about 4,000 psi to about 6,000 psi. In at least one embodiment, the blended polypropylene resin has a flexural modulus (as determined by ASTM D882; 1% Secant) of about 150,000 psi to about 300,000 psi, such as about 200,000 psi to about 275,000 psi. such as about 215,000 psi to about 245,000 psi.Resin processing:

[0038] Generally, polyolefin resins of the present disclosure are processed into strip-like products for use as containment straps various baling operations.

[0039] In one or more embodiments, a conventional screw-type apparatus is arranged to produce a tube having a predetermined diameter and wall thickness via extrusion of the polyolefin resin. The material is extruded using a temperature of about 150 °C to about 300 °C. The tube having a predetermined width and wall thickness issues from the extruder die and passes immediately into a sizing sleeve where it is cooled by indirect heat exchange with a cooling liquid and at the same time stretched slightly to produce a desired wall thickness. The cooled tube is conveyed through the sizing sleeve at a rate greater than the rate at which the polyolefin resin is extruded, as the difference in conveyance rate and extrusion rate allows for more precise control of the wall thickness of the tube. The tube is then conveyed through a heating apparatus, wherein the tube is reheated and drawn in one or more directions. In such instances, the tube is drawn in the machine and transverse directions followed by being subjected to a cooling gradient, so as to cool the drawn portion of the tube after is conveyed through the heating apparatus. The drawn portion of the tube is then collapsed to form a two layer film which can then be wound, spooled, or otherwise collected.

[0040] In one or more alternative embodiments, a conventional screw-type apparatus is arranged to produce a strip having a predetermined width and thickness via extrusion of the polyolefin resin.The polyolefin resin is extruded using a temperature of about 150 °C to about 300 °C. Upon exiting from the extruder, the strip is suitably supported by a roll conveyor or table and fed directly to a pair of opposed forming rolls positioned with their axes of rotation extending perpendicular to the direction of movement of the polyolefin extrudate. The forming rolls are driven in synchronized relationship and have a cooperating outer surface configuration which is arranged to form the polyolefin strip product to its desired cross-sectional configuration which can be varied longitudinally along the polyolefin strip product. Additionally or alternatively, conventional coextrusion techniques can be implanted to form polyolefin strip products having one or more layers and / or one or more polyolefin compositions. The polyolefin strip product can then be wound, spooled, or otherwise collected. Additionally or alternatively, the polyolefin strip product to a desired length and width using any one or more methods know to one of ordinary skill in the art.

[0041] Additionally or alternatively, strip-like products for use as containment straps in various baling operations can be produced via any one or more additional processes known to one of ordinary skill in the art. In some embodiments, straps formed from resins and processes disclosed herein can have a width of about 0.25 in. to about 0.88 in., such as about 0.5 in. to about 0.6 in., and a thickness of about 0.015 in. to about 0.03 in., such as about 0.02 in. to about 0.025 in. In some embodiments, straps formed from resins and processes disclosed herein can have a length of about 1 meter to about 50 meters, such as about 5 meters to about 25 meters.Method of baling and using the straps

[0042] Straps formed using polyolefin resins described above can be used to bind and / or contain plastic waste and other components within a bale of recycled material. In one or more embodiments, a strapping apparatus can be used to apply one or more strapping materials to a bale of recycled materials having dimensions of height, length, and width. In some embodiments, the plastic waste bales have dimensions of height, length, and width. In one or more embodiments, the plastic waste bale has dimensions of about 30”x42”x48” and a bale density of about 15 lbs. / ft3to about 20 lbs. / ft3. In one or more embodiments, the plastic waste bale has dimensions of about 30"x48"x60" and a bale density of about 15 lbs. / ft3to about 20 lbs. / ft3. In one or more embodiments, the plastic waste bale has a weight of, at least, 35,000 lbs.

[0043] In some embodiments, a strapping apparatus is coupled to one or more independent tying systems and / or strapper heads for dynamically applying and / or attaching plastic straps or wire ties to a baled material. In some embodiments, the one or more independent tying systems can include a plastic tying system having a plastic closing mechanism (such as a welder) and / or a wire tying system having a wire closing mechanism (such as a knotter). In one or more embodiments, each of the one or more independent tying systems can be configured to incorporate straps havingindependently selected polymeric compositions, such as those formed from any one or more polyolefin resin described above. The one or more independent tying systems may be oriented along an x-axis of the strapping apparatus (width) and / or along a z-axis of the strapping apparatus (height), offset with respect to the front side and the rear side of the strapping apparatus along a y- axis corresponding to the front-to-rear depth of the strapping apparatus. In one or more embodiments, a common controller may be configured within the strapping apparatus to coordinate which straps are applied by the strapping machine to one or more bales of recycled material. In some embodiments, the common controller may be utilized to alternately apply plastic straps of different compositions to the baled material. Additionally, the common controller controls the number of straps applied to the bale, and the position and tension at which the straps are applied, such the recycled plastic waste material is contained within the bale without leakage thereof throughout transport and storage of the bale.

[0044] A bale of recycled material can be produced by any one or more processes known by one of ordinary skill in the art. In some embodiments, a bale of recycled material can be produced by receiving, by a strapping apparatus, a plurality' of recycled plastic waste material and applying at least one strap of a first tying medium provided by a first ty ing system. In some embodiments, a bale of recycled material can be produced by receiving, by a strapping apparatus, a plurality of recycled plastic waste material, applying at least one strap of a first tying medium provided by a first tying system, and applying at least one strap of a second tying medium provided by a second tying system. In such embodiments, the first and second tying mediums can be independently selected from the polyolefin resins discussed above.

[0045] In one or more embodiments, a bale of recycled material can be produced by (1) advancing the recycled material to be baled to a first position along the strapping apparatus, (2) applying at least one strap of a first tying composition by a first tying system, (3) advancing the material to be baled to a second position along the strapping apparatus, (4) applying at least one strap of a second tying composition by a second tying system, (5) advancing the material to be baled to a third position along the strapping apparatus, and (6) applying at least one strap of a third tying composition by a third tying system. In such embodiments, the first, second, and third tying compositions can be independently selected from the polyolefin resins discussed above. Additionally or alternatively, the recycled material to be baled can be advanced to a plurality of intermediate positions between the first position and third position. Upon each advancement to an intermediate position, one or more additional straps of polyolefin compositions (e.g., the same or different composition as the first or second ty ing compositions) are applied to the recycled material to be baled by one or more intermediate tying systems.

[0046] Overall, polyolefin resins disclosed herein can be implemented as alternative class of materials for straps used in baling operations of recycled plastic products. The polyolefin resins disclosed herein exhibit comparable physical and mechanical properties to various commercially available nylon materials. As such, replacement of such nylons with polyolefin materials and straps thereof, as described above, would alleviate processing issues (e.g.. gelation and material inhomogeneity) commonly associated with using current nylon straps in polyolefin recycling operations. Additionally, recycled waste plastic products are capable of further reprocessing into additional strap material, thus producing a cyclic economy of reused plastic materials.

[0047] The phrases, unless otherwise specified, "consists essentially of and "consisting essentially of do not exclude the presence of other steps, elements, or materials, whether or not, specifically mentioned in this specification, so long as such steps, elements, or materials, do not affect the basic and novel characteristics of the present disclosure, additionally, they do not exclude impurities and variances normally associated with the elements and materials used.

[0048] For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. Thus, evei ' point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0049] All documents described herein are incorporated by reference herein, including any priority documents and or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications can be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including” for purposes of United States law. Likewise whenever a composition, an element or a group of elements is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “is” preceding the recitation of the composition, element, or elements and vice versa.

[0050] While the present disclosure has been described with respect to a number of embodiments and examples, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope and spirit of the present disclosure.

Claims

CLAIMS1. A method of making a formed polyolefin strip, the method comprising: providing a polyolefin resin comprising a first polymer component and an optional second polymer component to form the polyolefin resin, wherein: the polyolefin resin has a density (as determined by ASTM D1505) of about 0.89 g / cm3to about 0.965 g / cm3and a melt index (as determined by ASTM D-1238; 190 °C with a 2.16 kg load) of about 0.25 g / 10 min to about 2.5 g / 10 min; extruding the polyolefin resin to form a polyolefin strip; forming the polyolefin strip via a pair of opposed forming rolls to produce a formed polyolefin strip; and collecting the formed polyolefin strip via winding, spooling, or a combination thereof.

2. The method of claim 1, wherein the first polymer component is an unprocessed high density polyethylene (HDPE) resin.

3. The method of claim 1, wherein the second polymer component is a high density polyethylene (HDPE) post-consumer resin (PCR).

4. The method of claim 1, wherein the second polymer component is a high density polyethylene (HDPE) copolymer post-consumer resin (PCR).

5. The method of claim 2, wherein the HDPE resin has a density (as determined by ASTM D1505) of about 0.94 g / cm3to about 0.975 g / cm3.

6. The method of claim 2, wherein the HDPE resin has a melt index (as determined by ASTM D-1238; 190 °C with a 2.16 kg load) of about 0.1 g / 10 min to about 10 g / 10 min.

7. The method of claim 3, wherein the HDPE PCR resin has a density (as determined by ASTM D1505) of about 0.91 g / cm3to about 0.97 g / cm3.

8. The method of claim 3, wherein the HDPE PCR has a melt index (as determined by ASTM D-1238; 190 °C with a 2. 16 kg load) of about 0.1 g / 10 min to about 10 g / 10 min.

9. The method of claim 1, wherein the first polymer component comprises about 25 wt% to about 100 wt% of the polyolefin resin.

10. The method of claim 1, wherein the second polymer component comprises about 0 wt% to about 75 wt% of the polyolefin resin.

11. A method of making a formed polyolefin strip, the method comprising: providing a polyolefin resin comprising a first polymer component and an optional second polymer component to form the polyolefin resin, wherein: the polyolefin resin has a density (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3and amelt index (as determined by ASTM D-1238; 230 °C with a 2.16 kg load) of about 0.5 g / 10 min to about 5 g / 10 min; extruding the polyolefin resin to form a polyolefin strip; forming the polyolefin strip via a pair of opposed forming rolls to produce a formed polyolefin strip; and collecting the formed polyolefin strip via winding, spooling, or a combination thereof.

12. The method of claim 11, wherein the first polymer component is an unprocessed polypropylene resin.

13. The method of claim 11, wherein the second polymer component is a polypropylene postconsumer resin (PCR).

14. The method of claim 11, wherein the second polymer component is a polypropylene copolymer post-consumer resin (PCR).

15. The method of claim 12. wherein the unprocessed polypropylene resin has a density (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3.

16. The method of claim 12, wherein the unprocessed polypropylene resin has a melt index (as determined by ASTM D-1238; 230 °C with a 2. 16 kg load) of about 0. 1 g / 10 min to about 20 g / 10 mm.

17. The method of claim 13, wherein the polypropylene PCR resin has a density (as determined by ASTM D792) of about 0.875 g / cm3to about 0.925 g / cm3.

18. The method of claim 13, wherein the polypropylene PCR has a melt index (as determined by ASTM D-1238; 230 °C with a 2. 16 kg load) of about 0.1 g / 10 min to about 20 g / 10 min.

19. The method of claim 11, wherein the first polymer component comprises about 25 wt% to about 100 wt% of the polyolefin resin.

20. The method of claim 11, wherein the second polymer component comprises about 0 wt% to about 75 wt% of the polyolefin resin.