Preparation method of printing material for three-dimensional printing

Abstract

The invention discloses a preparation method of a printing material for three-dimensional printing, the printing material is formed by mixing a new printing material, a first printing material and a second printing material, the new printing material is a printing material which is not used, the first printing material is a printing material which is not used and is not adhered to a three-dimensional printing piece, and the second printing material is a printing material which is not adhered to the three-dimensional printing piece. The second printing material is a printing material which has been used, is adhered to the three-dimensional printing piece, is removed from the three-dimensional printing piece and is not mixed with other solid particles. By adopting the technical scheme, compared with the prior art, the old powder can be utilized more sufficiently or more reasonably.

Description

Technical Field

[0001] The present application relates to the field of three-dimensional printing, and in particular to a method for preparing printing materials for three-dimensional printing. Background Art

[0002] The prior art can lay printing materials layer by layer on a gradually descending building platform of a mobile printing unit, and selectively sinter to obtain a three-dimensional printed part. After printing is completed using the above method, a three-dimensional printing intermediate is formed on the building platform of the mobile printing unit, and the three-dimensional printing intermediate includes a three-dimensional printed part and printing materials wrapped outside the three-dimensional printed part. The printing materials wrapped outside the three-dimensional printed part can be divided into printing materials adhered to the three-dimensional printed part and printing materials not adhered to the three-dimensional printed part. Among them, the printing materials adhered to the three-dimensional printed part are closer to the three-dimensional printed part than the printing materials not adhered to the three-dimensional printed part.

[0003] In the prior art, the three-dimensional printing intermediate formed on the building platform of the mobile printing unit needs to be post-processed before the three-dimensional printed part can be extracted. Post-processing is divided into a front-end post-processing process and a back-end post-processing process. The front-end post-processing process is carried out in a three-dimensional printing post-processing workstation. The three-dimensional printing post-processing workstation includes a main body, a powder suction device, an old powder storage device, a mixing device and a powder supply device. Among them, the main body is provided with a workbench, and the workbench is provided with a channel for the mobile printing unit to move in. The old powder storage device and the mixing device are installed on the main body, and the powder suction device is connected to the old powder storage device. A new powder storage device is also provided outside the three-dimensional printing post-processing workstation, and the new powder storage device is used to store unused printing materials. The new powder storage device and the old powder storage device are connected to the mixing device. The powder supply device is connected to the mixing device. The powder suction device is used to absorb the printing material wrapped outside the three-dimensional printed part, which includes the printing material adhered to the three-dimensional printed part and the printing material not adhered to the three-dimensional printed part. Generally, the part of the printing material adhered to the three-dimensional printed part has agglomeration. The operator needs to manually break up the lumps and then absorb them. The absorbed printing material enters the old powder storage device from the powder suction device until all the three-dimensional printed parts are extracted. The printing material stored in the old powder storage device can be referred to as old powder. At this time, there are still some lumps of printing material on the surface of the three-dimensional printed part that cannot be broken up manually, and need to be moved to the post-processing process for further post-processing. In the post-processing process, a solid particle injection device is used to process the surface of the three-dimensional printed part. The solid particle injection device uses high-pressure gas to spray solid particles to hit the surface of the three-dimensional printed part, so that the printing material still adhering to the surface of the three-dimensional printed part is separated from the three-dimensional printed part.

[0004] Before the printing task begins, the mobile printing unit needs to be moved to the 3D printing post-processing workstation for powder addition. When adding powder, new powder and old powder are mixed in a mixing device in a certain proportion according to the printing task. The mixing ratio is generally 20% new powder and 80% old powder. The mixed printing material is used for 3D printing and is called printing material for 3D printing. The printing material for 3D printing is added from the mixing device to the powder storage space under the building platform of the mobile printing unit through the powder supply device. After the powder addition is completed, the mobile printing unit moves to the 3D printer for 3D printing.

[0005] The applicant found that since the packing rate during 3D printing is only 8% to 12%, each time 3D printing is performed, some old powder will remain and not be used later. The packing rate here refers to the percentage of the volume of the 3D printed parts in the 3D printing intermediate product to the total volume of the 3D printing intermediate product after the 3D printing is completed. Therefore, the existing technology has the problem that the old powder is not fully and reasonably utilized. Summary of the invention

[0006] The purpose of the present application is to overcome the above-mentioned defects or problems existing in the background technology and to provide a method for preparing printing materials for three-dimensional printing, which can make more full or more reasonable use of old powder compared with the prior art.

[0007] In order to achieve the above purpose, the following technical solutions are adopted:

[0008] The first technical solution relates to a method for preparing a printing material for three-dimensional printing, which is mixed with a new printing material, a first printing material, and a second printing material. The new printing material is an unused printing material, the first printing material is a printing material that has not been used and is not adhered to the three-dimensional printed part, and the second printing material is a printing material that has been used and adhered to the three-dimensional printed part and has been removed from the three-dimensional printed part and is not mixed with other solid particles.

[0009] The second technical solution is based on the first technical solution, wherein the mass percentage of the new printing material is 5% to 25%, the mass percentage of the first printing material is 30% to 70%, and the mass percentage of the second printing material is 5% to 65%.

[0010] The third technical solution is based on the second technical solution, wherein, when the three-dimensional printed part generated by three-dimensional printing has requirements for mechanical strength, the mass percentage of the new printing material is 15% to 25%, the mass percentage of the second printing material is 5% to 35%, and the rest is the first printing material.

[0011] The fourth technical solution is based on the third technical solution, wherein, when the three-dimensional printed part generated by three-dimensional printing has requirements for mechanical strength, the mass ratio of the new printing material, the first printing material and the second printing material is 2:5:3.

[0012] The fifth technical solution is based on the second technical solution, wherein when the three-dimensional printed part generated by three-dimensional printing has requirements on color, the mass percentage of the second printing material is 5% to 25%.

[0013] The sixth technical solution is based on the fifth technical solution, wherein when the three-dimensional printed part generated by three-dimensional printing has requirements on color, the mass ratio of the new printing material, the first printing material and the second printing material is 2:6:2.

[0014] The seventh technical solution is based on the second technical solution, wherein, when the three-dimensional printed part generated by three-dimensional printing has cost requirements, the mass percentage of the new printing material is 5% to 15%, the mass percentage of the second printing material is 40% to 65%, and the rest is the first printing material.

[0015] The eighth technical solution is based on the seventh technical solution, wherein, when the three-dimensional printed part generated by three-dimensional printing has cost requirements, the mass ratio of the new printing material, the first printing material and the second printing material is 1:4:5.

[0016] The ninth technical solution is based on any one of the first to eighth technical solutions, wherein the second printing material is a printing material stored after the printing material adhering to the three-dimensional printed part is removed from the three-dimensional printed part by injecting gas.

[0017] The tenth technical solution is based on any one of the first to eighth technical solutions, wherein the first printing material and the second printing material are screened and then mixed with the new printing material.

[0018] Compared with the prior art, the above solution has the following beneficial effects:

[0019] After observation, testing and analysis, the applicant found that the printing material adhered to the 3D printed part was close to the 3D printed part and was subjected to higher temperature, so it was more severely aging and discoloring, and the mechanical properties of the 3D printed part were also lower. However, the printing material not adhered to the 3D printed part was far away from the 3D printed part and was subjected to lower temperature, so it was less severely aging and discoloring, and the mechanical properties of the 3D printed part were also higher.

[0020] In the first and second technical solutions, the old powder is divided into the first printing material that has been used and not adhered to the three-dimensional printed part and the second printing material that has been used and adhered to the three-dimensional printed part and removed from the three-dimensional printed part without mixing with other solid particles. This is conducive to selecting different mixing ratios according to different needs of the three-dimensional printed parts to be formed by the printing task, so as to more reasonably utilize the old powder while meeting the needs.

[0021] In the third and fourth technical solutions, since the three-dimensional printed part has requirements for mechanical strength, it is necessary to control the mass percentage of the second printing material so that it does not exceed 35%, and the mass percentage of the new printing material is not less than 15%, so that the printed three-dimensional printed part has good mechanical strength. Among them, the fourth technical solution is a preferred implementation of the third technical solution.

[0022] In the fifth and sixth technical solutions, since the three-dimensional printed part has requirements on color, it is necessary to control the mass percentage of the second printing material to not exceed 25%, so that the printed three-dimensional printed part will not show obvious color change. Among them, the sixth technical solution is a preferred implementation of the fifth technical solution.

[0023] In the seventh and eighth technical solutions, since the three-dimensional printed parts have cost requirements, it is necessary to control the mass percentage of the new printing material so that it does not exceed 15%, and at the same time use the second printing material as much as possible so that the old powder can be more fully utilized, especially the second printing material. The eighth technical solution is a preferred implementation of the seventh technical solution.

[0024] In the ninth technical solution, the second printing material removes the printing material adhering to the three-dimensional printed part from the three-dimensional printed part only by injecting gas. Therefore, compared with adopting a post-processing step to peel off the printing material adhering to the three-dimensional printed part, it can not only avoid other solid particles from being mixed into the second printing material, but also avoid the printing material closest to the three-dimensional printed part from being peeled off, so that the aging degree and mechanical properties of the second printing material are more controllable.

[0025] In the tenth technical solution, the first printing material and the second printing material are screened and then mixed with the new printing material, which is beneficial to prevent agglomerated printing materials from entering the printing material for three-dimensional printing, thereby ensuring the quality of three-dimensional printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the embodiment, the following briefly introduces the drawings required for use:

[0027] Figure 1 It is a structural schematic diagram of the mobile printing unit and the three-dimensional printing intermediate product in Example 1;

[0028] Figure 2 It is a three-dimensional diagram of the three-dimensional printing post-processing workstation in Example 1;

[0029] Figure 3 It is a front view of the three-dimensional printing post-processing workstation in the first embodiment;

[0030] Figure 4 for Figure 3 AA section view;

[0031] Figure 5 is a schematic diagram of a three-dimensional printing post-processing system in Example 1;

[0032] Figure 6 It is a front view of the three-dimensional printing post-processing workstation in the second embodiment;

[0033] Figure 7 for Figure 6 BB section view;

[0034] Figure 8 is a top view of the first matching portion in the second embodiment;

[0035] Fig. 9 It is a top view of the second matching portion in the second embodiment.

[0036] Description of main reference numerals:

[0037] 1. Mobile printing unit; 2. Build platform; 3. Powder storage space; 4. Powder supply cover; 5. 3D printing intermediate; 6. 3D printed part; 7. Printing material adhered to the 3D printed part; 8. Printing material not adhered to the 3D printed part; 9. 3D printed part post-processing workstation; 10. Main body; 11. Powder removal device; 12. Powder suction device; 13. First powder storage device; 14. Second powder storage device; 15. Mixing device; 16. Powder supply device; 17. Connecting device; 18. Workpiece Workbench; 19. First door; 20. Second door; 21. Discharge guide plate; 22. Passage; 23. Accommodating space; 24. First opening; 25. Second opening; 26. Carrying part; 27. Injection part; 28. Powder collecting part; 29. ​​Driving wheel; 30. Lifting section; 31. Receiving section; 32. Third opening; 33. First matching part; 34. Second matching part; 35. Vibrating screen; 36. New powder storage device; 100. 3D printing post-processing system; X, forward; Y, reverse. DETAILED DESCRIPTION

[0038] In the claims and the description, unless otherwise defined, the terms "first", "second" or "third", etc. are intended to distinguish different objects rather than to describe a specific order.

[0039] In the claims and the specification, unless otherwise defined, terms such as "center", "lateral", "longitudinal", "horizontal", "vertical", "top", "bottom", "inside", "outside", "up", "down", "front", "back", "left", "right", "clockwise", "counterclockwise" and the like indicating directions or positional relationships are based on the directions and positional relationships shown in the drawings and are only for the convenience of simplifying the description and do not imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction.

[0040] In the claims and the specification, unless otherwise defined, the term "fixed connection" or "fixed connection" should be understood in a broad sense, that is, any connection method in which there is no displacement relationship and relative rotation relationship between the two parties, that is to say, including non-detachable fixed connection, detachable fixed connection, integral connection and fixed connection through other devices or elements.

[0041] In the claims and the description, unless otherwise defined, the terms "includes", "has" and their variations mean "including but not limited to".

[0042] In the claims and the specification, unless otherwise defined, the term "provided with" means that the technical feature located thereafter is a part of the technical feature located therefor.

[0043] In the claims and the specification, unless otherwise defined, the term "injection of gas" means injection of high-pressure gas and does not include injection of solid particles.

[0044] In the claims and the specification, unless otherwise defined, the term "detachably anti-rotationally connected" means that the two can be detached or anti-rotationally connected along the direction of the rotation axis, and the anti-rotational connection is achieved by adopting non-rotating surface matching or other well-known matching methods so that the two cannot rotate relative to each other.

[0045] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the accompanying drawings.

[0046] Embodiment 1

[0047] See also Figure 1 , Figure 1 The mobile printing unit 1 and the 3D printing intermediate body 5 in the first embodiment have completed 3D printing. Figure 1As shown, the mobile printing unit 1 has a liftable building platform 2. After printing is completed, the building platform 2 is lowered to the lowest position. A powder storage space 3 is provided below the building platform 2, and the powder storage space 3 is used to store printing materials for three-dimensional printing. A powder supply port connected to the powder storage space 3 is provided on the building platform 2, and a powder supply cover 4 is provided on the powder supply port. A three-dimensional printing intermediate 5 is accommodated above the building platform 3. The three-dimensional printing intermediate 5 includes a three-dimensional printed part 6 and printing materials wrapped outside the three-dimensional printed part 6, and the printing materials include printing materials 7 adhered to the three-dimensional printed part and printing materials 8 not adhered to the three-dimensional printed part.

[0048] See also Figures 2 to 5 , Figures 2 to 5 The 3D printing post-processing workstation 9 in the first embodiment is shown. Figures 2 to 5 As shown, the 3D printing post-processing workstation 9 includes a main body 10, a powder removal device 11, a powder suction device 12, a first powder storage device 13, a second powder storage device 14, a mixing device 15, a powder supply device 16 and a connecting device 17.

[0049] like Figure 2 As shown, the body 10 includes a workbench 18, a first door 19, a second door 20 and a discharge guide plate 21. The workbench 18 is provided with a passage 22, and the passage 22 is for the mobile printing unit 1 to be attached to the workbench 18. The passage 22 is provided with a passage opening on the front surface of the workbench 18, and the mobile printing unit 1 enters the passage 22 through the opening. The passage 22 is provided with a rotating door at the opening, and the rotating door is used to open and close the passage opening. The workbench 18 is provided with an accommodating space 23 on the side of the passage 22. The upper surface of the workbench 18 is provided with a first opening 24 connected to the accommodating space 23, and the front surface of the workbench 18 is provided with a second opening 25 connected to the accommodating space 23. The first door 19 is rotatably connected to the workbench 18 around a horizontal rotation axis and is used to open and close the first opening 24. The second door 20 is rotatably connected to the workbench 18 around a vertical rotation axis and is used to open and close the second opening 24. The discharge guide plate 21 is located in the second door 20 and is rotatably connected to the workbench 18. The function of the discharge guide plate 21 will be described in detail later.

[0050] like Figures 2 to 5As shown, the powder removal device 11 is placed in the accommodating space 23. The powder removal device 11 is suitable for being placed on the three-dimensional printed part 6 to which the printing material is adhered from the first opening 24, and is suitable for taking out the three-dimensional printed part 6 from the second opening 25. The powder removal device 11 includes a carrier 26, a driving member (not shown in the figure), an injection member 27 and a powder collecting member 28. The carrier 26 is used to carry the three-dimensional printed part 6, the driving member drives the carrier 26 to move relative to the body 10, and the injection member 27 faces the carrier 26 and is used to inject gas to the three-dimensional printed part 6 on the carrier 26. The powder collecting member 28 is located below the carrier 26 and is used to collect the printing material removed from the three-dimensional printed part 6. In this embodiment, the carrier 26 is a track with holes. The holes on the track are used for the printing material to pass through so as to be collected by the powder collecting member 28. The carrier 26 is driven by the driving wheel 29 to move in the positive direction X or in the reverse direction Y. The surface of the carrier 26 suitable for carrying the three-dimensional printed part 6 is provided with a lifting section 30 and a receiving section 31. When the carrier 26 moves in the positive direction X, the lifting section 30 uses friction to lift the three-dimensional printed part 6 until the three-dimensional printed part 6 falls and is received by the receiving section 31. The three-dimensional printed part 6 keeps rolling during the lifting and falling cycle. In this embodiment, the receiving section 31 extends roughly in the front-to-back direction and is higher in the front and lower in the back. When the carrier 26 moves in the reverse direction Y, the receiving section 31 moves the three-dimensional printed part 6 it carries out of the powder removal device 11 from the discharge end away from the lifting section 30. In this embodiment, when the carrier 27 moves in the reverse direction Y, the discharge guide plate 21 rotates to the position as shown in FIG. Figure 2 The ejection member 27 is disposed at the first door 19 and is directed to the position where the lifting section 30 of the carrier 26 is connected to the receiving section 31 when the first door 19 closes the first opening 24. In this embodiment, the powder collecting member 28 is funnel-shaped.

[0051] like Figures 2 to 5 As shown, the powder suction device 12 absorbs the printing material that is not adhered to the three-dimensional printed part 6 in the three-dimensional printed intermediate 5 on the mobile printing unit 1 through negative pressure. The first powder storage device 13 is used to accommodate the first printing material, and the first printing material is the printing material obtained from the powder suction device 12. The second powder storage device 14 is used to accommodate the second printing material, and the second printing material is the printing material obtained from the powder collecting member 28. The first powder storage device 13 and the second powder storage device 14 are both connected to the vibrating screen 35 below. The first powder storage device 13 and the second powder storage device 14 are both connected to the mixing device 15 through the vibrating screen 35, and the mixing device 15 is used to mix the printing materials. The powder supply device 16 is connected to the mixing device 15 to supply the printing material mixed by the mixing device 15 to the powder storage space 3 through the powder supply port. The connecting device 17 is installed on the outer shell of the workbench 18 and is connected to the mixing device 15.

[0052] See also Figure 5 , Figure 5 The 3D printing post-processing system 100 in the first embodiment is shown. Figure 4 As shown, the three-dimensional printing post-processing system 100 includes the above-mentioned three-dimensional printing post-processing workstation 9 and a new powder storage device 36. The new powder storage device 36 is used to accommodate and store new printing materials, which are unused printing materials. The new powder storage device 36 is placed outside the three-dimensional printing post-processing workstation 9 and is connected to the mixing device 15 through the connecting device 17. The mixing device 15 is used to mix the new printing material, the first printing material and the second printing material.

[0053] In this embodiment, the front-end post-processing process is carried out in the following manner:

[0054] First, insert the mobile printing unit 1 into the channel 22 and attach it to the body 10. Open the first door 19. The printing material that is not adhered to the three-dimensional printed part 6 is gradually sucked into the first powder storage device 13 through the powder suction device 12, and the exposed three-dimensional printed part 6 and the three-dimensional printed part 6 with the printing material adhered are placed in the powder removal device 11 from the first opening 24. By continuously lifting the building platform 2, the above actions are repeated until all three-dimensional printed parts 6 are placed on the carrier 26 of the powder removal device 11. After the remaining powder in the mobile printing unit 1 is emptied by the powder suction device 12, the first door 19 is closed, the powder removal device 11 is started, and the driving member drives the carrier 26 to move relative to the body 10 in the positive direction X. The injection member 27 injects gas to the three-dimensional printed part 6 that is continuously lifted, dropped and tumbled on the carrier 26, so that part of the printing material is removed from the three-dimensional printed part 6 and collected by the powder collecting member 28. After the powder removal is completed, the second door 20 is opened, the discharge guide plate 21 is rotated to the position of the discharge end of the receiving section 31, and the driving member is controlled to drive the bearing member 26 to move in the reverse direction Y relative to the body 10, so that the three-dimensional printed part 6 is moved out of the workbench 18 through the discharge guide plate 21. The printing material collected by the powder collecting member 28 is stored in the second powder storage device 14.

[0055] In this embodiment, the post-processing steps are the same as those in the prior art and will not be described in detail here.

[0056] In this embodiment, the new printing material, the first printing material and the second printing material are mixed by a mixing device to form printing materials for three-dimensional printing in proportions as follows: the mass percentage of the new printing material is 5% to 25%, the mass percentage of the first printing material is 30% to 70%, and the mass percentage of the second printing material is 5% to 65%.

[0057] The specific mixing ratio needs to take into account the specific requirements for the three-dimensional printed part 6 generated by three-dimensional printing.

[0058] When the three-dimensional printed part 6 generated by three-dimensional printing has requirements for mechanical strength, the mass percentage of the new printing material is 15% to 25%, the mass percentage of the second printing material is 5% to 35%, and the rest is the first printing material. Preferably, the mass ratio of the new printing material, the first printing material and the second printing material is 2:5:3.

[0059] When the three-dimensional printed part 6 generated by three-dimensional printing has requirements on color, the mass percentage of the second printing material is 5% to 25%. Preferably, the mass ratio of the new printing material, the first printing material and the second printing material is 2:6:2.

[0060] When the three-dimensional printed part 6 generated by three-dimensional printing has cost requirements, the mass percentage of the new printing material is 5% to 15%, the mass percentage of the second printing material is 40% to 65%, and the rest is the first printing material. Preferably, the mass ratio of the new printing material, the first printing material and the second printing material is 1:4:5.

[0061] In this embodiment, a powder removal device 11 is additionally provided in the main body 10, and the powder removal device 11 removes part of the printing material adhering to the three-dimensional printed part 6 from the three-dimensional printed part 6 by spraying gas. The three-dimensional printed part 6 to which the printing material is adhered can be taken out of the three-dimensional printing intermediate 5 and placed into the powder removal device 11, so that the printing material 7 adhering to the three-dimensional printed part and the printing material 8 not adhering to the three-dimensional printed part can be separated, thereby providing a material basis and corresponding preparation for more rational use of old powder.

[0062] In this embodiment, the printing material 7 adhering to the three-dimensional printed part is removed by the powder removal device 11 without the need for manual removal or peeling by an operator, so the labor intensity is reduced, the post-processing time is shortened, and the efficiency is higher.

[0063] In this embodiment, the accommodating space 23 is located at the side of the channel 22, and the first opening 24 connected to the accommodating space 23 is located on the upper surface of the workbench 18. The operator can easily place the three-dimensional printed part 6 with the printing material adhered to it into the powder removal device 11 through the first opening 24. By opening and closing the first opening 24 through the first door 19, it is possible to avoid affecting the working environment of the operator when spraying gas to the three-dimensional printed part 6.

[0064] In this embodiment, the carrier 26 is driven by the driving member to move relative to the body 10, so that the gas ejected by the ejection member 27 can act on more three-dimensional printed parts 6 and more surfaces of the three-dimensional printed parts 6, which is conducive to improving the powder removal efficiency. The powder collecting member 28 is located below the carrier 26 to collect the printing material removed from the three-dimensional printed part 6, so as to facilitate the recycling of this part of the printing material.

[0065] In this embodiment, the carrier 26 is a track with holes. The carrier 26 can lift the three-dimensional printed part 6 and make the three-dimensional printed part 6 roll during the falling process, so that the gas sprayed by the injection member 27 can act on more three-dimensional printed parts 6 and more surfaces of the three-dimensional printed part 6, which is conducive to improving the powder removal efficiency. The printing material leaves the carrier 26 through the hole and is collected by the powder collecting member 28, so that the printing material can be fully recycled and can avoid being recycled by agglomeration. The injection member 27 is installed on the first door 19, so that the injection member 27 can spray gas to the carrier 26 below.

[0066] In this embodiment, the 3D printed part 6 is taken out through the second opening 25 opened on the front surface of the workbench 18, thereby avoiding the need to extract the 3D printed part 6 from the first opening 24, which is beneficial to reducing labor intensity and improving post-processing efficiency.

[0067] In this embodiment, the carrier 26 moves in the reverse direction so that the receiving section 31 moves the carried 3D printed part 6 out of the powder removal device 11, and the 3D printed part 6 can be automatically unloaded, which reduces labor intensity and improves post-processing efficiency.

[0068] In this embodiment, the discharge guide plate 21 is connected to the discharge end of the receiving section 31 , which is conducive to guiding the three-dimensional printed part 6 out of the workbench 18 . The discharge guide plate 21 is rotatably connected to the workbench 18 , which is conducive to storing the discharge guide plate 21 .

[0069] In this embodiment, the printing material 8 not adhered to the three-dimensional printed part and the printing material 7 adhered to the three-dimensional printed part are stored separately, which is conducive to more reasonable or more sufficient utilization of old powder.

[0070] In this embodiment, the mixing device 15 obtains and mixes the printing materials from the new powder storage device 36, the first powder storage device 13, and the second powder storage device 14, so as to make full use of the new powder, the printing materials 8 not adhered to the three-dimensional printed part, and the printing materials 7 adhered to the three-dimensional printed part, and adjust the proportion of various printing materials according to demand. At the same time, the printing materials mixed by the mixing device 15 are supplied to the mobile printing unit 1 through the powder supply device 16, so that the mobile printing unit 1 is more convenient to add powder, which is more conducive to the rational use of various printing materials.

[0071] In this embodiment, the printing material 7 adhered to the three-dimensional printed part is removed from the three-dimensional printed part 6 by injecting gas. Compared with adopting a post-processing step to peel off the printing material 7 adhered to the three-dimensional printed part, it can not only avoid the incorporation of other solid particles, but also avoid the printing material closest to the three-dimensional printed part from being peeled off, so that the aging degree and mechanical properties of the removed printing material 7 adhered to the three-dimensional printed part are more controllable.

[0072] In this embodiment, the old powder is divided into a first printing material that has been used and not adhered to the three-dimensional printed part and a second printing material that has been used and adhered to the three-dimensional printed part and removed from the three-dimensional printed part without being mixed with other solid particles. This is conducive to selecting different mixing ratios according to different needs of the three-dimensional printed part 6 to be formed by the printing task, so as to more reasonably utilize the old powder while meeting the needs.

[0073] In this embodiment, since the three-dimensional printed part 6 has requirements for mechanical strength, it is necessary to control the mass percentage of the second printing material so that it does not exceed 35%, and the mass percentage of the new printing material is not less than 15%, so that the printed three-dimensional printed part has better mechanical strength.

[0074] In this embodiment, since the three-dimensional printed part 6 has requirements on color, it is necessary to control the mass percentage of the second printing material so as not to exceed 25%, so that the printed three-dimensional printed part 6 will not have obvious color change.

[0075] In this embodiment, since the three-dimensional printed part 6 has cost requirements, it is necessary to control the mass percentage of the new printing material so that it does not exceed 15%, and at the same time use the second printing material as much as possible so that the old powder can be more fully utilized, especially the second printing material.

[0076] In this embodiment, the first printing material and the second printing material are screened and then mixed with the new printing material, which helps to prevent agglomerated printing materials from entering the printing material for three-dimensional printing, thereby ensuring the quality of three-dimensional printing.

[0077] Embodiment 2

[0078] See also Figure 6 and Figure 7 . Figure 6 and Figure 7 The three-dimensional printing post-processing workstation 9 in the second embodiment is shown. In the three-dimensional printing post-processing workstation 9 in this embodiment, the main body 10 is no longer provided with the second door 20, and the workbench 18 is no longer provided with the second opening 25. The carrier 26 is a rotating drum with holes on the side walls and the bottom wall, and the holes are used for the printing material to pass through to be collected by the powder collecting member 28. The carrier 26 has a third opening 32 facing the first opening 24, and the three-dimensional printed part 6 can be placed in the carrier 26 from the third opening 32. The injection member 27 is installed on the first door 19 and injects gas to the three-dimensional printed part 6 in the carrier 26. The driving member drives the carrier 26 to rotate around the rotation axis extending in the up-down direction. Specifically, as Figures 7 to 9As shown, the driving member is provided with a first matching portion 33 that rotates around the rotation axis, and the carrier 26 is provided with a second matching portion 34 that is suitable for being detachably connected to the first matching portion 33. In this embodiment, the cross section of the first matching portion 33 is hexagonal, and the cross section of the second matching portion 34 has a hexagonal hole to be connected to the first matching portion 33. In this embodiment, the first opening 24 is suitable for taking out the carrier 26. Therefore, after the powder removal is completed, the carrier 26 can be taken out from the first opening 24 along the direction of the rotation axis, and the three-dimensional printed part 6 is poured into the storage device. When the carrier 26 is placed in the accommodating space 23, the second matching portion 34 is connected to the first matching portion 33 to prevent rotation, so that the driving member can drive the carrier 26 to rotate. Of course, in other embodiments, the carrier 26 may not be taken out from the first opening 24. In this case, the operator is required to take out the three-dimensional printed part in the carrier 26 from the first opening 24.

[0079] The rest of this embodiment is the same as that of the first embodiment.

[0080] In this embodiment, the carrier 26 is a rotating drum with holes, and rotates around a rotation axis extending in the up-down direction, so that the injection member 27 installed on the first door 19 can also inject gas from top to bottom to more three-dimensional printed parts 6, which is conducive to improving the powder removal efficiency. The printed material leaves the carrier 26 through the hole and is collected by the powder collecting member 28, so that the printed material can be fully recycled and can be recycled without agglomeration.

[0081] In this embodiment, the first mating portion 33 and the second mating portion 34 are detachably connected to prevent rotation, so that the carrier 26 can be removed from the driving member and the three-dimensional printed part 6 can be taken out from the first opening 24, thereby eliminating the need to take the three-dimensional printed part 62 out of the carrier 6 piece by piece, thereby improving labor efficiency.

[0082] The above specification and description of the embodiments are used to explain the protection scope of the present application, but do not constitute a limitation on the protection scope of the present application.

Claims

1. A method for preparing a printing material for three-dimensional printing, characterized in that: It is a mixture of new printing material, a first printing material and a second printing material, wherein the new printing material is an unused printing material, the first printing material is a printing material that has not been used and is not adhered to the three-dimensional printed part, and the second printing material is a printing material that has been used and adhered to the three-dimensional printed part and has been removed from the three-dimensional printed part and is not mixed with other solid particles.

2. A method for preparing a printing material for three-dimensional printing as claimed in claim 1, characterized in that: The mass percentage of the new printing material is 5% to 25%, the mass percentage of the first printing material is 30% to 70%, and the mass percentage of the second printing material is 5% to 65%.

3. The method for preparing a printing material for three-dimensional printing according to claim 2, characterized in that: When the three-dimensional printed part generated by three-dimensional printing has requirements for mechanical strength, the mass percentage of the new printing material is 15% to 25%, the mass percentage of the second printing material is 5% to 35%, and the rest is the first printing material.

4. A method for preparing a printing material for three-dimensional printing as claimed in claim 3, characterized in that: When the three-dimensional printed part generated by three-dimensional printing has requirements for mechanical strength, the mass ratio of the new printing material, the first printing material and the second printing material is 2:5:

3.

5. The method for preparing a printing material for three-dimensional printing according to claim 2, characterized in that: When the three-dimensional printed part generated by three-dimensional printing has requirements on color, the mass percentage of the second printing material is 5% to 25%.

6. A method for preparing a printing material for three-dimensional printing as claimed in claim 5, characterized in that: When the three-dimensional printed part generated by three-dimensional printing has requirements on color, the mass ratio of the new printing material, the first printing material and the second printing material is 2:6:

2.

7. The method for preparing a printing material for three-dimensional printing according to claim 2, characterized in that: When the three-dimensional printed part generated by three-dimensional printing has cost requirements, the mass percentage of the new printing material is 5% to 15%, the mass percentage of the second printing material is 40% to 65%, and the rest is the first printing material.

8. A method for preparing a printing material for three-dimensional printing as claimed in claim 7, characterized in that: When the three-dimensional printed part generated by three-dimensional printing has cost requirements, the mass ratio of the new printing material, the first printing material and the second printing material is 1:4:

5.

9. A method for preparing a printing material for three-dimensional printing according to any one of claims 1 to 8, characterized in that: The second printing material is a printing material stored after the printing material adhering to the three-dimensional printed part is removed from the three-dimensional printed part by injecting gas.

10. A method for preparing a printing material for three-dimensional printing according to any one of claims 1 to 8, characterized in that: The first printing material and the second printing material are mixed with the new printing material after being screened.

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