An apparatus and method for precise deposition of dual-component materials in a 3D printing process

Abstract

The application discloses a device and method for realizing accurate deposition of double-component materials in a 3D printing process, which comprises a first feeding device, a second feeding device, a three-way connector and a static mixer; the three-way connector has a first inlet and a second inlet, the first inlet is communicated with the first feeding device, and the second inlet is communicated with the second feeding device; the first inlet is divided into two branch flow channels, which are a first branch flow channel and a third branch flow channel respectively, the first branch flow channel corresponds to a first outlet, the third branch flow channel corresponds to a third outlet, the first outlet is located at a first side of a first mixing unit of the static mixer, and the third outlet is located at a second side of the first mixing unit of the static mixer; the second inlet channel is also divided into a second branch flow channel and a fourth branch flow channel; the second branch flow channel corresponds to a second outlet, and the fourth branch flow channel corresponds to a fourth outlet; the fourth outlet is located at the first side of the first mixing unit of the static mixer, and the second outlet is located at the second side of the first mixing unit of the static mixer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing of multi-materials, and particularly to a method for realizing precise deposition of multi-materials in an extrusion type 3D printing process. BACKGROUND

[0002] In patent CN 113442258 B, a 3D printer and method for digital manufacturing of composite ceramic functional gradient material are disclosed. The method uses a Kenics static mixer to perform online mixing of two components, which can realize continuous gradient change between the two materials during the printing process, and provides a new solution for 3D printing in the aspect of personalized shaping of multi-materials. However, when using the Kenics static mixer for online mixing of multi-materials, the ratio of material components needs to be changed in real time as the shaping position changes. When materials A and B are mixed at a ratio of 1:1, the flow rates of the two materials are equal and the cross-sectional areas on both sides of the first mixing unit are equal, so the flow rates are consistent and materials A and B are mixed uniformly. However, when the ratio of materials is changed, for example, at a ratio of A:B = 1:2, the flow rates on both sides of the mixing unit will inevitably be inconsistent, and material B will flow twice as fast as material A. The slowly flowing material A can only mix with the second half of material B, so the first half of material B does not participate in mixing and instead interferes with the mixed material inside the pipe. After multiple ratio changes, the material ratio output by the extrusion head will have a serious error, and the performance of the shaped material cannot be guaranteed. SUMMARY

[0003] To overcome the above-mentioned deficiencies of the prior art, the present application provides a method for realizing precise deposition of double-component materials in a 3D printing process, which effectively solves the problems of low printing and shaping precision of double-component materials and poor reliability of functional gradient material shaping in the prior art, and can improve online mixing uniformity and mixing efficiency.

[0004] To achieve the above-mentioned purposes, the technical solutions adopted by the present application are as follows:

[0005] The device for realizing precise deposition of double-component materials in a 3D printing process disclosed in this embodiment comprises a first feeding device, a second feeding device, a three-way connector, and a static mixer.

[0006] The three-way connector has a first inlet and a second inlet, the first inlet is communicated with the first feeding device, and the second inlet is communicated with the second feeding device; a first flow channel corresponding to the first inlet is divided into two branch flow channels, which are a first branch flow channel and a third branch flow channel, an outlet corresponding to the first branch flow channel is a first outlet, and an outlet corresponding to the third branch flow channel is a third outlet; that is, material A entering from the first inlet is divided into two paths to enter the static mixer; a second flow channel corresponding to the second inlet is also divided into two outlet flow channels, which are a second branch flow channel and a fourth branch flow channel; an outlet corresponding to the second branch flow channel is a second outlet, and an outlet corresponding to the fourth branch flow channel is a fourth outlet; the fourth outlet is located on the first side of the first mixing unit of the static mixer, and the second outlet is located on the second side of the first mixing unit of the static mixer, and the first side and the second side are opposite; material B entering from the second inlet is divided into two paths; in the case that the flow rates of the materials A and B are inconsistent, the two outlets with fast flow rates are located on different sides, and the two outlets with slow flow rates are also located on different sides, so that the two outlets on the left are one fast and one slow, and the two outlets on the right are also one fast and one slow, so that the speeds on both sides are basically the same, and uniform mixing is ensured.

[0007] The static mixer is connected to the four outlet ends of the three-way connector, a first mixing unit of the static mixer is aligned with a central axis of the three-way connector, one side of the mixing unit is aligned with the first outlet and the fourth outlet, and the other side of the mixing unit is aligned with the second outlet and the fourth outlet, and the static mixer and the three-way connector are fixed by a locking nut.

[0008] Further, a distance between the first outlet and the fourth outlet is approximately equal to a width of the first flow channel, a distance between the second outlet and the third outlet is approximately equal to a width of the second flow channel, and in the case that there is no interference between the flow channels, the distance between the outlets is reduced as much as possible, so that the material with a fast flow rate can quickly contact the material with a slow flow rate, and then the material with a fast flow rate can flow together with the material with a slow flow rate, and thus good mixing is achieved.

[0009] Further, a distance between the outlets on different sides of the mixing unit is less than a diameter of the mixing pipe, and the positions of the outlets on the two sides of the mixing unit should be symmetrical.

[0010] Further, the three-way connector described above adopts a streamline design, the streamline design adopts a curvature and a smooth transition as much as possible, and the branch flow channels adopt a flow channel design as short as possible, and such a flow channel structure can reduce flow resistance and pressure loss along the way of the materials.

[0011] Further, the first feeding device is composed of a first screw valve and a first cylinder, the first cylinder is connected with the first screw valve, and the outlet of the first screw valve is connected with the first inlet.

[0012] Further, the first feeding device is composed of a second cylinder and a second screw valve, the second cylinder is connected with the second screw valve, and the outlet of the second screw valve is connected with the second inlet.

[0013] Further, the total volume of the flow field of the first flow channel of the three-way connector and the connected branch flow channel and the total volume of the flow field of the second flow channel and the connected branch flow channel are equal, which can ensure the synchronization of the flow of materials A and B.

[0014] Further, the fluid volumes of the first branch flow channel and the third branch flow channel are equal, which can ensure the synchronization of the flow of materials A from the first outlet and the third outlet of the three-way connector and the consistency of the flow rate.

[0015] Further, the fluid volumes of the second branch flow channel and the fourth branch flow channel are equal, which can ensure the synchronization of the flow of materials B from the second outlet and the fourth outlet of the three-way connector and the consistency of the flow rate.

[0016] The second aspect is a method for realizing precise deposition of dual-component materials in an extrusion-based 3D printing process, comprising the following steps:

[0017] During the printing process, the speed distribution is allocated according to the ratio of materials A and B, so as to control the flow rates of materials A and B, material A flows into the first flow channel from the first inlet of the three-way connector, flows out from the first outlet and the third outlet after being branched, enters the static mixer, and is distributed to the left and right sides of the first mixing unit of the static mixer; material B flows into the second flow channel from the second inlet of the three-way connector, flows out from the second outlet and the fourth outlet after being branched, enters the static mixer, and is distributed to the left and right sides of the first mixing unit of the static mixer; then, after being mixed by more mixing units, it is extruded from the extrusion head, so as to be deposited on the printing platform, and finally a functionally graded material is obtained.

[0018] The beneficial effects of the above embodiments of the present application are as follows:

[0019] The manufacturing method disclosed in the present application overcomes the problem of different synchronization of material mixing in the dynamic variable ratio process of the original dual-component extrusion head, and improves the mixing efficiency of online mixing of dual-component materials; specifically, through the branching of the three-way connector, the two sides of the mixing unit can always contain fast-flowing materials and slow-flowing materials, which avoids the flow lag on one side caused by inconsistent flow, and reduces the mixing delay.

[0020] The previous two outlet three-way connectors, due to the two outlets are far apart, two materials from the outlet extrusion after flowing through the first mixing unit of Knices static mixer can be converged; the improved three-way connector, two materials from the corresponding outlet extrusion can be mixed, so as to advance the convergence time, with the flow of the shear mixing in advance, so as to improve the mixing uniformity and improve the mixing efficiency; Because two materials from the three-way connector outlet extrusion produces contact, when the ratio of materials A and B is 1:2, the material A with fast flow will produce relative motion with the material B with slow flow, so that the material A drives the material B to move, reducing the component flow error; BRIEF DESCRIPTION OF DRAWINGS

[0021] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description of the exemplary embodiments of the application, serve to explain the application, and do not constitute an improper limitation on the application.

[0022] Figure 1 is a schematic diagram of a two-component feeding device in the application;

[0023] Figure 2 is a partial enlarged schematic diagram of Figure 1 ;

[0024] Figure 3 is a schematic diagram of the internal flow channel of the three-way connector used in the application;

[0025] Figure 4 is a partial enlarged schematic diagram of Figure 3 ;

[0026] Fig. 5(a), Fig. 5(b), Fig. 5(c) are three views of the three-way connector used in the application;

[0027] Fig. 5(d) is a three-dimensional schematic diagram of the three-way connector used in the application;

[0028] In the figure: 1. first cylinder, 2. first screw valve, 3. second screw valve, 4. second cylinder, 5. three-way connector, 501. first inlet, 502. second inlet, 503. second flow channel, 504. first flow channel, 505. first outlet, 506. second outlet, 507. third outlet, 508. fourth outlet, 6. locking nut, 7. Kenics static mixer, 701. first mixing unit. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed description is exemplary, and is intended to provide further explanation of the application. Unless otherwise specified, all technical and scientific terms used in the application have the same meaning as generally understood by those skilled in the art to which the application belongs.

[0030] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0031] For the convenience of description, if the terms of "upper", "lower", "left", "right" appear in the present application, they only mean the same direction as the upper, lower, left and right directions of the drawings themselves, and do not limit the structure, but only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0032] As introduced in the background, there are deficiencies in the prior art. In order to solve the above technical problems, the present application proposes a device and method for realizing precise deposition of dual-component materials in 3D printing process.

[0033] In a typical embodiment of the present application, as shown in Figure 1 , Figure 2 , Figure 3 , Figure 4 , as shown in Fig. 5(a), Fig. 5(b), Fig. 5(c), Fig. 5(d), the device for realizing precise deposition of dual-component materials in 3D printing process disclosed in the embodiment comprises two sets of feeding devices, a three-way connector 5 and a Kniecs static mixer 7; the two sets of feeding devices are connected with the Kniecs static mixer 7 through the three-way connector 5; the specific implementation is as follows:

[0034] The two sets of feeding devices in the embodiment are each composed of a screw valve and a barrel, wherein the first set of feeding devices comprises a first barrel 1 and a first screw valve 2, the first barrel 1 is connected with the first screw valve 2, the outlet of the first screw valve 2 is connected with a first inlet 501 of the three-way connector 5, and the first set of feeding devices comprises a second barrel 4 and a second screw valve 2, the second barrel 4 is connected with the second screw valve 2, and the outlet of the second screw valve 2 is connected with a second inlet 502 of the three-way connector 5;

[0035] The above-mentioned three-way connector 5 has two inlets (first inlet 501 and second inlet 502) and four outlets (first outlet 505, second outlet 506, third outlet 507, and fourth outlet 508). The first inlet 501 corresponds to a first flow channel that is divided into two sub-flow channels, i.e., a first sub-flow channel and a third sub-flow channel. The first sub-flow channel corresponds to the first outlet 505, and the third sub-flow channel corresponds to the third outlet 507. The first outlet 505 is located on the left side of the Kniecs static mixer 7, and the third outlet 507 is located on the right side of the Kniecs static mixer 7. That is, the material A entering from the first inlet is divided into two paths, i.e., left and right paths. The second inlet 502 corresponds to a second flow channel that is also divided into two outlet flow channels, i.e., a second sub-flow channel and a fourth sub-flow channel. The second sub-flow channel corresponds to the second outlet 506, and the fourth sub-flow channel corresponds to the fourth outlet 508. The fourth outlet 508 is located on the left side of the first mixing unit of the Kniecs static mixer 7, and the second outlet 506 is located on the right side of the first mixing unit of the Kniecs static mixer 7. The material B entering from the second inlet is also divided into two paths, i.e., left and right paths. In the case where the flow rates of the materials A and B are inconsistent, the two outlets with faster flow rates are located on different sides, and the two outlets with slower flow rates are also located on different sides, so that the two outlets on the left side have one fast and one slow, and the two outlets on the right side also have one fast and one slow. This makes the speeds of the materials A and B on both sides substantially the same, ensuring uniform mixing of the materials A and B.

[0036] Further, the distance between the first outlet and the fourth outlet is approximately equal to the width of the first flow channel, and the distance between the second outlet and the third outlet is approximately equal to the width of the second flow channel. In the case where there is no interference between the flow channels, the distance between the outlets is minimized as much as possible, so that the material with a faster flow rate can quickly contact the material with a slower flow rate, and then the material with a faster flow rate can flow together with the material with a slower flow rate, thereby achieving good mixing.

[0037] The above-mentioned Kniecs static mixer 7 is connected to the four outlet ends of the three-way connector 5. The central axis of the first mixing unit 701 of the static mixer is aligned with the central axis of the three-way connector 5. One side of the mixing unit is aligned with the first outlet and the fourth outlet, and the other side of the mixing unit is aligned with the second outlet and the fourth outlet. The static mixer and the three-way connector are fixed by a locking nut.

[0038] Further, the above-mentioned three-way connector 5 adopts a streamlined design that uses the largest possible curvature and smooth transition. The divided flow channels use the shortest possible flow channel design. This flow channel structure can reduce the flow resistance and pressure loss of the material along the way.

[0039] Furthermore, the total volume of the first flow channel and the branch flow channel connected thereto of the three-way connector 5 is equal to the total volume of the second flow channel and the branch flow channel connected thereto, which can ensure the synchronization of the flow of materials A and B.

[0040] Furthermore, the fluid volumes of the first and third diverter channels are equal, which can ensure that material A flows out of the first and third outlets of the three-way connector synchronously and at a consistent outflow rate; the fluid volumes of the second and fourth diverter channels are equal, which can ensure that material B flows out of the second and fourth outlets of the three-way connector synchronously and at a consistent outflow rate;

[0041] Secondly, based on the above-mentioned device, this embodiment further proposes a method for achieving precise deposition of two-component materials in an extrusion-based 3D printing process, comprising the following steps:

[0042] Use Solidworks software to perform geometric modeling on the parts to be printed, and then export the model as an STL file;

[0043] Use the Arduino software to set up the Marlin firmware, turn on the hybrid module and open the virtual extruder, that is, set up dual extruders and a single extruder;

[0044] Use the software Repetier-Host to print and slice the geometric model and generate G-code;

[0045] Use software Repetier-Host to edit G-code for material component distribution and use color mixing instruction M165A U B V Switch the material ratio, where U and V are the ratio factors of material A and material B, respectively, and U + V = 1. Calculate the volume of the Kenics mixer to obtain mixing delay compensation. Test the material rheology to obtain the delay caused by viscous flow. Based on the total delay, calculate the spatial position of the compensation delay. Insert the mixing instruction M165 based on the compensated spatial position to switch the material ratio.

[0046] Import the G_code with material distribution into the printer for gradient printing;

[0047] The two screw valves in the printing process are allocated according to the proportion of materials A and B, so as to control the flow of materials A and B, then material A flows into the first flow channel from the first inlet of the three-way connector, flows out from the first outlet and the third outlet after being divided, enters the Kenics static mixer, and material A is allocated to the left and right sides of the first mixing unit; material B flows into the second flow channel from the second inlet of the three-way connector, flows out from the second outlet and the fourth outlet after being divided, enters the Kenics static mixer, and material B is allocated to the left and right sides of the first mixing unit; then after being mixed by more mixing units, it is extruded from the extrusion head, so as to be deposited on the printing platform, and finally the functional gradient material is obtained.

[0048] Further, the method is suitable for various multi-material 3D printing processes based on extrusion, and the embodiment is only used as an example of screw valve extrusion. When using air pressure extrusion, plunger extrusion or fused deposition modeling to form functional gradient materials by double components, the method can be used to improve the printing head. And the method is only used as an example of double components. When multiple components are printed, the flow channel can be increased to improve the scheme.

[0049] Finally, it should be noted that the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations.

[0050] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An apparatus for achieving precise deposition of dual component materials in a 3D printing process, comprising a first feed device, a second feed device, a tee connector, a static mixer; characterized in that, The three-way connector has a first inlet and a second inlet, the first inlet is communicated with the first feeding device, and the second inlet is communicated with the second feeding device; a first flow channel corresponding to the first inlet is divided into a first branch flow channel and a third branch flow channel, an outlet corresponding to the first branch flow channel is the first outlet, and an outlet corresponding to the third branch flow channel is the third outlet; a second flow channel corresponding to the second inlet is divided into a second branch flow channel and a fourth branch flow channel; an outlet corresponding to the second branch flow channel is the second outlet, and an outlet corresponding to the fourth branch flow channel is the fourth outlet; the first outlet and the fourth outlet are located on a first side of a first mixing unit of the static mixer, and the second outlet and the third outlet are located on a second side of the first mixing unit; the first side is opposite to the second side. The total volume of the flow field of the first flow channel and the branch flow channels connected thereto is equal to the total volume of the flow field of the second flow channel and the branch flow channels connected thereto; the distance between the first outlet and the fourth outlet is equal to the width of the first flow channel; and the distance between the second outlet and the third outlet is equal to the width of the second flow channel.

2. The apparatus for enabling precise deposition of bi-component material in a 3D printing process as claimed in claim 1, wherein, The volumes of the flow fields of the first branch flow channel and the third branch flow channel are equal.

3. The apparatus for enabling precise deposition of bi-component material in a 3D printing process as claimed in claim 1, wherein, The volumes of the flow fields of the second branch flow channel and the fourth branch flow channel are equal.

4. The apparatus for enabling precise deposition of bi-component materials in a 3D printing process as claimed in claim 1, wherein, The first feeding device is composed of a first screw valve and a first barrel, the first barrel is connected with the first screw valve, and the outlet of the first screw valve is connected with the first inlet.

5. The apparatus of claim 1, wherein, The first feeding device is composed of a second barrel and a second screw valve, the second barrel is connected with the second screw valve, and the outlet of the second screw valve is connected with the second inlet.

6. The apparatus of claim 1, wherein, The first mixing unit of the static mixer is aligned with the central axis of the three-way connector.

7. The apparatus of claim 1, wherein, The flow channel of the three-way connector adopts a streamlined design. 8.A method for realizing precise deposition of two-component materials in a 3D printing process, using the device for realizing precise deposition of two-component materials in a 3D printing process according to any one of claims 1-7, characterized in that, During the printing process, the rotational speed is distributed according to the ratio of materials A and B, so as to control the flow rates of materials A and B; material A flows into the first flow channel from the first inlet of the three-way connector, flows out from the first outlet and the third outlet after being divided, enters the static mixer, and is distributed to the left and right sides of the first mixing unit of the static mixer; material B flows into the second flow channel from the second inlet of the three-way connector, flows out from the second outlet and the fourth outlet after being divided, enters the static mixer, and is distributed to the left and right sides of the first mixing unit of the static mixer; then, after being mixed by more mixing units, the materials are extruded from the extrusion head, so as to be deposited on the printing platform, and finally, a functionally graded material is obtained.

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