Abstract:
A process for chrome plating a non-ferrous object includes copper plating the non-ferrous object which has had burrs and surface irregularities removed. The surface of the copper plated object is smoothed, and copper plate irregularities removed, by moving dry abrasive media over the object for a pre-determined period of time. Typically, this is done by placing the copper plated object into a finishing machine having dry abrasive media therein. The object is then chrome plated.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention generally relates to the process of chrome plating. More particularly, the present invention relates to a process for preparing a non-ferrous object for chrome plating utilizing dry abrasive media over the pre-plated object.  
           [0002]    The process of chrome plating non-ferrous objects and the preparation for chrome plating such objects are well-known. A non-ferrous object is molded, die cast, forged or otherwise created. Due to the creation process, burrs and other irregularities are formed on the surface of the object. Such burrs and irregularities are removed by a variety of processes, including the placement of the object into a finishing machine having wet abrasive media therein.  
           [0003]    Vibratory and barrel finishing machines are well-known in order to deburr, improve surfaces, clean and polish the surfaces. Such a process is often referred to as mass finishing, as many parts or objects can be placed within the machine and deburred or otherwise polished simultaneously. The media used in vibratory and barrel finishing processes are primarily pre-formed metallic, ceramic, or plastic media formed in cylinders, triangles, cone shapes, etc. The primary functions of the media are to keep the parts separated and provide the abrasives to perform the cutting or deburring operation to the surfaces, or to perform a brightening or cleaning action on the surfaces. The size, shape and abrasiveness of the media can be selected to perform the necessary task. Traditionally, this process has been performed as a wet process with water or other wet solution within the media.  
           [0004]    After the non-ferrous object in question has been subjected to the deburring and polishing processes, it is dried and then pre-plated. Typically, the non-ferrous object is copper plated by hanging the object in a bath with copper solution. Electricity is applied and the copper is plated onto all exposed surfaces of the object. This copper plating process is necessary as the nickel/chrome in the chrome plating process will adhere to copper, but not necessarily to other metals or surfaces.  
           [0005]    After the copper plating process, the object must once again be finished in order to remove plate irregularities and otherwise smooth the surface of the plated object. The wet media mass finishing machines are not typically used as it has been found that the aqueous solution adversely reacts with the copper plated onto the object. Thus, the objects are typically hand polished or buffed.  
           [0006]    However, this process presents many drawbacks. Hand polishing and buffing is time consuming and thus expensive due to the labor costs involved. Also, hand buffing causes buffing agents or compounds to become impregnated into the copper plate coat. Polishing mistakes can also create poorly polished objects. These drawbacks can cause blistering of the final chrome plated object, or otherwise create rejects due to divots, scratches, uncovered porosity, etc., which are difficult to detect before chrome plating the object. Presently, it is estimated that the cost of poor quality polishing contributes at least several dollars to the cost of every good wheel produced and increases administrative costs and unusable inventory by hundreds of thousands of dollars. In the wheel industry, it is estimated that approximately 12% to 22% of chrome plated wheels are eventually rejected. Currently, the indirect and direct cost of polishing methods for chrome plated aluminum wheels is at least $22.00, roughly 50% of the overall plated wheel cost.  
           [0007]    Accordingly, there is a continuing need for an improved polishing and preparation process for the chrome plating of non-ferrous objects. The present invention fulfills this need and provides other related advantages.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention resides in a process for chrome plating a non-ferrous object. Typically, wet abrasive or grinding media is used to remove burrs and surface irregularities of the non-ferrous object after it is molded, die cast, etc. The object is then pre-plated, such as by copper plating.  
           [0009]    The present invention removes copper plate irregularities and otherwise smooths the surface of the copper plated object by moving dry abrasive media over the copper plated object for a pre-determined time. This step typically comprises placing the copper plated item into a finishing machine having dry abrasive media therein. Preferably, the dry abrasive media is light weight so as to easily flow over the surface of the object. For example, the media may comprise a resin or plastic abrasive media.  
           [0010]    Removing the copper plate irregularities and otherwise smoothing the surface of the copper plated object in this fashion eliminates the high cost of manual labor and produces a very smooth surface with very few rejects. Thereafter, the object is chrome plated to finish the process. 
       
    
    
       [0011]    Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.  
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The accompanying drawings illustrate the invention. In such drawings:  
         [0013]    [0013]FIG. 1 is a flow-chart depicting the steps taken in accordance with the present invention.  
         [0014]    [0014]FIG. 2 is a perspective view of an unfinished non-ferrous metal object in the form of a wheel;  
         [0015]    [0015]FIG. 3 is a perspective view of the wheel being placed into a wet finishing chamber;  
         [0016]    [0016]FIG. 4 is a perspective view of the wheel being inserted into wet media of the finishing chamber;  
         [0017]    [0017]FIG. 5 is a perspective view of the wheel and media being moved relative to one another to deburr the wheel;  
         [0018]    [0018]FIG. 6 is a perspective view of the wheel being removed from the finishing tank;  
         [0019]    [0019]FIG. 7 is a perspective view of the wheel being pre-plated in a copper bath;  
         [0020]    [0020]FIG. 8 is a perspective view of the wheel in a dry finishing tank;  
         [0021]    [0021]FIG. 9 is a perspective view of the wheel suspended in a chrome bath; and  
         [0022]    [0022]FIG. 10 is a perspective view of the finished chrome plated wheel. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]    The present invention resides in a process for preparing a non-ferrous object for chrome plating. More particularly, the present invention resides in a process for polishing pre-plated objects which are to be chrome plated in order to improve the polishing of such objects, reduce the rejection rate for such chromed objects, and reduce the cost of the polishing process.  
         [0024]    With reference now to FIG. 1, a flow-chart is illustrated depicting steps taken in accordance with the process of the present invention. With reference to FIGS. 1 and 2, an object, such as an unfinished wheel  10  which has been molded, die cast, forged, or otherwise created is provided ( 100 ). Typically, such objects are non-ferrous metal objects which are intended to be chrome plated. Due to the molding, die casting, forging, or other creating process, the object  10  typically includes burrs and other imperfections.  
         [0025]    With reference now to FIGS. 1 and 3- 6 , the wheel  10  is deburred in a wet finishing chamber  12  ( 102 ). With particular reference to FIGS.  3 - 6 , wheels and other non-ferrous objects have traditionally been deburred in wet finishing tanks, such as vibratory chambers, centrifugal equipment, or the illustrated drag finishing machine having media  14  therein and a source of water  16  or other aqueous solution. The non-ferrous object, in this case the wheel  10  is placed within the chamber  12 , with the media  14  and aqueous solution  16  with the object  10  dragged through the media  14  and aqueous solution  16 , or the media  14  in aqueous solution  16  moved around the object to remove the burrs and other imperfections of the object  10 . This process is well-known in the art. The type of media may vary according to the object which requires deburring or polishing. For example, media may comprise gravel, metallic balls or objects, or more preferably small pre-formed plastic pellets. In the illustrated process, the wheel  10  is suspended from an arm  18  which pitches the wheel  10  at a pre-determined angle and moves or drags the wheel  10  through the wet media  14  and  16 . After a pre-determined time period, or it is determined that the wheel  10  is sufficiently deburred or polished, it is removed from the wet chamber  12 , as illustrated in FIG. 6.  
         [0026]    With reference now to FIG. 7, after deburring and initial polishing, the wheel  10  or other non-ferrous object is suspended by wires  20  or the like into a chamber  22  holding a copper bath solution, or other pre-plating solution. The wheel  10  is then subjected to an electro-plate process ( 104 ) in the copper bath, as is well known in the art.  
         [0027]    The aforementioned steps of the present invention are well-known and described above in prior procedures. Typically, as described above, the non-ferrous object would then be published by robot or hand. However, such polishing has been found to be very expensive, have a high rejection rate, and time consuming. As described above, pre-plating, in particular copper pre-plating, has not been amenable to a second wet polishing step. However, the inventors have discovered that the pre-plated wheel when run through a dry finishing machine, that is a finishing chamber  26  having dry media  14  therein, produces superior results. With reference to FIG. 8, the pre-plated wheel  10  is placed into any appropriate chamber  26 , such as the illustrated drag finishing chamber.  
         [0028]    A modified La Habra Welding Inc. Spin Finish machine has been found to be particularly useful in treating and polishing wheels. The automotive wheels that have been copper plated and ready for pre-plate finish prior to final chrome plating are fixed onto the arm  18  or other assembly and pitched and angled to promote best contact between the wheel  10  and the dry media  14 . Preferably, plastic abrasive media is used in the chamber  26 .  
         [0029]    Plastic media has a long-standing reputation as providing high-quality finishes specifically in pre-plate applications. Plastic or urethane media having a light weight and relatively light abrasiveness renders the media  14  highly mobile enabling the media  14  to float easily around the object  10  and remove pre-plating imperfections, such as any burrs, the shallowing of valleys or crevices, etc., formed on the object  10  during the pre-plating process.  
         [0030]    In a particularly preferred embodiment, approximately 1,600 pounds of PFS-5/16 P-BG and PFS-1/2 P-BG plastic abrasive media are charged into the finish machine  26  in a 50:50 mix ratio. The size and ratio distribution are selected because of the advantage of easy access and flow afforded by the media into the wheel  10 . Machine speed is set at approximately 27 rpm, and cycle time is set at 20 minutes. At these settings, a finish on the copper substrate is produced that renders it suitable for a final brilliant chrome plating without any additional work. Due to the fact that a dry abrasive media  14  is utilized, the copper plating does not adversely react to any aqueous solutions.  
         [0031]    Although the pre-plated wheel  10 , when removed from the dry media  14  appears to be scratched and not nearly as smooth as the pre-plated object  10  and before this process, test have confirmed that in fact the pre-plated wheel  10  is much smoother and the imperfections removed to a greater degree than hand polishing.  
         [0032]    With reference to FIG. 9, after the pre-plated wheel  10  has been polished in the dry finishing chamber ( 106 ), it is then electroplated in a chrome bath ( 108 ). The process of chrome plating a non-ferrous object is well known, and illustrated by suspending the wheel  10  by wires  20  or the like in a chamber  28  containing a chrome bath  30  and applying electricity to chrome-plate the object ( 110 ).  
         [0033]    The resultant object, as illustrated in FIG. 10, is a chrome-plated wheel with a brilliant finish. Although there has traditionally been a 12%-22% rejection rate for hand polished wheels, this rate of rejection has been reduced to approximately 2%-4% using the process of the present invention. The actual chrome finish has been found to be more brilliant using the present invention as well. It is believed that this is due to the impregnation of buffing material during the hand-buffing process, whereas the use of dry media  14  does not impregnate the copper plated wheel  10  whatsoever. Currently, it is estimated that the manual polishing of pre-plated wheels or other objects is approximately $15.00, robotic or turntable polishing is approximately $9.00, yet the polishing of pre-plated objects for chrome plating using the present invention is only approximately $4.00. Thus, the present invention realizes a significant cost savings in the chrome plate process. Due to the automation of the process, labor rates can be significantly reduced and the production rate of objects can be increased significantly.  
         [0034]    Although an embodiment has been described in detail for purposes of illustration, various modifications may be made without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.