Patent Publication Number: US-2018043611-A1

Title: Method and system for manufacture of 3d multi-colored objects

Description:
TECHNOLOGY FIELD 
     The apparatus and method are related to the field of additive manufacturing and particularly to additive manufacturing devices. 
     BACKGROUND 
     Three dimensional objects manufacturing process includes deposition of a resin layer, imaging of the layer and curing or hardening of the imaged segments of the layer. The layers are deposited (added) on top of each other and because of it the process is called additive manufacturing process by means of which a computer generated 3D models is converted into a physical object. The process involves generation of a plurality of material layers of different or identical shape. The layers are laid down or deposited on top (or bottom) of each of the preceding layer until the amount of layers results in a desired three dimensional physical object. 
     The material from which the layers of the three-dimensional physical object are generated could come in liquid, paste, powder, gel and other forms. Conversion of such materials into a solid form is typically performed by suitable actinic radiation or heat. 
     Most objects manufactured today by additive processing are of uniform (monochromatic) color, their color commonly being the original color of the resin. Increasing demand for multi-color objects has led to various attempts to color the manufactured object most of which involve either post-manufacturing painting or employment of pre-colored resin filaments and alternating between the filaments as desired. However such suggested solutions can increase costs of manufacture due to the materials themselves being expensive, be time consuming and/or slow down throughput time requiring manual labor in case of hand painting the finished object or stopping mid-process to change pre-colored filaments. 
     Manufacturing of 3D multi-coloreds spans over a large range of applications. This includes prototype manufacture, small runs of different products manufacture, decorations, sculptures, architectural models, and other physical objects. 
     One obstacle experienced in the current multi-color or variable material 3D additive manufacturing is in the need of cleaning the extrusion head and/or nozzle after or before any change of material to be deposited. This process can be time consuming and costly. 
     It is the purpose of this disclosure to provide apparatus, methods and materials that support faster, lower cost and automatic manufacturing of multi-colored three-dimensional objects. 
     SUMMARY 
     The current three-dimensional multi-colored object manufacturing system and technique relies on online deposition of a pigmented and non-pigmented pseudoplastic material in gel aggregate state. The gel flows through a deposition nozzle because the applied agitation shears the bonds and breakdown in the elasticity of the fluid. The elasticity recovers immediately after leaving the nozzle, and the gel solidifies under curing energy to maintain its shape and strength. 
     In one example, a three-dimensional multi-colored object manufacturing system can include one or more delivery tubing that deliver pigmented pseudoplastic material in gel aggregate state from one or more dedicated storage or material supply tanks into extrusion head nozzle to be deposited for manufacturing a 3D multi-colored object. 
     In another example, three-dimensional multi-colored object manufacturing system can include a bidirectional pump configured to supply colorless pseudoplastic material in gel aggregate state and to allow colored pseudoplastic material or gel to be drawn directly into the system extrusion head via an extrusion head nozzle opening to be later deposited via the same opening for manufacturing a 3D multi-colored object. 
    
    
     
       LIST OF FIGURES AND THEIR DESCRIPTION 
         FIG. 1  which is a partial plan view and block diagram simplified illustration of an example of a system suitable for manufacture of a multi-colored three-dimensional object in accordance with an example; 
         FIG. 2  is a partial plan view and block diagram simplified illustration of system suitable for manufacture of a multi-colored three-dimensional multi-color object in accordance with another example; 
         FIG. 3  is a partial plan view and block diagram simplified illustration of a system suitable for manufacture of a multi-colored three-dimensional multi-color object in accordance with yet another example; 
         FIGS. 4A, 4B, 4C and 4D  collectively referred to as  FIG. 4 , depict the implementation of the system suitable for manufacture of a multi-colored three-dimensional multi-color object of  FIG. 3 ; 
         FIG. 5  is a plan view simplified illustration of a dispensed 3D object in accordance with still another example; and 
         FIG. 6  is a plan view simplified illustration of a partially dispensed 3D object in accordance with another example. 
     
    
    
     DESCRIPTION 
     The term “Colorless” as used in this disclosure means the color of a material in its “natural” post-manufacturing state resulting solely from its method of manufacture and having no color-producing additives. 
     One three-dimensional object manufacturing technique relies on the deposition of material in gel aggregate state. The gel flows through an extrusion or deposition nozzle because the applied agitation and pressure shears the inter-particle bonds and induces a breakdown in the elasticity of the material. The material recovers immediately after leaving the nozzle, and the gel almost solidifies to maintain its shape. 
     Reference is made to  FIG. 1  which is a partial plan view and block diagram simplified illustration of an example of a system suitable for manufacture of a multi-colored three-dimensional objects or structures in accordance with an example. System  100  can include a storage or material supply tank  102  adapted to store a colorless resin, material, liquid or gel such as, for example, a pseudoplastic high viscosity material  104 . Material supply tank also could include an agitator-pump  108  configured to agitate and shear thin the pseudoplastic high viscosity material or gel  104 , to reduce material  104  viscosity to cause the material to flow. 
     Agitator-pump  108  could be such as Graco S20 supply system commercially available from Graco Minneapolis, Minn. U.S.A., or a barrel follower dispensing pump Series  90  commercially available from Scheugenpflug AG93333 Neustadt a.d.Donau Germany. Agitator-pump  108  in addition to agitation also develops a pressure higher than atmospheric pressure such that the pseudoplastic material  104  flows through a delivery tubing or system  112  to extrusion (head)  114  and extruded or deposited via an opening in nozzle  116 . 
     System  100  can include an X-Y-Z movement system  124  configured to move the extrusion nozzle  116  in a three coordinate system. Alternatively, a table  120  could be made to move in a three coordinate system. In another example, the movement in three directions (X-Y-Z) could be divided between the extrusion nozzle  116  and table  120 . System  100  also includes a computer  128  configured to control operation of movement system  124 , agitator-pump  108  pseudoplastic material steering operation and value or magnitude of the pressure higher than atmospheric pressure. Computer  128  is further adapted to receive the three-dimensional (3D) object  132  data and generate from the received data the X-Y-Z movement commands and distance such that the pseudoplastic material  104  is extruded through extrusion (head) nozzle  116  opening in an image wise manner. The X-Y-Z movement could be performed in a vector mode, depending on the object to be printed. Computer  128  could also be configured to optimize the decision on the printing mode. 
     System  100  can further include a source of radiation  136 . Source of radiation  136  could be such as FireJet FJ200commercially available from Phoseon Technology, Inc., Hillsboro Oreg. 97124 USA. Source of radiation 136 provides UV radiation with total UV power of up to 900W and wavelength range of 380-420 nm. Alternatively, a UV lamp such as for example, mercury vapor lamp model Shot 500 commercially available from CureUV, Inc., Delray Beach, Fla. 33445 USA. Source of radiation  136  operates in a continuous manner and the radiation is selected to harden the pseudoplastic material  104 . Computer  128  could also be configured to control operation of source of radiation  136  and synchronize it with the printing mode. In the remaining  FIGS. 2-4 , source of radiation  136  has been removed for clarity of explanation. 
     Extrusion nozzle  116  can include a reception volume  202  defined in  FIG. 2  by a phantom line border, which communicates with a volume  204  inside extrusion head  114  narrows towards and opens to nozzle  116 . Reception volume  202  can receive material  104  pumped into extrusion head  114  volume  204  by agitator-pump  108  and dispense received material  104  through nozzle  116 . Reception volume  202  can be coated with a material such as, for example, Teflon® to avoid adhesion thereto of dispensing materials. 
     As shown in  FIG. 2 , which is a partial plan view and block diagram simplified illustration of system suitable for manufacture of a multi-colored three-dimensional multi-color object in accordance with another example. System  200  can be generally similar in construction to system  100  of  FIG. 1  designed to support multicolored printing of 3D objects. Additionally to storage or material supply tank  102  of system  100 , system  200  can also include one or more tanks  206 / 208  containing one or more types of coloring material  216 / 218  selected from a group of types of coloring materials including pigments, dyes, color particles and any other suitable type of coloring material in liquid, gel, beads or any other suitable form. Such materials, mixed with a colorless pseudoplastic material or gel can form a colored pseudoplastic material or gel. Color materials can be added in advance to form a pre-colored pseudoplastic material or gel or during a 3D object manufacturing process thus provided colored pseudoplastic material or gel online. 
     Additionally and optionally, materials  216 / 218  stored in one or more tanks  206 / 208  can include a pre-colored pseudoplastic material or gel. 
     Additionally and optionally, one or more tanks  206 / 208  can include materials having physical and chemical characteristics different than the physical and chemical characteristics of material  104  so that to include areas of variable physical properties in the finished product as will be explained in greater detail below. 
     Such material  216 / 218  can be selected from a group of materials including wax or wax mixtures, oil based materials, surface finish materials such as matte finish materials and any other suitable material. 
     System  200  can also include additional delivery tubing  206  and  208  that open into reception volume  202  of extrusion head  114  extrusion nozzle  116 . Tanks  206 / 208  can include agitator-pumps (not shown) similar to agitator-pump  108 . 
     Reference is now made to  FIG. 3 , which is a partial plan view and block diagram simplified illustration of a system suitable for manufacture of a multi-colored three-dimensional multi-color object in accordance with yet another example. System  300  can be generally similar in construction to system  100  of  FIG. 1 . Extrusion head  114  can also house a bidirectional progressive cavity pump  302 , the bi-directionality thereof indicated by an arrow designated reference numeral  350  that can cause material flow from inside reception volume  202  onto table  120  via nozzle  116 , or alternatively, cause fluid to flow from outside extrusion head  114 , such as from a tank  308  into reception volume  202  via same nozzle  202 . Bidirectional pump  302  can be such as a ViscoTec RD-EC progressive cavity pump/dispenser commercially available from ViscoTec, Inc., P.O. Box 4091 Visalia, Calif. 93278, USA. 
     System  300  can also include one or more independent storage or material supply tanks  304 / 306 / 308  containing one or more types of coloring material  314 / 316 / 318  selected from a group of types of coloring materials or gels including pigments, dyes, color particles and any other suitable type of coloring material. 
     Alternatively, additionally and optionally, one or more tanks  304 / 306 / 308  can include materials each having physical and chemical characteristics different than the other or than the physical and chemical characteristics of material  104  so that to include areas of variable physical properties in the finished product as will be explained in greater detail below. 
     Such materials can be selected from a group of materials including wax or wax mixtures, oil based materials, surface finish materials such as matte finish materials and any other suitable material. 
     Coloring materials or gels  314 / 316 / 318  could include, for example, pigments with each pigment having a color different than that of the material or gel in another storage or material supply tank. 
     In system  300 , extrusion head  114  Pump  302  controlled by computer  128  can be moved from a dispensing position, depicted in  FIG. 3  by Roman numeral (I) to a drawing position depicted in  FIG. 3  by Roman numeral (II). In this configuration, when extrusion head  114  nozzle  116  is in dispensing position (I), material or gel  312 / 314 / 316  can be dispensed via nozzle  116  to manufacture at least a portion of a 3D multi-colored  132 . As will be explained in greater detail below, X-Y-Z movement system  124  ( FIG. 1 ) controlled by computer  128  can move head  114  nozzle  116  from dispensing position (I) to drawing position (II) dipping nozzle  116  in at least one of storage or material supply tanks  302 / 304 / 306  drawing therefrom a quantity of respective coloring material or gel  312 / 314 / 316 . The drawn quantity can be drawn through nozzle  116  into reception volume  202  to be later dispensed through nozzle  116  after X-Y-Z movement system  124  ( FIG. 1 ) moves head  114  nozzle  116  back into dispensing position (I). Thus, in system  300 , extrusion head  114  extrusion nozzle  116  draws material to be dispensed and extrudes the drawn material through the same opening. 
     Referring now to  FIGS. 4A, 4B, 4C and 4D  collectively referred to as  FIG. 4 , which depict the implementation of system  300  of  FIG. 3 . The implementation of system  300  can be carried out by the following cycle of steps: one step, shown in  FIG. 4A  illustrates head  114  nozzle  116  in drawing position (II) with nozzle  116  dipped in at least one of storage or material supply tanks  302 / 304 / 306  such as, for example, storage or material supply tank  302 . At this stage, pump  302  operating direction is reversed in a direction indicated by an arrow designated reference numeral  370  so that to draw a quantity of coloring material or gel  312  from storage or material supply tank  302 . The drawn volume can enter reception volume  202  ( FIG. 2 ), which has been evacuated by a same volume of material  104  concurrently drawn by pump  302  back into storage or material supply tank  102 . 
     Once the desired quantity of coloring material or gel  312  has been drawn, X-Y-Z movement system  124  ( FIG. 1 ) can move head  114  nozzle  116  back into dispensing position (I) as shown in  FIG. 4B . When in position, pump  302  operating direction is reversed once again as indicated by an arrow designated reference numeral  390  and the quantity of coloring material or gel  312  previously drawn from storage or material supply tank  306  can be deposited in its entirety in one or more first layer  132 - 1  onto table  120  thus completing the second step. In this stage, the volume of dispensed coloring material or gel  312  reception volume  202  can be concurrently replaced by material or gel  104  drawn by pump  302  from storage or material supply tank  102 . 
     The quantity of drawn coloring material or gel  312  can be calculated by computer  128  to be the exact quantity required to be deposited by head  114  nozzle  116  onto the 3D multi-colored  132  being manufactured. The quantity of material or gel  312  drawn from storage or material supply tank  306  is such so that it can be deposited in its entirety and any residual coloring material or gel  312  inside reception volume  202  ( FIG. 2 ) is negligible. 
     At this point a third step can begin in which and as depicted in  FIG. 4C , X-Y-Z movement system  124  ( FIG. 1 ) can move head  114  nozzle  116  once again into drawing position (II) dipping nozzle  116  at least one other storage or material supply tank  302 / 304 / 306  such as, for example, storage or material supply tank  304 . At this stage, pump  302  operating direction is reversed once again in a direction indicated by an arrow designated reference numeral  370  so that to draw a quantity of coloring material or gel  314  from storage or material supply tank  304 . The drawn volume can enter reception volume  202  ( FIG. 2 ), which has been evacuated by a same volume of material  104  concurrently drawn by pump  302  back into storage or material supply tank  102 . 
     Once the desired quantity of coloring material or gel  314  has been drawn, X-Y-Z movement system  124  ( FIG. 1 ) can move head  114  nozzle  116  back into dispensing position (I) as shown in  FIG. 4D . When in position, pump  302  operating direction is reversed once again as indicated by an arrow designated reference numeral  390  and the quantity of coloring material or gel  314  previously drawn from storage or material supply tank  304  can be deposited in its entirety in one or more second layer  132 - 2  onto one or more first layer  132 - 1  thus completing the forth step. In this stage, the volume of dispensed coloring material or gel  312  reception volume  202  can be concurrently replaced by material or gel  104  drawn by pump  108  from storage or material supply tank  102 . 
     This can be repeated as desired alternating between deposition of colorless material or gel  104  and any one or more coloring material or gel. The above described system and method simplify and reduce cost of manufacturing of multi-colored three-dimensional objects as well as allow online multi-color manufacturing and shortened throughput time. 
     Additionally and optionally, coloring materials  216 / 218 / 314 / 316 / 318  in one or more tanks  206 / 208 / 304 / 306 / 308  can be replaced with materials having physical and chemical characteristics different than the physical and chemical characteristics of material  104  so that to include areas of variable physical properties in the finished product. Such materials, having physical and chemical characteristics different than the physical and chemical characteristics of material  104 , can be any type of material that would allow for easy and quick separation of layers so that to serve as a detachment layer separating between two abutting portions of a manufactured 3D object or between a manufactured 3D object and a support surface on which the object has been manufactured. Such materials can be selected, for example, from a group of materials including wax or wax mixtures, oil based materials, surface finish materials such as matte finish materials and any other suitable material. 
     One advantage of the system and method described above is in that materials of various color and/or physical and chemical characteristics can be drawn and extruded via extrusion head  114  nozzle  116  without cleaning the extrusion head and/or nozzle. 
     In another example shown in  FIG. 5 , which is a plan view of a dispensed 3D object, a 3D object  500  can be manufactured employing the above described system and method. A system such as system  300  ( FIG. 3 ) can deposit one or more layers  502  initially on table  120  using a material physical and chemical characteristics different than the physical and chemical characteristics of material  104  ( FIG. 1 ) such as a material including wax or wax mixtures or an oil based material. This can be followed by dispensing one or more layers of material  104  on top of one or more layers  502  and completing 3D object  500 . The adherence properties of a material such as material  502  having waxy or oily characteristics are reduced thus supporting easy and rapid removal of 3D object  500  from table  120 . 
     In yet another example shown in  FIG. 6 , which is a plan view of a partially dispensed 3D object, an incomplete 3D object  600  is a horse&#39;s head being manufactured employing the above described system and method. Similarly to the example of  FIG. 5 , a system such as system  300  ( FIG. 3 ) can deposit one or more layers  602  initially on table  120  using a material physical and chemical characteristics different than the physical and chemical characteristics of material  104  ( FIG. 1 ) such as a material including wax or wax mixtures or an oil based material. As described above, this can be followed by dispensing one or more layers of material  104  on top of one or more layers  502  and completing 3D object  500 . The adherence properties of a material such as material  502  having waxy or oily characteristics are reduced thus supporting easy and rapid removal of 3D object  500  from table  120 . Furthermore, to manufacture the 3D horse head, a support  550  must be deposited as well to support the horse&#39;s muzzle  504 . the last layer to be deposited upon which will rest the to be printed layers of the horse&#39;s muzzle can also be printed from material  502  having waxy or oily characteristics thus supporting easy and rapid separation of the finished horse&#39;s muzzle from support  550 . 
     It will be appreciated by persons skilled in the art that the present disclosure is not limited to what has been particularly shown and described hereinabove. Rather, the scope of the method and system includes both combinations and sub-combinations of various features described hereinabove as well as modifications and variations thereof which would occur to a person skilled in the art upon reading the foregoing description and which are not in the prior art.