Patent Publication Number: US-2022219360-A1

Title: Metallic non-painting injection molding for vehicles

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Korean Patent Application No. 10-2021-0003307, filed on Jan. 11, 2021, the entire contents of which is incorporated herein for all purposes by this reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a metallic unpainted injection molding for a vehicle, and more particularly, to a metallic unpainted injection molding for a vehicle, capable of improving marketability by preventing a flake line occurring during injection molding from being exposed to an outside. 
     Description of Related Art 
     Recently, as the demand for eco-friendly non-painting materials is increasing, the demand for metallic materials that can realize a metallic texture appearance similar to that of metallic painting by itself without a painting process is increasing. 
     In particular, plastic materials for interior and exterior vehicles are increasingly using materials that have no gloss or low gloss for generating a luxurious feel. 
     Accordingly, for the application of non-painting materials, the development of a metallic material in which metal particles are applied to the material itself is continuously in progress. 
     However, after injection molding, an unpainted material requires additional mold changes due to appearance problems of a molded product caused by metal particles in the material, e.g., weld lines and flow patterns, or the application of the material itself is limited. 
     In the instant case, the flow pattern indicates a plurality of periodic stripes appearing on a surface of an injection-molded product in a direction crossing a flow direction, and is also referred to as a flow mark or a tiger mark. 
     This flow pattern is a phenomenon that appears according to fluctuation of a flow of a resin in the mold, and as a length of the flow increases, it appears as a defect in appearance of a flake line made of stripes near an end portion of the flow. 
     To solve the above problems, in the related art, researches such as on adjusting a shape and aspect ratio of metal particles or improving a surface coating material of metal particles are continuously being conducted, but there is a limit in ameliorating appearance problems such as pulling, agglomeration, and orientation of metal particles during injection molding by only improving the metal particles themselves. 
     Accordingly, there is a demand for research and development to prevent the flow pattern from deteriorating the appearance quality of the flow pattern during injection molding. 
     The information included in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and may not be taken as an acknowledgment or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
     BRIEF SUMMARY 
     Various aspects of the present invention are directed to providing a metallic unpainted injection molding for a vehicle, configured for improving marketability by preventing a flake line occurring during injection molding from being exposed to an outside. 
     One or more embodiments of the present invention provide a metallic unpainted injection molding for a vehicle, molded by injecting metallic resins into a molding part inside an injection mold through a plurality of gates to be molded, wherein at least a groove line is molded in a boundary section where metallic resins meet each other in the molding part. 
     Furthermore, the metallic unpainted injection molding may have a penetration hole of a shape which is formed to extend along a width direction of the vehicle in a center portion, and may include a skid plate which is formed with the at least a groove line having a corresponding groove in a predetermined section starting from opposite corners of the penetration hole, respectively. 
     Furthermore, in the groove lines, a first groove line may be connected to a first lower side corner of the penetration hole based on a vehicle height direction, and is disposed to be inclined along an external surface of the skid plate corresponding to a first side corner, and a second groove line may be connected to a second lower side corner of the penetration hole based on the vehicle height direction, and is disposed to be inclined along the external surface of the skid plate corresponding to a second side corner. 
     The metallic resin may be supplied and injection-molded through the injection mold including a runner disposed at an inlet side of the injection mold to supply plasticized and melted metallic resin therethrough and a gate disposed between the runner and the molding part among the plurality of gates to introduce the plasticized and melted metallic resin supplied from the runner into the molding part. 
     Injection molding may be performed by use of the injection mold which is set in a temperature range of 50° C. or more than 50° C. and 60° C. or less than 60° C. 
     The metallic resin may be provided by mixing polypropylene (PP), a pigment, aluminum particles, rubber particles, and an additive in a predetermined amount, respectively. 
     The aluminum particles may have a circular disk shape, to express a metallic texture by specularly reflecting light. 
     The aluminum particles have a particle size which is set in a range of 16 μm or more than 16 μm and 40 μm or less than 40 μm. 
     The aluminum particles may be added in a range of 3% or more than 3% and 4% or less than 4% of a total content. 
     The metallic resin may be set in a temperature range of 210° C. or more than 210° C. and 230° C. or less than 230° C. 
     The metallic unpainted injection molding according to various exemplary embodiments of the present invention may improve marketability by preventing the flake line generated during injection molding from being exposed to the outside. 
     Furthermore, the metallic unpainted injection molding according to various exemplary embodiments of the present invention may have an effect of reducing cost by eliminating painting and plating processes, which are post-treatment processes on an external surface of a molding. 
     Furthermore, the metallic unpainted injection molding according to various exemplary embodiments of the present invention ameliorates coating film peeling through deletion of the painting process, reduces field claims, and reduces harmful substances generated during the painting process, improving the environment. 
     The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a view for describing an injection mold for manufacturing a metallic unpainted injection molding for a vehicle according to various exemplary embodiments of the present invention. 
         FIG. 2  illustrates a metallic unpainted injection molding for a vehicle according to various exemplary embodiments of the present invention. 
         FIG. 3  and  FIG. 4  illustrate views for describing a manufacturing method of a metallic unpainted injection molding for a vehicle according to various exemplary embodiments of the present invention. 
     
    
    
     It may be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the present invention. The specific design features of the present invention as included herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particularly intended application and use environment. 
     In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the present invention(s) will be described in conjunction with exemplary embodiments of the present invention, it will be understood that the present description is not intended to limit the present invention(s) to those exemplary embodiments. On the other hand, the present invention(s) is/are intended to cover not only the exemplary embodiments of the present invention, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the present invention as defined by the appended claims. 
     Hereinafter, various Exemplary embodiments of the present application will be described more fully with reference to the accompanying drawings, in which embodiments of the present invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. 
     Parts that are irrelevant to the description will be omitted to clearly describe the present invention, and like reference numerals designate like elements throughout the specification. 
       FIG. 1  illustrates a view for describing a molding for determining a control amount of an electronic controlled suspension system according to various exemplary embodiments of the present invention. 
     Referring to  FIG. 1 , a metallic unpainted injection molding  1  (see  FIG. 2 ) for a vehicle according to various exemplary embodiments of the present invention may be molded by injecting a metallic resin  30  (see  FIG. 3 ) into an injection mold  20 . 
     The injection mold  20  may include a runner  23 , a gate  25 , and a cold slug well  27 . 
     The runner  23  may be disposed at an inlet side of the injection mold  20 . 
     The runner  23  is configured to supply the metallic resin  30  which is plasticized and melted. 
     In the instant case, the runner  23  may include a hot runner  230  and a cold runner  231 . 
     The hot runner  230  may be positioned at the entrance of the injection mold  20 , and may have a predetermined temperature configured for maintaining a molten state of the flowing metallic resin  30 . 
     The cold runner  231  is formed at a rear side of the hot runner  230  based on a traveling direction of the metallic resin  30 . 
     The cold runner  231  is configured to transfer the metallic resin  30  supplied from the hot runner  230  to a molding part  21  in the injection mold  20 . 
     The cold runner  231  may have a lower temperature than the hot runner  230 . 
     The gate  25  is formed at a rear end portion of the cold runner  231  based on the traveling direction of the metallic resin  30 . 
     The gate  25  is disposed between the cold runner  231  and the molding part  21  to introduce the metallic resin  30  supplied from the cold runner  231  into the molding part  21 . 
     Furthermore, the cold slug well  27  is mounted at one side of the gate  25 . 
     The cold slug well  27  may be configured to prevent the cured metallic resin  30  from flowing into the molding part  21 . 
     An overall temperature of the injection mold  20  is set in a range of 50° C. or more than 50° C. and 60° C. or less than 60° C. 
     Meanwhile, the metallic resin  30  may be provided by mixing a thermoplastic compound  31 , a pigment  33 , aluminum particles  35 , rubber particles  37 , and an additive  39  in a predetermined amount, respectively. 
     In the instant case, the thermoplastic compound  31  may be, e.g., polypropylene (PP), or may be, e.g., polyamide (PA), polycarbonate (PC), polyethylene (PE), polyphenylene ether (PPE), polyether ether ketone (PEEK), polyphenylene sulfide (PPS), polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene (ABS), polybutylene terephthalate (PBT), or a mixture of two or more thereof, in addition to polypropylene. 
     Furthermore, the pigment  33  is for eliminating a painting process, and adds a color which is actually exposed in appearance. 
     The aluminum particles  35  may have a circular disk shape, to apply a material configured for expressing a metallic texture by specularly reflecting light therefrom. 
     The aluminum particles  35  may have a particle size which is set in a range of 16 μm or more than 16 μm and 40 μm or less than 40 μm. 
     Furthermore, the aluminum particles  35  may be added in a range of 3% or more than 3% and 4% or less than 4% of a total content. 
     In addition to the aluminum particles  35 , a material of the metal particles may be selected depending on metallic appearance required in the metallic unpainted injection molding  1 . 
     A component of the metal particles may be any metal or an alloy of two or more metals, and specifically, may be aluminum or an aluminum-based alloy as described above, but the present invention is not limited thereto. 
     Furthermore, for the additive  39 , one or more additives  39  commonly added to a composition of the metallic resin  30 , e.g., at least one component selected from light diffusing agents, antioxidants, lubricants, ultraviolet absorbers, light stabilizers, impact modifiers, matting agents, flame retardants, or mixtures of two or more thereof, may be further included. 
     Furthermore, the metallic resin  30  may adjust a content of the additive  39  depending on a mixing amount of the aluminum particles  35  for a metallic texture. 
     The metallic resin  30  may be changed by controlling a mixing amount of a thermoplastic resin so that the metallic resin  30  not only performs a function of the portion, but also exhibits excellent metallic texture properties in an external element. 
     The metallic resin  30  may be set to a melting temperature in the range of 210° C. or more and 230° C. or less. 
     The metallic resin  30  as described above is eco-friendly because the painting process may be eliminated by applying a high-brightness metallic composite material. 
       FIG. 2  illustrates a metallic unpainted injection molding for a vehicle according to various exemplary embodiments of the present invention, and  FIG. 3  and  FIG. 4  illustrate views for describing a manufacturing method of a metallic unpainted injection molding for a vehicle according to various exemplary embodiments of the present invention. 
     The metallic unpainted injection molding  1  for a vehicle according to various exemplary embodiments of the present invention may be manufactured by injecting the metallic resin  30  into the injection mold  20  as described above. 
     Referring to  FIG. 2 , for example, the metallic unpainted injection molding  1  may include a skid plate  10 . 
     The skid plate  10  is a component disposed in the front of the vehicle, and a penetration hole  11  is formed to extend along a width direction of the vehicle. 
     The skid plate  10  is formed with groove lines  13  having grooves in a predetermined section starting from opposite corners  110  and  111  on the penetration hole  11 , respectively. 
     That is, the groove lines  13  may be respectively formed at opposite sides of the skid plate  10  based on the width direction of the vehicle. 
     For example, the groove line  13  is connected to the first lower side corner of the penetration hole  11  based on a vehicle height direction, and is disposed to be inclined along an external surface of the skid plate  10  corresponding to the first side corner  110 . 
     For example, the groove line  13  is connected to the second lower side corner of the penetration hole  11  based on the vehicle height direction, and is disposed to be inclined along an external surface of the skid plate  10  corresponding to the second side corner  111 . 
     Referring to  FIG. 3  and  FIG. 4 , the groove lines  13  are formed at positions in the injection mold  20 , where metallic resins  30  injected through the gates  25  configured at opposite sides of the skid plate  10  respectively meet each other with respect to the vehicle height direction. 
     Although the metallic unpainted injection molding  1  according to various exemplary embodiments of the present invention has been described using the skid plate  10  as an example, it is not necessarily limited thereto, and it may include a bumper molding, interior and exterior garnishes, exterior mirror scalps, various fillers, etc. 
     Accordingly, the metallic unpainted injection molding  1  according to various exemplary embodiments of the present invention may improve scratch resistance, stain resistance, and impact resistance by applying a high-brightness metallic composite material. 
     Furthermore, the metallic unpainted injection molding  1  according to various exemplary embodiments of the present invention may reduce cost by eliminating painting and plating processes, which are post-treatment processes, on an external surface of a molding. 
     The metallic unpainted injection molding  1  according to various exemplary embodiments of the present invention may improve marketability by preventing the flake line generated during injection molding from being exposed to the outside. 
     That is, the metallic unpainted injection molding  1  may improve appearance quality by including a weld line or a flow mark in the groove lines  13 . 
     For the present reason, the metallic unpainted injection molding  1  may increase freedom of design, improve moldability, and secure productivity. 
     Furthermore, the metallic unpainted injection molding  1  according to various exemplary embodiments of the present invention ameliorates coating film peeling through deletion of the painting process, reduces field claims, and reduces harmful substances generated during the painting process, improving the environment. 
     For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner”, “outer”, “up”, “down”, “upwards”, “downwards”, “front”, “rear”, “back”, “inside”, “outside”, “inwardly”, “outwardly”, “interior”, “exterior”, “internal”, “external”, “forwards”, and “backwards” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. It will be further understood that the term “connect” or its derivatives refer both to direct and indirect connection. 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described to explain certain principles of the present invention and their practical application, to enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the present invention be defined by the Claims appended hereto and their equivalents.