Abstract:
An apparatus and related method for forming a three dimensional polymer based part including a die tool having a specified shape and size and exhibiting an exposed polymer adhering surface corresponding in configuration to a polymeric based part to be created. A bin is filled with a polymer material in particulate form and, upon positioning the die tool overhead, the die tool is inserted into the bin, such as by either lowering the tool or raising the bin. The tool is positioned within the bin such that the exposed and adhering surface is in contact with the particulate material. Heat is applied to either or both the die tool and the bin particulate and, in combination with an optional vibrating motion imparted to the bin, causes a specified volume of polymer material to adhere and to form upon the exposed surface of the die tool.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    The present invention claims the priority of U.S. Provisional Application Serial No. 60/374,771 filed Apr. 24, 2002, and entitled Description of Plastic Stamping Process Details for Run Off and Holes of Part, as well as U.S. Provisional Application Serial No. 60/413,139, filed Sep. 25, 2002, and entitled Heated and Particulate Drawing Process. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to apparatuses and methods for aggregating a plasticized resin or composite in a drawing process and through the application of heat. More particularly, the present invention discloses a drawing process and assembly for creating a plasticized part, using a heated die surface lowerable into a bin of resinous material in pellet or aggregate form, as well as a related process for coating a heated structural steel member drawn in continuous fashion through a like bin of resinous material.  
           [0004]    2. Description of the Prior Art  
           [0005]    The prior art is well documented with various examples of article forming assemblies and methods and which in particular incorporate the use of heated and/or compression technology and in which to form a three dimensional resin based article. The objective in each instance is to create a plasticized/resinous based article in a desired time and cost efficient basis.  
           [0006]    General examples drawn from the prior art include U.S. Pat. No. 5,073,329, issued from Carrara, and which teaches an apparatus and method for forming seals, such as composite seals in rubber/meta or other materials, and which includes supplying a raw elastomeric mixture in the form of a suitably shaped extrusion. A transfer machine with a plurality of carriers is provided, each having hinged mold halves defining a mold cavity therebetween, a volume of a blank of raw elastomeric material being deposited on a first and opened mold half. The mold halves are closed and the blank of raw material both compressed and heated to form the desired finished product and as is defined by the specified mold cavity.  
           [0007]    U.S. Pat. No. 3,600,753, issued to Otto, teaches a differential pressure forming mold wherein a sheet of deformable plastic is supported between a mold assembly having a plurality of article forming mold cavities and an opposed mold assembly having a plurality of cavity aligned, projecting plug assists. A plate is incorporated within the mold assembly, having the plug assists, and is operative to prevent ballooning of portions of the sheet surrounding those portions which are moved into the mold cavities by the plug assists and is mounted for relative movement with the plug assists. The plate is moved toward the mold assembly having the mold cavities to clamp the edges of the plastic sheet thereto, prior to the time the plug assists are moved into the cavities to stretch the sheet and mechanically move portions of the sheet into the mold cavities. Thereafter, a differential pressure condition is created to move the sheet portions finally into intimate engagement with the mold cavities.  
           [0008]    U.S. Pat. No. 5,118,380, issued to Gatarz et al., teaches a rim flexible manufacturing insert for a molding press having an upper movable platen adapted to support a male mold member and a fixed lower platen adapted to support a female mold member. The molding press includes a mix head system and a hydraulic ejector system supported below the fixed lower platen. The manufacturing insert includes a table having a platen surface with legs depending downwardly therefrom, the legs being removably securable to the fixed lower platen of the molding press. The platen surface includes an enlarged opening therethrough and a mix head support system is supported below the platen surface intermediate the legs of the table. The mix head support system includes a mix head support and a slide system for permitting three dimensional movement of the mix head from a first position where the mix head extends through the enlarged opening in the platen surface and to a second position where the mix head is beyond the upper platen.  
           [0009]    U.S. Pat. No. 5,617,631, issued to Nguyen, teaches a method of making a liquid ink printhead orifice plate which includes the ink carrying features and a flat mandrel. Once the orifice plate has been stamped, excess material is removed from the orifice plate to reveal ink carrying features of the stamped orifice plate. The orifice plate mandrel is formed by electroforming a mandrel on an etched silicon wafer which defines a plurality of ink carrying channels and ink reservoirs. The electroform mandrel can be made of any number of metal which includes nickel.  
           [0010]    Finally, U.S. Pat. No. 6,318,988, issued to Wrobbel, teaches a tool which enables articles to be deep-drawn without difficulty, even when the material used is of low elasticity and/or when a decorative sheet is used to produce a composite article. The tool includes a die which has a recessed zone which extends between a die opening and die contour or an undercut. The recessed zone is delimited on one side at right angles to an end of the die and, in order to hold a decorative sheet in place, a mounting is fitted on a part of the recessed zone facing the end of the die.  
         SUMMARY OF THE PRESENT INVENTION  
         [0011]    The present invention discloses an apparatus and method for forming a three dimensional and polymer based part. The apparatus includes including a die tool having a specified shape and size and exhibiting an exposed polymer adhering surface corresponding in configuration to a polymeric based part to be created. A bin is filled with a polymer material, typically a synthetic plastic or the like, in particulate form and, upon positioning the die tool overhead, the die tool is inserted into the bin, such as by either lowering the tool or, in the preferred disclosed embodiment, by raising the bin.  
           [0012]    The tool is positioned within the bin such that the exposed and adhering surface is in contact with the particulate material. Heat is applied to either or both the die tool and the bin aggregate and, in combination with an optional vibrating motion imparted to the bin, causes a specified volume of polymer material to adhere and to form upon the exposed surface of the die tool over a predetermined time period.  
           [0013]    In one preferred embodiment, each of a plurality of individual die tools are supported in suspended fashion from a conveyor and, in successive fashion, are contacted with the particulate material in the bin and withdrawn after the specified period of time. The plastic (thermoplastic) part formed upon the die tool is capable of being removed, such as by peeling off, when in the green or thermo-reacting stage and during which it is still flexible and easy to bend.  
           [0014]    In a further preferred embodiment, the die tool is substituted by an elongated and structural member, typically a steel beam or reinforcing rod, and which is translated in axially extending fashion through a suitably constructed and configured bin of particulate filled material. Heat is again applied, typically to the beam, rod, etc., and prior to it being translated through the aggregate filled bin and the desired volume of particulate material adhered to the surface of the beam or rod. In this manner, the surface of the structural steel member is coated with a rust-inhibiting material.  
           [0015]    Also disclosed is a method of forming a three dimensional polymer coating upon a die tool, the tool having a specified shape and size and exhibiting an exposed polymer adhering surface corresponding in configuration to a polymeric based part to be created. The method steps include filling a bin with a polymer material in particulate form, heating the die tool to a specified temperature, inserting the die tool into the bin and such that the polymer adhering surface is in contact with the particulate material, and withdrawing the die tool from the bin upon a desired volume of the polymer material adhering to the exposed surface.  
           [0016]    Additional steps include applying a ceramic coating about an extending perimeter of the adhering surface of the tool and/or about at least one aperture defined in the die tool. Other steps again include vibrating the bin in an elevated position, within which is contained the specified die tool, and of peeling off the semi-molten polymer material following the withdrawing of the tool from the bin. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    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:  
         [0018]    [0018]FIG. 1 is a perspective view of a die tool upon which is adhered a three dimensional volume of a resinous particulate according to a preferred embodiment of the present invention;  
         [0019]    [0019]FIG. 2 is a side view of the die tool, substantially as illustrated in FIG. 1, mounted between ceramic insulation portions and in order to define a particulate adhering surface according to the present invention;  
         [0020]    [0020]FIG. 3 is an enlarged view of a portion of the die tool and adjoining insulating portion according to the present invention and further showing an insulating plug covering an aperture formed in the adhering die tool surface;  
         [0021]    [0021]FIG. 4 is an illustration of the die tool and ceramic surround portions, as substantially shown in FIG. 2, and further illustrating a first pre-inserting position of the die tool into a bin of polymerized particulate according to the present invention;  
         [0022]    [0022]FIG. 5 is an illustration of an inserted and vibrating position of the die tool within the aggregate bin and by which a volume of particulate is caused to adhere to the exposed surfaces of the die tool according to the present invention;  
         [0023]    [0023]FIG. 6 is a further side view illustration of a withdrawn position of the die tool and further showing a release position of the formed and particulate material from the die tool according to the present invention; and  
         [0024]    [0024]FIG. 7 is an illustration of an alternate process according to the present invention for coating a heated structural steel member drawn in continuous fashion through a bin of resinous material. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    Referring now to the drawing figures, and in particular to FIGS. 1 and 2, a die tool is generally illustrated at  10  according to a first preferred embodiment of the present invention and upon which a polymer or plasticized three dimensional part is formed. An exposed surface  12  is illustrated forming a portion of an underside (typically polished and attracting) surface  14  of the die tool  10 .  
         [0026]    The surfaces  12  and  14  are understood to provide a negative recess for the creation of a three dimensionally constructed article including at least one high quality surface, this corresponding to the built-up surface of the part. A preferred application of the built-up part to be created is for use in creating a suitable plastic/resin based automobile part such as a wheel liner (generally understood to correspond to the part to be created from the negative die surfaces  12  and  14  illustrated herein), door panel, and interior plastic part (panel, liner, bumper, etc.).  
         [0027]    The plasticized or polymeric article thus created can include such other applications as a plastic shingle, for homes, plastic siding, shower units, Jacuzzi units, swimming pool parts, and hollow panels filled with different materials used in such as third world housing constructions. Other and additional uses of the three-dimensional parts thus created may include, without limitation, such as those as for use in recreation land and sea vehicles.  
         [0028]    Referring again to FIG. 1, the die tool  10  may be constructed of a suitable metallic (such as steel, aluminum or the like) material and include any specified configuration and by which the polymer attracting surface  14  associated therewith corresponds to the desired three dimensional part to be created. As best illustrated in FIG. 2, a conveyor mechanism  16  and attachment  18  may be incorporated to support, in plural and spaced apart fashion, each of a plurality of the die tools  10 .  
         [0029]    Insulating and non-polymer adhering portions, such as a ceramic coated material, are indicated at  20  and  22  in FIG. 2 and are understood to secure to the die tool  10  in order to encircle a periphery of the polymeric attracting surface  14 . As also shown in FIG. 1, pairs of apertures are illustrated at  24  and  26 , in corresponding fashion to opposite ends  28  and  30 , respectively, of the die tool  10 . The apertures are intended to define corresponding apertures in the three dimensional part to be created and, viewing again FIG. 2, insulating coatings (or patches), see at  32  and  34 , respectively, are applied over the apertures  24  and  26  and so that the part thus created includes the same apertures defined therein. Reference is also made to the enlarged partial view of FIG. 3 and which illustrates the selected insulating patch  34  in covering fashion over a selected one of the apertures  26 . As further shown in FIG. 1, a lengthened recess  36  formed in an upper surface of the die tool  10  and may correspond to the configuration of the projection  12  associated the adhering surface  14 , as well as to facilitate engagement of the conveyor mechanism attachment  18 .  
         [0030]    Referring now to FIG. 4, a bin is generally illustrated at  38  and which may be filled with a volume of the plasticized (blank) material in particulate form  40 . The particulate material  40  is contemplated as including such as a high polymer or like synthetic material, which exhibits desired thermoplastic properties. It is also contemplated other types of polymers, polymeric based resins, and the like may also be employed within the scope of the invention and by which a desired three dimensional quantity of such material in particulate form is caused to aggregate and to adhere to the exposed and attracting surface  14  of the die tool  10 . Additionally, other types of synthetic resins, such further including thermo-set resins, can be employed within the scope of the invention and in order to create the desired part from both a structural and material content perspective.  
         [0031]    The bin  38  is illustrated in both FIGS. 4 and 5 in cutaway fashion and so that the large volume of plasticized (blank) resin  40  is illustrated held within the bin interior. Additional features of the bin  38  include the provision of a plurality of heating coils, see at  42 , formed within the outer walls of the bin. The coils  42  enable preheating of the particulate volume, within a desired temperature range and which may include, without limitation, a temperature in the range of 100° F. in one preferred variant.  
         [0032]    As is further understood that die tool  10  (with associated and particulate adhering surfaces  12  and  14 ) is also preheated prior to applying within the bin  38 . In one preferred application, the die surfaces  12  and  14  are preheated to a temperature (such as in a range of 350° F. to 500° F.), while the ceramic surfaces  20 ,  22 ,  32 , and  34 , only elevate to a temperature in the range of 100° F. and corresponding generally to the preheated temperature of the particulate  40 .  
         [0033]    In order to operate in as efficient a manner as possible, it is desirous to operate the bin  38  in a successive elevating and retracting manner in combination with the advancement of successive die tools along the conveyor. In FIG. 4, the bin  38  is illustrated in its substantially lowered position, this further defined by a pedestal base  44  in a lower most retracted configuration and by which the conveyor  16  may translate (advance) a selected die tool  10  in suspended and overhanging fashion above the bin particulate  40 .  
         [0034]    The bin  38  in FIG. 5 is further illustrated in an upper most raised position (caused by the expansion of the pedestal base in the manner further illustrated at  44 ′ and which is understood to be caused by such as a hydraulic or pneumatic lift mechanism) and by which the die tool  10  is inserted into the bin  38  such that the exposed and adhering surface  14  is caused to be in contact with the particulate material  40 . As further referenced in FIG. 5, the bin  38  may be vibrated (see vibration lines indicated at  46 ) and by which a specified volume of the particulate material  40  is encouraged to adhere and to form upon the polished and attracting surfaces  12  and  14  of the die tool  10  and while at the same time being dissuaded from adhering to the ceramic coating surfaces of the encircling and insulating material defining a parting line with the adhering surfaces of the die tool.  
         [0035]    It is further understood that the desired three dimensional build-up of polymer material upon the die tool is a variable of the pre-heated temperature of the die tool, secondarily that of the particulate bin  40 , and as well as the time period during which the die tool  10  is immersed within the bin  38  in contact with the particulate  40 . Along these lines, parts exhibiting other thicknesses, as well as material properties, can be constructed by altering the temperatures and/or material content of the particulate bin  40  and within the scope of one skilled in the art.  
         [0036]    Referring to FIG. 6, the die tool  10  is illustrated in a subsequently withdrawn and advanced position by which a three dimensional part created, see generally at  48 , is removed from the die tool  10 . In particular, the part  48  may be peeled away (see arrow  50 ) or otherwise detached from the die tool surfaces  12  and  14 , in a semi-fluid (green) or thermo-reacting stage and during which it is still flexible and easy to bend. As further again illustrated in FIG. 6, the part  48  thus created corresponds to the impression of the die surfaces  12  and  14  (in the illustrated example being a wheel well interior) and which exhibits at least one high quality surface corresponding to the polished facing surfaces  12  and  14  of the die tool and including a raised middle  52  (corresponding to projecting surface  12  of the die tool) as well as apertured ends  54  and  56  corresponding to the apertures previously illustrated at  24  and  26  (and associated ceramic coverings  32  and  34 ) formed in the die tool.  
         [0037]    Referring to FIG. 7, a further preferred embodiment of the present invention is illustrated at  58  and by which the die tool  10  illustrated in the earlier embodiment is substituted by an elongated and structural member  60 . The structural member  60  is typically an elongated steel beam, as illustrated, but which may also include such as a metal reinforcing rod or any other suitable elongated and appropriately particulate adhering construction.  
         [0038]    The elongate structural member  60  is translated in axially extending fashion through a suitably constructed and configured bin  62  of particulate filled  64  material (see further cutaway portion defined by interior walls  66 ). Heat is again applied, typically to the beam, rod, etc., in the manner indicated by arrows  68  and prior to the structural member  60  being translated through the aggregate filled bin  62 . A desired volume of particulate material is thereby caused to adhere to the surface of the structural member, see further at  70  and as the elongated member  60  is withdrawn from the bin  62 , in the manner further illustrated by arrow  72 .  
         [0039]    In the above disclosed manner, the surface of the structural steel member is coated with a rust-inhibiting material according to a desired thickness and/or material contact based upon the input parameters (particulate composition, temperature input) of the present invention. It is also understood that the configuration of the bin  62  may be adjusted, such as by sizing apertures on opposite faces thereof, to correspond to the cross sectional outline of the elongated structural member to be passed therethrough and so that a minimal quantity of the particulate material  64  may be spilled or otherwise lost due to the effects of gravity.  
         [0040]    Also disclosed is a method of forming a three dimensional polymer coating upon a die tool, the tool having a specified shape and size and exhibiting an exposed polymer adhering surface corresponding in configuration to a polymeric based part to be created. The method steps include filling a bin with a polymer material in particulate form, heating the die tool to a specified temperature, inserting the die tool into the bin and such that the polymer adhering surface is in contact with the particulate material, and withdrawing the die tool from the bin upon a desired volume of the polymer material adhering to the exposed surface.  
         [0041]    Additional steps include applying a ceramic coating about an extending perimeter of the adhering surface of the tool and/or about at least one aperture defined in the die tool. Other steps again translating the die tools in succeeding fashion over the particulate filled bin, elevating the bin to immerse the die tool, vibrating the bin in the elevated position to facilitate particulate formation and adherence upon the die tool, and peeling off the semi-molten polymer material following the withdrawing of the tool from the bin.  
         [0042]    Having described our 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: