Patent Publication Number: US-2013248096-A1

Title: Molded-In-Color Panel And Method For Molding

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. Application Ser. No. 11/766,813 filed Jun. 22, 2007, the disclosure of which is incorporated in its entirety by reference herein. 
    
    
     TECHNICAL FIELD 
     The multiple embodiments of the present invention relate to molded-in-color panels and molds for creating molded-in-color panels. 
     BACKGROUND 
     Vehicle panels are an example of molded-in-color panels. Vehicle panels may be on the interior or exterior of a vehicle, commonly have surfaces, which are exposed to a viewable environment. These exposed surfaces are often referred to as class-A surfaces. It is desirable to create these class-A surfaces to have few or no surface defects or flaws when compared to non class-A surfaces. Since class-A surfaces are exposed to a viewable environment, these surfaces are formed using tighter tolerances and greater detail. Non class-A surfaces are not exposed in the viewable environment and may have visible surface defects and flaws. 
     Vehicle panels with class-A surfaces are not typically injection-molded or compression-molded unless the vehicle panels are painted in a secondary painting operation, covering surface defects. Painting the vehicle panel in a secondary painting operation requires additional time and cost to create the vehicle panel. Paint is also susceptible to peeling, chipping, blistering and/or delamination. 
     Molded-in-color plastics are a lower cost option for programs to consider instead of current painted technologies and/or other decorative alternatives, such as paint film or other laminates. Molded-in-color plastics are also environmentally friendly because molded-in-color plastics do not require a secondary painting process so molded-in-color plastics may be easily recycled and manufacturing of molded-in-color plastics does not generate volatile organic compounds. 
     SUMMARY 
     A method for creating a molded-in-color panel in a mold is disclosed. The method includes providing a mold having a first mold member and a second mold member. One of the first mold member and the second mold member has an appearance portion forming surface and the other of the first mold member and the second mold member has a concealed portion forming surface corresponding with the appearance portion forming surface. The concealed portion forming surface forms a concealed portion of a panel and is free of any protuberances and ancillary structural members for facilitating ideal surface characteristics of an appearance portion of the panel. Molded-in-color resin is injected in the mold and cooled to form a molded-in-color panel. At least one ancillary structural member is welded to the concealed portion of the panel. 
     In another embodiment, a molded-in-color panel is disclosed. The molded-in-color panel is formed providing a mold having a first mold member and a second mold member. One of the first mold member and the second mold member has an appearance portion forming surface and the other of the first mold member and the second mold member has a concealed portion forming surface corresponding with the appearance portion forming surface for forming a concealed portion of a panel. The concealed portion forming surface is free of any protuberances and ancillary structural members for facilitating ideal surface characteristics of an appearance portion of the panel. Molded-in-color resin is injected in the mold and the molded-in-color resin is cooled to form a molded-in-color panel. At least one ancillary structural member is welded to the concealed portion of the panel. 
     In another embodiment, a system for creating a molded-in-color element in a mold is disclosed. The system has an injection molding machine having a first mold member and a second mold member. One of the first mold member and the second mold member has an appearance portion forming surface and the other of the first mold member and the second mold member has a concealed portion forming surface corresponding with the appearance portion forming surface for forming a concealed portion of a panel. The concealed portion forming surface is free of any protuberances and ancillary structural members for facilitating ideal surface characteristics of an appearance portion of the panel. Molded-in-color resin can be injected in the mold at a sufficient flow rate so that the molded-in-color resin flows without disruption over the first mold member and second mold member to form a molded-in-color element to facilitate ideal surface characteristics of the appearance portion of the molded-in-color element. The system includes a laser welding station to weld at least one accessory on the molded-in-color element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevation view of a mold; 
         FIG. 2  is top plan view of the mold of  FIG. 1 ; 
         FIG. 3  is a cross-section view of the mold of  FIG. 2  taken along line  3 - 3  and a welding station; 
         FIG. 4  is a schematic view of a welding station embodiment for joining a panel and a structural component together; 
         FIG. 5  is a cross-section view of a panel formed in the mold of  FIG. 3  and a plurality of structural components; 
         FIG. 6  is another cross-section view of the panel and the plurality of structural components of  FIG. 5  joined together; and 
         FIG. 7  is a partial cross-section view of a panel joined together with a structural component. 
     
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
     Molded-in-color panels may be formed using injection-molding or compression-molding. When forming molded-in-color panels, creating class-A surfaces results in a visible appearance of knit lines, mold flow lines, and sink marks. Although molded-in-color plastics offer benefits, it is still extremely difficult to mold parts in color without visible appearance of knit lines, flow lines or sink marks on a class-A surface. In addition, when metallic molded-in-color resin is utilized, creating a defect-free class-A surface is extremely difficult because metallic molded-in-color resin has a high propensity for surface defects. 
     Referring now to  FIG. 1 , a mold for creating a molded-in-color panel is illustrated and referenced generally by numeral  10 . The panel  10  may be any suitable molded-in-color panel  10 . In one embodiment, the panel  10  is a vehicle panel  10 , which is employed on an interior or exterior of a vehicle. Of course, any molded-in-color panel  10  is contemplated within the scope of the present invention. The mold  10  has a first mold half  12  and a second mold half  14 . In another embodiment, the mold  10  may have three or more mold portions, which collectively form the mold  10 . Any number of mold portions is contemplated within the scope of the present invention. 
     In one embodiment, the first mold half  12  is referred to as a cavity because the first mold half  12  may have a substantial recess for receiving the second mold half  14 . The second mold half  14  is referred to as a core because the second mold half  14  has a substantial projection which is received in the cavity  12 . 
     The core  14  may be moveable relative to the cavity  12 . By providing a stationary cavity  12  and a moveable core  14 , a vehicle panel may be retained within the mold  10  on the core  14  after molding the vehicle panel, which may be generally easily ejected or removed after the mold  10  is opened. It is also contemplated within the scope of the invention that the cavity  12  may be moveable while the core  14  is stationary. If three or more mold portions are employed, at least one mold portion may be moveable relative to at least a second mold portion. 
     Referring now to  FIG. 2 , a top plan view of the mold  10  of  FIG. 1  is illustrated. To create a vehicle panel  16 , a heated resin is injected into the mold  10  through a resin inlet. In one embodiment, the resin inlet is a gate. 
     The heated resin has molded-in-color so that a secondary painting operation is not required. In one embodiment, the heated resin and the colorant may be separately injected into the mold  10 . The resin may have material properties comparable with a thermoplastic polyolefin (TPO) or a polycarbonate-acrylonitrile butadiene styrene (PC/ABS). 
     The resin may contain metallic molded-in-color for vehicle panel applications for use in the interior of the vehicle, for example. Using a metallic molded-in-color resin in a typical mold creates large amounts of surface defects, which are not visually appealing. The metallic molded-in-color resin may achieve a low gloss, quality, metallic appearance once injection-molded or compression-molded. The resulting vehicle panel delivers an enhanced metallic appearance over paint and offers a low-cost option to using aluminum and/or decorative films. 
     Referring now to  FIG. 3 , the mold  10  of  FIG. 2  is illustrated in cross-section taken along line  3 - 3 . The mold  10  has a cavity  12 , which is stationary, and a core  14 , which is moveable relative to the cavity  12 . The cavity  12  may also be moveable relative to the core  14 . The mold  10  is illustrated in a closed position while a vehicle panel  16  is being formed. The first forming surface  20  of the cavity  12  and the second forming surface  22  collectively provide an outer boundary for the vehicle panel  16 . 
     The cavity  12  has a first forming surface  20  for cooperating with a second forming surface  22  of the core  14 . In another embodiment, three or more forming surfaces are provided to collectively define the outer boundary of a vehicle panel. Heated resin flows over the first forming surface  20  and the second forming surface  22  to fabricate a vehicle panel. The heated resin may be introduced into the mold  10  in any suitable known manner. 
     As depicted, the second forming surface  22  of the core  14  is free of any protuberances such as ancillary structural elements, any features that are not required for an appearance of an exposed, visible side  21  of the vehicle panel  16  or any changes in a concealed side  23  without corresponding changes in the exposed, visible side  21 . The protuberance free second forming surface  22  allows heated resin to freely flow over the second forming surface  22  without disturbance. Since the heated resin flows without disturbance over the second forming surface  22 , the vehicle panel  16  formed in the mold  10  is free of visible knit lines, flow lines and sink marks on an exposed, visible side  21  of the vehicle panel  16 . Ideal surface characteristics for the exposed, visible side  21  are desired so that the vehicle panel  16  is visually pleasing. 
     The vehicle panel  16  formed in the mold  10  has an exposed, visible side  21  and a concealed side  23 . The exposed, visible side  21  is visible when mounted on a vehicle. To produce the visually pleasing vehicle panel  16 , the design of the second forming surface  22  eliminates all protuberances formed in the second forming surface  22 , including any ancillary structural elements. Examples of ancillary structural elements include, but are not limited to, brackets, ribs, gussets, bosses, connecting members, retention members, fasteners, and/or push-pins. The ancillary structural elements are separately formed and welded to the vehicle panel at a welding station, which is illustrated in  FIG. 4  and generally referenced by numeral  18 . 
     Referring to  FIG. 4 , a laser welding station  18  is illustrated as one example of a welding station. Of course, any suitable welding station is contemplated within the scope of the present invention. The laser welding station  18  has a robot  25  to support a laser welding end effecter  27 . The laser welding station  18  has a first weld fixture  29  to support a vehicle panel  16  and a second weld fixture  31  to support an ancillary structural component  24 . The invention contemplates any suitable first and second weld fixtures  29 ,  31 . The laser end effecter  27  on the robot  25  produces a laser beam  33  to produce a weld zone  35  between the vehicle panel  16  and the ancillary structural component  24 . The laser  27  may rotate about the second weld fixture  31 , as indicated by an arcuate arrow, to adequately join the vehicle panel  16  and the ancillary structural component  24 . 
     With reference to  FIG. 5 , a vehicle panel  16  formed in the mold  10  of  FIGS. 1-3  and ancillary structural components  24 - 30  are illustrated. In one embodiment, the ancillary structural component is a rib  24 , which extends along a length of the vehicle panel  16 . In another embodiment, the ancillary structural component is a connecting member  24  to connect the vehicle panel  16  to the vehicle once the connecting member  24  is welded to the vehicle panel  16 . 
     An additional ancillary structural component  26  is illustrated as a push-pin  26 . The push-pin  26  facilitates retention of the vehicle panel  16  on a vehicle once the push-pin  26  is welded to the vehicle panel  16 . Another ancillary structural component  28  is depicted as a bracket  28 . The bracket  28  is utilized to removably attach the vehicle panel  16  to a vehicle once the bracket  28  is welded to the vehicle panel  16 . Yet another ancillary structural component  30  is illustrated as a gusset  30 . The gusset  30  supports a corner of the vehicle panel  16  once the gusset  30  is welded to the vehicle panel  16 . Any amount of ancillary structural components  24  is contemplated within the scope of the present invention. 
     As discussed above, the vehicle panel  16  is formed free of protuberances on the concealed side  23  to facilitate ideal surface characteristics on the exposed, visible side  21 . Since the vehicle panel  16  is formed without protuberances on the concealed side  23 , the ancillary structural components  24 - 30  are not integrally formed with the vehicle panel  16 . 
     In one embodiment, the ancillary structural components  24 - 30  are individually molded. The ancillary structural components  24 - 30  may be injection-molded, compression-molded, vacuum-molded or extruded. The ancillary structural components  24 - 30  may be fabricated in any suitable known manner so that the ancillary structural components  24 - 20  may be welded to the vehicle panel  16 . 
     The ancillary structural components  24 - 30  may be, but are not limited to being brackets, ribs, gussets, bosses, connecting members, retention members, fasteners, and/or push-pins. Any known ancillary structural components  24 - 30  may be utilized within the scope of the present invention. In one embodiment, a plurality of structural components  24 - 30  are provided and the plurality of structural components  24 - 30  are all welded to the vehicle panel  16 . The ancillary structural components  24 - 30  may be all identical, may differ in size and/or shape, or may be varying amounts of differing types altogether of ancillary structural components  24 - 30 . 
     In one embodiment, the ancillary structural components  24 - 30  are formed while the vehicle panel  16  is produced. In another embodiment, the ancillary structural components  24 - 30  are fabricated at a different time and/or place from the vehicle panel  16 . The vehicle panel  16  is suitably transported from the mold  10  to the welding station  18 , as illustrated in  FIG. 4 . The ancillary structural components  24 - 30  are transported to the welding station  18  where the ancillary structural components  24 - 30  are welded to the vehicle panel  16 . In one embodiment, the ancillary structural components  24 - 30  are laser welded to the vehicle panel  16 . In another embodiment, the ancillary structural components  24 - 30  are friction welded to the vehicle panel. Any known laser welding, friction welding or other thermoplastic joining station may be utilized so that the vehicle panel  16  and the ancillary structural components  24 - 30  are joined together, as depicted in  FIG. 6 . Any known manner of joining preformed ancillary structural components  24 - 30  to the preformed vehicle panel  16  is contemplated within the scope of the present invention. 
     To weld the vehicle panel  16  and the ancillary structural components  24 - 30  together, both the vehicle panel  16  and the ancillary structural components  24 - 30  should have overlapping melting temperatures. In one embodiment, the overlapping melting temperatures of the vehicle panel  16  and the ancillary structural components  24 - 30  correspond with a temperature the welding station produces when the vehicle panel  16  and ancillary structural components  24 - 30  are placed under a laser of the laser welding station for a specified period of time. 
     Referring now to  FIG. 7 , a partial view of a vehicle panel  16  is illustrated joined together with an ancillary structural component  24 . A weld zone  35  exists between the vehicle panel  16  and the ancillary structural component  24  that does not disrupt the exposed, visible side  21  of the vehicle panel  16 . An adequate penetration weld may be employed so that the weld does not alter the finish of an exposed, visible side  21  of the vehicle panel  16 . 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.