Patent Publication Number: US-2018043612-A1

Title: Device for printing a three dimensional cosmetic article from a build material comprising a cosmetic formula

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to devices for three dimensional printing. In particular, the present invention is directed to a device for printing by fusion deposition a three dimensional cosmetic article from a build material comprising a cosmetic formula. 
     Description of the Prior Art 
     Three dimensional (“3D”) printers for additive fabrication are well known. An example of such a printer is disclosed in U.S. Pat. No. 8,529,240 to Mayer. The device disclosed by Mayer uses a controller and other hardware, a positioning assembly with a stepper motor, an extruder and a build plate to fabricate an article from a 3D computer model via additive deposition of plastic build material. Relatively rigid plastic filament build material is fed from a spool into the extruder by the stepper motor where it is melted by the heater and extruded through a nozzle. Mayer does not disclose a piston for advancing the build material. 
     U.S. Pat. Appln. No. 2015/0314141 to Choi discloses a printer modified to receive and process cosmetic components. The printer is described as a device that deposits substances (dyes, pigments, etc.) at a very specific location of an underlying substrate to create a chosen desired color that is formed on the substrate. The substrate is a pre-existing supply or article of cosmetic material. In other words, Choi discloses a printer for selectively printing color to an existing cosmetic formula substrate or article, but does not disclose printing a three-dimensional cosmetic article from a build material comprising a cosmetic formula. 
     U.S. Pat. No. 8,172,473 to Salciarini discloses a method for manufacturing a cosmetic applicator using photopolymerization or sintering via laser light to solidify flowing build material in slices. The article produced is a cosmetic applicator (mascara brush, comb, etc.), not a cosmetic article made from a build material comprising a cosmetic formula. 
     WO/2016/020435 to Jaunet et al. discloses a method for additive manufacturing of a 3D object comprising a cosmetic composition by direct projection, but the method is described as including a pump (not shown or described) to spray (direct projection) successive layers of cosmetic build material. The build material is sprayed in droplets of relatively small size to form thin successive layers. The reference does not include an extruder for extruding build material in relatively thick layers. 
     WO/2016/020442 to Jaunet et al. discloses a method for additive manufacturing of a 3D object comprising a cosmetic composition by direct projection, but the method is described as using a photoactivatable material and illumination to activate the photoactivatable material. WO/2016/020454 to Jaunet et al. discloses a method for additive manufacturing of a 3D object comprising a cosmetic composition by application of a powder binding activator. WO/2016/020447 to Jaunet et al. discloses a method for additive manufacturing of a 3D object comprising a cosmetic composition by application of a photoactivatable material onto a powder. The present invention does not include photoactivatable material, powder binding activator or application of a photoactivatable material onto a powder. 
     Known 3D printers are not suitable for producing 3D articles from a build material comprising a cosmetic formula in successive thick layers by fusion deposition. Build materials comprising cosmetic formulas contain components such as silicones and waxes that are not readily printed in thick layers using known 3D printing technology. Such components may cause the build materials comprising cosmetic formulas to be softer in the pre-build and post build state, and to flow, harden and cool differently during the build process when compared to typical relatively hard plastic build materials used for 3D printing, particularly when printed in relatively thick successive layers. 
     Accordingly, there is a need for a device for printing a three dimensional cosmetic article from a build material comprising a cosmetic formula wherein the device includes an extruder for extruding successive layers of build material. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a device for printing a three dimensional cosmetic article from a build material comprising a cosmetic formula. 
     It is another object of the invention to provide a build material extruder for a device for printing a three dimensional cosmetic article from a build material comprising a cosmetic formula. 
     It is another object of the invention to provide an annular cooling means for a device for printing a three dimensional cosmetic article from a build material comprising a cosmetic formula. 
     It is another object of the invention to provide an improved nozzle including a hemispherical chamber for a device for printing a three dimensional cosmetic article from a build material comprising a cosmetic formula. 
     It is another object of the invention to provide a device that facilitates printing of build materials with glass-transition temperature ranges wider than polymers that are typically used in 3D printing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is front, top and left side perspective view of a 3d printer incorporating the device of the invention; 
         FIG. 2  is front, top and left side perspective enlarged view of the device; 
         FIG. 3  is an enlarged view of the extruder of the device; 
         FIG. 4  is a sectional view of the extruder shown in  FIG. 3 ; 
         FIG. 5  is a sectional view of the extruder shown in  FIG. 3 ; 
         FIG. 6  is an exploded perspective view of the build plate of the device; 
         FIG. 7  is an assembled perspective view of the build plate in  FIG. 6 ; 
         FIG. 8  is an exploded perspective view of the build plate of the device showing alternative inserts for the build plate; 
         FIG. 9  is a top, front and left side perspective view of the fan assembly; 
         FIG. 10  is a bottom, front and left side perspective view of the fan assembly shown in  FIG. 9 ; 
         FIG. 11  is a top, front and left side perspective view of the fan duct of the assembly shown in  FIGS. 9 and 10 ; 
         FIG. 12  is a top, rear and right side perspective view of the fan duct of the assembly shown in  FIGS. 9 and 10 ; 
         FIG. 13  is an exploded top, front and left side perspective view of the fan duct of the assembly shown in  FIGS. 9 and 10 ; 
         FIG. 14  is a bottom and front perspective view of the device; and 
         FIG. 15  is a front and top perspective and sectional view of various embodiments of a build material stick. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIGS. 1-15 , a device for printing a three dimensional article from a build material comprising a cosmetic formula is shown generally at reference number  2 . A print head assembly  129  is supported on a base machine  130 , such as, for example, a MakerBot Replicator  2  or similar printer. The base machine has a positioning assembly (shown generally at  27 ) including a top frame rail  131 , x-axis support platform  132  and gantry rails  134  for the supporting and positioning the print head assembly  129 . A flexible wiring sheath  135  connects the print head assembly  129  to the base machine  130  in electrical communication. The print head assembly  129  includes an extruder  4  with a barrel  105  having an inner wall  5  defining a cylinder  6 . The cylinder  6  has a first end  7  and a second end  8 . A piston  104  is mounted in the first end  7  of the cylinder  6  such that the piston  104  is able to advance and retract in the cylinder  6 . The piston  104  has a front wall  9  and a rear wall  10  connected by an outwardly directed sidewall  11 . The sidewall  11  is shaped and dimensioned to be received and fit closely in the cylinder  6 . The front wall  9  of the piston  104  is directed toward the second end  8  of the cylinder  6 . The piston may be made of any suitable material, but a preferred material is 6061 aluminum. A seal  106  may be provided between the sidewall  11  of the piston  104  and the inner wall  5  of the cylinder  6 . The seal is preferably an elastomeric O-ring secured in a circumferential groove  3  in the sidewall  11  of the piston  104 . The seal is preferably an oil-resistant Buna-N material. 
     A nail  113  is secured to the barrel  105  at the second end  8  of the cylinder  6 . The nail  113  may be made of any suitable material, but a preferred material is 6061 aluminum. The nail  113  has a hollow portion  12  in fluid communication with the cylinder  6 . At an end of the nail opposite the cylinder  6 , the hollow portion  12  preferably terminates in a hemispherical chamber  111 . An extrusion nozzle  112  is also secured to the opposite end of the nail  113 . The nozzle  112  is a 4 mm nozzle made of brass. The extrusion nozzle  112  has a nozzle outlet  13  at a distal end and a nozzle inlet  15  at a proximal end connected in fluid communication by a nozzle duct  14 . The hemispherical chamber  111  of the nail  113  is in fluid communication with the nozzle inlet  15 , and the nozzle inlet  15  is in fluid communication with the nozzle outlet  13  via the nozzle duct  14 . 
     A reservoir  16  for receiving a quantity of the build material is defined by a portion of the cylinder  6  between the front wall  9  of the piston  104  and the nozzle  112 , including the hollow portion  12  and the hemispherical chamber  111  of the nail  113 . The build material is preferably provided to the reservoir  16  in the form of a stick  115 . The piston  104  is adapted to apply pressure to the build material stick  115  in the reservoir  16  to extrude the build material through the nozzle  112  when the piston  104  is advanced in the cylinder  6  and to apply suction to the build material stick  115  to withdraw the build material into the nozzle  112  when the piston  104  is retracted in the cylinder  6 . 
     A motor  108  ( FIGS. 3, 5 ) is connected to the piston  104  to advance and retract the piston  104  in the cylinder  6 . The motor  108  may be, for example, a MakerBot Replicator  2 / 2 X NEMA 17 Hybrid Stepper Motor. The motor  108  and barrel  105  are mounted on a supporting upper chassis  109 . The chassis may be made of any suitable metal or plastic material. Alternatively, the chassis may be 3D printed from PLA build material. The motor  108  is preferably a stepper motor. The motor  108  may be connected to the piston via a linkage  100  and drive rod  101 . The linkage is made from aluminum or another suitable metal or plastic material, or may be 3D printed from PLA build material. The drive rod is preferably made from steel for durability. The drive rod  101  is connected to a spindle  17  of the motor  108  by a sleeve-like connector  107 . The drive rod  101  is connected to the motor  108  such that rotational movement of the spindle  17  of the motor  108  is transmitted directly to the drive rod  101 . The drive rod has external threads  18 . A drive nut  103  is fixedly secured to the linkage  100 . The drive nut  103  has internal threads  19  that cooperatively engage the external threads  18  of the drive rod  101 . Rotation of the drive rod  101  in the drive nut  103  translates rotational movement of the motor into linear movement of the linkage  100  which in turn moves the piston  104  linearly in the cylinder  6 . When the motor spindle rotates in a first direction, the rotational movement of the rod is translated into linear movement of the drive nut and linkage, and in turn the piston such that the piston advances in the cylinder (moving the front wall of the piston away from the first end of the cylinder towards the second end of the cylinder). When the motor rotates in the opposite direction, the piston is retracted in the cylinder (the front wall of the piston moves away from the second end of the cylinder). A handle  119  is provided on the drive rod  101  so that the piston can be advanced or retracted manually by turning the drive rod. 
     Preferably, a rod bearing  102  is secured to the linkage  100 . At least a portion of the drive rod  101  passes through a bore  20  in the rod bearing  102 . The bore  20  of the rod bearing  102  may have internal threads  21  that cooperatively engage the external threads  18  of the drive rod  101 . Alternatively, the bore may have a smooth wall (not shown). The rod bearing is positioned and adapted to secure the alignment of the drive rod  101  and linkage  100  with respect to the other parts of the extruder structure and components. The drive nut and rod bearing are made from any suitable metal or plastic material. In the present case, the drive nut and rod bearing are made from brass. 
     A build plate  123  ( FIGS. 1, 2, 7 and 8 ) is located below the nozzle  112 . 
     A substrate  121  for supporting the cosmetic article is removably secured on the build plate  123  between the build plate  123  and the nozzle  112  to receive the build material from the nozzle  112 . The substrate may be 3D printed from PLA build material, or may be any other suitable metal or plastic material that is cosmetic formula compatible. Preferably, the build plate  123  has a substrate recess  124  cooperatively shaped to securely receive and position the substrate  121  through the printing process. The substrate recess  124  securely holds the substrate  121  in place during the printing operation. Preferably, a build plate  123  of a modular design is provided allowing substrates having different shapes, thicknesses and sizes to be inserted and held by the build plate with little or no re-tooling or modification of build plate  123 . As illustrated in  FIGS. 6, 7 and 8 , a sizing recess  128  may be provided that is dimensioned larger than the substrate  121  to accommodate a sizing insert  122 ,  126   a ,  126   b . The device  2  may be used to 3D print cosmetic articles of varying size and type. For example, the device  2  may be used to 3D print lipstick, lip balm, eye shadow, eyebrow color, cheek makeup, moisturizers or deodorant in stick or bullet form, or foundation or color makeup in cake form (for inserting in compacts), each requiring a substrate  121  of a different shape and/or dimension. A sizing insert  122 ,  126   a ,  126   b  may be provided for each substrate shape and/or dimension required to vary the size of the substrate recess  124  as needed (see, for example, sizing inserts  122 ,  126   a  and  126   b  in  FIG. 8 ). Each sizing insert  122 ,  126   a ,  126   b  has a substrate void  26  (corresponding to the substrate recess  124  discussed above). The substrate void  26  is cooperatively shaped and dimensioned to receive a correspondingly shaped and dimensioned substrate  121 . The substrate void  26  securely holds the substrate  121  in place in the sizing insert, which in turn is secured to the build plate, during the printing operation. Screws  127  may be provided to secure the sizing insert  122 ,  126   a ,  126   b  to the build plate  123 . With the sizing insert  122 ,  126   a ,  126   b  provided in the insert recess  128 , the substrate recess  124  is defined by the substrate void  26  in the sizing insert  126 . An additional clearance  125  may be provided in the insert to facilitate removal of the substrate  121  including the 3D printed article after the printing process has completed. The insert system simplifies and expedites change-over of the substrate holding platform. The insert system provides an advantage over specialized, machined build plates for each different substrate size or shape. The inserts may be 3D printed or otherwise inexpensively manufactured to speed development and fabrication and allow shipping of a simple, light part, rather than an entire, larger build plate. Inserts can be made faster than a full build plate. The insert system allows faster adjustment for variable substrate thicknesses. 
     The positioning assembly  27  is provided to position the nozzle  112  relative to the build plate  123  in horizontal and vertical directions. 
     A controller  28  is coupled in a communicating relationship with the extruder  4  and the positioning assembly  27  via the wiring sheath  135 . The controller  28  is programmed to position the nozzle relative to the build plate and to advance or retract the build material stick  115 , such that build material is selectively advanced through the nozzle  112  to be deposited onto the substrate to fabricate the cosmetic article in a three dimensional shape. 
     Preferably, the build material comprises the pre-formed stick  115  (shown partially extruded through the nozzle  112  in  FIG. 4 , and in  FIG. 15  at reference numbers  144 - 147 ). An example of a build material formula is: 
     
       
         
           
               
               
               
             
               
                   
               
               
                 Material 
                 Approx % 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 Castor Oil 
                 15.0 
                   
               
               
                 Caprylic/Capric Triglycerides 
                 3.0 
               
               
                 Carnuba Wax 
                 3.0 
               
               
                 Long Chain Alcohol 
                 20.0 
                 Preferably, alcohols greater 
               
               
                 Long Chain Ester 
                 9.0 
                 than 5 methyl/methylene units 
               
               
                 Citrate Ester 
                 10.0 
               
               
                 Paraffin Wax 
                 10.0 
               
               
                 Silicone 
                 5.0 
               
               
                 Pigments 
                 10.0 
               
               
                 Pearls 
                 5.0 
               
               
                 Texture/Aesthetic/Optical 
                 10.0 
                 Preferably, silicas, 
               
               
                 Powders 
                   
                 polyurethanes, PMMA, 
               
               
                   
                   
                 PSQ, etc. 
               
               
                   
               
            
           
         
       
     
     The pre-formed build material stick  115  preferably has a width in a range from 0.125 inches to 3 inches and a length in a range from 0.5 inches to 12 inches. The preferred stick is round in cross-section with a diameter of 0.5 inches and a length of 4 inches. In determining the dimensions of the stick the forces required to drive, advance, retract and extrude build material in stick form must be taken into consideration. Accordingly, the dimensions will necessarily change depending on the formula and constitution of the build material. It has been found that sticks in the range of sizes above are compatible with the operations of the device disclosed herein, including the torque produced by the stepper motor  108 . As the entire print mechanism moves in sudden, reciprocating motions, keeping the mass of moving parts (e.g., the extruder and related parts) to a minimum is of prime concern. For example, an extruder dimensioned to accommodate larger sticks of build material will in turn have larger mechanical components and require more torque to drive and thus heavier motors. The relatively smaller size of the preferred stick of build material, 0.5 inches wide by 4 inches long, is suitable for use with existing hardware and software that are optimized for plastic filament feedstock (e.g., the MakerBot printer). This preferred size allows for modification of existing 3D printer hardware and software to allow printing of a cosmetic build material. Cosmetics such as, for example, lipstick, are generally fragile. Accordingly, the preferred size is suitable to provide the required strength, rigidity, degree of compressibility and a reasonable bulk required for practical printing applications. The preferred size also makes the sticks practical to handle, load, and store, especially for consumers or beauty advisors. In addition, the preferred size of the stick is close to the size of known lipstick bullets, so the same machinery and facilities can be used to cast the build material sticks. 
     Sticks can be molded with one end in a hemispherical shape  29  (see  FIG. 15 ) to assist insertion and speed starting each print cycle. The hemispherical shaped end would preferably match the shape of the hemispherical chamber  111  in the nail  113 . 
     A heating element  110 , illustrated as a coil, is secured proximal to the nozzle  112 . The heating element  110  is positioned and adapted to melt the build material  115  prior to extrusion from the nozzle  112 . As illustrated, the heating element  110  surrounds a portion of the nail  113  adjacent to the nozzle. Heat is provided by the heating element to the nail in the vicinity of the hemispherical chamber  111 . The hemispherical chamber  111  thus becomes a heating chamber for the build material. Preferably, melting of the solid or semi-solid build material is restricted to a portion of the reservoir in the nail  113 , i.e., to the hemispherical chamber  111  and the nozzle  112 . Restricting the amount of build material  115  that is melted at any given time prevents excess melted build material from escaping through the nozzle via gravity. By restricting the amount of build material melted at any given time, greater control and precision is provided to the extrusion process. To facilitate the restriction of melting of the build material, the barrel  105  is made from a polycarbonate plastic material that has a low thermal conductivity. Preferably, the barrel  105  is made from a plastic material that is non-heat conductive or very low heat conductive. Preferably, the material of the barrel  105  has a thermal conductivity that is less than 3 Btu/(ft h oF). 
     When the piston  104  advances in the cylinder  6 , the build material  115  in the form of a stick is pushed from the reservoir  16  into the hemispherical chamber  111  of the nail  113 , where it is heated and melted. The melted build material is pushed into the nozzle inlet  15 , through the nozzle duct  14  and extruded out through the nozzle outlet  13  as a bead  116  of build material. The portion of the stick  115  that is still in the cylinder  6  does not melt because the barrel  105  is made of a material having a low thermal conductivity. The heat applied to the nail  113  and in turn to the hemispherical chamber  111 , is not transferred to the barrel  105  or the build material remaining in the cylinder  6 . When the piston  104  is retracted in the cylinder  6 , suction is exerted on the build material  115 , particularly if the build material is in solid or semi-solid stick form. This suction is in turn exerted on the liquefied build material in the hemispherical chamber  111  and the nozzle  112 . Accordingly, the liquefied build material retracts sufficiently into the nozzle outlet  13  so that no excess build material drips or is applied to the article  25  being printed. As with conventional 3D printing software, the controller  28  is programmed to create a build material retraction action during normal operations to prevent droplets of melted build material from continuing to be extruded during non-printing toolpath or print head assembly motions. The O-ring seal  106  between the inner wall  5  of the barrel  105  and the piston  104  creates a partial vacuum inside the reservoir during piston retraction, thus retracting the build material along with the piston. This is preferred to effect accurate printing actions. The vacuum of the piston retraction eliminates the need to secure the build material to the piston mechanically, or to secure the build material in the reservoir mechanically (e.g., by a valve). 
     An important aspect of the invention is providing proper cooling profiles to the build material after it has been extruded and fused onto the article being printed. Accordingly, an annular airflow (indicated by downwardly directed arrows at  117  in  FIG. 4 ) is provided around a circumference of the cosmetic article being printed to cool, fuse and harden the build material after the build material is extruded and deposited on the article. The means for cooling includes a fan  118 , such as, for example, a Shark Parts 100706 Blower Fan for MakerBot Replicator  2 . The fan  118  is in fluid communication with an air intake  22 , a duct  114  and an air outlet  139 . The fan conducts air from the intake  22  through the duct  114  to the outlet  139 . The duct may be formed in two parts, bottom half  141  and top half  142 . The duct parts may be made from a suitable plastic or other material by any known methods. Alternatively, the duct parts may be 3D printed from PLA build material. The duct  114  comprises a flange  137  (see  FIGS. 9-13 ) to secure the duct to the fan housing  23 . At a lower end of the duct  114 , a top opening  138  is provided for insertion of the nozzle  112  through the duct  114 . Opposite the top opening  138  is a bottom opening or outlet  139 . The nozzle  112  projects through the top opening  138  and outlet  139  such that it is exposed below the duct  114 . The body of the nail  113  substantially covers and closes the top opening  138 . In contrast and as best illustrated in  FIG. 10 , the outlet  139  is substantially larger in diameter than the nozzle  112 . Accordingly, air forced through the duct easily passes through the gap between the nozzle  112  and the perimeter of the outlet  139 . 
     The outlet  139  is shaped and adapted to direct the air annularly and downwardly around the circumference of the article being printed (see arrows indicated at  117  in  FIG. 4 ). Preferably, the outlet  139  has a circular configuration and is positioned coaxially around the nozzle  112  as described above and illustrated in  FIG. 10 . In this way, the annular airflow  117  coming from the outlet  139  is directed downwardly around the periphery of the article (not shown) being printed. In order to ensure an annular airflow from the circular duct, at least one internal baffle  140  is provided in the duct to create a uniform outflow from the air outlet  139 . 
     To stabilize the duct with respect to the nozzle  112 , a duct support  136  is provided on the duct  114 . The duct support  136  presses against a bottom  143  of the lower chassis  120  (see  FIG. 14 ). The duct support  136  stabilizes the duct  114  and the fan  118  with respect to the other components of the extruder structure. 
     The substrate  121  on which the article is printed may become an integral part of the article printed. It supports the article when the article is removed from the build plate and may continue to support the article when the article is secured in a primary package such as, for example, a lipstick case or a cosmetic compact. The substrate can be in the form of a flat plate as illustrated, or alternatively, may be a cup or a pan (not shown), such as a cup that holds a lipstick bullet in a lipstick riser mechanism, or such as a pan that holds a cake of color cosmetic in a compact. The substrate  121  may be made of any suitable material, such as, for example, paper, foil, plastic sheet, paperboard, molded plastic piece, metal, etc. 
     To further enhance the cooling capability of the device, the fan is a variable speed fan, and the device has a switch  24  for selecting a speed of the variable speed fan to adjust the rate of cooling of the article being printed. For example, the fan speed may be selectively adjusted for printing an article with a specific part geometry or part size requiring less or more cooling air. The fan speed may be adjusted for printing a build material having a formula requiring less or more cooling air. Sensors (not shown) may be provided to the device to automatically adjust temperatures for a particular formula, size, geometry, etc. 
     The device as claimed provides at least the following advantages. The device permits printing of build materials with glass-transition temperature ranges significantly wider than polymers that are typically used in 3D printing or fused deposition modeling (FDM) printing. Traditional polymers such as ABS, Nylon, PET and PLA used in traditional 3D or FDM printing are selected and formulated precisely for their ability to melt and solidify quickly and predictably due to sharply-defined glass transition temperatures. In contrast, cosmetic products typically have, for example, waxes, oils, silicones and other ingredients that give a build material that includes a cosmetic formula a much wider glass transition temperature or even multiple glass transition temperatures. Some of these build materials are comprised mostly of solid waxes and liquid oils which form a structure called a wax-oil gel. The device as claimed allows wax-oil gels to be printed at temperatures lower than the drop point and standard processing temperatures. Lower-temperature 3D or FDM printing of cosmetic materials allows a higher degree of print accuracy as the material is not fully liquefied, which it would be at a standard processing temperature. The print-useful glass transition range typically spans 10° C. for typical 3D or FDM printing polymer build materials. In contrast, the print-useful glass transition range for cosmetic formula based build materials, including, for example, wax-oil gels, typically spans over 20° C. 
     Traditional polymers such as ABS, Nylon, PET and PLA used in traditional 3D or FDM printing are selected and formulated precisely for their ability to melt and solidify quickly and predictably. This is necessary as those materials are formed as filament feedstock and fed into the melting zone as a continuous strand. While filament feedstock systems have practical advantages, their feedstock drive mechanisms require the feedstock to be rigid and hard in order to advance the strand by applying frictional force to the sides of the filament feedstock. In contrast, cosmetic based build materials such as lipstick and other relatively soft cosmetic materials are too malleable to print effectively as filament feedstock. The piston drive extruder of the present device, particularly when used with a pre-formed stick of build material to enhance the advance and retract function of the system, solves the problem of feeding cosmetic based build materials for fusion deposition modeling. The piston extruder provides a new and unique method for feeding cosmetic based build material to 3D print a cosmetic article. The device also distinguishes over systems already developed for chocolate and other consumables wherein the build material is fully-melted in the reservoir. In the present invention the piston, particularly when used with pre-formed stick of cosmetic build material, precisely controls back-and-forth motion of the build material in the nozzle. The precise back and forth motion of the build material in the nozzle is required to create accurate prints and avoid excess material extrusion. Accordingly, the device is more accurate than a system with a fully-melted build material. 
     Also, as the feedstock may remain solid until the point of extrusion, heavier formula ingredients do not separate out within the reservoir as they can do in fully-melted feed systems. This is critical for cosmetic products where dense minerals may be critical components of the formulas, and premature formula separation is often a problem. 
     It is understood that various modifications and changes in the specific form and construction of the various parts can be made without departing from the scope of the following claims.