A multi-material multi-process synchronous printing and sintering device and method

Abstract

The present application discloses a multi-material multi-process synchronous printing and sintering device, including a ring-shaped conveying platform, on which a polymer 3D printer, a functional material printer and a flash lamp sintering device are sequentially installed. A multi-material multi-process synchronous printing and sintering method includes the following steps: on the ring-shaped conveying platform, a polymer 3D printer, a functional material printer and a flash lamp sintering device are sequentially installed in a clockwise or counterclockwise manner and synchronously controlled; the printer and the flash lamp sintering device are fixed in position, and the ring-shaped conveying platform transports the printed body to be processed to the bottom of the relevant equipment. By integrating the additive manufacturing equipment and the flash lamp sintering equipment onto one platform, the present invention has the ability to sinter online without transferring to other platforms, and has high manufacturing efficiency; it can produce devices with complex geometric shapes and functions through multi-material and multi-process mixed printing, expand the use of manufacturing structures, and meet small-scale personalized production needs.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a multi-material multi-process synchronous printing and sintering device and method thereof. Background Art

[0002] Multi-material and multi-process hybrid printing is one of the future development directions in the field of additive manufacturing technology. Compared with single-material additive manufacturing, it can directly manufacture devices with complex shapes and multiple functions without assembly. The integration of metals, polymers and even ceramic materials in the same product is considered to be the most revolutionary aspect of additive manufacturing technology compared to traditional manufacturing technology. In additive manufacturing, functional materials can be used as signal transmission wires, electrode materials, sensor materials and heating elements, etc., which is of great significance to the realization of product functions. However, in multi-material additive manufacturing, functional materials are generally deposited in the form of ink. The solvents and organic additives must be removed through post-processing steps to form a continuous film or wire to realize their functions. Functional material inks and polymers usually have incompatible processing temperatures. How to selectively solidify and sinter the functional material ink on it without destroying the polymer matrix is ​​one of the difficulties in multi-material additive manufacturing. In addition, the most commonly used method at present is thermal sintering, that is, pausing printing, moving the printed object into an oven for sintering, and resuming the printing process after sintering. It involves platform transfer and has low manufacturing efficiency.

[0003] Therefore, achieving selective sintering of functional material inks on a polymer matrix to prepare devices with complex shapes and multiple functions, and having multiple devices working online simultaneously to improve manufacturing efficiency, is a research hotspot and technical challenge that needs to be overcome in industry and academia, and it also has potential value in teaching. To this end, we proposed a multi-material and multi-process synchronous printing and sintering device and method to solve the above problems. Summary of the invention

[0004] The present application provides an online sintering device and method for functional materials on a polymer matrix in hybrid printing, so as to realize the curing and sintering of functional material ink on a temperature-sensitive polymer matrix printed, and efficiently prepare functional devices with complex shapes. To achieve the above-mentioned invention objectives.

[0005] The present application provides a multi-material and multi-process synchronous printing and sintering device, comprising an annular conveying platform, on which a polymer 3D printer, a functional material printer and a flash lamp sintering device are sequentially installed, and the polymer 3D printer, the functional material printer and the flash lamp sintering device are sequentially arranged clockwise or counterclockwise along the annular conveying platform.

[0006] Preferably, the flash lamp sintering device uses a xenon lamp.

[0007] A multi-material multi-process synchronous printing and sintering method, comprising the following steps:

[0008] S1, on the ring conveying platform, the polymer 3D printer, the functional material printer and the flash lamp sintering device are installed in sequence in a clockwise or counterclockwise manner and synchronously controlled;

[0009] S2, adding a polymer matrix material to the polymer 3D printer, and adding a functional material ink to the functional material printer;

[0010] S3, the polymer 3D printer prints the polymer matrix material on the annular conveying platform to form a polymer matrix;

[0011] S4, the annular conveying platform starts to move the polymer matrix to the bottom of the functional material printer;

[0012] S5, the functional material printer prints functional material ink on the polymer matrix to form a mixed printed body;

[0013] S6, the annular conveying platform is started again to move the mixed printed body to the flash lamp sintering device;

[0014] S7, subjecting the mixed printed body to multiple cycles of flash lamp sintering treatment through the flash lamp sintering device;

[0015] S8, the annular conveying platform is started again to move the sintered mixed printed body to the polymer 3D printer, and prints polymer materials to encapsulate the above-mentioned printed device;

[0016] S9, if the device to be printed is multi-layered, the annular conveying platform (1) will continue to rotate, and the above steps S4-S8 will be repeated until the device preparation is completed.

[0017] Preferably, the polymer 3D printer, the functional material printer and the flash lamp sintering device can work simultaneously.

[0018] Preferably, the flash lamp sintering process is carried out by heating the sintered steel sheet with an energy density of 30-50 J / cm 2 The pulsed light treatment lasts for 8-40 seconds, and the cooling phase lasts for 15-60 seconds.

[0019] Preferably, the flash lamp sintering process is performed 1-5 times.

[0020] Preferably, the polymer matrix material includes photosensitive resins such as Vero and Tango series, engineering plastics such as ABS and PC, and bioplastics such as PLA and PCL.

[0021] Preferably, the printing methods of the functional material printer include inkjet printing (IJP), aerosol jet printing (AJP) and direct write printing (DIW).

[0022] Preferably, the functional material ink includes nanosilver ink, nanocopper ink, nanosilver wire ink, conductive polymer solution PEDOT:PSS, carbon nanotube ink and graphene ink.

[0023] It can be seen from the above technical scheme that the present application provides a multi-material and multi-process synchronous printing and sintering device and method thereof. When in use, a polymer 3D printer for printing polymer matrix materials, a functional material printer for printing functional material ink, and a flash lamp sintering device system can work simultaneously, and can be synchronously controlled by the same control system to improve manufacturing efficiency; taking the printing of three print bodies as an example, the print bodies are referred to as A, B, and C respectively; first, according to the designed model, polymer matrix A is printed with a polymer 3D printer; after the printing of polymer matrix A is completed, the annular conveying platform rotates to move polymer matrix A to the bottom of the functional material printer, at which time, the polymer 3D printer starts to print polymer matrix B; at the same time, the functional material printer prints a functional ink pattern on polymer matrix A to obtain a mixed print body A, and after the printing of polymer matrix B and mixed print body A is completed, the annular conveying platform rotates, and the mixed print body A is moved to the bottom of the xenon lamp of the flash lamp sintering system for sintering, and the polymer matrix B is moved to the bottom of the functional material printer to prepare a mixed print body B. At this time, the 3D printer prints the polymer matrix C, the functional material printer prints the mixed print body B on the polymer matrix B, and the flash lamp sintering device flash lamp sinters the mixed print body A; after the slowest program among the above three steps is completed, the annular conveying platform rotates, and the polymer 3D printer continues to print the polymer material until the preparation of device A is completed, and then the preparation of mixed print body B and mixed print body C is completed to achieve synchronous operation of each equipment.

[0024] Generally speaking, compared with the functional material printing and flash lamp sintering process, polymer matrix printing consumes a longer time. Therefore, after completing the corresponding polymer matrix printing, the annular conveying platform can rotate. In general, the annular conveying platform will operate after completing the longest step of the three steps of polymer matrix printing, functional material printing, and flash lamp sintering.

[0025] The present invention connects a 3D printer for printing polymer matrix materials, a printer for printing functional materials and a flash lamp sintering device through an annular crawler, so as to realize small-scale personalized production. The above-mentioned printer and sintering equipment are integrated on the same platform, and the printer for printing matrix materials, the printer for printing functional materials and the flash lamp sintering system can work at the same time, so the present invention can improve manufacturing efficiency.

[0026] In multi-material additive manufacturing, a key factor is to integrate the preparation of functional films or conductive lines in a way that is compatible with other technologies, that is, to minimize the conversion between manufacturing platforms. In flash sintering, nano-ink absorbs the wide-spectrum, high-energy pulsed light generated by the xenon lamp and heats up quickly. It has the ability to sinter online without transferring to other platforms (such as ovens), meeting the needs of fast, efficient, and highly integrated.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The device has both shape and function: Through the setting of polymer 3D printer, functional material printer and flash lamp sintering device, the integration of polymer and functional materials can be realized. According to the design requirements, device products with complex shapes and multiple functions can be printed, which reduces the production cycle of personalized products and quickly completes the assembly of the design;

[0029] 2. Online sintering: Through the setting of the ring conveying platform, the polymer 3D printer, functional material printer and flash lamp sintering equipment are integrated into an integrated system, realizing online sintering, avoiding the transfer of materials between different platforms, and improving manufacturing efficiency;

[0030] 3. High manufacturing efficiency: Through the setting of the ring conveying platform, the polymer 3D printer, functional material printer and flash lamp sintering equipment are integrated into an integrated system, and each device can work at the same time, further improving the manufacturing efficiency;

[0031] 4. Personalized production: Through the setting of polymer 3D printer, functional material printer and flash sintering device, products with complex shapes and different functions can be printed according to design requirements, without assembly, reducing the production cycle of products, which is conducive to small-scale personalized production;

[0032] 5. It can print out products with different structures and functions, which can be used in teaching. In experiments, the designs of different students can be quickly printed out for experiments, which is helpful for understanding on-site teaching.

[0033] In summary, the present invention has the ability to sinter online without transferring to other platforms, multiple devices work at the same time, and the manufacturing efficiency is high. It can directly manufacture product devices with different properties through multi-material mixed printing without assembly, meet small-scale personalized production, meet both production needs and teaching needs, and quickly produce designed products according to design drawings, so as to practice related designs, quickly meet the needs between different designs, convert multiple different designs into products, conduct case teaching, improve teaching quality from practice, and multiple devices work at the same time with high manufacturing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the implementation cases. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0035] Figure 1 This is a schematic diagram of the structure of a multi-material multi-process synchronous printing and sintering device proposed by the present invention;

[0036] In the picture: 1 annular conveying platform, 2 polymer 3D printer, 3 functional material printer, 4 flash lamp sintering device. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0038] See also Figure 1 , a multi-material multi-process synchronous printing and sintering device, including an annular conveying platform 1, a rotating platform or an annular crawler can be selected to realize the cyclic operation of the platform, the best matching station is four, namely two printing stations, a sintering station and a pickup station, to meet the production of personalized design from zero to one, the annular conveying platform 1 is sequentially installed with a polymer 3D printer 2, the types of the polymer 3D printer 2 include Polyjet technology and fused deposition manufacturing (FDM) and direct writing (DIW), a functional material printer 3 and a flash lamp sintering device 4, the printing methods of the functional material printer 3 include inkjet printing (IJP), aerosol jet (AJP) and direct writing Printing (DIW), the flash lamp sintering device 4 adopts a xenon lamp. During the flash lamp sintering, the nano ink absorbs the wide-spectrum, high-energy pulsed strong light generated by the xenon lamp and heats up quickly. The polymer 3D printer 2, the functional material printer 3 and the flash lamp sintering device 4 are arranged clockwise or counterclockwise along the annular conveying platform 1 in sequence. The above-mentioned printers and flash lamp sintering equipment are integrated on the same platform. The printer for printing the matrix material, the printer for printing the functional material, and the flash lamp sintering system can work at the same time, and have the ability to sinter online without transferring to other platforms (such as ovens), meeting the needs of fast, efficient, and highly integrated, and can realize small-scale personalized production.

[0039] A multi-material multi-process synchronous printing and sintering method, comprising the following steps:

[0040] S1, on the annular conveying platform 1, the polymer 3D printer 2, the functional material printer 3 and the flash lamp sintering device 4 are sequentially installed in a clockwise or counterclockwise manner and synchronously controlled, so that the polymer 3D printer 2, the functional material printer 3 and the flash lamp sintering device 4 can work simultaneously through the same control system to meet the requirements of fast and efficient production;

[0041] S2, adding polymer matrix materials to the polymer 3D printer 2, the polymer matrix materials include but are not limited to photosensitive resins Vero, Tango series, engineering plastics ABS, PC, bioplastics PLA, PCL, which meet the use of 3D printing, adding functional material ink to the functional material printer 3, the functional material ink includes nano silver ink, nano copper ink, nano silver wire ink, conductive polymer solution PEDOT:PSS, carbon nanotube ink and graphene ink, which can be used for electrodes, wires, sensor sensitive materials, heating, flash lamp sintering, the functional material ink absorbs the wide spectrum, high energy pulsed strong light generated by the xenon lamp to quickly heat up, and the solvent and organic additives in the ink are quickly removed;

[0042] S3, the polymer 3D printer 2 prints the polymer matrix material on the annular conveying platform 1 to form a polymer matrix. The 3D printing types selected for the printing of the polymer matrix material include Polyjet technology, fused deposition manufacturing (FDM) and direct writing (DIW). When printing, first use CAD software to make a three-dimensional software map, convert the three-dimensional view into an STL file, import the STL file into the control software of the functional material printer 3 for slicing, and then print it out layer by layer;

[0043] S4, the annular conveying platform 1 starts to move the polymer matrix to the bottom of the functional material printer 3, and the printing method of the functional material printer 3 includes but is not limited to inkjet printing (IJP), aerosol jet printing (AJP) and direct writing printing (DIW);

[0044] S5, the functional material printer 3 prints functional material ink on the polymer matrix to form a mixed printed body;

[0045] S6, the annular conveying platform 1 is started again to move the mixed printed body to the flash lamp sintering device 4;

[0046] S7, the mixed printed body is subjected to multiple cycles of flash lamp sintering treatment by the flash lamp sintering device 4, the flash lamp sintering device 4 uses a xenon lamp, and the flash lamp sintering treatment is performed by an energy density of 30-50 J / cm 2The pulsed strong light treatment lasts for 8-40s, and the cooling stage lasts for 15-60s. Depending on the functional material ink, the flash lamp sintering treatment is performed 1-5 times.

[0047] S8, the annular conveying platform 1 is started again to move the sintered mixed printed body to the polymer 3D printer 2, and prints polymer materials to encapsulate the above-mentioned printed device;

[0048] S9, if the device to be printed is multi-layered, the annular conveying platform 1 will continue to rotate, and the above steps S4-S8 will be repeated until the device preparation is completed, and finally the prepared functional device is taken out.

[0049] Example 1

[0050] FDM 3D printing PLA substrate, direct writing printing of nanosilver ink on the substrate and flash sintering to prepare conductive circuits, as follows:

[0051] Use CAD software to make a 3D software drawing, convert the 3D view into an STL file, and import the STL file into the printer's control software for slicing. The printing speed is set to 80mm / s, and the non-printing moving speed is set to 150mm / s. The printing size of the FDM 3D printer is 50*50*10mm 3 PLA substrate.

[0052] Direct-write printing is highly tolerant to the surface roughness of the substrate. Due to the limitation of FDM printing accuracy, silver wires are directly printed on the PLA substrate after printing. Repetier-Host software is used for slicing, and the printing speed is set to 20mm / s, the non-printing moving speed is 100mm / s, the filling density is 60%, and the needle diameter is 0.63mm.

[0053] The PLA material is not completely transparent and can absorb some pulse light. Therefore, after the mixed printing is completed, multiple cycles of sintering are used to avoid damaging the substrate by heating too fast or too high. The energy in the illumination stage is 40J / cm 2 , flash sintering for 10 seconds, cooling for 20 seconds, flash sintering for 10 seconds, cooling for 20 seconds, and finally flash sintering for 10 seconds to complete the mixed printing and corresponding sintering.

[0054] After sintering is completed, the cross section of the wire is measured using a scanning electron microscope (SEM) or an optical microscope, and the resistivity of the silver wire sintered by flash lamp sintering is calculated from the resistance value and the cross-sectional area. According to the previous experimental results and based on the above flash lamp sintering parameter settings, the resistivity of the silver wire after flash lamp sintering can be obtained, as shown in Appendix 1;

[0055] Table 1 After flash sintering, the resistivity of the flash sintered silver wire was measured

[0056] Sample 1 2 3 4 5 Resistivity (μΩ.cm) 88.27 82.19 85.31 81.45 75.03

[0057] Example 2

[0058] Polyjet 3D printed Gray60 substrate, inkjet printed PEDOT:PSS ink on the substrate and flash sintered to prepare the sensor as follows:

[0059] Use CAD software to make a 3D software drawing, convert the 3D view into an STL file, import the STL file into the printer's control software for slicing, and use a Polyjet 3D printer to print a 40*40*2mm size. 3 Gray60 substrate.

[0060] After the Gray60 substrate is printed, the PEDOT:PSS electrode is printed on it by inkjet. The viscosity of the PEDOT:PSS aqueous solution is adjusted to 6mPa·s, the surface tension is adjusted to 25mN·s, and filtered with a 0.22μm needle filter. A clean ink cartridge is added. The corresponding electrode pattern is drawn and the PEDOT:PSS conductive electrode is printed with an inkjet printer.

[0061] After the hybrid printing is completed, the flash lamp sintering is carried out. Since the light absorption rate of PEDOT:PSS and the substrate is relatively low, a relatively low energy is used for continuous treatment, that is, the energy in the illumination stage is 30J / cm 2 , flash lamp sintering for 30s, and the mixed printing and corresponding sintering are completed.

[0062] According to the previous experimental results and the above flash sintering parameter settings, the change of the resistance value of the PEDOT:PSS electrode during flash sintering with the sintering time can be obtained, as shown in Table 2. The resistance value is obtained by in-situ measurement during the flash sintering process. The surface resistance of the PEDOT:PSS film measured after flash sintering is less than 200Ω / □, which can be used for sensor preparation, etc.

[0063] Table 2 Changes of PEDOT:PSS electrode resistance with sintering time during flash lamp sintering

[0064] Time(s) 0 1 3 6 9 12 15 Resistance value(Ω) 105399 84263 49713 23140 1964 300 223 Time(s) 18 21 24 27 30 33 37 Resistance value(Ω) 193 180 178 175 173 169 164

[0065] Generally speaking, compared with the functional material printing and flash sintering process, polymer matrix printing takes longer time, so the ring track can rotate after the corresponding polymer matrix printing is completed. In general, the ring track moves after the longest step of the three steps of polymer matrix printing, functional material ink printing, and flash sintering is completed.

[0066] The product devices prepared by this method meet the production and use requirements. According to the design requirements, a variety of products with different properties can be quickly and personalized to meet the needs of fast, efficient and highly integrated.

[0067] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope of the present application is indicated by the claims.

[0068] It should be understood that the present application is not limited to the precise structure described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The above-described embodiments of the present application do not constitute a limitation on the scope of protection of the present application.

Claims

1. A multi-material multi-process synchronous printing and sintering method, characterized in that: Printing and sintering are performed using a multi-material multi-process synchronous printing and sintering device, the device comprising an annular conveying platform (1), on which a polymer 3D printer (2), a functional material printer (3) and a flash lamp sintering device (4) are sequentially installed, and the polymer 3D printer (2), the functional material printer (3) and the flash lamp sintering device (4) are sequentially arranged along the annular conveying platform (1) in a clockwise or counterclockwise manner; The method comprises the following steps: S1, on the annular conveying platform (1), a polymer 3D printer (2), a functional material printer (3) and a flash lamp sintering device (4) are sequentially installed in a clockwise or counterclockwise manner and synchronously controlled; S2, adding a polymer matrix material to the polymer 3D printer (2), and adding a functional material ink to the functional material printer (3); S3, the polymer 3D printer (2) prints the polymer matrix material on the annular conveying platform (1) to form a polymer matrix, and the 3D printing types selected for printing the polymer matrix material include Polyjet technology, fused deposition modeling (FDM) and direct writing (DIW); S4, the annular conveying platform (1) starts to move the polymer matrix to the bottom of the functional material printer (3), and the printing method of the functional material printer (3) includes inkjet printing (IJP), aerosol jet printing (AJP) and direct writing (DIW); S5, the functional material printer (3) prints functional material ink on the polymer matrix to form a mixed printed body; S6, the annular conveying platform (1) is started again to move the mixed printed body to the flash lamp sintering device (4); S7, subjecting the mixed printed body to multiple cycles of flash lamp sintering treatment through the flash lamp sintering device (4); S8, the annular conveying platform (1) is started again to move the sintered mixed printed body to the polymer 3D printer (2), and prints the polymer material to encapsulate the printed device; S9, if the device to be printed is multi-layered, the annular conveying platform (1) will continue to rotate, and the above steps S4-S8 will be repeated until the device preparation is completed.

2. The multi-material multi-process synchronous printing and sintering method according to claim 1, characterized in that: The flash lamp sintering device (4) adopts a xenon lamp.

3. The multi-material multi-process synchronous printing and sintering method according to claim 1, characterized in that: The polymer 3D printer (2), the functional material printer (3) and the flash lamp sintering device (4) are capable of working simultaneously.

4. The multi-material multi-process synchronous printing and sintering method according to claim 1, characterized in that: The flash lamp sintering process is carried out by using an energy density of 30-50 J / cm 2 The pulsed light treatment lasts for 8-40 seconds, and the cooling phase lasts for 15-60 seconds.

5. The multi-material multi-process synchronous printing and sintering method according to claim 1, characterized in that: The flash lamp sintering process is performed 1 to 5 times.

6. The multi-material multi-process synchronous printing and sintering method according to claim 1, characterized in that: The polymer matrix material includes photosensitive resin Vero, Tango series, engineering plastics ABS, PC, bioplastics PLA, PCL.

7. The multi-material multi-process synchronous printing and sintering method according to claim 1, characterized in that: The functional material ink includes nano silver ink, nano copper ink, nano silver wire ink, conductive polymer solution PEDOT:PSS, carbon nanotube ink and graphene ink.

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