Abstract:
A system for removing soluble support material from a prototype part may include a container for receiving the prototype part. A pump may be in fluid communication with the container and may be configured to pump a solution into the container and out of the container. A cooling module, such as a heat exchanger, may be in fluid communication with the pump. A temperature sensor may be operatively coupled to the cooling module and may activate the cooling module if a sensed temperature exceeds a threshold.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 62/202,134, filed Aug. 6, 2015, the contents of which are hereby incorporated in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to processes for creating rapid prototype parts. More particularly, the present disclosure relates to removing temporary support material generally utilized in the production of rapid prototype parts. 
       TECHNICAL BACKGROUND 
       [0003]    Fused Deposition Modeling (FDM) is one method among a few capable of developing rapid prototype parts or functional models from a thermoplastic material such as ABS (acrylonitrile butadiene styrene) and polycarbonate. FDM utilizes a computer numeric controlled (CNC) extruder-head that squeezes a fine filament of melted thermoplastic through a modeler nozzle. The controller, operating in accord with pre-select, known variables, activates the modeler nozzle to deposit heated plastic layer-by-layer to form the desired geometric shape. In some instances where select features of the part are left unsupported as a result of the part&#39;s orientation, the FDM-based machine may incorporate the use of a second nozzle for extruding therethrough support material to create support structures for any cantilevered portions of the part. In cases where the part&#39;s build comprises small, intricate features, a water soluble support material may be used to further facilitate or ease removal from the part&#39;s build upon completion. Once the appropriate supporting layer is built, thermoplastic, as discussed above, is extruded through the modeler nozzle to form the part&#39;s build. Once the part has finished its successive layers and the build is complete, the part is removed from the FDM-based machine for inspection and final surface preparation, which may include removal of any support material, additional machining, and/or application of a finish coating material. 
         [0004]    In instances where a water soluble support material is used, the art offers a range of techniques for removing the support material from the rapid prototype part. One such technique may simply involve immersing the part in a suitable solvent repeatedly via manual or automated means and manually removing the support material using a brush or a pointed tool. Another technique commonly employed in the art may involve placement within a conventional immersion parts washer of the type generally designed to remove grease, carbon, resins, tar, and other unwanted petroleum-based residuals from automotive parts and machine shop equipment. Typically, the conventional immersion parts washer of this type may comprise operable features of ultrasonics to facilitate the cleansing action of the solvent. Although the operable feature noted above may or may not adequately address the removal of support material, the conventional immersion parts washer can be costly in terms of purchase, maintenance and operation, particularly for this limited purpose, and inappropriate in a variety of environmental settings. Given that most machinery having rapid prototype part making capabilities is operated from within an office setting or a similarly suited environment, the coinciding use of a conventional immersion parts washer makes it unacceptable and inappropriate in maintaining a sound, clean environment. Further, some conventional immersion parts washer may expose one to unacceptable health risks, particularly those having ultrasonic capabilities (see World Health Organization Report on Ultrasound and Ultrasonic Noise, Geneva 1982). 
         [0005]    Accordingly, there remains a need for a dedicated apparatus capable of removing water soluble support material from a rapid prototype part and operating side-by-side with a rapid prototype part making machine commonly placed and operated in an office setting or a similarly suited environment. 
       SUMMARY OF THE DISCLOSURE 
       [0006]    According to various example embodiments, a system for removing soluble support material from a prototype part may include a container for receiving the prototype part. A pump may be in fluid communication with the container and may be configured to pump a solution into the container and out of the container. A flow control subsystem may control a rate of flow of the solution into the container and out of the container. 
         [0007]    The flow control subsystem may include a variable frequency drive in electrical communication with the pump. The flow control subsystem may include a valve in fluid communication with at least one of a pressure hose or a suction hose. 
         [0008]    Additional objects, advantages, and features will become apparent from the following description and the claims that follow, considered in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    Various embodiments will now be described by way of example with reference to the accompanying drawings, in which: 
           [0010]      FIG. 1  is a perspective view of one example embodiment illustrating a support removal apparatus equipped with a basket; 
           [0011]      FIG. 2  is a side cross sectional view of the embodiment of  FIG. 3  taken on line  2 - 2  of  FIG. 3  illustrating a manifold assembly and strainer basket situated within an interior chamber; 
           [0012]      FIG. 3  is a top view of the embodiment of  FIG. 1  illustrating a work surface mounted to a retention tank; 
           [0013]      FIG. 4  is a side cross sectional view of the embodiment of  FIG. 3  taken on line  4 - 4  of  FIG. 3  illustrating a strainer basket and a manifold assembly; 
           [0014]      FIG. 5  is a perspective view of the embodiment of  FIGS. 1 and 3  illustrating a support removal apparatus equipped with a lid; 
           [0015]      FIG. 6  is a side cross sectional view of the embodiment of  FIGS. 1 and 3  illustrating an alternative manifold assembly having an elongate tubular member; 
           [0016]      FIG. 7  is a side cross sectional view of the embodiment of  FIGS. 1 and 3  illustrating an alternative manifold assembly having an elongate tubular member connected to an inlet fitting; 
           [0017]      FIG. 8  is a partial side cross sectional view of the embodiment of  FIGS. 1 and 3  illustrating an elongate tubular member connected to a second end of an outlet piping; 
           [0018]      FIG. 9  is a functional block diagram illustrating functional relationships between a microprocessor, a thermocouple, pump, heating element, and level indicator; 
           [0019]      FIG. 10  is a perspective view of another example embodiment illustrating a retention tank equipped with a box manifold; 
           [0020]      FIG. 11  is a side cross sectional view of the embodiment of  FIG. 10  taken on line  11 - 11  of  FIG. 13  illustrating a drain box fitted with an intake side; 
           [0021]      FIG. 12  is a side cross sectional view of the embodiment of the  FIG. 13  taken on line  12 - 12  of  FIG. 13  illustrating a box manifold and heating element mounted therebelow and encased in a heat chamber; 
           [0022]      FIG. 13  is a side elevational view of the embodiment of  FIG. 10  illustrating a drain box and box manifold mounted to a retention tank; 
           [0023]      FIG. 14  is a side cross sectional view of the embodiment of  FIG. 10  taken on line  14 - 14  of  FIG. 10  illustrating a box manifold and a heating element mounted therebelow and a drain box positioned across therefrom; 
           [0024]      FIG. 15  is a front elevational view of the embodiment of  FIG. 10  illustrating a box manifold; 
           [0025]      FIG. 16  is a side cross sectional view of the embodiment of  FIG. 15  taken on line  16 - 16  of  FIG. 15  illustrating a box manifold; 
           [0026]      FIG. 17  is a side cross sectional view of the embodiment of  FIG. 15  taken on line  17 - 17  of  FIG. 15  illustrating a box manifold; 
           [0027]      FIG. 18  is a top view of the embodiment of  FIG. 15  illustrating liquid flows through a retention tank equipped with a pump and a three-way ball valve; 
           [0028]      FIG. 19  is a functional block diagram of the embodiment of  FIG. 10  illustrating functional relationships between a microprocessor communicatively coupled to a thermocouple, pump, heating element, level indicator, and a three-position selector switch; 
           [0029]      FIG. 20  is a perspective view of the embodiment of  FIG. 10  illustrating a storage cabinet housing a retention tank; 
           [0030]      FIG. 21  is a perspective view of the embodiment of  FIG. 10  illustrating a drop basket; 
           [0031]      FIG. 22  is a front elevational view of the embodiment of  FIG. 10  illustrating a drop box; 
           [0032]      FIG. 23  is a system diagram illustrating a system for removing soluble support material from a rapid prototype part according to another embodiment; 
           [0033]      FIG. 24  is a perspective view of a container forming part of the system of  FIG. 23  according to yet another embodiment; 
           [0034]      FIG. 25  is another perspective view of the container of  FIG. 24 ; 
           [0035]      FIG. 26  is a perspective view of the container of  FIGS. 24-25  illustrating an open mouth portion; 
           [0036]      FIG. 27  is a perspective view of the container of  FIGS. 24-25  with a sealing arrangement shown as detached from the container; 
           [0037]      FIG. 28  is a side view of one example embodiment of the sealing arrangement; 
           [0038]      FIG. 29  is a perspective view of a container having multiple inlet ports and multiple outlet ports according to still another embodiment; 
           [0039]      FIG. 30  is a perspective view of an example system for removing soluble support material from a rapid prototype part, according to an embodiment; 
           [0040]      FIG. 31  is a perspective view of an example system for removing soluble support material from a rapid prototype part, according to an embodiment; and 
           [0041]      FIG. 32  is a perspective view of an example system for removing soluble support material from a rapid prototype part, according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0042]    While the disclosed subject matter is susceptible of being embodied in many different forms, various embodiments are illustrated in the accompanying drawings and are described in detail hereinafter with the understanding that the present disclosure is to be considered to exemplify the principles of the disclosed subject matter and is not intended to limit the subject matter to the embodiments illustrated and presented herein. The embodiments described herein may have utility as an apparatus for removing soluble supports from a rapid prototype part produced from a rapid prototype part making machine such as those that incorporate Fused Deposition Modeling (FDM) technology. 
         [0043]    Referring now to  FIGS. 1-5 , there is shown generally at  10  a support removal apparatus comprising a tank assembly  12  having means for heating and agitating an aqueous cleaning solution and a cabinet  14  having an interface controller  16  mounted on an exterior panel  18  thereof for temporally controlling heat and agitation outputs. In some embodiments, an aqueous cleaning solution that is well suited for this application comprises a mixture of 25-70 weight percent sodium or potassium hydroxide and 5-30 weight percent sodium or potassium carbonate, collectively forming a granular sodium or potassium composition suitable for mixing with water. For example, a concentration ratio of 1.05 pounds of granular sodium or potassium composition per one gallon of water suitably serves in removing water soluble support material from rapid prototype parts within a tolerable temperature range noted hereinafter. 
         [0044]    The tank assembly  12 , as shown in  FIGS. 2 and 3 , comprises a retention tank  20  having four side walls  22  substantially arranged and connected to one another to form a box-like structure having a bottom leading edge  24  fixedly attached to and along the perimeter of a base  26 , collectively forming an interior chamber  28  for containing and holding the aqueous cleaning solution. In the illustrated embodiment, an aperture  30  extending through the base primarily serves as means for removing aqueous cleaning solution from the interior chamber for purposes of repair and maintenance and like activities. Retention of aqueous cleaning solution in the interior chamber  28  as well as removal therefrom and through the aperture is principally controlled by a valve  32  connected in line to a drain pipe  34  having an input end  36  threadably connected to a drain sleeve  38  mounted to and over the aperture at an exterior side  40  of the base and an output end  42  terminating at an external waste line or sump collector. 
         [0045]    As shown in  FIGS. 1 and 2 , one side wall  22  of the retention tank preferably comprises intake and outlet apertures  44 ,  46  for passage of intake and outlet piping  48 ,  50 , respectively, each having first ends  48   a ,  50   a  attached to intake and outlet sides  52   a ,  52   b  of a pump  52  mounted exterior to the retention tank and housed within an interior portion  54  of the cabinet. Pumps most suited for this application comprise of types having centrifugal or magnetic operable means, to name a couple known in the art to possess favorable characteristics to hydraulically convey and circulate aqueous cleaning solution in and through the retention tank  20 . However, regardless of the pump type used, pump seals as well as other operable components thereof are preferably fabricated from materials which are compatible for use in a corrosive, caustic environment given the alkalinity of the aqueous cleaning solution. Accordingly, seals made from ethylene propylene diene monomer (EPDM) or VITON® and metallic components made from stainless steel tolerably perform well within the predetermined range of operation (temperature and pH) without deleterious impact to pump performance. As depicted in  FIG. 2 , a second end  50   b  of the outlet piping  50  is adaptably mounted to a manifold assembly  56  principally serving as means for agitating the aqueous cleaning solution contained within the retention tank. In some embodiments, the manifold assembly is housed within a portion of the interior chamber  28  and comprises at least one nozzle head  58  threadably mounted to the second end of the outlet piping. In an alternative arrangement, one of which utilizes more than one nozzle head, the manifold assembly comprises a pipe tree fitting  60  having a feed end  62  fixedly attached to the second end  50   b  of the outlet piping and more than one branch ends  64  extending therefrom to evenly distribute the incoming flow into an equivalent number of nozzle heads  58 . It is noted herein that the manifold assembly  56  may comprise one or more in number with each being selectively arranged about the retention tank  20  to provide for opposing, cross interaction of flows from each nozzle head, suitably needed in some instances to achieve the desired level of agitation or turbulence within the interior chamber  28 . In this alternative arrangement, the outlet piping is further divided with appropriate fittings commonly available in the art and selectively connected to a predetermined number of pipe tree fittings  60  each having multiple branch ends  64  fitted with a nozzle head  58 . Each nozzle head, as best illustrated in  FIGS. 2 and 4 , comprises a nozzle tip  66  and a threaded body  68  threadably mounted to each branch end  64 . In order to develop and continually establish a predominate level of agitation within the interior chamber, each nozzle tip is suitably configured with an orifice  70  having a diameter ranging from 0.05 to 0.375″. In this diametric range combined with a pump capacity ranging from 3-30 gallons per minute at a power output ranging from 0.04-2 HP, each nozzle tip  66  is substantially capable of developing an output pressure ranging from 5 to 60 psi, respectively. In this pressure range, each nozzle tip provides for a jet stream having a tight dispersion pattern capable of reaching and interacting with and reflecting off the opposing side wall of the retention tank  20  to uniformly agitate the aqueous cleaning solution within the interior chamber. In instances where the retention tank comprises a larger volumetric capacity, more than one manifold assembly  56 , as described above, may be needed to create and maintain homogenous agitation of the aqueous cleaning solution for sustained and continued removal of support material from the rapid prototype part(s). In an alternative embodiment, the manifold assembly in lieu of the nozzle head  58  may comprise of an elongate tubular member  72  having an inlet fitting  74  hydraulically attached and extending perpendicularly thereto and a plurality of orifices  76  being positioned about an outer face  78  thereof, substantially in the manner shown in  FIG. 6 . Assembly of the elongate tubular member to the second end  50   b  of the outlet piping is accomplished by a sleeve  80  having a first end  82  fixedly attached thereto and a second end  84  having at least two concentric depressions  86  for accepting therein an equivalent number of o-rings  88 . As illustrated in  FIG. 8 , a free end  90  of the inlet fitting  74  is slidably positioned onto and over the second end  84  and moved thereabout until the o-rings are completely encased within the inner confines of the inlet fitting. In the embodiment shown in  FIG. 8 , each orifice  76  situated about the outer face  78  comprises a wall  92  having a anterior portion  94   a  thereof extending perpendicular thereto and a posterior portion  94   b  extending angularly outward a predetermined amount from a midpoint position  94   c  in the wall, specifically where the anterior portion terminates within the confines of the wall. 
         [0046]    As illustrated in  FIG. 2 , a second end  48   b  of the intake piping  48  comprises a basket strainer  96  having a plurality of apertures  98  extending therethrough for passage of the aqueous cleaning solution during cyclic circulation thereof while effectively eliminating the passage of small rapid prototype part(s) and residual support material suspended in solution. A backing plate  100  fixedly attached to the basket strainer and having a threaded coupling  102  fixedly attached thereto suitably serves as means for mounting the strainer basket to the second end of the intake piping, substantially in the manner shown in  FIG. 2 . To further mitigate undesirable interaction of small rapid prototype part(s) in suspension with the manifold assembly  56  and basket strainer, where positive and negative pressure is respectively observed, the retention tank  20  is fitted with a plate guard  104  to divide the interior chamber  28  into first and second compartments  106 ,  108 . In the embodiment of  FIG. 2 , the plate guard comprises an upper leading edge  110  and a plurality of nozzle apertures  112  extending therethrough to accommodate an equivalent number of nozzle heads  58  for sustained and continued passing of the aqueous cleaning solution into the second compartment  108  of the interior chamber  28 . Mounting of the plate guard within the interior chamber is substantially accomplished by attaching the upper leading edge  110  to a portion of a work surface  114  suitably situated above and attached to the retention tank. All unattached edges of the plate guard are selectively positioned away from the side walls  22  and base a predetermined distance to form an elongate opening  116  therealong, purposefully to maintain circulation of the aqueous cleaning solution contained within the interior chamber of the retention tank. To enhance circulation of the aqueous cleaning solution to a greater extent than that provided by the elongate opening, the plate guard  104  further comprises a plurality of openings  104   a  collectively positioned near the bottom thereof adjacent to the base  26 . Preferably each opening is sized accordingly to hinder movement of most rapid prototype part(s) from the second compartment into the first compartment, toward the basket strainer  96 , predominantly caused by the presence of negative pressure thereat. 
         [0047]    To further assist the cleansing action of the aqueous cleaning solution for effective removal of support material from rapid prototype part(s), the retention tank is configurably fitted with a heating element  118  having an internal end  120  situated within the interior chamber and an external end  122  electrically connected to an output line of a microprocessor  124 . As shown in  FIG. 4 , the heating element is mounted adjacent to the base in the first compartment  106 , specifically being positioned most near the side wall where the manifold assembly  56  and basket strainer are located to facilitate distribution of heat to the aqueous cleaning solution via the pump  52  feeding solution into the first and second compartments. Although numerous types of heating elements may be suited for this application, it has been found that a heating element  118  having a power rating ranging from 50-300 Watts/sq. in., substantially heats the aqueous cleaning solution to 90-180° F. within a modest time range of at least 15-90 minutes, respectively. The heating element may comprise a variety of geometric configurations and design features such as those having an internal end selectively shaped as a band, cable, tubular cartridge, strip, to name a few most widely known and available in the art, providing each meets the above operating specifications. It is noted herein that certain embodiments may alternatively employ a heating element mounted externally to the retention tank in lieu of the heating element mounted internally in the interior chamber. In such embodiments, the retention tank primarily serves as a suitable conductor in transmitting heat to the aqueous cleaning solution. In similar regard in terms of substantiating the number of nozzle heads  58 , a retention tank comprising a larger volumetric capacity may necessitate a heating element having a higher heatable surface area and output to maintain the overall effectiveness of the aqueous cleaning solution. Given the operating characteristics of the aqueous cleaning solution in terms alkalinity, the internal end preferably comprises a sheath fabricated from materials such as stainless steel 304 or 316, INCONEL®, INCOLOY®, MONEL™, or titanium, collectively of the type capable of resisting premature failure of the heating element during operative conditions. Working in conjunction with the heating element, a thermocouple  126  mounted to the retention tank  20  suitably serves as means for controlling the temperature of the aqueous cleaning solution within a tolerable range noted hereinbefore. As depicted in  FIG. 4 , the thermocouple comprises an external lead  128  electrically connected to the input side of the microprocessor  124  and an internal probe  130  extending inwardly within the first compartment for which is readily capable of sensing the ambient temperature of the aqueous cleaning solution and making timely and minute adjustments to the heating element  118  via the microprocessor. Like the heating element in terms of material choice, the internal end comprise a sheath  132  fabricated from or coated with a material most compatible for operation in a corrosive environment. In addition to the available means for heating and agitating the aqueous cleaning solution, a level indicator  134  of the type shown in  FIG. 4  provides means for activating power to the microprocessor to permit activation of a timer switch  136  which correspondingly controls the duration of operating the heating element and pump  52 . Further, the level indicator suitably serves as a safety device insofar of eliminating premature activation of the pump when the interior chamber  28  is absent of aqueous cleaning solution. Level indicators comprising operable features of optics, magnetic, mechanical means, to name a few commonly available in the art, may be suited for this application providing each comprises means for connectivity to the microprocessor  124 . As illustrated in  FIG. 9 , the microprocessor selectively controls outputs to the pump and heating element operably based on time and temperature set points established by the operator or manufacturer. In the embodiment shown in  FIG. 4 , a temperature set point of approximately 150° F., as set by the manufacturer, establishes effective performance of the aqueous cleaning solution. Time input, on the other hand, is selectively controlled by the user via the interface controller  16  comprising means for displaying operating variables of temperature and time. An example of a suitable microprocessor for this application is the type manufactured by the Watlow Company of St. Louis, Mo., specifically being designated as Watlow Series 935B. It should be understood that many other types of microprocessors may be used in this application providing it comprises capabilities to control the desired outputs noted above. It is further understood that all electrical components described above, including the pump, heating element, thermocouple, level indicator and microprocessor, may be electrically wired in any known manner. In operation, with reference to  FIG. 9 , power is initially supplied to a start switch  137  which subsequently activates the level indicator  134 . Upon the level indicator detecting the level of the aqueous cleaning solution in the retention tank, power is further transmitted to the microprocessor, at which time the timer is activated by the operator to set the temporal limits for operating the pump  52  and heating element  118 . Process startup is finally achieved by the operator activating a controller start button integrally made part of the microprocessor. It is noted herein that the heating element only operates within a temperature range of approximately 40° F. to the set point of 150° F., notwithstanding the time inputs, in contrast to the pump  52  which operates for the full duration of the time input. Upon expiration of the timer&#39;s set limits, power to the pump as well as the heating element is disabled via the microprocessor  124 . Reactivation of the cleaning cycle substantially involves re-setting the timer function and activating the controller start button. 
         [0048]    As noted above, the retention tank  20  is fitted with a work surface  138  of the type comprising a recessed portion  140  having an opening  142  extending therethrough, collectively being contained within an upper ledge  144  extending along the perimeter of the work surface. The work surface, particularly the recessed portion, primarily serves in containing and channeling the aqueous cleaning solution downwardly toward the retention tank in the event of inadvertent spillage caused by the removal of rapid prototype parts from the second compartment  108 . In the embodiment illustrated in  FIGS. 1 and 3 , the opening comprises a geometric configuration and size substantially conforming to an accessible opening  146  of the second compartment. To mitigate further loss of aqueous cleaning solution, primarily due to evaporation, the work surface further comprises a lid  148  having a geometric configuration substantially conforming to the opening  142  of the recessed portion and a handle  150  fixedly attached to an upper surface  152  thereof to provide means for removing and placing the lid onto and over the accessible opening  146 . In some applications, the lid, as shown in  FIG. 1 , is adaptably fitted with a basket  154  hanging downwardly therefrom for holding small rapid prototype parts which easily suspend in solution and readily move about the interior chamber  28 . In this regard, the basket comprises perforated walls  156  substantially arranged to form an interior portion  157  capable of containing the rapid prototype parts yet permitting the passing of aqueous cleaning solution upon removal from the retention tank. In the embodiment shown in  FIG. 1 , the basket  154  comprises an overall geometric configuration substantially capable of fitting within the confines of the second compartment  108  and passing unhindered through the opening  142 . Access to the basket is made possible by a parts opening  158  extending through one of its perforated walls  156  and when placed within the interior chamber, the parts opening abuts up against the sidewall  22  of the retention tank to impede outgoing flow of rapid prototype parts into the interior chamber. As illustrated in  FIGS. 1 and 5 , the cabinet  14  further comprises features for operation and maintenance, including an access panel  160  removable therefrom to gain access to the pump  52  and other operable components and, as noted earlier, an interface controller display and the start switch  137  mounted externally on the cabinet. In most applications, the work surface  138  is welded to the retention tank and collectively placed into and attached to the cabinet by a plurality of screws. 
         [0049]    An alternative embodiment is shown in  FIGS. 10-19 . In lieu of the manifold assembly  56  used in the embodiment shown in  FIGS. 1-9 , the retention tank  20  comprises a large opening  164  to accommodate a box manifold  166  having a plurality of nozzle heads  58  for enhanced agitation of the aqueous cleaning solution contained within the interior chamber and a drain box  168  integrally made part thereof for enhanced circulation and removal of aqueous cleaning solution from the retention tank. The box manifold  166  comprises an outer casing  170  having an inlet adapter  172  mounted externally thereto and a pressure box  174  collectively formed by an inner backside  176  of the outer casing as reinforced by an interior reinforcing plate  178  integrally made part of the outer casing and a backing plate  180  used in supporting the nozzle heads  58 . As denoted by path E in  FIG. 18 , the inlet adapter  172  is hydraulically connected to an outlet stem  182  of a three-way ball valve  184 . As illustrated in  FIGS. 16 and 17 , the backing plate comprises a plurality of apertures  186  extending therethrough to receive an equal number of collars  188  each having internal threads  189 . In assembled form, each collar is fixedly attached to the backing plate  180  by a bead of weld placed about its outer circumference, with the threaded body  68  of each nozzle head  58  being threadably connected to the collar. Similar to the embodiment shown in  FIGS. 1-9  in terms of protecting the nozzle head from suspended matter, each nozzle tip  66  is positioned within a cavity  190  substantially formed by the backing plate and a nozzle plate  192  attached thereto by a plurality of screws  194  and the like. In order to sustain passing of the aqueous cleaning solution into the interior chamber, yet mitigating the passage of small rapid prototype parts and residual support material into the box manifold  166 , the nozzle plate comprises a plurality of small apertures  196  each being positionally aligned with each of the nozzle heads, substantially as illustrated in  FIGS. 16 and 17 . A gasket  198  situated in between the reinforcing and backing plates mitigates leakage of the pressure box  174  and ensures sustained and continuous pressure thereat for passing of the aqueous cleaning solution through the nozzle head  58  and forcibly into the interior chamber  28 . 
         [0050]    Referring now to  FIGS. 10 and 11 , the drain box  168  generally extends the full width of the side wall of the retention tank  20  and comprises an intake side  200  and a bottom  202  coinciding with the base. An outlet opening  204  extending through the bottom of the drain box receives an outlet line  206  extending therefrom and terminating at an intake side  208  of the pump, as denoted by path C in  FIG. 18 . A water input opening  210  extending through the bottom  202  suitably receives a fitting  212  for connecting pipe therefrom to a ball valve  214  primarily serving as means for feeding fresh water from an external water source  215  into the drain box  168  and subsequently into the retention tank  20 , as denoted by paths A and B in  FIG. 18 . Like the second end of the intake piping, the intake side  200  is suitably fitted with a screen  216  to inhibit the passage of small rapid prototype parts and residual support material into and through the drain box, pump and ball valve, yet affording continuous passage of the aqueous cleaning solution. Like the embodiment illustrated in  FIGS. 1-9 , the retention tank  20  of the alternative embodiment comprises a thermocouple  218  having an internal probe  218   a  positioned within the drain box for measuring the ambient temperature of the aqueous cleaning solution and controlling heat inputs to the microprocessor and a heating element  220  having an internal end  220   a  of the band type suitably situated near the base and housed in a heat chamber  221  substantially extending about the width of the side wall  22  and placed opposite to the location of the drain box  168 , below the box manifold, and an external end  220   b  communicatively coupled to the microprocessor  124 . A screen  221   a  similar to the one attached on the intake side of the drain box is mounted to an elongate opening  221   b  of the heat chamber. The retention tank of the embodiment shown in  FIGS. 10-22  further comprises a level indicator  222  to the likes discussed for use with the embodiment shown in  FIGS. 1-9 , particularly of the type substantially capable of measuring the level of the aqueous cleaning solution within the interior chamber  28  to ensure inoperative status of the pump  52  in the event that the solution level is inadequate to support flow through the pump and box manifold and further ensure that each nozzle head is situated below the solution level. As respectively denoted by paths D and F in  FIG. 18 , the three-way ball valve  184  further comprises an intake stem  224  hydraulically connected to a discharge side  226  of the pump and a drain stem  228   a  hydraulically connected to an external drain line  228   b , which collectively serve in circulating and removing the aqueous cleaning solution in and from the interior chamber  28 . Although operation of the embodiment shown in  FIGS. 10-22  is substantially similar to the embodiment shown in  FIGS. 1-9  in terms of controlling temperature, flow and time functions, the embodiment shown in  FIGS. 10-22  further comprises a three-position selector switch  229  having operable modes designated as off, clean parts, and drain tank, as best illustrated in  FIG. 19 . In the clean parts mode, the embodiment shown in  FIGS. 10-22  functions similarly to the preferred embodiment with exception that the user can locally operate the incoming water supply by manually turning a handle  230  made part of the ball valve  214  in the direction of flow, after which the tank fills with the aqueous cleaning solution to a predetermined level. Time inputs are subsequently entered into the microprocessor  124  via the interface controller and the controller start button is activated to power the heating element and pump for a set duration of time. The drain mode primarily serves as means for bypassing the microprocessor  124  insofar to simultaneously activate the pump  58  and a magnetic switch  231  made integrally part of the three-way ball valve to direct flow outwardly from the retention tank via path F in  FIG. 18 . 
         [0051]    The embodiment shown in  FIGS. 10-22  can be fitted with a work surface  138  having recessed features and means to mitigate evaporative loss of the aqueous cleaning solution during operation. Further, the embodiment shown in  FIGS. 10-22  can be housed in a cabinet  14  to the likes described for the embodiment shown in  FIGS. 1-9 . Alternatively, as shown in  FIG. 20 , the embodiments shown in  FIGS. 1-9 and 10-22  may be suitably housed in a storage cabinet  232  having accessible storage capacity  234 , an integral work platform  236  and a localized water source  238  and drain hydraulically connected to an external water supply and drain line, respectively. In this configuration, the retention tank  20  comprises a mounting flange  240  extending outwardly from and along an upper perimeter  242  integrally made part thereof, which substantially serves as means for securing and attaching the retention tank to the integral work platform of the storage cabinet. In mitigating evaporative loss to the likes of the cabinet used for the embodiment shown in  FIGS. 1-9 , the storage cabinet  232  may comprise a cover  244  having a hinge  246  mounted along its back leading edge and a handle  248  attached to an exterior surface  250  thereof. A backstop  252  fixedly mounted to the work platform  236  suitably serves in controlling the extent to which the cover moves beyond the location of the cover&#39;s hinge and provides means for maintaining the vertical orientation of a drop basket  254  alternatively made part of the cover, particularly of the type shown in  FIG. 21 . A pair of sliding brackets  256  each having a movable slide bar  258  to engage an opening  260  extending through an end wall of the back stop serves as means for locking the cover to the back top  252  in a substantial vertical orientation. The drop basket  254 , as shown in  FIGS. 21 and 22 , comprises an overall rectangular configuration having a top lid  262  hingedly attached to one corner thereof and secured in place by a frontal latch  264  engaging a s-shaped member  266  mounted to a front side  268  of the drop basket. A pair of handles  270  mounted to an exterior surface  272  of the top lid  262  serves as means for lifting and lowering the top lid from and to the drop basket  254 . Mounting of the drop basket to the cover  244  is primarily accomplished by upwardly and downwardly orientated lip brackets  274   a ,  274   b  configured in such a manner to slidably engage and lock with one another. As shown specifically in  FIG. 22 , the upwardly orientated lip bracket is attached to a backside of the cover  244  and engages the downwardly orientated lip bracket as attached to a backside of the drop basket. 
         [0052]    It can be seen from the foregoing that there is provided in accordance with this disclosure a simple and easily operated device, which is particularly suited to operate side-by-side with a rapid prototype parts making machine in an office setting or similarly suited environment. The support removal apparatus  10  is completely functional in removing water soluble supports efficiently from rapid prototype parts given suitable operability in terms of aqueous cleaning solution type and concentration, agitation, and temperature. 
         [0053]    The components comprising the support removal apparatus may be fabricated from a variety of materials, providing such selection or use of materials possess the capacity to withstand premature corrosion given the presence and use of an alkaline aqueous cleaning solution, notably falling within an applicable pH range of 8-11. Accordingly, it may be desirable to construct the retention tank  20 , work surface  138 , lid  148  and nozzle heads  58  from 316 stainless steel, pipe and fittings from a polymeric material such as polyamide (PA) or acrylonitrile-butadiene-styrene (ABS), and cabinet  14  and storage cabinet  232  from a lower grade stainless steel. It is noted herein that the retention tank, nozzle head, work surface, and integral work platform may be alternatively fabricated from materials to lessen the overall weight of the support removal apparatus yet maintaining sufficient resistance to corrosion, such as polypropylene, polyoxymethylene, polyphenylene, ABS, or PA. Similarly, the pump, thermocouple, heating element, and level indictor, particularly exposed operable components of each, are fabricated from a high grade stainless steel (316) or coated with an impervious, corrosive-resistant material such as epoxy. 
         [0054]    According to another embodiment, a container can be used to improve the efficiency of the process of removing soluble support material from a rapid prototype part.  FIG. 23  is a system diagram illustrating a system  300  for removing soluble support material from a rapid prototype part using an aqueous cleaning solution. The system  300  includes a container  302 , which is discussed in greater detail below in connection with  FIGS. 24-28 . Another implementation of the container  302  is depicted in and discussed below in connection with  FIG. 29 . The container  302  defines a volume for receiving the rapid prototype part (not shown in  FIG. 23 ) and has an inlet port  304  and an outlet port  306 . A sealing arrangement  308 , such as a clamp, substantially seals the container  302  after the rapid prototype part has been placed inside the container  302 . With the container  302  substantially sealed in this way, the aqueous cleaning solution is substantially prevented from leaking out of the container  302  as it flows through the container  302 . 
         [0055]    A basin  310  stores the aqueous cleaning solution. By way of example and not limitation, the aqueous cleaning solution may comprise alcohol, sodium hydroxide, or potassium hydroxide. The basin may be formed of any material that is compatible with the aqueous cleaning solution, such as a polymer or a metal. The basin  310  has an inlet port  312  and a drain basket  314 . A pump  316  is connected in fluid communication with the basin  310 . In operation, the pump  316  pumps the aqueous cleaning solution from the basin  310  through tubing  318  and  320  and into the container  302  via the inlet port  304 , which is coupled to the tubing  320 , and thus to the pump  316 , by a connector  322 . The connector  322  may be implemented as a quick coupler type connector. The tubing  318  and  320  and the connector  322  may be formed from any material that is compatible with the aqueous cleaning solution, i.e., by any material that will not be damaged by exposure to the aqueous cleaning solution. 
         [0056]    The aqueous cleaning solution removes the soluble support material from the rapid prototype part and is discharged from the container  302  through the outlet port  306 . The outlet port  306  is connected in fluid communication with the basin  310  via a connector  324  that is coupled to outlet port  306  and to tubing  326 , which may be formed from any material that is compatible with the aqueous cleaning solution. The connector  324  may be implemented as a quick coupler type connector. The aqueous cleaning solution flows through the tubing  326  and reenters the basin  310  through the inlet port  312 . After the aqueous cleaning solution reenters the basin  310 , it is once again pumped out of the basin  310  by the pump  316  through the drain basket  314 . The drain basket  314  may incorporate a mesh screen or other filter for filtering out particles of soluble support material that were removed from the rapid prototype part. 
         [0057]    In some embodiments, the aqueous cleaning solution is heated to improve its efficiency in removing soluble support material. For example, the aqueous cleaning solution may be heated to a temperature between 50 degrees Fahrenheit and 200 degrees Fahrenheit. Heating the solution can be accomplished using a heater  328  disposed within the basin  310 . It will be appreciated by those of skill in the art that, if the basin  310  is formed from a material having a relatively low melting point, such as certain polymers, it may be desirable to employ a circulation heater (not shown) disposed around, for example, tubing  326 , in lieu of the heater  328  disposed within the basin  310  in order to avoid damaging the basin  310 . 
         [0058]      FIG. 24  and  FIG. 25  are perspective views of one example implementation of the container  302 . The container  302  includes a liner  400  that has an exterior surface. The liner  400  may be formed from any of a variety of chemically resistant materials, i.e., materials that will not be damaged by the aqueous cleaning solution. By way of example and not limitation, the liner  400  may be formed from nylon, a polyolefin such as polypropylene, or a fluoropolymer such as PTFE, TEFLON®, or FEP. It is desirable that the liner  400  is resistant both to the chemicals used in removing the soluble support material or substrate and to the temperatures involved in the process. It is also desirable that the liner  400  is degradable. Alternatively, the liner  400  could incorporate less chemically resistant materials, such as ABS or PVC. In such embodiments, the liner  400  would degrade after a number of uses and would need to be replaced. 
         [0059]    In the embodiment of  FIGS. 24 and 25 , the liner  400  is expandable to define a mouth portion  402  at one end and is heat sealed at the opposite end  404 . When the liner  400  is expanded, the liner  400  defines a volume into which the rapid prototype part (not shown in  FIG. 24 ) can be received. After the rapid prototype part is received in the container  302 , the sealing arrangement  308  substantially seals the mouth portion  402  so that the aqueous cleaning solution is substantially prevented from leaking out of the mouth portion  402 . 
         [0060]    In the embodiment shown in  FIG. 24 , the inlet port  304  and the outlet port  306  are heat sealed on the other two sides of the exterior surface of the liner  400 . Alternatively, the inlet port  304  and the outlet port  306  may be affixed to or formed on the exterior surface of the liner  400  by any suitable process, including, for example, insert molding. Both the inlet port  304  and the outlet port  306  are in fluid communication with the volume defined when the liner  400  is expanded. In operation, the aqueous cleaning solution is introduced into the volume through the inlet port  304 , which is in fluid communication with the basin  310  storing the aqueous cleaning solution via the tubing  318  and  320  and the connector  322 . In one example embodiment, the aqueous cleaning solution is supplied to the inlet port  304  at a pressure of approximately 3-60 pounds per square inch (psi). The aqueous cleaning solution removes the soluble support material from the rapid prototype part and is discharged from the container  302  through the outlet port  306 , which is connected to the tubing  326  via the connector  324 . As the aqueous cleaning solution flows out of the container  302 , it may carry the removed soluble support material with it through the tubing  326  back to the basin  310 , where the removed soluble support material is filtered by the drain basket  314  before the aqueous cleaning solution is pumped back to the container  302 . 
         [0061]      FIGS. 26 and 27  are additional perspective views of the container  302  of  FIGS. 24-25 .  FIG. 26  shows the liner  400  and the mouth portion  402  having been expanded to define a volume  410  for receiving a rapid prototype part  412  having aqueous soluble support material deposited on it.  FIG. 27  illustrates the sealing arrangement  308  as detached from the container  302 . It will be appreciated by those of skill in the art that the container  302  may be sealed by folding or crimping the mouth portion  402  of the liner  400  and engaging the sealing arrangement  308 . 
         [0062]      FIG. 28  is a side view of one example embodiment of the sealing arrangement  308 . In the embodiment of  FIG. 28 , the sealing arrangement  308  is implemented as a clamp. The clamp has a clamp body  430  into which the folded or crimped mouth portion  402  of the liner  400  is placed. After the mouth portion  402  has been placed in the clamp body  430 , one or more thumbscrews  432  are tightened to compress the folded or crimped mouth portion  402  and thereby substantially seal the mouth portion  402 . In this way, a substantially airtight and watertight seal is provided, and leakage of the aqueous cleaning solution from the mouth portion  402  is substantially prevented. While a single thumbscrew  432  is visible in the side view of  FIG. 28 , it will be appreciated that multiple thumbscrews  432  may be employed, as shown in  FIGS. 23-25, 27, and 29 . 
         [0063]    The efficiency of the cleaning process by which the aqueous cleaning solution removes the soluble support material from the rapid prototype part is affected by a number of factors, including, but not limited to, the concentration of the aqueous cleaning solution, the temperature of the aqueous cleaning solution, the duration for which the rapid prototype part is subjected to the cleaning process, the flow rate at which the aqueous cleaning solution is supplied to the container  302 , and any pressure differential between the inlet port  304  and the outlet port  306 . 
         [0064]    One factor affecting the efficiency of the cleaning process is the existence of a pressure differential between the inlet port  304  and the outlet port  306 . The pressure differential is a function of the difference in cross-sectional area between the inlet port  304  and the outlet port  306 . No effect on efficiency has been observed in embodiments in which the diameter, and therefore the cross-sectional area, of the outlet port  306  is larger than that of the inlet port  304 . Surprisingly, however, when the diameter of the outlet port  306  is the same size as or smaller than the diameter of the inlet port  304 , an improvement in efficiency of 100%-300% has been observed; in such embodiments, the cleaning process has been observed to be completed substantially more quickly relative to embodiments in which the outlet port  306  is larger than the inlet port  304 . It is hypothesized that when the outlet port  306  is smaller than the inlet port  304 , pressure is created inside the container  302 , resulting in faster agitation of the soluble support material from the rapid prototype part. 
         [0065]    Another way of increasing the effective cross sectional area of the inlet port  304  or the outlet port  306  is to employ multiple inlet ports  304  or multiple outlet ports  306 , or both.  FIG. 29  is a perspective view of a container  450  having multiple inlet ports  452  and multiple outlet ports  454  according to still another embodiment. The container  450  may be substituted for the container  302  in the system  300 , with appropriate modifications to the system  300  to accommodate the multiple inlet ports  452  and/or multiple outlet ports  454 . For example, additional tubing similar to tubing  320  and  326  and additional connectors similar to connectors  322  and  324  may be required. Alternatively, manifolds may be used to connect multiple inlet ports  452  or multiple outlet ports  454  to a single connector or tubing. It will be appreciated that, while  FIG. 29  depicts two inlet ports  452  and two outlet ports  454  and  FIGS. 23-28  depict a single inlet port  304  and a single outlet port  306 , some embodiments may employ a single inlet port and multiple outlet ports or, conversely, multiple inlet ports and a single outlet port. In short, any number of inlet ports and outlet ports, in any combination, may be employed. 
         [0066]    The embodiments described herein may result in certain advantages. For instance, it has been observed that under otherwise comparable conditions, e.g., similar temperature conditions and similar concentrations of aqueous cleaning solution, the time to remove soluble support material from a rapid prototype part can be reduced from, for example, five or more hours to approximately 30 minutes. This increased efficiency can result in increased throughput. Further, the container used in the process is relatively easy to manufacture and assemble and can be retrofitted on existing equipment. Accordingly, little, if any, modification is required to existing equipment. 
         [0067]    When removing support material from a rapid prototype part, it may be desirable to control the amount of agitation imparted to the support material by the aqueous cleaning solution. If excess agitation is applied, for example, the rapid prototype part may be damaged or destroyed. Accordingly, in some embodiments, the flow rate of the aqueous cleaning solution may be controlled. 
         [0068]      FIG. 30  is a perspective view of an example system  3000  for removing soluble support material from a rapid prototype part, according to an embodiment. A rapid prototype part may be placed in a container  3002 , such as a basin. A fluid, such as water or an aqueous cleaning solution, may be introduced into the container  3002  via a pump  3004 . A pressure hose  3006  may carry the fluid into the container  3002 , and a suction hose  3008  may remove fluid from the container  3002 . 
         [0069]    A variable frequency drive system  3010  may control the flow rate of fluid through the pressure hose  3006  and suction hose  3008  by controlling the pump rate of the pump  3004 . The variable frequency drive system  3010  may be connected to a power source via a power cord  3012  and may have a control  3014 , such as a dial (shown in  FIG. 30 ) or a knob, to vary the frequency output by the variable frequency drive system  3010 . Using the control  3014 , a user may adjust the rate at which fluid flows through the system  3000  and, thus, the agitation applied to dissolve and remove support material from the rapid prototype part. 
         [0070]      FIG. 31  is a perspective view of an example system  3100  for removing soluble support material from a rapid prototype part, according to an embodiment. A rapid prototype part may be placed in a container  3102 , such as a basin. A fluid, such as water or an aqueous cleaning solution, may be introduced into the container  3102  via a pump  3104 . A pressure hose  3106  may carry the fluid into the container  3102 , and a suction hose  3108  may remove fluid from the container  3102 . 
         [0071]    A valve  3110  may be located on the pressure hose  3106  to control the flow rate of fluid through the pressure hose  3106  and suction hose  3108 . It will be appreciated by those of skill in the art that the valve  3110  may be located elsewhere in the system  3100 , e.g., on the suction hose  3108 . By rotating the valve  3110  to partially open or close the valve  3110 , a user may adjust the rate at which fluid flows through the system  3100  and, thus, the agitation applied to dissolve and remove support material from the rapid prototype part. 
         [0072]      FIG. 32  is a perspective view of an example system  3200  for removing soluble support material from a rapid prototype part, according to an embodiment. A rapid prototype part may be placed in a container  3202 , such as a basin. A fluid, such as water or an aqueous cleaning solution, may be introduced into the container  3202  via a pump  3204 . A pressure hose  3206  may carry the fluid into the container  3202 , and a suction hose  3208  may remove fluid from the container  3202 . 
         [0073]    A variable frequency drive system  3210  may control the flow rate of fluid through the pressure hose  3206  and suction hose  3208  by controlling the pump rate of the pump  3204 . The variable frequency drive system  3210  may be connected to a power source via a power cord  3212  and may have a control  3214 , such as a dial (shown in  FIG. 32 ) or a knob, to vary the frequency output by the variable frequency drive system  3210 . Using the control  3214 , a user may adjust the rate at which fluid flows through the system  3200  and, thus, the agitation applied to dissolve and remove support material from the rapid prototype part. 
         [0074]    A valve  3216  may be located on the pressure hose  3206  to control the flow rate of fluid through the pressure hose  3206  and suction hose  3208 . It will be appreciated by those of skill in the art that the valve  3216  may be located elsewhere in the system  3200 , e.g., on the suction hose  3208 . By rotating the valve  3216  to partially open or close the valve  3216 , a user may adjust the rate at which fluid flows through the system  3200  and, thus, the agitation applied to dissolve and remove support material from the rapid prototype part. 
         [0075]    A temperature sensor  3218  may sense the temperature of the container  3202 , as shown in  FIG. 32 , to control the temperature of the aqueous cleaning solution. The temperature sensor  3218  may be positioned to sense the temperature of another portion of the system  3200 , such as the pressure hose  3206  and/or the suction hose  3208 . The temperature sensor  3218  may be implemented, for example, as a temperature sensor as disclosed in co-pending U.S. patent application Ser. No. 13/613,775, filed Sep. 13, 2012 and entitled “TEMPERATURE CONTROL APPARATUS,” the disclosure of which is hereby incorporated by reference in its entirety. It will be appreciated that the temperature sensor  3218  may be implemented as a different type of temperature sensor, such as a thermocouple. 
         [0076]    It is to be understood that even though numerous characteristics and advantages of various embodiments have been set forth in the description, together with details of the structure and function of various embodiments, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles described herein to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.