阅读说明：本技术 用于输送用于打印三维(3d)对象的材料的系统和方法 (System and method for delivering material for printing three-dimensional (3D) objects ) 是由 亚伦·罗尼·沙菲尔 于 2018-11-04 设计创作，主要内容包括：一种用于将多个层的粉末输送到用于打印至少一个3D对象的三维(3D)打印系统的输送系统,该输送系统包括：具有圆形光敏外表面的可旋转滚筒、包括用于存储粉末的容器的料斗单元,其中料斗单元被配置为将粉末分配到可旋转滚筒的光敏外表面上。输送系统还包括包含具有导电外表面的可移动输送板的输送单元、用于将输送板移动到3D打印系统的工作室的引擎、被配置为给可旋转滚筒充电的一个或更多个充电电极、被配置为给输送板充电的充电单元。可移动输送单元还被配置为：将分配的多个层从可旋转滚筒外表面电吸引和相继吸引到其导电外表面；以及通过将吸引的多个层电排斥到工作室中而将吸引的多个层转移到工作室。(A transport system for transporting multiple layers of powder to a three-dimensional (3D) printing system for printing at least one 3D object, the transport system comprising: a rotatable drum having a circular photosensitive outer surface, a hopper unit comprising a receptacle for storing powder, wherein the hopper unit is configured to dispense powder onto the photosensitive outer surface of the rotatable drum. The transport system also includes a transport unit including a movable transport plate having an electrically conductive outer surface, an engine for moving the transport plate to a working chamber of the 3D printing system, one or more charging electrodes configured to charge the rotatable drum, a charging unit configured to charge the transport plate. The movable transport unit is further configured to: electrically and sequentially attracting the dispensed plurality of layers from the outer surface of the rotatable drum to the electrically conductive outer surface thereof; and transferring the attracted plurality of layers to the working chamber by electrically repelling the attracted plurality of layers into the working chamber.)

1. A transport system for transporting layers of powder to a three-dimensional (3D) printing system for printing at least one 3D object, the transport system comprising:

a rotatable drum having a circular photosensitive outer surface;

a hopper unit comprising a container for storing the powder, wherein the hopper unit is configured to dispense the powder onto the photosensitive outer surface of the rotatable drum;

a transport unit comprising a movable transport plate having an electrically conductive outer surface, the transport unit being connectable to an engine for moving the transport plate to a working chamber of the 3D printing system;

one or more charging electrodes configured to charge the rotatable drum;

a charging unit configured to charge the conveyance plate; and

wherein the movable transport unit is further configured to:

electrically and sequentially attracting the plurality of layers from the outer surface of the rotatable drum to the electrically conductive outer surface thereof; and

transferring the attracted plurality of layers to the working chamber by electrically repelling the attracted plurality of layers into the working chamber.

2. The system of claim 1, wherein the conductive outer surface is coated with one or more layers of insulating material.

3. The system of claim 1, wherein the powder comprises a non-conductive powder material or a conductive powder material.

4. The system of claim 1, wherein the hopper unit comprises one or more layers of insulating material.

5. The system of claim 1, wherein the rotatable drum comprises a cleaning unit configured to clean the photosensitive outer surface of the rotatable drum.

6. The system of claim 1, wherein the conveyor unit comprises a cleaning unit configured to clean a surface of the conveyor plate.

7. The system of claim 1, the system comprising:

a plurality of rotatable cylinders having a circular photosensitive outer surface for receiving the plurality of layers, respectively, wherein each of the plurality of rotatable cylinders comprises:

the hopper units, wherein each hopper unit comprises the container for storing the powder or other one or more types of powder;

a cleaning unit configured to clean the photosensitive outer surfaces, respectively;

one or more charging electrodes configured to apply an electrostatic charge to each respective rotatable drum of the plurality of rotatable drums;

an energy scanning unit, wherein each energy unit comprises an energy source configured to selectively emit a light beam towards a respective light sensitive outer surface for discharging the light sensitive outer surface in accordance with a predefined image structure of the at least one 3D object;

and wherein the movable transport plate is configured to successively attract and electrically attract the plurality of layers from the plurality of rotatable rollers to form a powder layer at the plate outer surface, and to transfer the powder layer to the working chamber in a layer-by-layer manner by electrically repelling the powder layer into the working chamber.

8. The system of claim 7, wherein the working chamber comprises:

a working surface configured to receive the plurality of layers and to be stepped down; and

an energy head for melting the plurality of layers.

9. The system of claim 8, wherein the energy head is a laser head configured to apply a focused laser beam to a given area of each of the plurality of layers corresponding to a selected cross-sectional area of a model of a 3D object in a manner such that each layer is secured to an underlying layer according to CAD cross-sectional data of the selected cross-sectional area of the model.

10. The system of claim 7, wherein the 3D printing system is a compression system.

11. The system of claim 10, wherein the compression system comprises:

a container having a cavity;

a receiving surface for receiving a plurality of layers from the conveyor plate; and

a top press for pressing the received plurality of layers and forming a densified powder layer.

12. The system of claim 11, wherein the densified powder layer is sintered.

13. The system of claim 12, wherein one of the densified powder layers includes material that may not be sintered.

14. A method for delivering layers of powder to a 3D printing system for generating one or more 3D objects, the method comprising:

rotating at least one drum having a photosensitive surface;

charging the at least one rotating drum for receiving the plurality of layers from a hopper unit at the photosensitive surface;

moving a conveyor unit tangentially to the working chamber relative to the at least one roller, wherein the conveyor unit comprises a movable conveyor deck having a flat conductive outer surface;

charging the transfer plate for successively attracting the plurality of layers from the photosensitive surface of the at least one roller;

switching the electrical polarity of the conveyor plate for repelling the plurality of layers into the working chamber once the conveyor plate is located above or near the working chamber.

15. The method of claim 14, comprising fusing the repelled layers by an energy unit for creating the one or more 3D objects.

16. The method of claim 14, comprising compressing each of the repelled plurality of layers.

17. The method of claim 16, comprising sintering the compressed plurality of layers.

18. The method of claim 16, wherein the plurality of layers comprises a first type of powder material and a second type of powder material, wherein the second powder material has a higher sintering temperature than the first powder material.

19. The method of claim 14, comprising moving the conveyor unit at a rate synchronized with the speed of the rotatable drum.

20. A transport system for transporting multiple layers of powder for printing at least one 3D object, the transport system comprising:

a plurality of rotatable cylinders, wherein each of the plurality of rotatable cylinders has a photosensitive outer surface for receiving the plurality of layers, respectively, and wherein each of the plurality of rotatable cylinders comprises:

a hopper unit, wherein the hopper unit comprises a container for storing one or more materials in powder form;

a cleaning unit configured to clean respective photosensitive outer surfaces of the plurality of rotatable cylinders;

one or more charging electrodes configured to apply electrostatic charges to the rotatable drums, respectively;

a scanning energy unit, wherein the scanning energy unit comprises an energy source configured to selectively emit a light beam towards respective photosensitive outer surfaces of the plurality of rotatable cylinders for discharging the photosensitive outer surfaces according to a predefined image structure of the at least one 3D object;

a transport unit comprising a movable transport plate having an electrically conductive outer surface, the transport unit being connectable to an engine for moving the transport plate to a working chamber of the 3D printing system;

a charging unit configured to charge the conveyance plate; and

wherein the movable transfer plate is configured to sequentially attract and electrically attract the plurality of layers from the plurality of rotatable rollers to form a plurality of layers of powder material at the plate outer surface, and to transfer the plurality of layers of powder material to the working chamber in a layer-by-layer manner by electrically repelling a material layer into the working chamber.

Technical Field

The present invention relates generally to three-dimensional printing systems and methods, and more particularly to systems and methods for transferring material to a three-dimensional printing system.

Incorporation by reference

All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

Background

Three-dimensional (3D) printing, also known as Additive Manufacturing (AM), has become increasingly popular with advances in technology, different methods of forming 3D models by additive manufacturing techniques have been proposed.

In recent years, an electrophotographic method and system used in two-dimensional (2D) printing are implemented in a 3D printing method. According to the related art (2D) printing, an electrophotographic system includes a conductive support drum coated with a photoconductive material, in which an electrostatic latent image is formed by uniformly charging and then image-wise exposing (image-wise exposing) the photoconductive layer by a light source. The electrostatic latent image is then moved to a development station where toner is applied to the uncharged areas of the photoconductive insulator to form a visible image. The formed toner image is then transferred to a substrate (e.g., printing paper) and adhered to the substrate using heat or pressure.

An example of an additive manufacturing system for printing three-dimensional parts using Electrophotography is described in U.S. patent No. 8,488,994 entitled "Electrophotography-based additive manufacturing system with transfer-medium service locations". The additive manufacturing system comprises: a rotatable photoconductive member; a developing station configured to develop a layer of material on a surface of the rotatable photoconductor member; a rotatable transfer medium configured to receive the development layer from a surface of the rotatable photoconductive member; and a platen (tension) configured to receive the developed layer from the rotatable transfer medium in a layer-by-layer manner. The additive manufacturing system also includes a plurality of service loops configured to move portions of the rotatable transfer medium at different linear velocities while maintaining a net rate of rotation of the rotatable transfer medium at a substantially steady state for full rotation.

Fig. 1 illustrates a selective laser melting (S L M) system 100 for dispensing material in powder form in a 3D printing system according to the prior art the system 100 comprises a melting container 101, a powder container 102 and a laser head 103, the laser head 103 being configured to emit a laser beam for melting an image of a powder layer dispensed from the powder container 102 to the melting container 101. in particular, in operation, once the melting process of a single layer (e.g. the top layer) is completed, the carrier plate 106 (holding the powder 104 and the printing matrix 105) is moved downwards while the carrier plate 108 is moved upwards and the roller 109 or plate dispenses the powder layer from the powder container 102 to the container 101 to be melted by the laser head 103.

Summary of The Invention

According to a first embodiment of the present invention, there is provided a transport system for transporting a plurality of layers of powder to a three-dimensional (3D) printing system for printing at least one 3D object, the transport system comprising: a rotatable drum having a circular photosensitive outer surface; a hopper unit comprising a container for storing the powder, wherein the hopper unit is configured to dispense the powder onto the photosensitive outer surface of the rotatable drum; a transport unit comprising a movable transport plate having an electrically conductive outer surface, the transport unit being connectable to an engine for moving the transport plate to a working chamber of the 3D printing system; one or more charging electrodes configured to charge the rotatable drum; a charging unit configured to charge the conveyance plate; and wherein the movable transport unit is further configured to: electrically and sequentially attracting the plurality of layers from the outer surface of the rotatable drum to the electrically conductive outer surface thereof; and transferring the attracted plurality of layers to the working chamber by electrically repelling the attracted plurality of layers into the working chamber.

In some embodiments, the conductive outer surface of the conveyor plate is coated with one or more layers of an insulating material.

In many embodiments, the powder comprises a non-conductive powder material or a conductive powder material.

In many embodiments, the hopper unit comprises one or more layers of insulating material.

In many embodiments, the rotatable drum comprises a cleaning unit configured to clean the photosensitive outer surface of the rotatable drum.

In many embodiments, the conveyor unit comprises a cleaning unit configured to clean a surface of the conveyor plate.

In many embodiments, the delivery system comprises: a plurality of rotatable cylinders having a circular photosensitive outer surface for receiving the plurality of layers, respectively, wherein each of the plurality of rotatable cylinders comprises: hopper units, wherein each hopper unit comprises the container for storing the powder or other powder type or types; a cleaning unit configured to clean the photosensitive outer surfaces, respectively; one or more charging electrodes configured to apply an electrostatic charge to each respective rotatable drum of the plurality of rotatable drums; an energy scanning unit, wherein each energy unit comprises an energy source configured to selectively emit a light beam towards the respective light sensitive outer surface for discharging the light sensitive outer surface in accordance with a predefined image structure of the at least one 3D object; and wherein the movable transport plate is configured to successively attract and electrically attract the plurality of layers from the plurality of rotatable rollers to form a powder layer at the plate outer surface, and to transfer the powder layer to the working chamber in a layer-by-layer manner by electrically repelling the powder layer into the working chamber.

In many embodiments, the working chamber comprises: a working surface configured to receive the plurality of layers and to be stepped down; and an energy head for melting the plurality of layers.

In many embodiments, the energy head is a laser head configured to apply a focused laser beam to a given area of each of the plurality of layers corresponding to a selected cross-sectional area of a model of a molded 3D object according to CAD cross-sectional data of the selected cross-sectional area of the model in such a way that each powder layer is secured to an underlying layer.

In many embodiments, the 3D printing system is a compression system.

In many embodiments, the compression system comprises: a container having a cavity; a receiving surface for receiving a plurality of layers from the conveyor plate; and a top press for pressing the received plurality of layers and forming a densified powder layer.

In many embodiments, the densified powder layer is sintered.

In many embodiments, one of the densified powder layers includes material that may not be sintered.

According to a second aspect of the present invention, there is provided a method for delivering a plurality of layers of powder to a 3D printing system for generating one or more 3D objects, the method comprising: rotating at least one drum having a photosensitive surface; charging the at least one rotating drum for receiving the plurality of layers from a hopper unit at the photosensitive surface; moving a conveyor unit tangentially to the working chamber relative to the at least one roller, wherein the conveyor unit comprises a movable conveyor deck having a flat conductive outer surface; charging the transfer plate for successively attracting the plurality of layers from the photosensitive surface of the at least one roller; switching the electrical polarity of the conveyor plate for repelling the plurality of layers into the working chamber once the conveyor plate is located above or near the working chamber.

In many embodiments, the method includes melting the repelled plurality of layers by an energy cell for creating the one or more 3D objects.

In many embodiments, the method includes compressing each of the repellent plurality of layers.

In many embodiments, the method includes sintering the compressed plurality of layers.

In many embodiments, the plurality of layers includes a first type of powder material and a second type of powder material, wherein the second powder material has a higher sintering temperature than the first powder material.

In many embodiments, the method includes moving the conveyor unit at a rate synchronized with the speed of the rotatable drum.

According to a third embodiment of the present invention, there is provided a transport system for transporting multiple layers of powder for printing at least one 3D object, the transport system comprising: a plurality of rotatable cylinders, wherein each of the plurality of rotatable cylinders has a photosensitive outer surface for receiving the plurality of layers, respectively, and wherein each of the plurality of rotatable cylinders comprises: a hopper unit, wherein the hopper unit includes a container for storing powder; a cleaning unit configured to clean the respective photosensitive outer surfaces of the plurality of rotatable cylinders; one or more charging electrodes configured to apply electrostatic charges to the rotatable drums, respectively; a scanning energy unit, wherein the scanning energy unit comprises an energy source configured to selectively emit a light beam towards respective photosensitive outer surfaces of the plurality of rotatable cylinders for discharging the photosensitive outer surfaces according to a predefined image structure of the at least one 3D object; a transport unit comprising a movable transport plate having an electrically conductive outer surface, the transport unit being connectable to an engine for moving the transport plate to a working chamber of the 3D printing system; and a charging unit configured to charge the conveyance plate; and wherein the movable transport plate is configured to successively attract and electrically attract the plurality of layers from the plurality of rotatable rollers to form a powder layer at the plate outer surface, and to transfer the powder layer to the working chamber in a layer-by-layer manner by electrically repelling the powder layer into the working chamber.