Abstract:
A method of manufacturing a three-dimensional object operates a platen configured to facilitate the release of objects produced by a three-dimensional object printer. The method includes moving a first plate and a second plate to form a platen, the first plate having a plurality of parallel members and the second plate having a plurality of parallel members, the first plate and the second plate being moved to interlock the plurality of parallel members of the first plate with the plurality of parallel members of the second plate to form the platen, at least one of the first plate and the second plate being independently movable. At least one of the first plate and second plate is moved to release a three-dimensional object formed by the printer from the platen.

Description:
TECHNICAL FIELD 
       [0001]    The device and method disclosed in this document relates to three-dimensional object printing and, more particularly, to removal of a three-dimensional object from a platen on which the object was formed. 
       BACKGROUND 
       [0002]    Digital three-dimensional manufacturing, also known as digital additive manufacturing, is a process of making a three-dimensional solid object of virtually any shape from a digital model. Three-dimensional printing is an additive process in which one or more printheads or ejector heads eject successive layers of material on a substrate in different shapes. The substrate is supported either on a platform that can be moved three dimensionally by operation of actuators operatively connected to the platform, or the printhead or printheads are operatively connected to one or more actuators for controlled movement of the printhead or printheads to produce the layers that form the object. Three-dimensional printing is distinguishable from traditional object-forming techniques, which mostly rely on the removal of material from a work piece by a subtractive process, such as cutting or drilling. 
         [0003]    Manufacturing of three-dimensional printed parts at high speed is a significant challenge because many of the processes involved are time consuming and often done manually. Automation has provided for higher speed and more efficient processing of three-dimensional printed parts. One area of concern relates to removal of the three-dimensional printed part from the build platen. Often the three-dimensional printed part sticks to the build platen and can be challenging to remove. Current methods for part removal include heating, impacting, scraping, and freezing. These methods are generally cumbersome, time consuming, and risk damaging the part or the build platen. What is needed is a method for removing a three-dimensional printed part from a build platen that is fast, reliable, and easily automated. 
       SUMMARY 
       [0004]    A method of manufacturing a three-dimensional object operates a two-part platen to facilitate the release of objects produced by the platen. The method includes moving a first plate and a second plate to form a platen, the first plate having a plurality of parallel members and the second plate having a plurality of parallel members, the first plate and the second plate being moved to interlock the plurality of parallel members of the first plate with the plurality of parallel members of the second plate to form the platen, at least one of the first plate and the second plate being independently movable, operating a plurality of ejectors to eject drops of material towards the platen and form layers of material with reference to digital image data of a three-dimensional object to produce the three-dimensional object on the platen, and operating at least one of the first plate and the second plate to release the three-dimensional object from the platen. 
         [0005]    A printer for manufacturing a three-dimensional object includes a two-part platen configured to facilitate the release of an object from the platen. The printer includes a plurality of ejectors configured to eject drops of material, a first plate having a plurality of parallel members, a second plate having a plurality of parallel members, at least one actuator operatively connected to one of the first and the second plate, and a controller operatively connected to the first plate, the second plate, the at least one actuator and the plurality of ejectors. The controller is configured to operate the at least one actuator to move one of the first plate and the second plate to interlock the plurality of parallel members of the first plate with the plurality of parallel members of the second plate to form a platen, operate the plurality of ejectors to eject drops of material towards the platen and form layers of material with reference to digital image data of a three-dimensional object to produce the three-dimensional object on the platen, and operate at least one of the first plate and the second plate to release the three-dimensional object from the platen. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The foregoing aspects and other features of method and printer are explained in the following description, taken in connection with the accompanying drawings. 
           [0007]      FIG. 1  shows a three-dimensional object printer configured for automated part removal. 
           [0008]      FIG. 2  shows a method for operating a printer to automatically remove printed parts from a platen. 
           [0009]      FIGS. 3 a  and 3 b    show parts formed on a platen with and without a wax base. 
           [0010]      FIG. 4  shows a method for operating at least one of a first plate and a second plate to release a printed part. 
           [0011]      FIGS. 5 a , 5 b , and 5 c    demonstrate the method of  FIG. 4  without a wax base. 
           [0012]      FIGS. 6 a , 6 b , and 6 c    demonstrate the method of  FIG. 4  with a wax base. 
           [0013]      FIG. 7  shows a different method for operating at least one of a first plate and a second plate to release a printed part. 
           [0014]      FIGS. 8 a , 8 b , and 8 c    demonstrate the method of  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    For a general understanding of the environment for the method and printer disclosed herein as well as the details for the method and printer, reference is made to the drawings. In the drawings, like reference numerals designate like elements. 
         [0016]      FIG. 1  shows a three-dimensional object printer  100  configured for automated part removal. The printer comprises a platen  104  and an ejector head  108 . The ejector head  108  has a plurality of ejectors configured to eject material onto a surface  112  of the platen  104 . The printer  100  also includes an at least one actuator  116  configured to operate the platen. The printer  100  further includes a controller  120  operatively connected to the ejector head  108  and the actuator  116  and configured to operate the ejector head  108  and the actuator  116 . 
         [0017]    The platen  104  includes a first plate  124  and a second plate  128 . The first plate  124  has a plurality of parallel members  132  that extend from a body  136 . Similarly, the second plate  128  has a plurality of parallel members  140  that extend from a body  144 . The plurality of members  132  of the first plate  124  is configured to interlock with the plurality of members  140  of the second plate  128  to form the platen  104 . In one embodiment, the actuator  116  is configured to move the second plate  128  up and down relative the first plate  124 , which is fixed in place. As used herein, “up” refers to a direction that is normal to the surface  112  of the platen  104  and, from the surface  112 , points toward the ejector head  108 . Similarly, as used herein, “down” refers to a direction that is normal to the surface  112  of the platen  104  and, from the surface  112 , points away from the ejector head  108 . In one embodiment, the actuator  116  is also configured to pivot the second plate  128  about an axis that is parallel to the surface  112  of the platen  104  and perpendicular to the plurality of parallel members  140  of the second plate  128 . In some embodiments, other actuators are included and configured to similarly operate the first plate  124 . 
         [0018]    In another embodiment, the actuator  116  is configured to move the second plate  128  horizontally relative to the first plate  124 . As used herein, “horizontally” means a direction that is parallel to the surface  112  of the platen and parallel with a longitudinal axis of the plurality of parallel members  140  of the second plate  128 . In one embodiment, the actuator  116  is also configured to disengage with the second plate  128  to enable complete removal of the second plate  128  from the printer  100 . In some embodiments, other actuators are included and configured to similarly operate the first plate  124 . 
         [0019]    In some embodiments, the printer  100  includes a heater implemented with heating elements  148 , which are configured to heat one or both of the first plate  124  and the second plate  128 . The controller  120  is operably connected to the heating elements  148  and is configured to operate the heating elements  148  to heat one or both of the first plate  124  and the second plate  128 . 
         [0020]    A method  200  for operating the printer  100  to automatically remove printed parts from the platen  104  is shown in  FIG. 2 . In the description of the method, statements that the method is performing some task or function refers to a controller or general purpose processor executing programmed instructions stored in non-transitory computer readable storage media operatively connected to the controller or processor to manipulate data or to operate one or more components in the printer to perform the task or function. The controller  120  noted above can be such a controller or processor. Alternatively, the controller can be implemented with more than one processor and associated circuitry and components, each of which is configured to form one or more tasks or functions described herein. 
         [0021]    When the method  200  is performed, it begins by moving a first plate and a second plate to form a platen (block  204 ). The controller  120  operates the actuator  116  to move the second plate  128  into an interlocked position with the first plate  124  to form the surface  112  of the platen  104 , as shown in  FIG. 1 . Next, the method  200  operates ejectors to eject material to form a three-dimensional object on the platen (block  208 ). In one embodiment, the controller  120  operates a first plurality of ejectors of the ejector head  108  to eject material onto the surface  112  of the platen  104  to form one or more parts  300 , shown in  FIG. 3 a   . In some embodiments, each of the parts  300  is formed with a layer of support material separating each part from the platen  104 . In another embodiment, the controller  120  first operates a second plurality of ejectors of the ejector head  108  to eject wax onto the surface  112  of the platen  104  to form a wax base  304 , shown in  FIG. 3 b   . The wax base  304  has a footprint that is larger than each of the parts  300  such that the parts  300  are all formed on the wax base  304 , as shown in  FIG. 3 b   . After forming the wax base  304 , the controller  120  operates the first plurality of ejectors of the ejector head  108  to eject material onto the wax base  304  to form the parts  300 . 
         [0022]    Next, the method  200  operates at least one of the first and second plates to release the three-dimensional object from the platen (block  212 ). The controller  120  operates the actuator  116  to move the second plate  128  so as to at least partially separate the plurality of parallel members  140  of the second plate  128  from the plurality of parallel members  132  of the first plate  124 . In this way, the parts  300  are released from at least one of the first plate  124  and the second plate  128 . In some embodiments, discussed below with respect to  FIG. 4 , the controller  120  further operates the actuator  116  to release the parts  300  from both of the first plate  124  and the second plate  128 . In other embodiments, discussed below with respect to  FIG. 7 , the parts  300  remain stuck to one of the first plate  124  and the second plate  128 . 
         [0023]    A method  400  for operating at least one of the first and second plates to release the three-dimensional object from the platen is shown in  FIG. 4 . The method  400  is one embodiment of the step corresponding to block  412  of the method  200 . Once a three-dimensional object is formed on the platen, the method  400  moves the second plate down relative to the first plate (block  404 ). The controller  120  operates the actuator  116  to move the second plate  128  down relative to the first plate  124 . In moving the second plate  128  down, the parts  300  become separated from the second plate  128 , as shown in  FIG. 5 a   . In the case where the wax base  304  is ejected, the wax base  304  becomes separated from the second plate  128 , as shown in  FIG. 6   a.    
         [0024]    Next, the method  400  moves the second plate up relative to the first plate (block  408 ). The controller  120  operates the actuator  116  to move the second plate  128  up relative to the first plate  124 . Particularly, the actuator  116  moves the second plate  128  past the first plate  124  so as to separate the parts  300  from the first plate  124 , as shown in in  FIG. 5 b   . In the case where the wax base  304  is ejected, the wax base  304  is separated from the first plate  124 , as shown in  FIG. 6 b   . By performing the described sequence of movements, the printer  100  breaks any adhesion between the parts  300  or the wax base  304  and the surface  112  of the platen  104  so the parts  300  or the wax base  304  are more easily removed from the platen  104 . 
         [0025]    Next, the method  400  pivots the second plate relative to the first plate (block  412 ). The controller  120  operates the actuator  116  to pivot the second plate  128  relative to the first plate  124 , as shown in  FIG. 5 c    and  FIG. 6 c   . In one embodiment in which the wax base  304  is not formed, the parts  300  tumble off the second plate  128  onto a conveyor  504 , as shown in  FIG. 5 c   . When the wax base  304  is not formed, the orientation of the parts  300  is not necessarily maintained during removal. In another embodiment in which the wax base  304  is formed, the wax base  304  and the parts  300  slide off the second plate  128  onto the conveyor  504 , as shown  FIG. 6 c   . When the wax base  304  is formed, the orientation of the parts  300  is maintained during removal. 
         [0026]    A method  700  for operating at least one of the first and second plates to release the three-dimensional object from the platen is shown in  FIG. 7 . The method  700  is another embodiment of the step corresponding to block  412  of the method  200 . Once a three-dimensional object is formed on the platen, the method  700  heats the first plate (block  704 ). The controller  120  operates the heating elements  148  to heat the first plate  124 . By heating the first plate  124 , the printer  100  weakens any adhesion between the parts  300  and the first plate  124 . 
         [0027]    Next, the method  700  moves the second plate horizontally relative to the first plate (block  708 ). The controller  120  operates the actuator  116  to move the second plate  128  horizontally relative to the first plate  124  to at least partially separate the second plate  128  from the first plate  124 , as shown in  FIG. 8 a    and  FIG. 8 b   . In moving the second plate  128 , shear forces break any remaining adhesion between the parts  300  and the heated first plate  124 . In some embodiments, the controller  120  then disengages with the second plate  128  to enable it to be removed completely from the printer  100  with the parts  300  stuck to it, as shown in  FIG. 8 c   . In one embodiment, the parts  300  remain stuck to the second plate  128  during post-processing steps, such as wax removal. In this way, the parts are kept together as a group and their orientations are maintained. 
         [0028]    It will be appreciated that variants of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems, applications or methods. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.