METALLIC SPEAKER COVER WITH MULTICOLORED FABRIC-LIKE APPEARANCE AND METHOD FOR MANUFACTURING IT

Abstract

A metallic speaker cover, encompassing a base made of expanded metal; a pretreatment film that adheres to the expanded metal base; a multi-colored powder coating film that adheres to the pretreatment film, wherein the multi-colored powder coating has a surface that has a fabric-like appearance, wherein the multi-colored powder coating film includes a coating formula designed to match a base color layer, and wherein the coating formula includes an initial predetermined particle size distribution.

Description

TECHNICAL FIELD

[0001] Several aspects of this disclosure relate to metallic speaker covers having a multi-colored, fabric-like appearance and to methods of making such products. STATE OF THE ART

[0002] US 6,279,678 B1 discloses a loudspeaker assembly with a closed top wall and an opposite open end, a first sound source, and a second sound source, with the exposed portion of the first sound source oriented in an opposite direction to the exposed portion of the second sound source. A cover includes an expanded metal mesh and conceals the components of the loudspeaker assembly.

[0003] US 2020 / 0 384 734 A1 shows a film for receiving a metal layer, comprising a thermoplastic resin, wherein the film is transparent.

[0004] US 10 135 130 B1 shows a system for concealing electronic devices on a utility pole, wherein the utility pole carries an arm with at least one lamp, wherein the system has a covering hood and a cover.

[0005] In general, speaker grilles must be an integral part of the vehicle's interior design theme. The materials used to make such grilles are closely related, and the interior design theme includes leather, fabrics, hard and soft plastic trim, fabric-covered plastic trim, and various metal parts with which the speaker grille must visually harmonize.

[0006] Traditionally, the surface treatments of metallic audio covers are chosen to provide a distinct contrast in surface and texture to the rest of the passenger compartment. In the past, the original equipment manufacturer would choose a single material / color / tone / surface treatment for the audio cover, creating a contrast with the rest of the interior. This motif was typically used to highlight proprietary premium audio packages and systems.

[0007] The automotive industry's transition to electric propulsion has recently spurred a drive to reduce weight and streamline interior components. This paradigm shift now more frequently requires metallic audio covers to essentially mimic the luster, texture, and color of adjacent fabrics or other material patterns to create a harmonious styling motif.

[0008] Historically, metallic speaker grilles have been manufactured from a variety of metals, including low-carbon steel alloys, aluminum, stainless steel, and other low-cost metals with a high strength-to-weight ratio. Based on the unique physical properties of each metal and alloy, the thickness of the base material of the audio grille is typically selected to provide sufficient strength after the open area for sound transmission is created, to withstand wear during manufacturing, and after the intermediate product is converted into a finished audio grille.

[0009] Several processes are available to create open areas for sound transmission in the speaker grille. These include punch perforation, laser perforation, waterjet cutting, drilling, photochemical etching, and metal stretching, among others. Each open area creation method produces a unique "texture" of the metallic surface, ranging from relatively smooth to coarse / wavy. Depending on the process chosen, an open area for sound transmission can be created in a single metal blank or while the metal is still in coil form. Creating the open area in coils generally offers better economics and higher throughput. Once the open area is created, the material coils or blanks are converted into formed metallic covers using conventional metal forming processes such as stamping, piercing, forming, CAM forming, and the like.

[0010] Optionally, pretreatment may be considered to clean the cover prior to subsequent coatings or to prevent the metal from oxidizing prior to finishing. These pretreatments can range from mere surface cleaning to chemical etching, which removes metal, to the application of a physical coating, including primers, zinc phosphate, iron phosphate, electroplating, e-coating, and the like.

[0011] Conventional finishing techniques for metallic audio covers use solid-color or tinted coatings. Finishing techniques for solid-color coatings include thermosetting powder coatings, solvent-based lacquers and enamels, water-based paints, colored anodizing, PVD (physical vapor deposition), tinted clear coats, and the like.

[0012] Wet painting uses solvent-based paint systems, including lacquer and enamel. Historically, they were applied with a spray gun to a variety of metal parts, including audio covers. These coatings can be clear, opaque, or solid-colored. Other solid elements can be added to these coatings to enhance color depth, such as pearlescent, metallic, and other solid particles. For environmental reasons, this type of coating is only used when a completely smooth surface is required. The wet painting process cannot produce a multicolored surface that simulates a fabric-like appearance on metallic audio covers.

[0013] Metal anodizing involves applying a tinted coating to a metal surface. Metallic parts are dipped in a single-color chemical, which creates an anodized layer of the coating on the surface of the part. As with wet-painting approaches, conventional anodizing processes cannot produce a multi-colored surface that simulates a fabric-like appearance on metallic audio covers.

[0014] With conventional PVD techniques, a single solid color material is evaporated in a vacuum chamber and deposited onto the surface of a metallic audio cover. Like the other techniques mentioned above, the PVD process cannot produce a multicolored surface that simulates a fabric-like appearance on metallic audio covers.

[0015] Conventional powder-coated audio covers typically produce a single, monolithic color. Such techniques cannot create a multi-colored finish that simulates a fabric-like appearance on metallic audio covers.

[0016] The prior art described above represents conventional methods for creating monochromatic / monochrome appearances on metallic speaker grilles. These conventional surface treatments are not sufficiently capable of simulating the color and texture of multicolored fabrics. In particular, the surface appearance of automotive speaker grilles manufactured using conventional techniques lacks one or more steps necessary to simulate the appearance of multicolored fabrics. What is desired is a speaker grille that resembles a woven or fabric in terms of color, gloss, surface topography, and other performance requirements.

[0017] State-of-the-art processes produce only a solid-color coating that doesn't mimic a fabric-like appearance. The industry desires a metallic audio cover that offers the enhanced acoustics and durability that these coatings offer, while retaining the appearance of a woven or fabric finish and possessing antimicrobial properties. SUMMARY

[0018] Several aspects of this disclosure relate to a product and method for manufacturing metallic audio component or speaker covers with a multicolored, fabric-like appearance. In particular, the disclosed techniques provide a balance between the primary elements necessary to simulate the appearance of multicolored fabrics in a metallic audio cover.

[0019] Various process steps involve combinations of multi-colored coatings, low-gloss, and metallic patterns with a surface area and surface topography suitable to match those of a target fabric. Through appropriate combinations, the goal is to provide a metallic audio cover that offers improved acoustic properties and the durability of metallic audio covers, as well as a surface that resembles a fabric.

[0020] Of similar importance is the ability to apply an antimicrobial surface treatment to these metallic audio grilles during the painting process. In addition to the inherent disadvantages of fabric speaker grilles, such as staining and cracking, antimicrobial properties are important in light of current and future health concerns.

[0021] In a preferred series of process steps, a conventional or non-conventional expanded metal pattern is first selected and attempted to match the surface texture of a target material. In addition to the metal pattern itself, the film formation of the pretreatment (if applicable) and the film formation of the multi-colored coating must also be considered. The combination of pattern and layered film formation mimics the target material in the desired manner. Furthermore, the final coating preferably has a gloss level that matches that of the target material.

[0022] The above-described advantages and other advantages and features of the present disclosure are readily apparent from the following detailed description of the preferred embodiments and method steps when considered in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows a perspective view of a representative expanded metal sample before it is subjected to the subsequent processing steps. Fig. Figure 2 shows an enlarged view of an expanded metal sample showing some of its characteristic properties. Fig. Figure 3 shows a representative process flow diagram. Fig. Figure 4 shows an enlarged three-quarter view of a portion of a fabric-like, multicolored speaker cover made of expanded metal. Fig. Figure 5 shows an enlarged section through an expanded metal sample coated with a primer film and a multicolored paint layer. DETAILED DESCRIPTION

[0023] As will be appreciated by those skilled in the art, various features of the present disclosure illustrated and described with reference to one of the figures may be combined with features illustrated in one or more other figures to produce embodiments of the present disclosure not explicitly illustrated or described. The illustrated feature combinations represent representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.

[0024] In a preferred series of process steps, a process begins by selecting an expanded metal pattern. Fig. Figure 1 shows an image of conventional raw expanded metal before it undergoes further processing. In metal stretching, a stretching tool is used to create a pattern in a continuous coil of a malleable alloy, such as low-carbon steel or aluminum, using a bypass shearing process. Elements of the design pattern to be selected include the type or size of the stretching tool, the material thickness, the material type, and the process variables / settings for the expanded metal processing machine, as described in Fig. 2 are shown.

[0025] Conventional expanded metal samples are produced using a contoured sawtooth pattern shear blade with a flattened “saw tip.” The spacing between the teeth and the shape of the individual teeth are some of the factors that influence a pattern that matches the surface topography of a target material. Changing these factors affects the expanded pattern introduced into the metal and its dimensions. Representative elements of a 2D / 3D surface that matches that of the target material include, with reference to Fig. 2 SWD (Short Way of Diamond - mesh width) and LWD (Long Way of Diamond - mesh length), as well as SWO (Short Way of Opening - opening width) and LWO (Long Way of Opening - opening length), ST (Strand Thickness - strand thickness) and SW (Strand Width - strand width).

[0026] One goal of the presented process is to produce a fabric-like metallic loudspeaker that has the appearance of a fabric—that is, the property of a fabric that immediately catches the eye of the observer. This property is related to the surface of the fabric. The appearance of the fabric is directly related to the construction, weave, degree of twist, material used, and the reflective properties of the material. www.textileadvisor.com / 2019 / 02 / fabricappearance-fabric-properties-of.html.

[0027] Fabrics of interest for interior upholstery are typically multi-colored, woven fabrics with relatively low luster. Many woven patterns are available. Generally, these patterns are relatively fine, so the substrate they cover is not visible. Illustrative examples are shown at www.midwestfabrics.com / fabric / automotive-upholsteryfabric.html and are incorporated by reference. According to this source, automotive upholstery can be characterized using factors such as category (e.g., OEM Detroit number), color (white, gray, black, red, beige, brown, blue, green, tan, purple, and silver), fabric content (polyester, vinyl, woven, nylon / polyester, and tweed), vehicle make, year, and price. This source defines 218 items for automotive upholstery fabrics.

[0028] Fig. Figure 3 is a process flow diagram describing representative steps for configuring an audio cover with a fabric-like appearance.

[0029] The powder coating chemical, the powder's color palette, the powder's particle size, and the additives used to control gloss are all factors that influence the fabric-like appearance. A preferred embodiment uses specialized polyester chemicals (TGIC - triglycidyl isocyanurate - a chemical compound used as a curing agent in some powder coatings) or polyester urethane chemicals. These chemicals have proven capable of meeting the performance requirements for automotive interior trim.

[0030] Fig. Figure 5 shows a representative cross-sectional view of a finished loudspeaker grille. The substrate of the grille is made of expanded metal. On top of the expanded metal is a pretreatment film that at least partially penetrates the expanded metal and forms a base for a multicolored powder coating film. During the electrostatic powder coating process, virtually the entire surface of the raw expanded metal is encased in the pretreatment layer. This pretreatment film layer is then preferably completely encased in the multicolored powder coating film with a fabric-like appearance, as described. The inner Class A surface is the surface of primary interest because it borders the target fabric it is intended to mimic. By performing the disclosed method steps, surface A-A of the top surface of the target fabric is mimicked by surface B-B of the loudspeaker grille.The sound penetrates the open spaces created by the expanded metal mesh. The . Fig. The section through the expanded metal sample shown in Figure 5 shows the layering described here.

[0031] To coordinate color matching and color harmony within a specific interior trim system, Master Color Panels are provided by the original equipment manufacturer. Powder coating formulas are developed to match a base color layer. This color match is prepared to include a specific particle size distribution. The secondary color is formulated using the same process as the original color match; however, the particle size distribution curve is modified to enhance the appearance of the secondary color on a metal mesh surface. The desired result is a metallic speaker grille that appears like a fabric or woven fabric.

[0032] Details on representative powder coating process parameters and a powder coating troubleshooting guide can be found at www.tcipowder.com / resources / troubleshooting-guide / chapter-eleven-powder-curing-process, which are incorporated by reference.

[0033] The expanded metal undergoes one or more pretreatment steps to improve the adhesion of the powder to the expanded metal substrate. With appropriate pretreatment, lasting corrosion resistance can be achieved. Such pretreatment steps often include cleaning the substrate to remove contaminants and oils, rinsing, and chemical conversion of the cleaned and rinsed substrate surface. Such conversion may include, for example, chromate conversion for aluminum and iron phosphate conversion for ferrous metals.

[0034] Most conversion coatings contain a film that alters the physical and chemical properties of the expanded metal surface. The film can often exhibit a gray to blue sheen or a blue to golden sheen.

[0035] Gloss is measured by shining a known amount of light onto a surface and measuring the reflectance. www.glossmeters.com / GlossIntro2.html. Most fabrics used in automotive interiors have a relatively low gloss level, typically between 3 and 9% at a 60-degree viewing angle. In the preferred embodiment, the gloss level of a finished fabric-like powder-coated expanded metal audio cover, which most closely matches the fabric system, is between 5 and 7% at a 60-degree viewing angle. Those skilled in the art will understand that the gloss chemical formulation and the final gloss appearance can be adjusted upward or downward depending on the desired appearance of the finished audio cover.Process variables in the manufacture of a fabric-like metallic speaker grille include surface texture, number of powder particle colors, powder particle sizes, ratio of colors to particle sizes, and average gloss level.

[0036] One goal is to provide an accent that harmonizes with a specific interior design theme. A desired result is a soft, fabric-like appearance, created by a multicolored, speckled appearance that conveys a perceived 2D / 3D dimensionality simulating fabric. In contrast, conventional approaches produce a solid-color coating that lacks a fabric-like appearance.

[0037] In one approach, metallic audio covers are processed through an electrostatic powder coating system that applies a chemical designed to match the color and gloss of the target fabric. This powder coating chemical must be applied at the correct stage of film formation and then cured, preferably using a controlled two-stage curing system. Such a controlled application and curing system have been shown to provide uniform color, appropriate gloss, satisfactory appearance, and other performance characteristics. These characteristics include resistance to various solvents, detergents, salt spray, abrasion, scratches, antimicrobial properties, and resistance to discoloration, as well as color matching and recognizable texture to a master sample.If desired, one or more films can be applied using a powder coating process.

[0038] As used herein, the term "antimicrobial" refers to a property or coating that contains an active ingredient that makes it effective against the growth of bacteria and fungi. Antimicrobial coatings can include solvent-based, water-based, liquid, or powder coatings. See, for example, www.microban.com / antimicrobialsolutions / applications / antimicrobial-paints. Suitable formulations are available, for example, from Microban at www.microban.com. The antimicrobial agent can be added to the pretreatment film and / or the multi-colored powder coating film.

[0039] The processes described here take the production of enhanced audio covers to the next level in terms of texture and the simulation of a fabric-like appearance using alternative coating techniques and chemistries. These techniques allow the production of audio covers with surface treatments that provide a fabric-like surface consistent with the styling motif.

[0040] The advantages of the disclosed method steps include at least some of the following: Lower costs Improved durability No adhesives required (unlike fabric-covered grilles) Convex and concave shapes are possible that cannot be represented with fabric Fewer components Lower system-level complexity.

[0041] Tests have shown that a fabric-covered plastic audio cover and the disclosed powder-coated audio cover with a fabric-like appearance are very similar to each other. A normal observer cannot easily distinguish the surface color, texture, and gloss level of the two products.

[0042] While the best mode has been described in detail, those skilled in the art will recognize that various alternative method steps, designs, and embodiments are within the scope of the following claims. While various embodiments have been described as advantageous or preferred over other embodiments with respect to one or more desired characteristics, those skilled in the art will recognize that sacrificing one or more characteristics may be acceptable in order to achieve desired system attributes, depending on the specific application and implementation. These attributes include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc.Those embodiments discussed herein that are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for certain applications.

Claims

[1] A metallic speaker cover comprising a base made of expanded metal; a pretreatment film that adheres to the expanded metal base; a multi-colored powder coating film adhered to the pretreatment film, the multi-colored powder coating having a surface that has a fabric-like appearance, wherein the multi-colored powder coating film includes a coating formula designed to match a base color layer, and wherein the coating formula includes an initial predetermined particle size distribution. [2] A metallic loudspeaker cover according to claim 1, wherein the expanded metal base is characterized by at least one factor from a first group consisting of - SWD (Short Way of Diamond - mesh width), - LWD (Long Way of Diamond - stitch length), - SWO (Short Way of Opening), - LWO (Long Way of Opening), - ST (Strand Thickness), and - SW (Strand Width). [3] A metallic speaker cover according to claim 1 or 2, wherein the expanded metal base includes at least one material selected from a second group consisting of a low carbon steel alloy, aluminum, an aluminum alloy, and stainless steel. [4] A metallic speaker cover according to any one of claims 1 to 3, wherein the expanded metal base includes openings free of the pretreatment film and the multi-colored powder coating film to allow the passage of sound through the speaker cover. [5] A metallic speaker cover according to any one of claims 1 to 4, further comprising one or more antimicrobial agents. [6] A metallic loudspeaker cover according to any one of claims 1 to 5, wherein the pretreatment film cleans the expanded metal base prior to one or more subsequent coatings and includes a physical layer comprising at least one component selected from the third group consisting of a primer, zinc phosphate, iron phosphate, a galvanic material, and an electrocoating. [7] A metallic speaker cover according to any one of claims 1 to 6, wherein the multi-colored powder coating film has an outer surface resembling a fabric or fabric-like material for automobiles. [8] A metallic speaker cover according to any one of claims 1 to 7, wherein the multi-colored powder coating film further includes one or more subsequent color formulations each having a particle size distribution curve different from the initial predetermined particle size distribution to enhance a secondary or subsequent color appearance on a metal mesh surface. [9] The metallic speaker cover of any one of claims 1 to 8, further comprising an outer surface facing a viewer, the outer surface being characterized by a gloss, texture, and color that mimic the corresponding properties of an adjacent fabric, the gloss having a gloss level of about 5-7% at a viewing angle of 60 degrees. [10] A method of manufacturing a metallic loudspeaker cover, which method comprises the following steps, which are not necessarily carried out in the order given: Providing a base of expanded metal; Adhering a pretreatment film to the expanded metal base; and Powder coating of one or more multi-colored films adhering to the pretreatment film, wherein the multi-coloured powder coating has a surface that has a fabric-like appearance, wherein the step of powder coating includes using a coating formula consistent with a base color layer and selecting an initial predetermined particle size distribution. [11] The method of claim 10, wherein the step of providing a base of expanded metal includes the steps of selecting at least one factor from a fourth group consisting of - SWD (Short Way of Diamond - mesh width), - LWD (Long Way of Diamond - stitch length), - SWO (Short Way of Opening), - LWO (Long Way of Opening), - ST (Strand Thickness), and - SW (Strand Width). [12] A method according to claim 10 or 11, wherein the step of providing a base of expanded metal includes providing a metal selected from a fifth group consisting of a low carbon steel alloy, aluminum, an aluminum alloy, and stainless steel. [13] A method according to any one of claims 10 to 12, wherein the step of providing a base of expanded metal includes providing openings free of the pretreatment film and the multi-colored powder coating film to allow the passage of sound through the speaker cover. [14] The method of any one of claims 10 to 13, further comprising the step of providing one or more antimicrobial agents. [15] A method according to any one of claims 10 to 14, wherein the step of adhering a pretreatment film to the expanded metal base includes the step of cleaning the expanded metal base prior to applying one or more subsequent coatings, the cleaning step providing a physical layer comprising a component selected from the group consisting of a primer, zinc phosphate, iron phosphate, a galvanic material, and an electrocoating. [16] A method according to any one of claims 10 to 15, wherein the step of powder coating includes providing a curing agent selected from a sixth group consisting of a polyester, triglycidyl isocyanurate, polyester urethane, and mixtures thereof to produce an exterior surface resembling a fabric or fabric-like material for automobiles. [17] A method according to any one of claims 10 to 16, wherein the powder coating step further includes using one or more subsequent color formulations each having a particle size distribution curve different from the initial predetermined particle size distribution to enhance a secondary or subsequent color appearance on a metal mesh surface. [18] The method of claim 17, wherein the step of powder coating further includes providing an outer surface facing a viewer, the outer surface being characterized by a gloss, texture, and color that mimic the corresponding properties of an adjacent fabric.

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