Patent Application
20240052954
With reference to the following description, the present invention relates to and discloses automotive fluid transport tubes and related methods of manufacturing. According to the non-limiting embodiments described below, the tube is constructed of a metal tubing not limited to a Cu-plated low carbon steel and includes a corrosion inhibiting intermediate layer further not limited to any of a zinc/aluminum, electroplated zinc or hot dip aluminum. Additional layers may include any of chrome free conversion coating for passivation, an electroplated zinc or a hot dip aluminum, along with a solvent based primer layer along with an outermost coating of a material incorporating a graphene powder. The outermost coating can include either any number of layers and can be constructed of a combination thermoplastic elastomer (TPE) with impact resistant properties coextruded with a polymer incorporating a graphene or graphene-oxide powder applied over the primer layer to provide a balance of toughness and hardness.
The mechanical properties of the graphene compounded polymer depends on the graphene loading—higher loading of graphene provides higher strength. The polymer used may be any of a thermoplastic, thermoset, elastomer or other natural or synthetic polymers and may be chosen from, but not restricted to, any of a polypropylene, nylon 6, nylon-12, nylon-6,12, polyethylene, terephthalate, polybutylene, polyvinyl fluoride, polyphthalamide, polyoxymethylene, polycarbonate, polyvinylchloride, polyester, and polyurethane. The polymer can also include a fiber additive not limited to any of a glass fiber, metal fiber, ceramic fiber or carbonaceous (e.g. aramid) fibers.
Fluid transport tubing in vehicles perform the critical function of carrying fuel, brake fluids and transmission oil coolants during vehicle operation. Addressing specifically a fuel line tube, these are usually constructed of single-wall furnace welded low carbon steel, owing to its ease of formability and low cost of raw material. Brake line tubes are usually configured as double walled brazed tubing, and as required to sustain fluids at higher pressures. Contributing factors to the failure of the low carbon steel tubing can be due to any of abrasion, corrosion or stone-impacts, such as which can compromise safe operation of the automotive vehicle.
To reduce vulnerability to corrosion, a Zinc-Aluminum alloy, electroplated Zinc or hot dip aluminum maybe applied directly on the steel tubing. In order to protect the corrosion inhibiting layer from harsh environmental conditions and stone impingement a thermoplastic polymer layer is usually extruded as a top-coat. In use, the thermoplastic polymer layer may be exposed to broken clips, exposed wiring, or plastic convolutes, depending on the location of the tubing, and under cyclic or continuous contact conditions lead to breach of the thermoplastic polymer layer. In order to further protect this thermoplastic polymer layer, another layer of polymer, usually of multifold thickness, is added either in the form of a heat shrink polymer or another extruded layer. The mentioned tubing construction, while commonly prevalent in the automotive industry, is not an efficient design as it not only adds to the weight of the overall tubing but also involves additional manufacturing steps and related cost.
As is also known, graphene is a two-dimensional planar nanomaterial comprising of sp2 bonded carbon atoms packed in the honeycomb lattice. Many of the material properties, such as high tensile strength, high thermal and electrical conductivity, that makes graphene lucrative stems from the unique bonding structure of the planar graphene. However, the application of graphene at a macroscopic scale for applications as in the automotive industry continues to be a challenge.
Given the above background description, U.S. Pat. No. 10,625,487, to Kerin, Jr. et al., teaches a coated metal pipe for use as an automotive fluid transport tube and including any of a single or double walled tubing formed into a circular cross sectional profile. An intermediate primer layer is applied over the tubing. A polyamide incorporating a graphene powder is further applied over the intermediate layer.
A further example of the prior art is shown by the automotive fluid tubing of Picco et al., U.S. Pat. No. 6,915,820 which is configured for carrying any of gasoline/diesel fuel or hydraulic fluid and is composed of a metal with a coating of aluminum, over which is extrusion coated a polyamide 12 layer and for improving the wear-resistance and corrosion-resistance of the tubing.
Berger et al., U.S. Pat. No. 9,556,358, teaches a method for coating of a metallic article, in which the metal surface is coated with a polymer or a two-component system that reacts to form a polymer following application to the metal surface. The composition includes a 70-2700 meq/kg olefinic double bonds which leads to stronger adhesion and to increased corrosion resistance.
US 2018/00453257, to Kawai et al., teaches a multi-layer coated film applied to a metal pipe and which covers an outer circumferential surface of the pipe. The coating film includes a chemical conversion layer containing a zirconium oxide and/or zirconium hydroxide. A primate layer contains a polyamide imide and/or an epoxy resin.
US 2018/0119871, also to Kawai, teaches a coated metal pipe in which the multi-layered coating includes a chemical conversation layer and a primer layer which further includes a polyamide imide and at least one kind of additive component selected from a polyamide, a fluorine resin, a silane coupling agent, and an epoxy resin.
The present invention discloses an automotive fluid transport tube including any of a single or double walled tubing formed into a circular cross sectional profile. The tube is constructed of a metal not limited to a Cu-plated low carbon steel and includes a corrosion inhibiting intermediate layer not limited to any of a zinc/aluminum, electroplated zinc or hot dip aluminum intermediate layer. Additional layers may include either of an optional chrome free conversion coating for passivation, an electroplated zinc or hot dip aluminum, along with a solvent based primer layer and an outermost coating of a material incorporating a graphene powder.
The outermost coating can include, without limitation, a combination of a thermoplastic elastomer (TPE) with impact resistant properties coextruded with a polymer incorporating a graphene or graphene oxide powder applied over the primer layer to provide a balance of toughness and hardness. The mechanical properties of the graphene compounded polymer or copolymer depends on the graphene loading—higher loading of graphene provides higher strength. The polymer may also include a fiber additive not limited to any of a glass fiber, metal fiber, ceramic fiber or carbonaceous (e.g. aramid) fiber.
The polymer used may be any of a thermoplastic, thermoset, elastomer or other natural or synthetic polymers and may be chosen from, but not restricted to, any of a polypropylene, nylon 6, nylon-12, nylon-6,12, polyethylene, terephthalate, polybutylene, polyvinyl fluoride, polyphthalamide, polyoxymethylene, polycarbonate, polyvinylchloride, polyester, and polyurethane.
Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which:
With non-limiting reference to the attached drawings the present invention teaches an automotive fluid transport tube of varying compositions, each of which being coated with a corrosion, abrasion and impact resistant multi-layer or mono coating system. The present invention also teaches a related method of manufacturing any tube covered under the present system, article or assembly.
In each variant disclosed, the tubing includes an outermost coating (including single and multi-layers) of an extruded polymer or co-polymer material incorporating a graphene powder, such providing high impact or wear resistance and superior insulating properties. For purposes of the present invention, the various ranges of coating thickness described subsequently herein are understood to represent preferred but non-limiting embodiments, and it is envisioned that other ranges can be employed unless otherwise indicated.
Referring initially to
A fourth layer 18 of a solvent based primer coating (such as by example but not limited to three micrometers) is then applied over the conversion coating 16. Solvent based coatings are understood to contain higher levels of organic compounds in comparison to water-based coatings and facilitate the application, drying and formation of a durable film. Finally, a fifth layer 20 of an extruded polymer or co-polymer top coat is applied over the primer coating, such as being reinforced with an extruded graphene or graphene oxide powder. As is known, graphene is a material constructed by carbon atoms bonded together in a repeating pattern of hexagons, whereas graphene oxide is an oxidized from of graphene laced with oxygen containing groups.
The mechanical properties of the graphene compounded polymer depicted in any of the related variants depends upon the graphene loading, with higher loadings of graphene providing higher strength. While not limiting to any specific loading, one non-limiting example can provide for loading in a range of 0.1% up to 25% by weight of graphene or graphene oxide with the desired polymer/copolymer matrix.
The range of polymers employed in the top coat or layer 20 can further include any of thermoplastic, thermoset, elastomer or other natural or synthetic polymers and may be chosen from, but not restricted to, any of a polypropylene, nylon 6, nylon-12, nylon-6,12, polyethylene, terephthalate, polybutylene, polyvinyl fluoride, polyphthalamide, polyoxymethylene, polycarbonate, polyvinylchloride, polyester, and polyurethane. It is further understood that this range of materials is applicable to the outer extruded layers according to any of the related variants
Without limitation, the outer layer 20 can further be reinforced with a two-dimensional allotrope of carbon such as graphene or arrangement of carbon nanotubes. Powdered multilayered graphene, such as which is fabricated by exfoliation techniques, is compounded with the outer layer by any range or percentage by weight loading. In each instance, the end goal is to provide superior properties to the outer layer of polymer material produced such that it exhibits improved mechanical properties, superior wear resistance and well as enhanced barrier resistance (such as protecting the interior of the tubing of heat/cold temperature extremes as well as establishing hydrophobic properties), as well as increased impact resistance to the underlying steel tubing.
As is also known, graphene is an atomic scale hexagonal lattice made of carbon atoms one atom layer in thickness. As is further known, graphene is a one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. Graphene can be viewed as an atomic-scale chicken wire made of carbon atoms and their bonds. The name comes from GRAPHITE+-ENE, and in which graphite itself consists of many graphene sheets stacked together.
The carbon-carbon bond length in graphene is approximately 0.142 nm. Graphene is the basic structural element of some carbon allotropes including graphite, carbon nanotubes and fullerenes. It can also be considered as an infinitely large aromatic molecule, the limiting case of the family of flat polycyclic aromatic hydrocarbons called graphenes. Measurements have shown that graphene has a breaking strength 200 times greater than steel, making it the strongest material ever tested. Accordingly, and as supported by the present description, a graphene powder combined with a variety of outer coating extruded polymers materials provides an environmental protective outer or top coat covering which provides superior corrosion, abrasion and impact resistance.
Referring to
As with the example of
Proceeding to
A fifth layer 60 of an extruded polymer or copolymer reinforced with combined with a graphene powder as a top protective layer. The fifth layer 60 exhibits similar properties and characteristics to those described at 20 in
Proceeding to
An optional third layer 76 of a conversion coating is again provided for passivation, followed by a fourth solvent based primer layer 78, with a top coat layer 80 of an extruded polymer or copolymer reinforced with a graphene powder extruded onto the primer coating and functioning as a top protective layer. As with the layers 20, 40, and 60 in the preceding embodiments, the outer polymer or copolymer layer with extruded graphene or graphene oxide powder provides the coated metal tube with enhanced mechanical properties, (environmental) barrier resistance and impact resistance over prior art coatings.
Proceeding to
An extruded polymer or copolymer reinforced with graphene or graphene oxide powder is provided as first 120 and second 122 top coats. Without limitation, any number of multi or subset layers can be incorporated into the outer polymer and copolymer coated metal pipe, with the individual coats each including any combination or sub-combination of materials, including any type of copolymer, as previously described and again not limited to any of a thermoplastic, thermoset, elastomer or other natural or synthetic polymer and which may be chosen from, but not restricted to, any of a polypropylene, nylon 6, nylon-12, nylon-6,12, polyethylene, terephthalate, polybutylene, polyvinyl fluoride, polyphthalamide, polyoxymethylene, polycarbonate, polyvinylchloride, polyester, and polyurethane.
The present invention further contemplates any plurality of extruded polymer top coats, which can be provided according to varied thicknesses corresponding to their specific compositions and in order to optimize the desired material properties of the tubing employed in a given application. This can further include, without limitation, segregating the use of the entrained graphene or graphene oxide powder in either of the intermediate 120 or uppermost 122 extruded polymer layers. Without limitation, the present invention envisions the use of any of singular or multiple polymer or copolymer layers, these being provided in any uniform or alternating arrangement.
Proceeding to
Finally,
Without limitation, the TPE layer 138 can further be substituted by an impact modified copolymer, along with the polymer subset layer reinforced with Graphene for providing the desired balance of toughness and hardness.
Additional to the materials previously disclosed herein, other impact modified copolymers can include (without limitation), acrylonitrile butadiene styrene (ABS), polycarbonate materials, high-density polyethylene (HDPE), polypropylene impact copolymer, or polyteafluoroethylene (PTFE).
Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims. This can further include the tubing being constructed, without limitation, of any of a copper plated low carbon steel, low carbon steel, stainless steel, or aluminum. The present invention further contemplates other application processes outside of extrusion for applying the outer polymer layer(s) to the tubing.
Among related variants, this can include the use of any suitable forming process not limited to extrusion and including other injection molding techniques for forming the outer polyamide/graphene powder layer about the inner metal tube and desired combination of intermediate corrosion inhibiting layers.
Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims. The detailed description and drawings are further understood to be supportive of the disclosure, the scope of which being defined by the claims. While some of the best modes and other embodiments for carrying out the claimed teachings have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims.
The foregoing disclosure is further understood as not intended to limit the present disclosure to the precise forms or particular fields of use disclosed. As such, it is contemplated that various alternate embodiments and/or modifications to the present disclosure, whether explicitly described or implied herein, are possible in light of the disclosure. Having thus described embodiments of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made in form and detail without departing from the scope of the present disclosure. Thus, the present disclosure is limited only by the claims.
In the foregoing specification, the disclosure has been described with reference to specific embodiments. However, as one skilled in the art will appreciate, various embodiments disclosed herein can be modified or otherwise implemented in various other ways without departing from the spirit and scope of the disclosure. Accordingly, this description is to be considered as illustrative and is for the purpose of teaching those skilled in the art the manner of making and using various embodiments of the disclosure. It is to be understood that the forms of disclosure herein shown and described are to be taken as representative embodiments. Equivalent elements, materials, processes or steps may be substituted for those representatively illustrated and described herein. Moreover, certain features of the disclosure may be utilized independently of the use of other features, all as would be apparent to one skilled in the art after having the benefit of this description of the disclosure. Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.
Further, various embodiments disclosed herein are to be taken in the illustrative and explanatory sense, and should in no way be construed as limiting of the present disclosure. All joinder references (e.g., attached, affixed, coupled, connected, and the like) are only used to aid the reader's understanding of the present disclosure, and may not create limitations, particularly as to the position, orientation, or use of the systems and/or methods disclosed herein. Therefore, joinder references, if any, are to be construed broadly. Moreover, such joinder references do not necessarily infer that two elements are directly connected to each other.
Additionally, all numerical terms, such as, but not limited to, “first”, “second”, “third”, “primary”, “secondary”, “main” or any other ordinary and/or numerical terms, should also be taken only as identifiers, to assist the reader's understanding of the various elements, embodiments, variations and/or modifications of the present disclosure, and may not create any limitations, particularly as to the order, or preference, of any element, embodiment, variation and/or modification relative to, or over, another element, embodiment, variation and/or modification.
It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. Additionally, any signal hatches in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise specifically specified.
The present application claims the priority of U.S. Ser. No. 17/462,518 filed Aug. 31, 2021. The '518 application in turn claims the priority of U.S. Ser. No. 63/074,641 filed Sep. 4, 2020.
| Number | Date | Country | |
|---|---|---|---|
| 63074641 | Sep 2020 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17462518 | Aug 2021 | US |
| Child | 18382603 | US |
