Magnet wire with thermoplastic insulation

Abstract

An electromagnetic wire including an extruded insulation formed of multiple layers of different materials is described. The electromagnetic wire may include a conductor and an insulation formed around the conductor. The insulation may include a first layer of extruded thermoplastic insulation formed around the conductor and a second layer of extruded thermoplastic insulation formed around the first layer of extruded thermoplastic insulation. The first layer may be formed of a first polymer material having a first thermal index, and the second layer may be formed of a second polymer material having a second thermal index higher than the first thermal index.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 062,501, filed on August 7, 2020, entitled “Magnet Wire with Thermoplastic Insulation,” the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] Embodiments of the present disclosure relate generally to magnet wire and, more particularly, to magnet wire including an extruded insulation formed from multiple layers of different materials. Background Art

[0004] Electromagnet wire, also known as winding wire or magnetic winding wire, is used in various motors and equipment, such as inverter drive motors, motor starter generators, transformers, etc. Typically, the magnet wire is constructed by applying an electrical insulator to a metal conductor (e.g., copper, aluminum, or alloy conductor). The insulator provides electrical integrity and prevents short circuits in the magnet wire. Conventional insulators are typically composed of polymer enamel films, which are applied in continuous layers and cured in an oven. The enamel layer is typically applied as a varnish containing a thermosetting polymer material suspended in a solvent, and the solvent is thermally cured to remove the solvent. In order to achieve higher dielectric strength and partial discharge performance to meet the increased electrical performance standards, it is usually necessary to apply a larger number of layers, and thus make the enamel thicker. However, each continuous passage through the furnace reduces the adhesion between the enamel and the conductor, and it is difficult to build an enamel thickness beyond a certain point. In addition, the increased enamel layer may cause the solvent to foam or bead and / or reduce flexibility. In addition, the method for applying the enamel insulator is energy intensive and inefficient, and the solvent used is usually a hazardous material that must be properly handled.

[0005] Recently, attempts have been made to form magnet wire insulation from extruded thermoplastic materials. Thermoplastic insulators are extruded onto bare conductors or conductors having a base enamel insulator. For example, a relatively thick layer of a high performance material, such as polyetheretherketone ("PEEK"), can be extruded onto a conductor. As another example, U.S. Patent 9,224,523 describes an magnet wire in which PEEK is extruded onto an enamel layer. Similarly, U.S. Patent 9,324,476 describes an magnet wire in which PEEK or polyaryletherketone ("PAEK") is extruded onto an enamel layer. Using certain high performance thermoplastic materials, insulating materials having properties similar to those of certain enamel materials can be formed. For example, PEEK can have properties similar to those of thermosetting polyimides.

[0006] However, relatively high performance thermoplastic materials are expensive and increase the cost of magnet wire relative to conventional insulation utilizing all enamel. For example, thermoplastic PEEK can have a cost two to four times greater than thermoset polyimide. Thus, there is an opportunity for an improved insulated magnet wire, and more specifically, an improved magnet wire including a thermoplastic insulation formed of multiple layers of different materials. In particular, there is an opportunity for an improved magnet wire including a base layer of a lower cost or lower performance first polymer material and a second layer of a higher performance second polymer material. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The detailed description is made with reference to the accompanying drawings. In the drawings, the leftmost digit of a reference number identifies the drawing in which the reference number first appears. The use of the same reference number in different drawings indicates similar or identical items; however, various embodiments may utilize elements and / or components other than those shown in the drawings. In addition, the drawings are provided to illustrate the example embodiments described herein and are not intended to limit the scope of the present disclosure.

[0008] Figure 1 is a perspective view of an exemplary magnet wire including an extruded insulation formed from multiple layers of different materials according to an illustrative embodiment of the present disclosure.

[0009] Figures 2A-2D is a cross-sectional view of an exemplary magnet wire construction including an extruded insulation formed from multiple layers of different materials according to an illustrative embodiment of the present disclosure.

[0010] Figure 3 is a schematic diagram of an exemplary system that may be used to form extruded insulation on magnet wire according to an illustrative embodiment of the present disclosure.

[0011] Figure 4 is a flow chart depicting an example method for forming a magnet wire including an extruded insulation formed from multiple layers of different materials according to an illustrative embodiment of the disclosure. DETAILED DESCRIPTION

[0012] Various embodiments of the present disclosure relate to an electromagnetic wire, which includes a conductor and an insulator formed around the conductor, wherein a plurality of layers are formed of different extruded polymer materials. The insulator may include at least a first layer of extruded thermoplastic insulator formed around the conductor and a second layer of extruded thermoplastic insulator formed around the first layer. The first layer may be formed of a first polymer material having a first thermal grade, a first thermal index, and / or a first melting temperature, and the second layer may be formed of a second polymer material different from the first polymer material and having a second thermal grade higher than the first thermal grade, a second thermal index higher than the first thermal index, and / or a second melting temperature higher than the first melting temperature. In some embodiments, the first layer of thermoplastic insulator may be formed directly around the conductor. In other embodiments, one or more base insulator layers may be formed around the conductor, and the first layer of thermoplastic insulator may be formed around the base insulator layer. For example, one or more layers of polymer enamel insulator layers may be formed around the conductor, and the first layer of thermoplastic insulator may be formed around the enamel.

[0013] Other embodiments of the present disclosure relate to methods of forming an electromagnetic wire, the electromagnetic wire comprising a conductor and an insulator formed around the conductor, the insulator comprising a plurality of different layers of extruded thermoplastic material. A conductor may be provided, and insulation may be formed around the conductor. Forming the insulation may include forming a first layer of thermoplastic insulation around the conductor and a second layer of thermoplastic insulation around the first layer. Forming the first layer may include extruding a first polymer material having a first thermal grade, a first thermal index, and / or a first melting temperature. Forming the second layer may include extruding a second polymer material different from the first polymer material and having a second thermal grade higher than the first thermal grade, a second thermal index higher than the first thermal index, and / or a second melting temperature higher than the first melting temperature.

[0014] In various embodiments of the present disclosure, various different polymer materials can be used as needed to form an extruded thermoplastic insulation layer. For example, a lower performance and / or cheaper material can be used to form the first layer, and a higher performance material can be used to form the second layer. In some embodiments, the first polymer material may include at least one of polyester, copolyester, nylon, polyphenylene sulfide ("PPSU"), polyphenylsulfone ("PPS"), polyethersulfone ("PESU"), cross-linked polyethylene, polycarbonate, polystyrene, acrylic, fluoropolymer and / or other suitable polyolefin materials. As needed, the first polymer material can be formed by a blend or mixture of multiple polymer materials. In some embodiments, the second polymer material can include at least one of polyetheretherketone ("PEEK"), polyaryletherketone ("PAEK") or polyetherketoneketone ("PEKK"). As needed, the second polymer material can be formed by a blend or mixture of multiple polymer materials.

[0015] As desired, the first polymer material and the second polymer material may be selected based on various suitable properties and / or cost considerations. In certain embodiments, the first polymer material may have a thermal rating or thermal index of 200° C. or less, and the second polymer material may have a thermal rating or thermal index of 220° C., 240° C. or more. As desired, in various embodiments, one or more additives may be incorporated into the extruded insulator layer, such as a compatibilizer (e.g., a compatibilizer used in a polymer blend, etc.), a filler material, an adhesion promoter, etc.

[0016] The first and second layers of the extruded thermoplastic insulation can also be formed to have various suitable thicknesses and thickness ratios. In some embodiments, the first layer can constitute at least fifty-five percent (55%), sixty percent (60%), or other suitable percentages of the thickness of the extruded insulation (e.g., the combined thickness of the first and second layers, etc.). For example, the first layer can constitute fifty-five percent (55%) to eighty percent (80%) of the thickness of the extruded insulation, and the second layer can constitute twenty percent (20%) to forty-five percent (45%) of the thickness of the extruded insulation. In various embodiments, other thickness percentages and / or thickness ratios can be used as desired. In addition, the entire extruded thermoplastic insulation (e.g., the combined first and second layers, etc.) can be formed to have various suitable thicknesses. In some embodiments, the extruded thermoplastic insulation can have a thickness between about 15 microns and about 200 microns, such as a thickness between 100 microns and 200 microns. In addition, the individual layers of the extruded thermoplastic insulation, such as the first and second layers, can be formed to have any suitable corresponding thicknesses.

[0017] By forming an extruded insulation having multiple layers including different materials, the cost of the magnet wire can be reduced relative to conventional magnet wire utilizing high performance thermoplastic polymers (such as PEEK). For example, a multi-layer insulation can include a first layer formed of a less expensive material and a second layer formed of a high performance material, and the total cost of the two layers can be lower than a single layer of a high performance material. The multi-layer insulation can also provide similar or improved performance (e.g., PDIV, dielectric breakdown, temperature rating, etc.) relative to a single layer insulation formed of a high performance material (e.g., PEEK).

[0018] Embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the present disclosure are shown. However, the present invention may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. The same reference numerals refer to the same elements throughout.

[0019] refer to Figure 1 , a perspective view of an exemplary magnet wire 100 including an extruded insulator according to an embodiment of the present disclosure is shown. The magnet wire 100 may include a center conductor 105 and an insulator 110 formed around the conductor 105. The insulator 110 may include at least two layers of extruded insulator. As shown, the insulator 110 may include a first layer 115 of extruded insulator formed around the conductor 105 and a second layer 120 of extruded insulator formed around the first layer 115. According to one aspect of the present disclosure, the first layer 115 and the second layer 120 may be formed of different polymer materials (e.g., different single materials, different material groups or material blends, etc.). In addition, in some embodiments, the first layer 115 may be formed directly on the conductor 105. In other embodiments, an optional base insulator 125 may be formed around the conductor 105, and the first layer 115 may be formed on the base insulator 125. The base insulator 125 may include any number of sub-layers as desired.

[0020] Figures 2A-2D are cross-sectional views of exemplary magnet wire constructions 200 , 220 , 250 , 270 including a plurality of different extruded insulation layers according to an illustrative embodiment of the disclosure. Figure 2A An exemplary magnet wire 200 is shown having a circular or annular cross-sectional shape with multiple layers of extruded insulation formed around a conductor 205. For example, a first layer 210 and a second layer 215 of extruded insulation can be formed around the conductor 205. Figure 2B Another exemplary magnet wire 220 having a circular cross-sectional shape is shown. The magnet wire 220 may include a conductor 225 and a first layer 230 and a second layer 235 of extruded insulation formed around the conductor 225. However, Figure 2B The magnet wire 220 also includes a base insulator 240 formed around the conductor 225 , wherein a first layer 230 of extruded insulation is formed around the base insulator 240 . Figure 2C An exemplary magnet wire 250 is shown having a rectangular cross-sectional shape with multiple layers of extruded insulation formed around a conductor 255. For example, a first layer 260 and a second layer 265 of extruded insulation can be formed around the conductor 255. Figure 2D Another exemplary magnet wire 270 is shown having a rectangular cross-sectional shape. Figure 1 and Figure 2B 100 of magnet wire, Figure 2D The magnet wire 270 includes a conductor 275 , a base insulator 290 formed around the conductor 275 , and first and second layers 280 , 285 of extruded insulation formed around the base insulator 290 .

[0021] We will now describe in more detail Figure 1Each layer or component of the magnet wire 100. Figures 2A-2D Exemplary magnet wires 200, 220, 250, 270 may include reference Figure 1 Indeed, the magnet wire may be formed with a variety of suitable cross-sectional shapes and insulation configurations as desired in various embodiments, provided that the insulation includes multiple extruded insulation layers formed from different polymer materials. Figures 1 to 2D The example configurations shown in are provided by way of non-limiting examples only.

[0022] Turning first to conductor 105, conductor 105 can be formed of various suitable materials and / or material combinations. For example, conductor 105 can be formed of copper, aluminum, annealed copper, oxygen-free copper, silver-plated copper, nickel-plated copper, copper-clad aluminum ("CCA"), silver, gold, conductive alloys, bimetallics, carbon nanotubes, or any other suitable conductive material. In addition, conductor 105 can be formed to have any suitable size and / or cross-sectional shape. As shown, conductor 105 can have a rectangular cross-sectional shape. In other embodiments, such as Figure 2A and Figure 2B In those embodiments shown in , the conductor 105 can have an annular or circular cross-sectional shape. In other embodiments, the conductor can be formed into a square shape, an elliptical or oval shape, or any other suitable cross-sectional shape. In addition, as desired for certain cross-sectional shapes (such as the illustrated rectangular shape), the conductor can have rounded corners, sharp corners, smooth corners, curved corners, angled corners, truncated corners, or otherwise formed corners.

[0023] The conductor 105 may also be formed to have any suitable size, such as any suitable gauge, diameter, height, width, cross-sectional area, etc. As a non-limiting example, the longer sides of the rectangular conductor 105 may be between about 0.020 inches (508 μm) and about 0.750 inches (19050 μm), and the shorter sides may be between about 0.020 inches (508 μm) and about 0.400 inches (10160 μm). An exemplary square conductor may have sides between about 0.020 inches (508 μm) and about 0.500 inches (12700 μm). An exemplary circular conductor may have a diameter between about 0.010 inches (254 μm) and about 0.500 inches (12700 μm). Other suitable sizes may be used as desired.

[0024] The conductor 105 may be formed, produced or otherwise provided using a variety of suitable methods and / or techniques. In certain embodiments, the conductor 105 may be formed by pulling an input material (e.g., a larger conductor, rod stock, etc.) through one or more dies to reduce the size of the input material to a desired size. As desired, one or more flatteners and / or rollers may be used to change the cross-sectional shape of the input material before and / or after the input material is pulled through any die. In certain embodiments, the conductor 105 may be formed in tandem with the application of part or all of the insulator system. In other words, the conductor formation and the application of the insulating material may be performed in tandem. In other embodiments, the conductor 105 of desired size may be preformed or obtained from an external source, and then the insulating material may be applied by a subsequent process.

[0025] In some embodiments, a base insulator 125 may be formed on the conductor 105 before applying the first layer 115 and the second layer 120 of extruded insulation. A variety of suitable materials may be used to form the base insulator 125 as desired. For example, the base insulator 125 may include one or more layers of polymer enamel, one or more layers of semiconductive layers, and / or one or more layers of tape or wrap. In some embodiments, the base insulator 125 may be formed directly on the conductor 105, for example, around the outer periphery of the conductor 105. In addition, the base insulator 125 may include a single layer of insulating material or multiple sub-layers of insulating material (e.g., multiple layers of enamel, etc.), as desired.

[0026] Where the base insulator 125 is formed with a plurality of sub-layers, any number of sub-layers may be used. In some embodiments, the sub-layers may be formed of the same substance or material (e.g., multiple enamel layers formed of the same polymer material, etc.). In other embodiments, at least two of the sub-layers may be formed of different materials. For example, different enamel layers may be formed of different polymer materials. As another example, one or more sub-layers may be formed of enamel, while another sub-layer is formed of a suitable tape or wrap.

[0027] As described above, the base insulator 125 may include one or more enamel layers. The enamel layer is usually formed by applying a polymer varnish to the conductor 105 and then baking the conductor 105 in a suitable enamel oven or furnace. The polymer varnish usually includes a thermosetting polymer solid material suspended in one or more solvents. After the varnish is applied, the solvent is removed due to baking or curing, thereby leaving a solid polymer enamel layer. As required, multiple enamel layers can be applied to the conductor 105. For example, a first enamel layer can be applied, and the conductor 105 can pass through an enamel oven or other suitable curing equipment. Then a second enamel layer can be applied, and the conductor 105 can pass through a curing device (or a separate curing device) again. The process can be repeated until the desired number of enamel coatings has been applied and / or until the desired enamel thickness or configuration has been achieved. As required, the enamel oven can be configured to facilitate the wire 100 to pass through the oven multiple times. Other curing devices that can be used in addition to the enamel oven or as an alternative to the enamel oven include, but are not limited to, infrared light systems, ultraviolet light systems, and / or electron beam systems.

[0028] In various embodiments, any number of enamel layers can be formed. In addition, each enamel layer and / or total enamel construction can have any desired thickness, for example, a thickness of about 0.0002, 0.0005, 0.007, 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.010, 0.012, 0.015, 0.017 or 0.020 inches, including the thickness in the range between any two of the above values, or including the thickness in the range of the minimum end or maximum end limited by one of the above values. Various different types of polymer materials can be used to form the enamel layer as required. The example of suitable material includes but is not limited to polyimide, polyamideimide, amideimide, polyester, polyesterimide, polysulfone, polyphenylene sulfone, polysulfide, polyphenylene sulfide, polyetherimide, polyamide, polyketone etc. In some embodiments, the base insulator 125 may include a polyimide ("PI") enamel, a polyamideimide ("PAI") enamel, or a combination thereof. As desired, one or more suitable filler materials may be incorporated into the enamel layer. Examples of suitable filler materials include, but are not limited to, inorganic materials (e.g., metals, etc.), organic materials, and / or other materials, such as any filler material described below with reference to the extruded insulator layer. In some embodiments, the filler material may enhance the corona resistance and / or one or more thermal properties (e.g., temperature resistance, cut-through resistance, thermal shock, etc.) of the enamel layer. The particles of the filler material may have any suitable size, such as any suitable diameter. In addition, any suitable blend or mixture ratio between the filler material and the polymer material of the enamel layer may be utilized.

[0029] Other types of base insulators 125 may be used in addition to or in place of enamel, as desired. In some embodiments, base insulator 125 may include one or more suitable wraps or tapes, such as polymer tapes wrapped around conductor 105 and / or any underlying layers. In other embodiments, base insulator 125 may include one or more layers of semiconductive material. The semiconductive layers may have a conductivity between that of conductor 105 and that of the insulator, and the use of one or more semiconductive layers may help equalize or "smooth out" non-uniform electric, magnetic, and / or electromagnetic fields that may stress the magnet wire insulation.

[0030] Continue to refer Figure 1 , the insulator 100 may include a plurality of extruded insulator layers formed around the conductor 105. According to one aspect of the present disclosure, at least a first layer 115 of extruded insulator may be formed around the conductor 105, and a second layer 120 of extruded insulator may be formed around the first layer 115. In addition, the first layer 115 and the second layer 120 may be formed of different thermoplastic polymer materials. For example, the first layer 115 may be formed of a lower performance and / or lower cost material than the second layer 120. In some embodiments, such as Figure 2A and Figure 2D In the embodiment shown in , the first layer 115 of extruded insulation can be formed directly around the conductor 105 without any intermediate insulation layer. In other embodiments, such as Figure 1 , Figure 2B and Figure 2D In the embodiment shown in FIG. 1 , a first layer 115 of extruded insulation may be formed on a base insulation 125 (eg, polymer enamel, etc.).

[0031] A variety of suitable materials and / or combinations of materials may be utilized to form the extruded insulation, such as the first layer 115 and the second layer 120. Examples of suitable materials include, but are not limited to, polyetheretherketone (“PEEK”), polyetherketoneketone (“PEKK”), polyetheretherketoneketone (“PEEKK”), polyetherketone (“PEK”), polyaryletherketone (“PAEK”), other suitable polymers including at least one ketone group, polyetherimide (“PEI”) (such as sold by Sabic Global Technologies) ), polyphenylsulfone ("PPSU") (such as sold by Solvay Specialty Polymers, Inc. ), polyethersulfone ("PESU"), polyphenylene sulfide ("PPS"), polybenzimidazole ("PBI"), polycarbonate, one or more polyesters (for example, polyethylene terephthalate ("PET"), etc.), one or more copolyesters, nylon, thermoplastic polyamide, thermoplastic polyimide ("TPI"), one or more acrylic materials, one or more fluoropolymers, polystyrene and / or various copolymers of multiple materials.

[0032] In certain embodiments, the first layer 115 may be formed of a lower performance and / or cheaper material, and the second layer 120 may be formed of a higher performance material. In certain exemplary embodiments, the first layer 115 may be formed of a first thermoplastic polymer material including at least one of polyester, copolyester, nylon, polycarbonate, acrylic, fluoropolymer, polyphenylene sulfide ("PPSU"), polyethersulfone ("PESU"), polyetherimide ("PEI"), or polyphenylsulfone ("PPS"). The second layer 120 may be formed of a second thermoplastic polymer material including at least one of polyetheretherketone ("PEEK"), polyaryletherketone ("PAEK"), or polyetherketoneketone ("PEKK"). In certain embodiments, one of the first layer 115 or the second layer 120 may be formed of a blend or mixture of multiple polymer materials. For example, the first layer 115 may be formed of a polymer blend including at least one of the exemplary materials listed above for the first layer 115. As another example, the second layer 120 can be formed from a polymer blend that includes at least one of the materials listed above as suitable for the second layer 120 (e.g., a blend including PEEK, etc.). Additionally, in some embodiments, the polymer material used to form the first layer 115 may be immiscible with the polymer material used to form the second layer 120.

[0033] In one example embodiment, the first layer 115 may be formed of PEI and the second layer 120 may be formed of PEEK. In another example embodiment, the first layer 115 may be formed of PEI and the second layer may be formed of PAEK. In another example embodiment, the first layer may be formed of PEI and the second layer may be formed of PEKK. In other example embodiments, the first layer may be formed of PPSU and the second layer may be formed of PEEK, PAEK or PEKK. In other example embodiments, the first layer may be formed of PESU and the second layer may be formed of PEEK, PAEK or PEKK. In other example embodiments, the first layer may be formed of PSU and the second layer may be formed of PEEK, PAK or PEKK. Other layer combinations may be used as desired.

[0034] Although the exemplary extruded insulation is described herein as having a first layer 115 and a second layer 120, the extruded insulation can be formed with any number of suitable layers. For example, in other embodiments, three or more layers of extruded materials can be coextruded or otherwise incorporated into the insulation system. For example, a combination of PPSU, PEI, and PEEK can be coextruded into a three-layer insulation. Other suitable combinations of materials, including any of the materials discussed herein, can alternatively be used to form three or more coextruded insulation layers.

[0035] In the case where the extruded layer (e.g., the first layer 115, the second layer 120, etc.) is formed of a polymer material as a blend, two or more component polymer materials can be blended or mixed together in the blend at any suitable blending rate or ratio. For example, each component material may constitute about 1.0% to about 99% by weight of the polymer blend. In certain embodiments, each component material (e.g., the first component material, the second component material, etc.) incorporated into the blend may constitute about 5%, 10%, 15%, 20%, 25%, 30%, 40%, 45%, 50%, 60%, 70%, 75%, 80%, 90% or 95% by weight of the blend, including weight percentages within a range between any two of the above values ​​(e.g., between about 5% and 95%, between about 10% and 90%, etc.), or including weight percentages within a range where the minimum or maximum value is defined by one of the above values ​​(e.g., at least 5%, at least 10%, no more than 95%, no more than 90%). The component materials and relative amounts of materials incorporated into the blend can be selected based on a variety of suitable factors including, but not limited to, material cost, processing characteristics, desired dielectric breakdown, desired partial discharge initiation voltage ("PDIV"), desired cut-through, desired heat aging properties, desired temperature rating, desired crystallinity, etc.

[0036] As desired, the first polymer material and the second polymer material used to form the first layer 115 and the second layer 120, respectively, may be selected based on various suitable properties and / or cost considerations. For example, the first polymer material may have a first melting point (or melting point) lower than the second melting point of the second polymer material. In certain embodiments, the first polymer material may have a melting point lower than 300°C, 250°C, 200°C, 180°C, or another suitable value. Then, the melting point of the second polymer material may be higher than the melting point of the first polymer material. Similarly, in certain embodiments, the first polymer material may have a first glass transition temperature lower than the second glass transition temperature of the second polymer material. In certain embodiments, the first polymer material may have a glass transition temperature lower than 300°C, 250°C, 200°C, 180°C, or another suitable value. Then, the second polymer material may have a glass transition temperature higher than the glass transition temperature of the first polymer material.

[0037] In various embodiments, the first polymer material and the second polymer material may be selected to have different thermal classifications (or thermal grades), thermal indices, or heat resistances. In other words, the first polymer material may have a first thermal grade, thermal index, or heat resistance that is lower than a second thermal grade, thermal index, or heat resistance of the second polymer material. Thermal grades, typically established by industry standard organizations (e.g., National Electrical Manufacturers Association, International Electrotechnical Commission, UL, etc.), establish maximum allowable temperatures for insulating materials and / or magnet wires. Exemplary thermal grades include, for example, 180°C, 200°C, 220°C, 240°C, and 250°C. The thermal index is typically defined as a number in degrees Celsius that compares temperature to the time characteristics of an electrical insulating material. It can be obtained by extrapolating an Arrhenius plot of life versus temperature to a specified time (typically 20,000 hours). As an example of the difference between a thermal grade and a thermal index, a material may have a thermal index of 230°C; however, the material will have a thermal grade of 220°C because it does not meet the requirements of the next available thermal grade of 240°C. In some embodiments, the first polymer material may have a thermal rating of 200°C or less, and the second polymer material may have a thermal rating of 220°C or more. In other embodiments, the first polymer material may have a thermal rating of 200°C or less, and the second polymer material may have a thermal rating of 240°C or more. In one exemplary embodiment, the first polymer material may be a PPSU material having a thermal rating of 200°C, and the second polymer material may be a PEEK material having a thermal rating of 240°C or more. In other embodiments, the first polymer material and the second polymer material may be selected to have different thermal indices. In other words, the first polymer material may have a first thermal index that is lower than the second thermal index of the second polymer material. For example, the first polymer material may have a thermal index of 200°C or less, and the second polymer material may have a thermal index greater than or equal to 220°C, 225°C, 230°C, 235°C, 240°C, 245°C, 250°C, 255°C, 260°C, or a thermal index included in a range between any two of the above values.

[0038] In addition, in certain embodiments, the first polymer material and the second polymer material can be selected to have different physical properties. For example, the first polymer material can include an amorphous material, and the second polymer material can include a semi-crystalline or crystalline material. Due to the unique crystal structure inside the material, the thermoplastic material with a semi-crystalline structure can provide desired mechanical properties and / or desired chemical resistance. However, semi-crystalline materials generally exhibit higher thermal expansion and contraction ratios during processing. For example, PEEK has an average mold shrinkage between about 1.1 and 1.5. This shrinkage is higher than that of an amorphous material, such as PPSU, which has a mold shrinkage ratio of about 0.7. The higher mold shrinkage ratio of a semi-crystalline material can produce larger residual stresses during the line extrusion process, which can result in relatively low adhesion properties. For thicker extruded magnet wires, this problem is exacerbated. Using a multilayer extrusion material according to an embodiment of the present disclosure can improve the adhesion properties of the extruded insulator while still allowing the extruded insulator (e.g., an outer layer of a semi-crystalline material, etc.) to provide desired mechanical properties, desired chemical resistance, and / or desired thermal properties. Additionally, if the materials used to form the multiple extruded insulator layers have similar volume resistivity and dielectric constants, the dielectric properties and electrical performance of the multilayer insulator can be similar to or better than those of an extruded insulator formed from a single material (e.g., PEEK, etc.).

[0039] As desired, in various embodiments, one or more additives may be incorporated into the extruded insulator layers, such as the first layer 115 and / or the second layer 120. For example, in certain embodiments, one or more compatibilizers may be added to the polymer material or polymer blend to increase the stability of the material or polymer blend. As another example, one or more fluoropolymers, such as polytetrafluoroethylene ("PTFE"), may be blended, mixed, added, or otherwise incorporated into the extruded insulator layer. As yet another example, one or more suitable filler materials may be added to the polymer material used to form the extruded insulator layer. Examples of suitable filler materials include, but are not limited to, inorganic materials such as metals, transition metals, lanthanides, actinides, carbon nanotubes, boron nitride, metal oxides, and / or hydrated oxides of suitable materials such as aluminum, tin, boron, germanium, gallium, lead, silicon, titanium, chromium, zinc, yttrium, vanadium, zirconium, nickel, etc. (e.g., titanium dioxide, silicon dioxide, or silicon dioxide, etc.); suitable organic materials such as polyaniline, polyacetylene, polyphenylene, polypyrrole, other conductive particles; and / or any suitable combination of materials (e.g., blends of metal oxides, etc.). In certain embodiments, the filler material may enhance corona resistance and / or one or more thermal properties (e.g., temperature resistance, cut-through resistance, thermal shock resistance, etc.). In certain embodiments, the filler material may include at least one of titanium dioxide, chromium dioxide, silicon dioxide, or boron nitride. The particles of the filler material can have any suitable size, and any suitable blending ratio or filling rate between the filler material and the polymer material can be utilized (e.g., a filling rate of about 5%, 10%, 15%, 20%, or 25%, or a filling rate included in a range between any of these values). In addition, where the filler comprises a blend of different materials, any suitable blending ratio can be used between the components of the filler.

[0040] In certain embodiments, a bonding layer or adhesion promoting layer can be formed between the first layer 115 and the second layer 120. A bonding layer can be formed as required using a combination of a variety of suitable materials and / or materials, including but not limited to polyesters, polyurethanes and / or polymer materials incorporating one or more adhesion promoters. As required, the bonding layer can be extruded or otherwise formed between the first layer 115 and the second layer 120. The use of a bonding layer or adhesion promoting layer can allow a variety of different polymer materials to be used for the first layer 115 and the second layer 120.

[0041] The first layer 115 and the second layer 120 of the extruded thermoplastic insulation can also be formed to have various suitable thicknesses and thickness ratios. In certain embodiments, the first layer 115 can constitute at least fifty-five percent (55%) of the thickness of the extruded insulation (e.g., the combined thickness of the first layer 115, the second layer 120, etc.). In other embodiments, the first layer 115 can constitute between fifty-five percent (55%) and eighty percent (80%) of the thickness of the extruded insulation, and the second layer 120 can constitute between twenty percent (20%) and forty-five percent (45%) of the thickness of the extruded insulation. In other embodiments, the first layer 115 can constitute between fifty-five percent (55%) and ninety percent (90%) of the thickness of the extruded insulation (or the total insulation), and the second layer 120 can constitute between ten percent (10%) and forty-five percent (45%) of the thickness of the extruded insulation. In various embodiments, other thickness percentages and / or thickness ratios can be used as desired. For example, the first layer 115 can constitute at least 51%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the total thickness of the extruded insulation, or a thickness within a range between any two of the above values. The second layer 120 can constitute approximately 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 49% of the total thickness, including thicknesses within a range bounded by one of the above values ​​at the maximum end, or a thickness within a range between two of the above values.

[0042] Additionally, in certain embodiments, various suitable thickness ratios may be used between the first layer 115 and the second layer 120. In various exemplary embodiments, the thickness ratio between the first layer 115 and the second layer 120 may be approximately 99 / 1, 95 / 5, 90 / 10, 85 / 15, 80 / 20, 75 / 25, 70 / 30, 60 / 40, 55 / 45, 51 / 49, or a ratio within a range between any two of the aforementioned values.

[0043] The above examples describe an electromagnetic wire in which the first layer 115 of the extruded polymer material is thicker than the second layer 120 of the high performance material. It has been found that the desired insulation performance can be achieved with a thicker first layer 115 while maximizing or increasing the cost of the electromagnetic wire. In other embodiments, the electromagnetic wire can be formed with two extruded layers, wherein the first layer 115 is thinner than the second layer 115. For example, the first layer 115 can constitute approximately 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 49% of the total thickness of the first and second layers, including thicknesses within a range between any two of the above values, or including thicknesses within a range bounded by one of the above values ​​as the maximum end. The second layer 120 can constitute approximately 51%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95% of the total thickness of the extruded insulation, including thicknesses within a range between any two of the above values, or including thicknesses within a range bounded by one of the above values ​​as the minimum end. Similarly, various suitable thickness ratios may be used between the first layer 115 and the second layer 120. In various exemplary embodiments, the thickness ratio between the first layer 115 and the second layer 120 may be approximately 1 / 99, 5 / 95, 10 / 90, 15 / 85, 20 / 80, 25 / 75, 30 / 70, 40 / 60, 45 / 55, 49 / 51, or a ratio in a range between any two of the above values. In other embodiments, the first layer 115 and the second layer 120 may be formed to have approximately equal thicknesses (e.g., approximately a 50 / 50 thickness ratio, etc.).

[0044] Although the first layer 115 and the second layer 120 are Figure 1115 and the second layer 120 are shown as a single layer, but in other embodiments, one or both of the first layer 115 and the second layer 120 may be formed of multiple sub-layers. Therefore, more than two separate extruded thermoplastic insulation layers may be included in the insulation 110 of the wire 100. In some embodiments, a plurality of lower cost or lower performance thermoplastic materials may be utilized to form the sub-layers of the first layer 115. In some embodiments, multiple sub-layers incorporated into an extruded layer (such as the first layer 115 or the second layer 120) may be formed of the same polymer material (e.g., a single polymer material, a polymer blend, etc.). In other embodiments, at least two sub-layers may be formed of different polymer materials. In an exemplary embodiment, a first sub-layer formed of a first material may provide greater adhesion to the underlying layers (e.g., the conductor 105, the base insulator 125, the underlying first layer 115), and a second sub-layer formed of a second material may provide other desired properties (e.g., electrical properties, mechanical properties, fluid resistance, etc.). In another exemplary embodiment, the first sub-layer may be formed as a filled layer, while the second sub-layer (formed from the same polymer material or a different polymer material) is unfilled. In fact, a wide variety of sub-layer configurations may be used as desired for the first layer 115 or the second layer 120. Thus, it should be understood that any suitable number of extruded insulation layers may be incorporated into the magnet wire 100.

[0045] In addition, the entire extruded thermoplastic insulator (e.g., the combined first layer 115 and second layer 120, etc.) can be formed to have various suitable thicknesses. In certain embodiments, the extruded thermoplastic insulator can have a thickness between about 15 microns and about 200 microns. In other embodiments, the extruded thermoplastic insulator can have a thickness between 100 microns and 200 microns. In various embodiments, the entire extruded thermoplastic insulator can have a thickness of about 15, 20, 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, or 600 microns, a thickness included in a range between any two of the above values, or a thickness included in a range defined by one of the above values ​​as a minimum end or a maximum end. Additionally, the various layers of extruded thermoplastic insulation, such as first layer 115 and second layer 120, may be formed to have any suitable respective thicknesses.

[0046] These exemplary thicknesses allow the extruded insulator to be thin enough to allow for relatively tight packing of the resulting magnet wire 100. Additionally, in certain embodiments, the extruded insulator can be formed to have a cross-sectional shape similar to the cross-sectional shape of the underlying conductor 105 and / or any base insulator 125. For example, if the conductor 105 has a rectangular cross-sectional shape, the extruded insulator can be formed to have a rectangular cross-sectional shape. In other embodiments, the extruded insulator can be formed to have a cross-sectional shape that is different from the cross-sectional shape of the underlying conductor 105 (and / or the underlying base insulator 125). As a non-limiting example, the conductor 105 can be formed to have an elliptical cross-sectional shape, while the extruded insulator is formed to have a rectangular cross-sectional shape. A variety of other suitable configurations will be understood.

[0047] The extrusion process can result in the formation of extruded insulator layers (e.g., first layer 115 and second layer 120) from approximately 100% solid material. In other words, the extruded insulator layers can be free of or substantially free of any solvent. Therefore, the application of the extruded insulator layers can be less energy intensive than the application of the enamel layer because no solvent needs to be evaporated. In some embodiments, the first layer 115 and the second layer 120 can be formed simultaneously. In other words, a single polymer extrusion step can be performed during which the first layer 115 and the second layer 120 are co-extruded around the conductor 105. In other embodiments, the first layer 115 and the second layer 120 can be formed via multiple separate or continuous extrusion steps or operations. In other words, the first layer 115 can be extruded, and then the second layer 120 can be extruded on the first layer 115. Any number of extrusion steps or operations can be performed as needed to construct the first layer 115 and the second layer 120 and any sublayers thereof.

[0048] In some embodiments, the extrusion process can be controlled so that the extruded first layer 115 and the second layer 120 have a relatively uniform thickness along the longitudinal length of the magnet wire 100. In other words, the extruded insulation and / or one or more extruded layers (e.g., the first layer 115, the second layer 120) can be formed to have a concentricity that is approximately close to 1.0. The concentricity of the extruded insulation (or extruded layer) is the ratio of the thickness of the extruded insulation to the thinness of the extruded insulation at any given cross-sectional point along the longitudinal length of the magnet wire 100. In some embodiments, the extruded insulation (or extruded layer) can be formed to have a concentricity between about 1.0 and 1.8. For example, an extruded insulator (or extruded layer) can be formed to have a concentricity of about 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.6, 1.7, 1.75, 1.8, a concentricity between any two of the above values, or a concentricity bounded by one of the above values ​​as a maximum (e.g., a concentricity of about 1.1 or less, a concentricity of about 1.3 or less, etc.). Similar to the extruded insulator layer, the application of one or more other insulator layers (e.g., base insulator layer 125, etc.) can also be controlled to produce a desired concentricity, such as any of the example concentricities discussed above with reference to the extruded insulator.

[0049] As described above, in some embodiments, the first layer 115 can be formed directly on the conductor 105 or the underlying base insulator 125. In other words, the first layer 115 can be formed on the underlying layer without using a binder, adhesion promoter, or adhesive layer. For example, the first layer 115 can be formed of a polymer material that provides the desired adhesion. As another example, the temperature of the magnet wire 100 can be controlled before applying the first layer 115 to eliminate the need for an adhesive layer. Therefore, the first layer 115 can be bonded to the underlying layer without using a separate adhesive. In other embodiments, one or more suitable binders, adhesion promoters, or adhesive layers can be bonded between the first layer 115 and the underlying layer. A variety of suitable adhesion promoters can be used as needed. Similarly, in some embodiments, the second layer 120 can be formed directly on the first layer 115. In other embodiments, one or more suitable binders, adhesion promoters, or adhesive layers can be bonded between the first layer 115 and the second layer 120. Similarly, binders, adhesion promoters, and / or adhesive layers can be optionally incorporated between various sub-layers of the extruded layer.

[0050] In other embodiments, one or more suitable surface modification treatments may be utilized on the conductor 105, any number of base insulator layers 125, and / or any number of extruded layers to promote adhesion to subsequently formed layers. For example, the surface of the conductor, enamel, base layer, or extruded layer may be modified by a suitable treatment to promote adhesion to a subsequently formed insulator layer (e.g., a subsequently formed enamel layer, a subsequently formed extruded layer, etc.). Examples of suitable surface modification treatments include, but are not limited to, plasma treatment, ultraviolet ("UV") treatment, corona discharge treatment, and / or gas flame treatment. The surface treatment may change the morphology of the conductor or insulator layer, and / or form functional groups on the surface of the conductor or insulator layer that enhance or promote the bonding of a subsequently formed insulator layer. Thus, the surface treatment may reduce interlayer delamination.

[0051] Due to the formation of an extruded insulation having multiple layers (e.g., a first layer 115 and a second layer 120) including different materials, the cost of the magnet wire 100 can be reduced relative to conventional magnet wires utilizing high-performance thermoplastic polymers (such as PEEK). For example, a multi-layer insulation can include a first layer 115 formed of a less expensive material and a second layer 120 formed of a high-performance material, and the total cost of the two layers 115, 120 can be lower than a single layer of high-performance material (e.g., all PEEK, etc.). Multiple extruded insulation layers can also provide similar performance, or in some cases, better performance (e.g., PDIV, dielectric breakdown, temperature rating, etc.) relative to a single layer insulation formed of a high-performance material (e.g., PEEK).

[0052] Extruded insulators formed from multiple layers including different materials and / or insulator systems including extruded insulators can have various suitable electrical performance parameters, such as various suitable PDIV values ​​and / or dielectric strength or breakdown strength values. In certain embodiments, multilayer extruded insulators and / or insulator systems including multilayer extruded insulators can provide a PDIV value of at least about 1000, 1100, 1200, 1250, 1300, 1350, 1400, 1450, 1500, 1550, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, or 2400 volts at 25°C, or a PDIV value in a range between any two of the above values. Similarly, in certain embodiments, the extruded insulator and / or insulator system comprising the extruded insulator may provide a dielectric strength value of at least about 10,000, 11,000, 12,000, 12,500, 13,000, 13,500, 14,000, 14,500, 15,000, 15,500, 16,000, 16,500, 17000, 17,500, 18,000, 18.500, 19,000, 20,000, 20,500 or 21,000 volts (e.g., as measured by a suitable industry standard test (e.g., a shotbox or foil test, etc.)), or a dielectric strength value within a range between any two of the foregoing values. In certain embodiments, the polymer materials used to form the first layer 115 and the second layer 120 may be selected to achieve desired electrical (eg, PDIV, dielectric strength, etc.) and / or chemical resistance properties for an intended magnet wire application.

[0053] Reference above Figure 1-2D The magnet wires 100, 200, 220, 250, 270 described are provided as examples only. In various embodiments, various substitutions may be made to the magnet wires 100, 200, 220, 250, 270 shown as desired. For example, in addition to extruded insulation formed from a polymer blend, various different types of insulation layers may be incorporated into the magnet wire. As another example, the cross-sectional shape of the magnet wire and / or one or more insulation layers may be varied. Indeed, the present disclosure contemplates a variety of suitable magnet wire configurations.

[0054] Various suitable systems and / or methods can be used as needed to connect the magnet wire (such as Figures 1 to 2D A plurality of extruded insulation layers are formed on any of the exemplary magnet wires of FIG. Figure 3, a schematic diagram of an exemplary system 300 for forming a plurality of extruded insulation layers is shown. System 300 may include various components that facilitate processing of magnet wire 305. As shown, system 300 may include a pay-off device 310, a preheater 315, an extruder 320, a cooling tank 325, and a take-up device 330. Each of these components, as well as other components that may be optionally incorporated into system 300, are described in more detail below.

[0055] refer to Figure 3 , a suitable pay-off device 310 can provide the magnet wire 305 to the components of the system 300, which are configured to form an extruded insulation. In some embodiments, the pay-off device 310 can provide the magnet wire 305 with a desired size (e.g., a desired cross-sectional shape, a desired diameter, a desired width and thickness, etc.). As desired, before the pay-off device 310 provides the magnet wire 305, a base insulation can also be formed on the magnet wire 305. In other embodiments, the pay-off device 310 can provide input materials to one or more components configured to form a conductor with a desired size and / or to one or more components configured to form a base insulation.

[0056] As needed, the system 300 may include one or more wire forming devices or components configured to receive input material (e.g., rod stock, etc.) and process the received input material to form a conductor of desired size. For example, the input material can be processed by a suitable rod decomposition device or rod mill, which pulls or pulls the input material through one or more molds that reduce the size of the input material to the desired size. As needed, one or more flatteners and / or rollers can be used to change the cross-sectional shape of the input material (e.g., to form a rectangular wire). As another example, the input material can be processed by a suitable conformal device or system that forms a conductor of desired size. As yet another example, the conductor can be formed via a 3D printing or additive manufacturing process.

[0057] In certain embodiments, system 300 may include one or more components or subsystems configured to form a base insulation on magnet wire 305 prior to forming the extruded insulation. For example, system 300 may include one or more enamel forming components, such as a varnish application system (e.g., an application die, etc.) and one or more curing devices (e.g., an enamel oven, a UV curing system, etc.), configured to form any suitable number of enamel layers on magnet wire 305. Other suitable base insulation forming components may be incorporated into system 300 as desired.

[0058] Continue to refer Figure 3, the system 300 may include one or more components configured to control the temperature of the magnet wire 305 before applying the extruded insulation. For example, the magnet wire 305 may pass through one or more preheaters 320 to reach the desired temperature before the extrusion process. The preheater 315 may include any suitable components configured to increase or raise the temperature of the magnet wire 305, such as one or more heating coils, heaters, ovens, etc. One or more cooling devices may also be used as needed. The temperature of the magnet wire 305 may be adjusted or controlled to achieve various suitable values ​​before extrusion. For example, in some embodiments, before extrusion, the temperature may be controlled at about 180°C or higher, 200°C or higher, or other desired temperatures. As another example, the temperature may be controlled at about 400°F or higher before extrusion. Controlling or maintaining the temperature at this level may promote adhesion between the extruded thermoplastic layer and the conductor or base insulation below.

[0059] One or more suitable extruders 320 or extrusion devices can be configured to receive the electromagnetic wire 305 and extrude multiple layers of thermoplastic insulation on the electromagnetic wire 305. In some embodiments, the extruder 320 can be configured to co-extrude the first layer and the second layer of extruded thermoplastic insulation. In other embodiments, the extruder 320 can be configured to apply the first layer and the second layer of extruded thermoplastic insulation continuously or successively. In some embodiments, each extruder 320 can be a single screw or multi-screw (e.g., twin screw, etc.) extruder, which is configured to receive input materials and process (e.g., mix, increase temperature, increase pressure, etc.) the input materials before extruding them onto the electromagnetic wire 305 through any number of suitable extrusion heads and / or other devices configured to apply the desired amount of thermoplastic insulation. As needed, the flow rate of the extruded insulation can be controlled to obtain the desired thickness. In addition, in some embodiments, one or more extrusion dies can be used to control the thickness and / or shape of the extruded insulation.

[0060] Various suitable operations may be performed to facilitate and / or optimize the coextrusion of multiple thermoplastic insulator layers (e.g., first and second extruded insulator layers). In certain embodiments, the melt temperature and / or viscosity of one or more extruded materials may be adjusted to optimize the compatibility and / or adhesion of the extruded materials. In certain embodiments, the conductor temperature may also be adjusted to optimize the compatibility and / or adhesion of one or more extruded materials.

[0061] Continue to refer Figure 3, the system 300 may include any suitable device configured to control the temperature of the magnet wire 305 after the extrusion process. In some embodiments, the extruded insulator can be heated after extrusion. In addition, in some embodiments, the process of cooling the extruded insulator before picking up the finished magnet wire 305 can be controlled. As a result of controlling the cooling rate of the extruded insulator, desired properties (e.g., desired crystallinity, etc.) can be achieved. The cooling device may include any suitable device and / or system configured to reduce the temperature of the finished magnet wire before picking up (or subsequent processing). In some embodiments, the cooling device may include a cooling tank 325, a quencher, or a liquid bath (e.g., a water bath), and the magnet wire 305 may pass through the cooling tank 325, the quencher, or the liquid bath for cooling. The temperature of the liquid in the bath can be controlled by recirculating the liquid. In addition, the cooling rate can be controlled based on controlling the liquid temperature and / or establishing the desired length of the cooling tank 325.

[0062] After the extruded insulator cools, the finished magnet wire 305 can be provided to one or more suitable pick-up devices 330, accumulators, or pickup devices. These devices can, for example, apply tension to the magnet wire 305, bundle the wire 305, and / or wind the finished wire 305 onto a spool. In other embodiments, the magnet wire 305 can be provided to one or more downstream devices or components before picking up. For example, the magnet wire 305 can be provided to one or more components configured to form additional insulation on the magnet wire 305, such as a subsystem configured to form a conformal insulation layer (e.g., a polyparaxylene layer, etc.) on the magnet wire 305. As another example, the magnet wire 305 can be provided to one or more components that are configured to form one or more articles from the magnet wire 305, such as a hairpin or coil that can be incorporated into a motor or other electrical device.

[0063] In some embodiments, the formation of the first extruded insulator layer and the second extruded insulator layer can be formed in tandem or inline with one or more other processes. For example, the formation of the extruded insulator can be formed in tandem with wire drawing or conductor formation and / or with the formation of one or more base insulator layers. In other embodiments, the magnet wire 105 can be picked up at any suitable step within the overall process and subsequently provided to another component or subsystem.

[0064] In addition, any suitable number of motors, flywheels, capstans and / or load cells can be incorporated into the system 300 to control the electromagnetic wire 305 through the system 300. Any suitable number of controllers (e.g., control units, computers, microcontrollers, etc.) can be configured to control the various components of the system 300. For example, one or more controllers can facilitate the synchronization of motors and / or line speeds within the system 300. As required, a controller and / or a combination of controllers can additionally control various other parameters, such as the flow rate of the varnish applied, the temperature of the enamel oven, the temperature of various heating / cooling devices, the flow rate of the extrusion device, the temperature of the liquid included in the quencher and / or the various tests performed on the electromagnetic wire 305. Each controller can be a separate component, or alternatively, incorporated into another device or component. In addition, any number of suitable communication channels (e.g., wired communication channels, wireless communication channels, etc.) can facilitate communication between a controller and one or more other components (e.g., one or more motors, another controller, other devices, etc.).

[0065] Reference above Figure 3 The system 300 described is provided as an example only. Various other suitable systems may be utilized to form an electromagnetic wire including multiple extruded insulation layers. These systems may include, for example, Figure 3 The system 300 may include more or fewer components. In addition, these systems may include Figure 3 Certain alternative components of system 300, Figure 3 The system 300 is provided by way of non-limiting example only. Indeed, the present disclosure contemplates a variety of suitable systems that may be used to form magnet wire.

[0066] Figure 4 4 is a flow chart depicting an exemplary method 400 for forming an electromagnetic wire including a plurality of extruded insulation layers according to an illustrative embodiment of the present disclosure. The method 400 may be performed using various suitable systems and / or devices. For example, a portion of the method 400 may be performed by Figure 3 The method 400 may be performed by the system 300 of FIG. 405. The method 400 may start at block 405 and a conductor may be provided. In some embodiments, a preformed conductor having a desired size may be provided. In other embodiments, an input material may be provided and processed to form a conductor having a desired size. For example, the input material may be processed by a rod mill, a flattener, and / or a roller to provide a conductor having a desired size.

[0067] At block 410, which is optional in some embodiments, a base insulator may be formed on the conductor. Various suitable base insulators and / or combinations of different types of base insulators may be formed as desired. For example, one or more enamel layers may be formed. In some embodiments, one or more layers of polyamideimide and / or polyimide enamel may be formed as the base insulator. As another example, one or more semiconductive layers may be formed.

[0068] At frame 415, a first thermoplastic polymer material and a second thermoplastic polymer material may be provided for extrusion. As described herein, a variety of suitable materials, combinations of materials and / or polymer blends may be provided as the first and second polymer materials. According to one aspect of the present disclosure, the first polymer material may be different from the second polymer material, and the materials may have different properties, such as different thermal indices, thermal grades, melting points, glass transition temperatures, etc. In certain embodiments, the first thermoplastic polymer material may include at least one of polyester, nylon, polyphenylene sulfide ("PPSU"), or polyphenylene sulfone ("PPS"). The second thermoplastic polymer material may include at least one of polyetheretherketone ("PEEK"), polyaryletherketone ("PAEK"), or polyetherketoneketone ("PEKK"). Other suitable materials may be provided as needed. In addition, in various embodiments, various fillers, compatibilizers, and / or other suitable additives may be incorporated into the polymer material as needed.

[0069] At frame 420, the temperature of the conductor or wire, whether or not it includes a base insulator, can be controlled before extrusion. For example, one or more suitable preheaters or other devices can be used to control the pre-extrusion temperature. Then a multilayer thermoplastic insulator can be formed at frame 425. For example, a first polymer material can be used to extrude a first layer, and a second polymer material can be used to form a second layer. In various embodiments, a first polymer insulator layer and a second polymer insulator layer can be extruded using various suitable techniques as needed. For example, at frame 430, a multilayer polymer insulator can be coextruded onto a wire. In other words, the first layer and the second layer can be coextruded. As another example, at frame 435, a multilayer polymer insulator can be continuously extruded onto a wire. In other words, a first layer can be extruded, and then a second layer can be extruded on the first layer. The multilayer thermoplastic insulator can be extruded using any suitable extrusion device and / or combination of extrusion devices. Then the temperature of the magnet wire and the extruded insulator can be controlled at frame 440 after extrusion. For example, a cooling tank and / or other suitable components can be used to cool the magnet wire after extrusion.

[0070] In some embodiments, method 400 can end after block 440. In other embodiments, one or more additional operations can be performed. For example, in some embodiments, one or more additional insulator layers (e.g., another extruded layer, a conformal layer, etc.) can be formed on the magnet wire. As another example, the magnet wire can be formed into one or more articles (e.g., a coil, a clip, etc.) that can be incorporated into an electrical appliance. Then, method 400 can end after the additional operations.

[0071] In various embodiments, Figure 4 The operations described and illustrated in method 400 may be implemented or performed in any suitable order as desired. In addition, in some embodiments, at least a portion of the operations may be performed in parallel. In addition, in some embodiments, more than one operation may be performed. Figure 4 Fewer or more operations than those described in .

[0072] Example

[0073] As described above, a variety of suitable polymer materials may be used to form the coextruded magnet wire insulation. Figure 1 The first layer 115 and the second layer 120 of the magnet wire 100. The embodiments listed in Tables 1 and 2 below are intended to be illustrative and non-limiting, and represent specific embodiments of the present disclosure in which certain exemplary polymer materials are used to form co-extruded magnet wire insulators. The wire samples discussed in the embodiments of Table 1 were all prepared as rectangular wires having a conductor width of approximately 3.384 mm, a conductor thickness of approximately 1.834 mm, and a tolerance of + / -0.015 mm. The conductor was formed of oxygen-free copper. In addition, the base insulator was formed of polyamideimide ("PAI"). The wire samples discussed in the embodiments of Table 2 were all prepared as rectangular wires having a conductor width of approximately 0.386 inches (approximately 9.80 mm) and a conductor thickness of approximately 0.150 inches (approximately 3.81 mm). The conductor was formed of aluminum, and no base insulator was formed on the conductor prior to extrusion. In other embodiments, the conductor may be formed of any suitable material having any suitable size. Additionally, any suitable base insulator may be used as desired, or alternatively, no base insulator may be included.

[0074] Referring to Table 1, several exemplary coextruded wire samples are provided. In particular, the first coextruded sample includes a first extruded layer of PEI and a second extruded layer of PEEK formed on PEI. The second coextruded sample includes a first extruded layer of PPSU and a second extruded layer of PAEK formed on PPSU. In addition, control samples of extruded single materials PEEK, PPSU (e.g., Radel5800) and PEI (e.g., Ultem 1000) are provided for comparison with the coextruded samples. The total thickness of the extruded insulation system is provided for each sample. For each coextruded sample, two materials (i.e., the first layer and the second layer) of approximately equal thickness are formed. In addition, measurement performance standards for extruded samples are provided. First, PDIV values ​​measured at room temperature are provided. Dielectric breakdown values ​​determined using a bomb box test are also provided. In the bomb box test, the magnet wire is immersed in a marble and tested until failure.

[0075]

[0076]

[0077] Table 1: Comparative samples of coextruded magnet wire

[0078] As shown in Table 1, some co-extruded insulator systems can provide similar or better performance than conventional single polymer extruded materials (e.g., PEEK, PPSU, PEI, etc.). For example, some co-extruded insulator systems can provide enhanced PDIV and / or dielectric breakdown performance. As shown in the figure, co-extruded PEI / PEEK and PPSU / PAEK samples show much higher PDIV values ​​than single polymer extruded samples. In fact, relative to single polymer samples (e.g., PPSU, PEI, etc.) much thicker than co-extruded samples, co-extruded samples show improved PDIV. In addition, the dielectric breakdown voltage of co-extruded samples is similar to or better than single polymer extruded samples. It should be noted that single polymer samples showing higher dielectric breakdown values ​​have thicker insulators than co-extruded samples, which results in higher dielectric breakdown voltages. Contrast single polymer samples with similar insulator thickness will have lower dielectric breakdown voltages. In addition, it is found that co-extruded samples have higher or improved chemical resistance relative to single polymer samples using PEI and PPSU. Additionally, the use of certain coextruded insulation systems can reduce overall insulation costs relative to conventional single polymer materials.

[0079] Referring to Table 2, several exemplary coextruded wire samples including first extruded layers and second extruded layers of different thickness ratios are provided. In particular, the first coextruded sample includes a first extruded layer of PPSU and a second extruded layer of PEEK formed on PPSU. The ratio of PPSU / PEEK thickness is about 75 / 25. The second coextruded sample also includes a first extruded layer of PPSU and a second extruded layer of PEEK formed on PPSU. The PPSU / PEEK thickness ratio is about 55 / 45. In addition, three different control samples of extruded single material PEEK are provided for comparison with the coextruded samples. The total thickness of the extruded insulation system is provided for each sample. In addition, measurement performance standards for extruded samples are provided. First, PDIV values ​​measured at room temperature are provided. Dielectric breakdown values ​​determined using a bomb box test are also provided.

[0080]

[0081] Table 2: Comparative samples of coextruded magnet wire

[0082] As shown in Table 2, the co-extruded insulator system containing PEEK on another extruded material provides similar performance to a conventional insulator containing only PEEK. It should be noted that the first co-extruded sample is formed to have a smaller thickness than several control samples of PEEK. Given a higher thickness, the PDIV of the second sample will increase and may be comparable to the thicker PEEK sample. In addition, the dielectric bomb box test measures the dielectric strength at the thinnest insulating area. In view of the novelty of the co-extrusion process used to form the co-extruded sample, some relatively thin insulating areas are included in the sample, resulting in a lower dielectric strength measurement. With the improvement and optimization of the co-extrusion process, wires with better concentricity can be formed, thereby improving the dielectric strength of the co-extruded insulator. In addition, even given an unoptimized manufacturing process, it has been noted that the 55 / 45 co-extruded sample has a dielectric strength comparable to that of the PEEK sample. Therefore, it has been observed and can be concluded that the electromagnetic wire formed with PEEK on a lower cost and lower performance material (e.g., PPSU, etc.) can have a PDIV and dielectric breakdown performance similar to that of a conventional electromagnetic wire containing only PEEK. Provided a threshold thickness ratio of a high performance material (eg, PEEK) is provided, desired overall insulation properties may be achieved with the coextruded magnet wire. However, the overall cost of the insulation system and magnet wire may be reduced relative to conventional magnet wires that include only extruded PEEK insulation.

[0083] Unless expressly stated otherwise or otherwise understood in the context of use, conditional language, such as "can," "may," "might," or "could" is generally intended to convey that certain embodiments may include certain features, elements, and / or operations, while other embodiments do not. Thus, such conditional language is generally not intended to imply that one or more embodiments require features, elements, and / or operations in any way, or that one or more embodiments must include logic for deciding, with or without user input or prompting, whether such features, elements, and / or operations are included or will be performed in any particular embodiment.

[0084] Many modifications and other embodiments of the disclosure set forth herein will be apparent with the benefit of the foregoing description and the teachings presented in the associated drawings. Therefore, it should be understood that the disclosure is not limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used only in a general and descriptive sense and not for the purpose of limitation.

Claims

1. An electromagnetic wire comprising: conductor; as well as an extruded insulator formed around the conductor, the extruded insulator comprising: a solid first layer formed around the conductor from a first thermoplastic polymer material having a first thermal index and comprising at least one of polyester, nylon, polyphenylene sulfide, or polyphenylene sulfone, the first layer comprising at least 55% of the thickness of the extruded insulation; as well as a solid second layer formed around the first layer and in contact with the entire outer periphery of the first layer, the second layer being formed of a second thermoplastic polymer material having a second thermal index higher than the first thermal index and comprising at least one of polyetheretherketone, polyaryletherketone or polyetherketoneketone, The extruded insulation has a partial discharge inception voltage of at least 1200 volts at 25°C. 2 . The magnet wire of claim 1 , wherein the first layer comprises 55% to 80% of the thickness of the extruded insulation and the second layer comprises 20% to 45% of the thickness of the extruded insulation. 3 . The magnet wire of claim 1 , wherein the first layer comprises 55% to 90% of the thickness of the extruded insulation and the second layer comprises 10% to 45% of the thickness of the extruded insulation.

4. The magnet wire of claim 1 wherein the thickness of the extruded insulation is between 15 microns and 200 microns.

5. The magnet wire of claim 1 wherein the extruded insulation has a thickness between 100 microns and 200 microns. 6 . The magnet wire according to claim 1 , wherein the first thermal index is 200° C. or less, and the second thermal index is 220° C. or more. 7 . The magnet wire according to claim 1 , wherein the first thermal index is 200° C. or less, and the second thermal index is 240° C. or more.

8. The magnet wire of claim 1, wherein the first thermoplastic polymer material comprises an amorphous material and the second thermoplastic polymer material comprises a semi-crystalline or crystalline material.

9. The magnet wire of claim 1, further comprising: A filler material is incorporated into one of the first thermoplastic polymer material or the second thermoplastic polymer material.

10. The magnet wire of claim 9, wherein the filler material comprises at least one of titanium dioxide, chromium dioxide, silicon dioxide, or boron nitride.

11. The magnet wire of claim 1 , wherein the extruded insulation further comprises: A base insulator is formed around the conductor, wherein the first layer is formed around the base insulator.

12. The magnet wire of claim 11 wherein the base insulation comprises at least one layer of polymer enamel.

13. The magnet wire according to claim 12, wherein: The at least one layer of polymer enamel includes one of polyimide or polyamideimide.

14. The magnet wire according to claim 1, wherein The first layer and the second layer are coextruded around the conductor.

15. The magnet wire of claim 1 wherein the first layer is formed directly on the conductor.

16. A method for forming an insulated magnet wire, the method comprising: Provide conductors; as well as forming an extruded insulation around the conductor, wherein forming the extruded insulation comprises: co-extrude a first layer and a second layer of thermoplastic insulation around the conductor, the first layer formed around the conductor, the first layer comprising a first thermoplastic polymer material, the first thermoplastic polymer material having a first thermal index and comprising at least one of polyester, nylon, polyphenylene sulfide, or polyphenylene sulfone; and a second layer surrounding the first layer and contacting the entire outer perimeter of the first layer, the second layer comprising a second thermoplastic polymer material having a second thermal index higher than the first thermal index; wherein the first layer comprises at least 55% of the thickness of the extruded insulation, and The second thermoplastic polymer material includes at least one of polyetheretherketone, polyaryletherketone or polyetherketoneketone.

17. The method of claim 16, wherein coextruding the first layer and the second layer comprises extruding the first layer, the first layer comprising 55% to 80% of the thickness of the extruded insulation, and extruding the second layer, the second layer comprising 20% ​​to 45% of the thickness of the extruded insulation.

18. The method of claim 16, wherein coextruding the first layer and the second layer comprises extruding the first layer, the first layer comprising 55% to 90% of the thickness of the extruded insulation, and extruding the second layer, the second layer comprising 10% to 45% of the thickness of the extruded insulation.

19. The method according to claim 16, wherein: Forming an extruded insulation around the conductor includes forming the extruded insulation to a thickness between 15 microns and 200 microns.

20. The method according to claim 16, wherein: Forming the extruded insulation around the conductor includes forming the extruded insulation to a thickness between 100 microns and 200 microns.

21. The method of claim 16, wherein extruding a first layer of thermoplastic insulation from a first thermoplastic polymer material comprises extruding a first layer comprising a blend of a plurality of polymer materials.

22. The method of claim 16, wherein extruding a second layer of thermoplastic insulation from a second thermoplastic polymer material comprises extruding a second layer comprising a blend of a plurality of polymer materials.

23. The method of claim 16, wherein extruding the first layer of thermoplastic insulation from a first thermoplastic polymer material comprises extruding the first layer from a first thermoplastic polymer material having a thermal index of 200°C or less, and Wherein extruding the second layer of the thermoplastic insulation from a second thermoplastic polymer material comprises extruding the second layer from a second thermoplastic polymer material having a thermal index of 220° C. or greater.

24. The method of claim 16, wherein extruding the first layer of thermoplastic insulation from a first thermoplastic polymer material comprises extruding the first layer from a first thermoplastic polymer material having a thermal index of 200°C or less, and Wherein extruding the second layer of thermoplastic insulation from a second thermoplastic polymer material comprises extruding the second layer from a second thermoplastic polymer material having a thermal index of 240° C. or greater.

25. The method of claim 16, wherein: Extruding a first layer of thermoplastic insulation from a first thermoplastic polymer material comprises extruding the first layer from an amorphous material, and Wherein extruding the second layer of the thermoplastic insulation from a second thermoplastic polymer material comprises extruding the second layer from a semi-crystalline or crystalline material.

26. The method of claim 16, further comprising: A filler material is incorporated into one of the first thermoplastic polymer material or the second thermoplastic polymer material.

27. The method of claim 26, wherein incorporating a filler material comprises incorporating at least one of titanium dioxide, chromium dioxide, silicon dioxide, or boron nitride.

28. The method of claim 16, further comprising: forming a base insulator around the conductor, Wherein forming the extruded insulation includes forming the extruded insulation around the base insulation.

29. The method according to claim 28, wherein: Forming the base insulator includes forming at least one layer of polymer enamel.

30. The method of claim 29, wherein: Forming at least one layer of polymer enamel includes forming at least one layer of polyimide or polyamideimide.

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