Patent Application
20250019529
Disclosed herein are multi-layer devices, such as tubes, conduit, tubular members, housings, enclosures, fabrics, materials, or any other suitable mechanical form factors, which comprise a multi-layer structure and incorporate at least one layer that comprises a mixture of a virgin high density polyethylene (HDPE) and a recycled HDPE.
In this specification where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions, or is known to be relevant to an attempt to solve any problem with which this specification is concerned.
Post-consumer recycled (PCR) resins and post-industrial recycled (PIR) resins (collectively referred to herein as “sustainable resins”) are technologically deficient in mechanical and rheological properties. This state of being may be due to adverse effects occurring in the closed loop of circular value chains driven by a wide range of marketplace entities, such as compounders, converters, brand owners, retailers, consumers, waste management, and the like. In addition, as diverse feedstocks for these sustainable materials progress along the circular value chains, certain effects resulting from lack of integrity, contaminations, molecular degradations, and the like, are adversely reflected on consistency. The net effects of the above are compromised end-use performance in the field, as well as processibility on the manufacturing floor.
Due to the above-discussed deficiencies of sustainable resins, there have been certain technological limitations in their commercial use in conduit applications. Thus, there may be a desire to address these deficiencies to enable commercial use of sustainable resins that can lead to much-needed sustainability and reduction of waste products.
While certain aspects of conventional technologies have been discussed herewith to facilitate disclosure of the disclosure, this application does not disclaim these technical aspects in any way, and it is contemplated that the claimed disclosure may encompass or include one or more of the conventional technical aspects discussed herein.
This disclosure at least partially addresses various technological problems noted above. For example, some embodiments of this disclosure may include a device, such as a tube, a conduit, a tubular member, a housing, an enclosure, a fabric, a material, or any other suitable mechanical form factor, which may contain a layer including a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments may include a device comprising: a tube including a first layer, a second layer, and a third layer, wherein the first layer is innermost, wherein the third layer is outermost, wherein the second layer extends between the first layer and the third layer, wherein the first layer is solid, wherein the third layer is solid, wherein the second layer is thicker than each of the first layer and the third layer, wherein the second layer consists (i) a HDPE or (ii) a combination of the HDPE and an additive where the HDPE is a major component and the additive is a minor component, wherein the HDPE includes a virgin HDPE and a recycled HDPE, wherein the virgin HDPE has (i) a weight average molecular weight inclusively between about 200,000 grams per mole (g/mol) and about 400,000 g/mol, (ii) a toughness inclusively between about 90 megapascal (MPa) and about 150 MPa, and (iii) an impact resistance inclusively between about 140 joules per meter (J/m) at a temperature inclusively between about 15 degrees Celsius and about 30 degrees Celsius and about 180 J/m at a temperature inclusively between about 15 degrees Celsius and about 30 degrees Celsius, wherein the virgin HDPE is more dense than the recycled HDPE, wherein the recycled HDPE has (i) a weight average molecular weight equal to or less than about 150,000 g/mol, (ii) a toughness equal to or less than about 32 MPa, and (iii) an impact resistance equal to or less than about 75 J/m at a temperature inclusively between about 15 degrees Celsius and about 30 degrees Celsius, wherein the first layer is exposed to an object and the second layer is not exposed to the object when the object longitudinally extends through the tube along the first layer.
Some embodiments include a device including at least a first layer, a second layer, and a third layer, where the second layer (i) extends between the first layer and the third layer and (ii) includes a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a method comprising: supplying a device to a user, wherein the device includes at least a first layer, a second layer, and a third layer, where the second layer (i) extends between the first layer and the third layer and (ii) includes a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a method comprising: manufacturing a device, wherein the device includes at least a first layer, a second layer, and a third layer, where the second layer (i) extends between the first layer and the third layer and (ii) includes a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a device including a layer including a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a method comprising: manufacturing a device including a layer including a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a method comprising: supplying a device to a user, wherein the device including a layer including a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a composition comprising: a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a method comprising: manufacturing a mixture of a virgin HDPE and a recycled HDPE.
Some embodiments include a method comprising: supplying a mixture to a user, wherein the mixture includes a virgin HDPE and a recycled HDPE.
Thus, more specifically disclosed herein is a composition of matter comprising: a first layer having a first and a second side, a second layer having a first and a second side, and a third layer having a first and a second side, wherein the second layer extends between and is in intimate contact with the first layer and the third layer such that the first side of the first layer is in face-to-face contact with the first side of the second layer, and the first side of the third layer is in face-to-face contact with the second side of the second layer; wherein the first and third layers consist essentially of a virgin thermoplastic resin; and wherein the second layer comprises virgin thermoplastic resin and recycled thermoplastic resin.
The second layer may comprise at least about 15% recycled thermoplastic resin, or at least about 30% recycled thermoplastic resin.
All references to singular characteristics or limitations of the disclosed method and device shall include the corresponding plural characteristic or limitation, and vice-versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made. The indefinite articles “a” and “an” mean “one or more.” The word “or” is used inclusively and should be read as “and/or.”
All combinations of method steps disclosed herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by the context in which the referenced combination is made.
The method disclosed herein can comprise, consist of, or consist essentially of the essential elements and steps described herein, as well as any additional or optional ingredients, components, or limitations described herein or otherwise useful.
The terminology used herein can imply direct or indirect, full or partial, and/or temporary or permanent action or inaction or connectivity. For example, when an element is referred to as being “on,” “connected” or “coupled” to another element, then the element can be directly on, connected or coupled to the other element or additional intervening elements can be present between the recited elements. The same is true of the phrase “operationally connected.” Elements that are operationally connected may be directly or indirectly connected. They may be physically in contact with one another, but are not required to be so. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
As used herein, each of terms “comprises,” “includes,” “incorporates”, “contains” and “comprising,” “including”, “incorporating”, and “containing” specify the presence of the stated features, integers, steps, operations, elements, or components, but do not preclude the presence or addition of one or more additional features, integers, steps, operations, elements, components, or groups thereof. The terms “consists of” and “consisting of” are close-ended, meaning the subsequently recited elements are present, but no other elements.
As used herein, a term “about” or “substantially” refers to a +/−10% variation from the stated variable, value, or term.
Although various terms, such as first, second, third, and so forth can be used herein to describe certain elements, components, regions, layers, or sections, note that these elements, components, regions, layers, or sections should not necessarily be limited by such terms. Rather, these terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. As such, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section, without departing from this disclosure.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by skilled artisans to which this disclosure belongs. These terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant technical field.
Intrinsic viscosity in combination with MW reveals essential information about a polymer's molecular structure, density, and branching.
As noted above, sustainable resins have certain technological deficiencies, such as deficiencies in mechanical and rheological properties. For example, sub-par mechanical and rheological properties of recycled resins (as compared to virgin resins) results in reduced processibility of the resins during the manufacturing process. These deficiencies also tend to adversely compromise the performance of the end-product when ultimately deployed as intended. Thus, recycled resins have not been widely deployed, for example, in conduit applications or other form factors.
Part of the problem is that recycled polymers originate from an extensive variety of sources. As a result, they have been subjected to an equally extensive variety of processing, including hygienic, thermal, and mechanical strains. Any number of industrial actors, such as compounders, converters, brand owners, retailers, consumers, waste managers, and the like, may have subsequently manipulated the resin. These actions negatively impact the mechanical and rheological properties of recycled resins. This is on top of the relatively low rate at which HDPE is recycled. In the U.S., in 2019, approximately 997.9 million pounds of HDPE was recovered for recycling. This amounts to only 19.6% of the virgin HDPE generated for use in the U.S. in 2019. (See Stina, 2019 Annual Plastic Recycling Report.) Use of post-consumer, recycled HDPE resins also present other difficulties, such as contamination of the resins with dyes, plasticizers, and other processing aids, molecular degradation from exposure to heat, sunlight, acids, bases, etc. These inconsistencies in the recycled HDPE feedstocks pose technological challenges during product development. Not surprisingly then, recycled materials are significantly compromised in their mechanical properties. The compromised mechanical properties of recycled resins result in increased failures in the field when the recycled resins are used in place of virgin resin.
For example, as shown in
Impact resistance values of these materials show a similar trend. As shown in
The sizable reduction in toughness seen in
The weight average (Mw) and number average (Mn) molecular weights of the recycled and virgin polymers were also analyzed. The results are shown in
As seen from
The lack of consistency in processability is further exacerbated by the sheer diversity of the recycled feedstocks themselves. As the raw feedstocks of these recycled materials are collected, chipped, combined, and then re-introduced into the market, it is perhaps inevitable that the lack of material uniformity would adversely impact processing consistency. To elucidate variations in the sustainable and virgin polymers, enthalpy, one of the measures of inherent thermal properties, was determined over multiple lots.
Recycled polymers exhibit variations in still other physical characteristics as compared to virgin polymers. Again, these variations and inconsistencies trickle down to adversely impact the quality of conduit (or any other final product) that includes these materials. Additional data showing differences in the rheological and inherent physical properties of sustainable and virgin polymers are shown in
Similar results are seen in the variability of the density across a lot of virgin HDPE versus a lot of recycled HDPE. See
As disclosed herein, these deficiencies in the processing of recycled polymers can be mitigated by incorporating the recycled resins into multi-layered conduit (or other form factors disclosed herein) configurations, wherein the ultimate mechanical properties of the multi-layered conduit (or other form factors disclosed herein) are superior to the mechanical properties of a single-layer or multi-layer conduit configurations consisting solely of virgin polymers or consisting solely of recycled polymers. For example, recycled resins can be included in single-layer or multi-layered conduit (or other form factors disclosed herein) configurations, such as micro-ducts (MDs), conduits, pipes, housings, enclosures, tubes, tubular members, cylinders, multi-dimensional volumes, and the like (without limitation), without compromising their respective end-use performance, while also making such configurations more sustainable because they use recycled materials.
For sake of brevity only, the following discussion will use the word “conduit” as a catch-all phrase to cover the various form factors disclosed in the immediately preceding paragraph, i.e., micro-ducts, conduits, pipes, housings, enclosures, tubes, tubular members, cylinders, multi-dimensional volumes, and the like, without limitation.
The composition of matter disclosed herein comprises recycled polymeric resins and virgin (e.g., fresh or freshly prepared) polymeric resins to counter these technological deficiencies. Any thermoplastic resin (both recycled and virgin) can be used, without limitation. Thermoplastic resin is defined broadly herein to include (by way of example and not limitation): poly(aklylenes) such as polyethylene, polypropylene, and the like, polycarbonates, polyacrylics, polyamides, polystyrenes, thermoplastic co-polymers such as ABS (Acrylonitrile Butadiene Styrene), polyesters, and the like. In general, high-density polyethylene (“HDPE”) is preferred. Again, for sake of brevity only, HDPE is used herein to denote high-density polyethylene itself, and any other recyclable thermoplastic resin, without limitation.
The virgin and recycled polymers may be incorporated into the conduit via chemistry-based approaches, such as by blending or mixing the virgin and recycled polymers together to yield a uniform polymeric composition comprising both virgin and recycled molecules that are intimately associated with one another at the molecular level. Alternatively, the virgin and recycled polymers can be associated with one another at a macro-scale, structure-based level as in multilayer constructions.
Certain adverse physical characteristics of the recycled resins may be attenuated by combining the recycled resins with virgin polymers to form a polymer blend, mixture, or composition containing both recycled and virgin polymers, with no additional ingredients or in combination or admixture with others compositions, blends, and the like. Additionally, in the multi-layer conduit configuration, a central (or non-central) layer containing the polymer blend, mixture, or composition may be surrounded or enclosed within layers that consist of or consist essentially of virgin polymers.
An illustrative example of such a multi-layer conduit configuration is shown in
Some versions of the composition of matter may involve a form factor (e.g., a tube, a conduit) including a first layer (e.g., plastic, polymer, metal, metal alloy, rubber, wood, HDPE, virgin HDPE, recycled HDPE), a second layer, and a third layer (e.g., plastic, polymer, metal, metal alloy, rubber, wood, HDPE, virgin HDPE, recycled HDPE). The first layer and the third layer may, as shown in numerals 10 and 14 in
The device may include a fourth layer (e.g., plastic, polymer, metal, metal alloy, rubber, wood, HDPE, virgin HDPE, recycled HDPE), a fifth layer (e.g., plastic, polymer, metal, metal alloy, rubber, wood, HDPE, virgin HDPE, recycled HDPE), a sixth layer (e.g., plastic, polymer, metal, metal alloy, rubber, wood, HDPE, virgin HDPE, recycled HDPE), or more layers, which may or may not be thicker, thinner, or be identical in thickness to the first layer, the second layer, or the third layer. For example, the fourth layer, the fifth layer, or the sixth layer may or may not extend, which includes interposing, between the first layer and the third layer or the first layer and the second layer or the third layer and the second layer. For example, at least one of the first layer, the second layer, or the third layer may be a single layer or a set of layers forming a single layer. For example, the fourth layer, the fifth layer, or the sixth layer may be a single layer or a set of layers forming a single layer. The first layer may or may not be innermost. The third layer may or may not be outermost. The first layer may be solid and unbroken in any way such that the second layer may be protected or isolated by the first layer. However, this configuration is not required and the first layer may be perforated. Likewise, the third layer may be solid and unbroken such that the second layer may be protected or isolated by the third layer. However, this configuration is not required and the third layer may be perforated.
When the device takes the form of a tube, a duct, or a conduit, then the tube, duct, or the conduit may be weather-proof or water-proof or weather-resistant or water-resistant. For example, the tube, duct, or the conduit may be buried below ground (e.g., soil) or deposited on a floor of a body of water (e.g., a river, a lake, a sea, an ocean). For example, the tube, the duct, or the conduit may house or convey cables, wires, ropes, fiber optic cables, electrical cables, fluids (liquids or gases), or other materials, whether used in telecommunications, electrical, medical, vehicular transportation, consumer products, construction, projectile barrels, missiles, rockets, trains, or fluid transportation industries. For example, the tube, duct, or the conduit may be used for housing and routing fiber optic cables, electrical cables (or wires, ropes, chains, lines, or other elongated items), data cables (or wires, ropes, chains, lines, or other elongated items), fluids (e.g., liquids, gases), or other objects, whether used in telecommunications, electrical, medical, vehicular transportation, consumer products, construction, projectile barrels, missiles, rockets, trains, or fluid transportation industries. For example, the tube, duct, or conduit may be included in aerostructures, wings, tails, ailerons, winglets, boats, submarines, ships, missiles, automotive frontal grills, car panels, windshields, wheels, tires, rollers, medical tubing, swallowable medical devices, implantable medical devices, rain-resistant or rain-proof clothing or shoes, snow-blower augers, cutting blades, door or cabinet hinges, pads, gauze, fabrics, or other objects. For example, the tube, duct, or the conduit may be used for housing and routing cables (or wires, ropes, chains, lines, or other elongated items), water (or other fluids or liquids or gases), or other objects, whether natural or artificial. For example, the tube, duct, or the conduit may be used to transport, pass, guide, convey a solid (e.g., objects, cables, chains, ropes, beads, particulates, powders, boxes), a sludge, or a fluid (e.g., liquid, gas, steam, water, alcohol, edible, non-edible, gasoline, oil) including electronic and telecommunication wires and fiber optics, singly or in plural, and which may be sheathed or unsheathed; water; aqueous and non-aqueous solvents and solutions; alcohol; alcohol-based solvents and solutions; inert and non-inert gases; or others. This transport, pass, guide, convey may be through or along a surface (e.g., inner, outer) that is coated, uncoated, structured, or configured, as disclosed herein.
Some embodiments may include a device comprising a tube including a first layer, a second layer, and a third layer, wherein the first layer is innermost, wherein the third layer is outermost, wherein the second layer extends between the first layer and the third layer, wherein the first layer is solid, wherein the third layer is solid, wherein the second layer is thicker than each of the first layer and the third layer, wherein the second layer consists (i) a high density polyethylene (HDPE) or (ii) a combination of the HDPE and an additive where the HDPE is a major component and the additive is a minor component, wherein the HDPE includes a virgin HDPE and a recycled HDPE, wherein the virgin HDPE has (i) a weight average molecular weight inclusively between about 200,000 grams per mole (g/mol) and about 400,000 g/mol, (ii) a toughness inclusively between about 90 megapascal (MPa) and about 150 MPa, and (iii) an impact resistance inclusively between about 140 joules per meter (J/m) at a temperature inclusively between about 15 degrees Celsius and about 30 degrees Celsius and about 180 J/m at a temperature inclusively between about 15 degrees Celsius and about 30 degrees Celsius, wherein the virgin HDPE is more dense than the recycled HDPE, wherein the recycled HDPE has (i) a weight average molecular weight equal to or less than about 150,000 g/mol, (ii) a toughness equal to or less than about 32 MPa, and (iii) an impact resistance equal to or less than about 75 J/m at a temperature inclusively between about 15 degrees Celsius and about 30 degrees Celsius, wherein the first layer is exposed to an object and the second layer is not exposed to the object when the object longitudinally extends through the tube along the first layer.
A particularly favored version of the device comprises at least a first layer, a second layer, and a third layer, where the second layer extends between the first layer and the third layer and comprises a mixture of a virgin HDPE and a recycled HDPE. In this favored version, the first and third layers may also consist essentially of virgin HDPE (or other virgin thermoplastic polymer resin). Here, the term “consist[s] essentially of” does not exclude conventional additives such as plasticizers, inks, dyes, release agents, and the like, that are used with thermoplastic polymers generally and HDPE specifically, but it does exclude the presence of recycled polymer resin.
Also disclosed herein is a method of supplying a device to a user. The device includes at least a first layer, a second layer, and a third layer, where the second layer extends between the first layer and the third layer, the second layer comprises a mixture of a virgin HDPE and a recycled HDPE, and the first and third layers consist essentially of virgin HDPE (or other virgin thermoplastic polymer resin).
Likewise disclosed herein is a method of manufacturing a device, wherein the device includes at least a first layer, a second layer, and a third layer, where the second layer extends between the first layer and the third layer, the second layer comprises a mixture of a virgin HDPE and a recycled HDPE, and the first and third layers consist essentially of virgin HDPE (or other virgin thermoplastic polymer resin). The method comprising bringing into intimate, face-to-face contact a first face of the first layer with a first face of the second layer, and a first face of the third layer with a second face of the second layer, such that the second layer is sandwiched between or encapsulated by the first and third layers. Any of the three layers may be continuous or perforated (uniformly or non-uniformly). The method can be accomplished via co-extrusion of the first, second, and third layers, or via lamination of the first, second, and third layers in a suitable lamination press.
By way of example and not limitation, Table 3 summarizes a series of conduits fabricated according to the present disclosure. Here, the inner layer (i.e., layer 12 in
To further identify effects of layer thicknesses and (a) symmetry in the 1¼″, three-layer conduits, different configurations were investigated each varying thicknesses by percentage such as [10//80//10] (Outer//Middle//Inner, mils) (Comparative Example 1), [30//60//10](Comparative Example 2), [25//50//25] (Comparative Example 3), and [30//40//30](Comparative Example 4). The corresponding toughness data is shown in
In the following examples, the middle layer of the three-layer construction includes a blend of the virgin and sustainable HDPE at 50/50 by wt % sheathed between the virgin HDPE layers of 10% and 20% in thickness by percentage, respectively, in a symmetric manner, resulting in the configurations of [10//80 (40/40 wt %)//10] (Example 1) and [20//60 (30/30 wt %)//20] (Example 2). Referring again to
It is contemplated by the present disclosure that the blended or mixed middle layer comprising the recycled polymer in combination with the virgin polymer, whether with or not with an additive where the HDPE is a major component and the additive is a minor component, can be as thick as technically tolerable, which may in turn be translatable into the thinnest possible inner/outer layers that can still deliver acceptable processibility and end-use product performance.
The blend or mix ratio of the sustainable polymer to the virgin polymer may or may not be limited, and can be any suitable blend or mix ratio that allows for the incorporation of the highest suitable amount of the sustainable polymer in the resin blend, while maintaining the unexpected and superior mechanical and rheological properties of the conduits that meet acceptable product and process requirements.
Various measurement techniques were used to measure the mechanical and rheological properties of the constituent polymers and resulting conduits including, but not limited to, melt flow index (MFI), density, and environmental stress-cracking resistance (ESCR).
MFI provides snapshot information on rheological properties, and is used to differentiate various HDPE grades such as extrusion, blow molding, injection molding, and the like. In addition, MFI can be used for quality control on various internal and external masterbatches (MB). The testing conditions to measure MFI are most commonly stated as temperature/load, and a 190° C./2.16 kg for the majority of HDPE resins and MBs according to ASTM D1238 has been conventionally used. One of the expected and prevalent deficiencies of the sustainable HDPE resins is molecular degradation, and MFI may provide a speedy verdict on the severity of any such molecular degradation resulting from strenuous life cycles of the sustainable polymers prior to incorporation into the resin blend of the present disclosure.
The density of HDPE ranges from about 0.93 g/cm3 to about 0.97 g/cm3, which is an insightful measure of inherent properties of the material. The density data of the incoming, sustainable HDPE resins may be used to determine whether to release such sustainable resins to production.
ESCR is frequently employed as a surrogate test method to predict longevity of materials/products, in an expedited manner. Due to its inherent nature of the abusive and harsh environment in which test specimens are placed, ESCR lends itself to evaluating integrity of the incoming, sustainable HDPE resins and thus can be effectively utilized to determine their suitability against criteria currently being in development.
As various changes could be made in the above methods and compositions without departing from the scope of the disclosure, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense. Any numbers expressing quantities of ingredients, constituents, reaction conditions, and so forth used in the specification are to be interpreted as encompassing the exact numerical values identified herein, as well as being modified in all instances by the term “about.” Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the subject matter presented herein are approximations, the numerical values set forth are indicated as precisely as possible. Any numerical value, however, may inherently contain certain errors or inaccuracies as evident from the standard deviation found in their respective measurement techniques. None of the features recited herein should be interpreted as invoking 35 U.S.C. § 112, paragraph 6, unless the term “means” is explicitly used.
The application claims the benefit of U.S. provisional application Ser. No. 63/454,132, filed Mar. 23, 2023, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63454132 | Mar 2023 | US |
