Method and device for forming multi-bubble fusion foaming structure based on direct bubble writing

Abstract

The present invention relates to the technical field of porous foaming structure preparation, and discloses a method and device for forming a multi-bubble fused foaming structure based on direct bubble writing. The forming method is: according to the performance requirements of the desired foaming structure, determine the material and structural morphology of the foaming structure; prepare ink according to the material of the foaming structure; pass the ink into a number of forming nozzles, and use a direct bubble writing process to print layer by layer, so that the single-layer porous foaming structure corresponding to each layer is stacked and connected layer by layer to obtain a multi-bubble fused foaming structure. The present invention uses a direct bubble writing process to achieve the fusion of multiple bubbles. After obtaining a single-layer porous foaming structure, the next layer of foaming structure is stacked on the single-layer porous foaming structure, and the layers are stacked and connected layer by layer, thereby realizing controllable bubble regulation and continuous manufacturing, and obtaining a multi-bubble fused foaming structure, which solves the problem that the bubble morphology in the traditional porous structure manufacturing process is mostly disordered and uncontrollable, and the molding quality is poor.

Description

Technical Field

[0001] The invention relates to the technical field of porous foaming structure preparation, and in particular to a method and device for forming a multi-bubble fusion foaming structure based on direct bubble writing. Background Art

[0002] The porous structure of porous materials, such as resin-based porous materials, can be divided into macroscopic large pores and microscopic small pores. Among them, the macroscopic large pores can be adjusted by adjusting the process parameters of the manufacturing process and controlling the gap size during the layer-by-layer stacking and connection process to achieve the adjustment of the size and distribution of the macropores. However, the manufacture of microscopic pores is mostly achieved by adding heat-expandable microspheres to the material, and during the manufacturing process, the temperature is controlled within the volatilization range of the heat-expandable microspheres, and the heat-expandable microspheres evaporate into gas to achieve the manufacture of internal small pores.

[0003] However, the above method is limited in the types of materials it can be applied to. Due to the difficulty and cost of the preparation operation, it is difficult to form a porous material with controlled pores, resulting in the existing porous materials being mostly disordered porous materials. The material properties of disordered porous materials are uneven and the quality is uncontrollable. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a method and device for forming a multi-bubble fusion foaming structure based on direct bubble writing, so as to solve the problem that traditional porous materials are mostly prepared into disordered porous structures and the material properties and quality are uncontrollable.

[0005] The method and device for forming a multi-bubble fusion foaming structure based on direct bubble writing of the present invention are realized by the following technical solutions:

[0006] The present invention provides a method for forming a multi-bubble fusion foaming structure based on direct bubble writing, comprising the following steps:

[0007] Step 1, ink preparation:

[0008] According to the performance requirements of the desired foaming structure, the material and structural form of the foaming structure are determined; according to the determined material of the foaming structure, the corresponding ink is prepared.

[0009] Step 2: Direct bubble writing process to form a multi-bubble fusion foaming structure:

[0010] The ink is passed into several forming nozzles, and a direct bubble writing process is adopted to print layer by layer from bottom to top according to the structural morphology of the determined foaming structure, so that the single-layer porous foaming structures corresponding to each layer are stacked and connected layer by layer to obtain the multi-bubble fused foaming structure.

[0011] It should be noted that the preparation method of the present invention is not limited to a particular material, and the material and structural form of the foam structure that can meet the performance requirements of the foam structure material actually required can be selected and determined. The performance requirements include but are not limited to any one or more of mechanical properties, electrical conductivity and thermal conductivity.

[0012] The present invention is not limited to a particular ink. According to the material of the foaming structure actually determined, the corresponding ink for forming the bubble shell can be prepared. For example, the ink material used to form the porous structure of the present invention includes a pure resin material or a resin-based composite material. In some preferred embodiments of the present invention, the resin-based composite material includes a liquid-curable resin material and a solid filler. The solid filler includes but is not limited to one or more of ceramics, semiconductors, metal nanoparticles and carbon nanotubes. Among them, when preparing a foaming structure with requirements for mechanical properties, ceramics can be selected as a solid filler for preparing porous materials; when preparing a foaming structure with requirements for electromagnetic properties, carbon nanotubes and the like can be selected as solid fillers.

[0013] Since the ink prepared by the present invention needs to be used in the direct bubble writing process, the prepared ink should meet the basic requirements of the ink used in the direct bubble writing process, such as the prepared ink should have a low viscosity and be able to cure under ultraviolet light or heat source, wherein the low viscosity value means that the ink prepared by the present invention should have a certain self-fluidity, such as the flow rate of the ink used in the printing process is 0.01mL / min~300mL / min. Easy to cure means that the ink prepared by the present invention should be able to cure quickly under light and / or heat source.

[0014] In order to make the formulated ink meet the above viscosity requirements, in some preferred embodiments of the present invention, the ink also includes a surfactant, so as to adjust the viscosity of the ink by adding the surfactant. In some more preferred embodiments of the present invention, the surfactant used includes but is not limited to one or more of fatty acid glycerides, sucrose fatty acid esters, fatty acid sorbitan and polysorbate. It should be emphasized that the present invention does not limit the specific addition amount of the surfactant, as long as the flow rate of the formulated ink is 0.01mL / min~300mL / min.

[0015] In order to make the formulated ink easier to form bubbles and more conducive to curing, in some preferred embodiments of the present invention, the formulated ink also includes one or more of a photoinitiator and a thermal initiator to promote the rapid curing of the ink under the action of light and / or heat. In some more preferred embodiments of the present invention, the photoinitiator used includes but is not limited to one or more of 2-hydroxy-2-methyl-1-phenylpropanone and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; wherein 2-hydroxy-2-methyl-1-phenylpropanone is also called 1173, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is also called TPO.

[0016] It should also be noted that in order to ensure that the present invention can utilize the direct bubble writing process to prepare a porous foam structure with controllable bubble morphology by layer-by-layer manufacturing, the present invention preferably establishes a corresponding three-dimensional model according to the structural morphology of the determined foam structure; along the height direction of the three-dimensional model, the three-dimensional model is sliced ​​to form a plurality of parallel slice layers. Then, the printing path is determined according to the shape characteristics of the plurality of parallel slice layers in the three-dimensional model, and the data corresponding to the printing path is imported into the direct ink writing printing device, and then printed layer by layer in sequence, so that each of the slice layers is printed to obtain a corresponding single-layer porous foam structure, and after the previous single-layer porous foam structure is solidified, the substrate is controlled to descend, and then the next single-layer porous foam structure is solidified, so that a plurality of single-layer porous foam structures are stacked and connected layer by layer in sequence, so as to obtain the multi-bubble fused foam structure.

[0017] It should be emphasized that in order to achieve the control of the relative density, open-cell and / or closed-cell structure of the single-layer porous foam structure, the present invention introduces a regulating gas into each of the molding nozzles when printing each of the single-layer porous foam structures, so that the ink introduced into each of the molding nozzles is continuously output in the form of a single bubble under the gas pressure provided by the regulating gas, and a plurality of single bubbles simultaneously output from different molding nozzles fuse during the falling process to form a deformed single bubble, which is deposited on a substrate moving relative to the molding nozzle after being cured under ultraviolet light, and forms a single-layer porous foam structure after being cured. Among them, the transition between the open and closed cells in the foam structure can be controlled by the gas type of the regulating gas, and in some preferred embodiments of the present invention, the regulating gas is one or more of air, oxygen, nitrogen, helium and argon. The relative density can be controlled by air pressure.

[0018] Based on the above, it can be seen that in the present invention, the bubble morphology of each single-layer foaming structure is controllable and the single-layer shape is programmable, so the macroscopic shape of the porous foaming structure manufactured by stacking and connecting single-layer foaming structures layer by layer is also programmable, that is, the present invention can achieve control over the multi-bubble fused foaming structure from both microscopic and macroscopic aspects, thereby providing adjustability of the local mechanical, electrical and transmission properties of the porous solid, so that the preparation method of the present invention is suitable for directional customization of materials for pressure sensing, sound control, heat exchange, catalysis, mechanical energy absorption and / or other applications.

[0019] In order to facilitate the fusion and deformation of bubbles in the bubble flow ejected from each forming nozzle, in some preferred embodiments of the present invention, a plurality of the forming nozzles are centrally symmetrically distributed on the same horizontal plane, the output end of each of the forming nozzles points to the axial direction of the central axis of symmetry, and the angle between the output end of each of the forming nozzles and the axial direction of the central axis of symmetry is 20°~40°, so that each forming nozzle ejects the bubble flow at a certain angle, so that the bubbles in the bubble flows from different forming nozzles contact at the central axis position and fuse and deform into a deformed single bubble.

[0020] In order to facilitate the formation of bubbles by the ink and regulating gas introduced through the forming nozzle, in some preferred embodiments of the present invention, each of the forming nozzles is a core-shell nozzle, and the core-shell nozzle includes a core flow channel and an external flow channel; wherein the input end of the core flow channel is connected to the gas source for conveying the regulating gas; the input end of the external flow channel is connected to the ink source for conveying the ink; the output end of the external flow channel is arranged at the periphery of the output end of the core flow channel, so that the regulating gas forms a gas core, and the ink forms a liquid shell covering the gas core at the gas-liquid contact surface after contacting the gas core, and is continuously ejected from the forming nozzle in the form of a single bubble to form a stable single bubble flow. And in some more preferred embodiments of the present invention, the cross section of the output end of the external flow channel is V-shaped, and the output end of the external flow channel is coaxially arranged with the output end of the core flow channel to ensure that the ink output from the external flow channel can completely cover the output end of the core flow channel, thereby forming bubbles, and the single bubble is continuously output to form a bubble flow. After ejection, the flowable single bubble stream is subjected to a curing process to form a solid polymer shell and, after curing, is deposited on a substrate moving relative to the nozzle, thereby producing a polymeric porous solid having a predetermined geometry.

[0021] In some preferred embodiments of the present invention, the inner diameter ratio of the core flow channel to the outer flow channel in each molding nozzle is 0.5~1.5:0.8; and the distance between the output end of the outer flow channel and the output end of the core flow channel is 1 mm. For example, in some preferred embodiments of the present invention, the diameter of the core flow channel of the molding nozzle is 0.6mm±0.02mm, and the diameter of the outer flow channel is 0.8mm±0.02mm, so as to minimize the variation.

[0022] like Figure 1 As shown, the present invention takes into account that when one molding nozzle is used for preparation, a single nozzle produces a single bubble flow, and the shape of the bubbles in the single bubble flow is mainly as follows Figure 1 The spherical cap-shaped and elliptical closed-cell bubbles shown in the figure, and by increasing the gas pressure at the same ink flow rate, or reducing the ink flow rate at the same gas pressure, the bubble morphology tends to change from the monodisperse bubbles shown in the figure to the polydisperse bubbles, but the porous foaming structure formed after curing is still mainly prepared with single bubbles, and the single bubble structure is simple and circular, and the fusion between bubbles cannot be achieved. In order to achieve the preparation of a porous foaming structure with controllable bubble morphology through the generation and fusion of porous bubbles, in some preferred embodiments of the present invention, the number of molding nozzles used is ≥2. In some more preferred embodiments of the present invention, when two molding nozzles are used for preparation, the bubbles in the two bubble streams generated by two different molding nozzles will undergo the following Figure 2 The fusion shown is composed of Figure 2 It can be seen that the fusion forms include coalescence between bubbles, deformation between bubbles and emptying between bubbles, which causes irregular deformation of bubbles, thereby enabling the preparation of a foamed structure through the generation and fusion of multiple bubbles. In some more preferred embodiments of the present invention, when four forming nozzles are used for preparation, the bubbles generated from the four different forming nozzles will undergo the following Figure 3 The fusion shown is composed of Figure 3 It can be seen that the fusion forms include coalescence between multiple bubbles, deformation between multiple bubbles and emptying between multiple bubbles. Based on the above, it can be seen that the present invention can adjust the bubble fusion form by adjusting the number of forming nozzles according to the actual needs of the actual foaming structure required to meet the needs of preparing different foaming structures.

[0023] In some preferred embodiments of the present invention, the present invention takes into account that a single-layer porous foam structure with a thickness that is too small will result in too low a forming efficiency, while a single-layer porous foam structure with a thickness that is too large will result in an uncontrollable bubble structure. Therefore, in order to improve the forming efficiency while ensuring the controllable bubble structure, the thickness of each single-layer porous foam structure is 0.1mm~2mm.

[0024] In some preferred embodiments of the present invention, during the curing process, the ultraviolet light condition is provided by a plurality of ultraviolet light sources, and the light intensity of the ultraviolet light source is 200mW / cm -2 ~300mW / cm -2 , and the angle between the illumination direction of the ultraviolet light source and the falling direction of the deformed single bubble is 10°~30°, so that the ejected liquid bubble flow can be completely cured in situ under the ultraviolet light provided by the ultraviolet light source.

[0025] The present invention also provides a multi-bubble fusion foaming structure molding device based on direct bubble writing, which is constructed according to the multi-bubble fusion foaming structure molding method based on direct bubble writing, and is used in the multi-bubble fusion foaming structure molding method based on direct bubble writing. The multi-bubble fusion foaming structure molding device of the present invention includes a plurality of molding nozzles, a gas storage tank, a gas pressure controller, a syringe, a syringe pump and a UV curing device.

[0026] Among them, several molding nozzles are circumferentially arranged on the same horizontal plane, and each molding nozzle is respectively provided with a core flow channel and an external flow channel, so as to facilitate the introduction of regulated gas into the molding nozzle through the core flow channel and the introduction of prepared ink into the molding nozzle through the external flow channel.

[0027] In some preferred embodiments of the present invention, the gas storage tank stores regulated gas therein, and the output end of the gas storage tank is communicated with the core flow channel of each of the molding nozzles to provide regulated gas to each of the molding nozzles.

[0028] In some preferred embodiments of the present invention, the gas pressure controller is arranged between the gas storage tank and the molding nozzle to regulate the gas pressure of the regulating gas entering the molding nozzle so that the gas pressure is adjustable within the range of 0.1kPa~50kPa.

[0029] In some preferred embodiments of the present invention, the syringe is used to fill the formulated ink; and the output end of the syringe is connected to the external flow channel of each of the molding nozzles through a delivery tube to provide ink to each of the molding nozzles.

[0030] In some preferred embodiments of the present invention, the syringe pump is connected to the syringe signal to adjust the output flow rate of the ink in the syringe so that the output flow rate of the ink is adjustable within the range of 0.01 mL / min to 300 mL / min. This allows the syringe pump and the gas pressure controller to adjust the output flow rate of the ink and the gas pressure of the regulating gas, respectively, so as to adjust the shape and size of a single bubble.

[0031] In some preferred embodiments of the present invention, the ultraviolet curing device is disposed below a plurality of the molding nozzles to perform real-time curing on the bubble flows ejected from the molding nozzles.

[0032] In some preferred embodiments of the present invention, the multi-bubble fusion foaming structure forming device further comprises a substrate moving device, which is arranged below the plurality of the forming nozzles and below the ultraviolet curing device, and is used to place a substrate and move the substrate relative to the plurality of the forming nozzles, so that the solidified bubble flow is deposited on the substrate placed on the substrate moving device and forms the multi-bubble fusion foaming structure. In some preferred embodiments of the present invention, the moving speed of the substrate relative to the forming nozzle is 1 mm / s to 50 mm / s.

[0033] In some preferred embodiments of the present invention, the multi-bubble fusion foaming structure forming device further includes a nozzle control device, which includes a mounting bracket for installation in a printing device; the mounting bracket is provided with a plurality of guide rails along a circumferential array; a slider is slidably connected in each of the guide rails, and an adjustable connector is bolted to each of the sliders, and the adjustable connector is T-shaped. A plurality of the forming nozzles are respectively provided at one end of the corresponding adjustable connector by bolts.

[0034] It should be noted that the present invention particularly sets the adjustable connector as a T-shaped structure, so that the adjustable connector has three connection ends, one of which can be set on the corresponding slider by bolts, one connection end can be used for the corresponding molding nozzle to be installed by bolts, and the other connection end can be used for the corresponding UV curing device to be connected. Thus, the installation angle of the adjustable connector can be adjusted by adjusting the bolts connecting the adjustable connector and the slider, and the angle adjustment and angle fixation of the adjustable connector can be achieved by tightening the bolts after adjusting to the required angle. By adjusting the bolts connecting the molding nozzle and the adjustable connector to the required angle and tightening the bolts, the angle adjustment and angle fixation of the molding nozzle can be achieved. For example, the angle between the output end of the molding nozzle 1 and the axial direction of the central symmetry axis can be adjusted to 20°~40°. In addition, the corresponding parts can be installed or disassembled according to the actual number of molding nozzles required, and the operation is simple and convenient.

[0035] In order to facilitate the installation of the UV curing device on the adjustable connecting member, in some preferred embodiments of the present invention, the UV curing device includes a plurality of UV curing units and a plurality of UV curing unit mounting members. Among them, the plurality of UV curing unit mounting members are respectively installed at the other end of the corresponding adjustable connecting member by bolts, and the plurality of UV curing units are respectively installed on the corresponding plurality of UV curing unit mounting members, so that the plurality of UV curing units are respectively located under the corresponding forming nozzles, and can be fixed by adjusting the angle between the UV curing unit mounting member and the adjustable connecting member, thereby achieving the fixing of the angle of the UV curing unit. For example, the angle of the UV curing unit can be adjusted so that the angle between the illumination direction of the UV light source and the falling direction of the deformed single bubble is 10°~30°, so that the plurality of UV curing units can respectively perform real-time curing on the bubble flow ejected from the corresponding forming nozzle.

[0036] In some preferred embodiments of the present invention, during the printing process, the present invention can realize the printing of a single-layer porous foam structure by adjusting the position of the substrate through the substrate moving device, wherein when adjusting the movement of the substrate, the movement speed of the substrate relative to the forming nozzle can be selected from any speed within the range of 1mm / s to 50mm / s. The present invention can also realize the printing of a single-layer porous foam structure by adjusting the position of the slider in each guide rail so that the slider drives a plurality of the forming nozzles to move accordingly.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention determines the morphology of the porous structure through the required structural performance, and after the configuration of the ink is completed, the ink is passed into several molding nozzles, and the fusion of multiple bubbles is realized through the direct bubble writing process. After the fused bubbles are solidified, they are sequentially deposited on a substrate moving relative to the molding nozzle to form a bubble layer. After solidification, a single-layer porous foaming structure is obtained, and the next layer of the required foaming structure is stacked on the single-layer porous foaming structure, so that the single-layer porous foaming structures corresponding to each layer are stacked and connected layer by layer, that is, a multi-bubble fusion foaming structure that meets the performance requirements of the required foaming structure is obtained. In addition, the present invention controls the bubble morphology and bubble fusion mode of the single layer by real-time adjustment of the gas pressure and the ink flow rate, so as to control the degree of continuous bubble generation and fusion and real-time solidification molding, and then can realize the control of the morphology of the formed porous structure, thereby realizing the controllable manufacturing of the performance of the final porous structure, and the formed porous structure has high molding quality, that is, the molding method of the present invention can realize the manufacturing of the required porous structure according to the realization requirements, and solves the problem of uncontrollable bubble morphology and poor molding quality in the traditional porous structure manufacturing process.

[0039] The bubble morphology of the porous foam structure of the present invention utilizes the different forms and combinations of single-layer bubbles in the manufacturing process to stack and connect the solidified single-layer foam structure layer by layer to achieve a solid porous foam structure with controllable bubble morphology. The morphology of the single-layer bubble can be determined by different forms of a single bubble flow or different combinations of multiple bubble flows, and the morphology of the single-layer bubble can be directly controlled by adjusting the number and intersection angle of the forming nozzles used to generate the bubbles, and the bubble morphology is controllable and can be adjusted in real time. Manufacturing. In the entire manufacturing process of the porous foam structure, the pressure of the gas used to form the inside of the forming nozzle and the flow rate of the ink used to form the external holes are directly regulated by the injection pump and the gas pressure controller.

[0040] The present invention forms bubbles inside a customized molding nozzle by controlling the ink used to mold a solid structure and the gas that forms an internal cavity. The forms of the bubbles can also be divided into monodisperse bubbles of a single bubble flow and polydisperse bubbles of multiple forms, as well as the coalescence, emptying and deformation of bubbles of multiple bubble flows. The fusion of the bubbles is determined by the number and spacing of the customized molding nozzles and the angle at the intersection. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the morphological changes of bubbles in a single bubble flow when one forming nozzle is used for preparation in the present invention.

[0042] Figure 2 This is a schematic diagram of the change in the morphology of bubbles when two bubble flows merge when two forming nozzles are used for preparation in the present invention.

[0043] Figure 3 This is a schematic diagram of the morphological changes of bubbles when four bubble flows merge when four forming nozzles are used for preparation in the present invention.

[0044] Figure 4 It is a schematic structural diagram of the molding nozzle of the present invention.

[0045] Figure 5 It is a schematic structural diagram of the multi-bubble fusion foaming structure forming device of the present invention.

[0046] Figure 6 It is a schematic structural diagram of the nozzle control device of the present invention. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0049] The present invention takes the preparation of a structure with some graded mechanical properties as an example, and is clearly and completely described in combination with the technical solutions in the following embodiments.

[0050] Example 1

[0051] This embodiment provides a method for forming a multi-bubble fused foaming structure based on direct bubble writing, comprising the following steps:

[0052] Step 1, ink preparation:

[0053] 1.1) Weigh the raw materials for ink preparation according to the following mass percentage ratio:

[0054] Pyrogallol 0.2wt%, triallyl isocyanurate 40wt%, pentaerythritol tetrakismercaptopropionate 28wt%, dipentaerythritol hexa(3-mercaptopropionate) 28wt%, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide 3.8wt%.

[0055] In this embodiment, pyrogallol is used as a free radical inhibitor to stabilize the ink formula, triallyl isocyanurate is used as a co-crosslinking agent for free radical reaction crosslinking, pentaerythritol tetramercaptopropionate is used as one of the monomers for the crosslinking reaction, dipentaerythritol hexa(3-mercaptopropionate) is used as one of the monomers for the crosslinking reaction, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is used as a photoinitiator for the crosslinking reaction.

[0056] Since the ink of this embodiment does not contain water solvent, its viscosity is higher than that of traditional water-based photocurable ink, the surface tension is large when bubbles merge, and the bubble combining effect is good.

[0057] 1.2) Dissolve the weighed pyrogallol in triallyl isocyanurate, and then dissolve it in pentaerythritol tetramercaptopropionate, dipentaerythritol hexa(3-mercaptopropionate) and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and mix well to obtain ink.

[0058] Step 2: Direct bubble writing process to form a multi-bubble fusion foaming structure:

[0059] 2.1) Determine the printing path based on the structural morphology of the foamed structure:

[0060] According to the determined structural form of the foaming structure, a corresponding three-dimensional model is established; along the height direction of the three-dimensional model, the three-dimensional model is sliced ​​to form a plurality of parallel slice layers. Then, according to the shape characteristics of the plurality of parallel slice layers in the three-dimensional model, a single-layer printing path of each geometric shape is determined.

[0061] 2.2) Program the single-layer printing path of each geometric shape in the form of a Gcode script, and load its corresponding data to the 3D printer through an SD card. Among them, the Gcode script is also called a G-code script, which is a language used for 3D printers and CAD / CAM software for CNC machining. The Gcode script usually contains instructions for the positioning of geometric shapes, cutting paths, and heating control.

[0062] 2.3) This embodiment uses 4 Figure 4 The core-shell nozzle shown is used as a forming nozzle 1, and each forming nozzle 1 includes a core flow channel 11 and an external flow channel 12; the diameter of the core flow channel 11 is 0.6mm, the diameter of the external flow channel 12 is 0.8mm, and the distance between the output end of the core flow channel 11 and the output end of the external flow channel 12 is 1mm. The four forming nozzles 1 are centrally symmetrically distributed on the same horizontal plane, and the output end of each forming nozzle 1 points to the axial direction of the central symmetry axis, and the angle between the output end of each core-shell nozzle and the axial direction of the central symmetry axis is 30°. The position of the core-shell nozzle is adjusted so that the bubbles extruded from each nozzle can intersect at a coalescence point to complete the fusion of the bubbles, and the vertical distance between the position of the fusion point and the nozzle mouth is 10mm.

[0063] 2.4) Connect the prepared ink to the input end of the external flow channel 12, and connect the air to the input end of the core flow channel 11 to control the ink flow rate to be stable at 3mL / min, and continuously adjust the gas pressure range of 18kPa until the bubbles form the desired fusion form, place the substrate 10cm below the nozzle, and start printing layer by layer according to the printing path of each layer. Apply ultraviolet light to the bubble fusion point to make the fused bubbles at 200mW / cm -2 ~300mW / cm -2 The sample was cured under a light intensity of 100 nm. Within 5 minutes after the cured fused bubbles were deposited on the substrate, they were irradiated with unfiltered UV light for 30 s to ensure that the sample was completely cured to form the first single-layer porous foam structure.

[0064] 2.5) After controlling the distance between the surface of the first single-layer porous foam structure and the bottom of the nozzle to 10 cm, repeat the operation of the above step 2.4) to form a second single-layer porous foam structure on the surface of the first single-layer porous foam structure, and repeat multiple times until the desired structure is formed, that is, a multi-bubble fused foam structure is obtained.

[0065] 2.6) Take out the prepared multi-bubble fusion foaming structure, tidy up the equipment, turn off the power, and disconnect and tidy up the pipes connecting the two ends of the molding nozzle 1.

[0066] Example 2

[0067] This embodiment provides a method for forming a multi-bubble fused foaming structure based on direct bubble writing, comprising the following steps:

[0068] Step 1, ink preparation:

[0069] 1.1) Weigh the raw materials for ink preparation according to the following mass percentage ratio:

[0070] Pyrogallol 0.2wt%, triallyl isocyanurate 40wt%, pentaerythritol tetrakismercaptopropionate 28wt%, dipentaerythritol hexa(3-mercaptopropionate) 28wt%, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide 3.8wt%.

[0071] In this embodiment, pyrogallol is used as a free radical inhibitor to stabilize the ink formula, triallyl isocyanurate is used as a co-crosslinking agent for free radical reaction crosslinking, pentaerythritol tetramercaptopropionate is used as one of the monomers for the crosslinking reaction, dipentaerythritol hexa(3-mercaptopropionate) is used as one of the monomers for the crosslinking reaction, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is used as a photoinitiator for the crosslinking reaction.

[0072] 1.2) Dissolve the weighed pyrogallol in triallyl isocyanurate, and then dissolve it in pentaerythritol tetramercaptopropionate, dipentaerythritol hexa(3-mercaptopropionate) and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and mix well to obtain ink.

[0073] Step 2: Direct bubble writing process to form a multi-bubble fusion foaming structure:

[0074] 2.1) According to the determined structural morphology of the foaming structure, a corresponding three-dimensional model is established; along the height direction of the three-dimensional model, the three-dimensional model is sliced ​​to form a plurality of parallel slice layers. Then, a single-layer printing path of each geometric shape is determined according to the shape characteristics of the plurality of parallel slice layers in the three-dimensional model.

[0075] 2.2) Write the single-layer printing path of each geometric shape in the form of a Gcode script, and load the data corresponding to the written Gcode script into the 3D printer through the SD card.

[0076] 2.3) This embodiment uses 4 Figure 4 The core-shell nozzle shown is used as a forming nozzle 1, and each forming nozzle 1 includes a core flow channel 11 and an external flow channel 12; the diameter of the core flow channel 11 is 0.6mm, the diameter of the external flow channel 12 is 0.8mm, and the distance between the output end of the core flow channel 11 and the output end of the external flow channel 12 is 1mm. The four forming nozzles 1 are centrally symmetrically distributed on the same horizontal plane, and the output end of each forming nozzle 1 points to the axial direction of the central symmetry axis, and the angle between the output end of each forming nozzle 1 and the axial direction of the central symmetry axis is 30°. The position of the core-shell nozzle is adjusted so that the bubbles extruded from each nozzle mouth can intersect at a coalescence point to complete the fusion of the bubbles, and the vertical distance between the position of the fusion point and the nozzle mouth is 10mm.

[0077] 2.4) Connect the prepared ink to the input end of the external flow channel 12, and connect the air to the input end of the core flow channel 11 to control the ink flow rate to be stable at 3mL / min, and continuously adjust the gas pressure range of 20kPa until the bubbles form the desired fusion form, place the substrate 10cm below the nozzle, and start printing layer by layer according to the printing path of each layer. Apply ultraviolet light at the bubble fusion point to make the fused bubbles at 200mW / cm -2 ~300mW / cm -2 The sample was cured under a light intensity of 100 nm. Within 5 minutes after the cured fused bubbles were deposited on the substrate, they were irradiated with unfiltered UV light for 30 s to ensure that the sample was completely cured to form the first single-layer porous foam structure.

[0078] 2.5) After controlling the distance between the surface of the first single-layer porous foam structure and the bottom of the nozzle to 10 cm, repeat the operation of the above step 2.4) to form a second single-layer porous foam structure on the surface of the first single-layer porous foam structure, and repeat multiple times until the desired structure is formed, that is, a multi-bubble fused foam structure is obtained.

[0079] 2.6) Take out the prepared multi-bubble fusion foaming structure, tidy up the equipment, turn off the power, and disconnect and tidy up the pipes connecting the two ends of the molding nozzle 1.

[0080] Example 3

[0081] This embodiment provides a method for forming a multi-bubble fused foaming structure based on direct bubble writing, comprising the following steps:

[0082] Step 1, ink preparation:

[0083] 1.1) Weigh the raw materials for ink preparation according to the following mass percentage ratio:

[0084] Pyrogallol 0.2wt%, triallyl isocyanurate 40wt%, pentaerythritol tetrakismercaptopropionate 28wt%, dipentaerythritol hexa(3-mercaptopropionate) 28wt%, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide 3.8wt%.

[0085] In this embodiment, pyrogallol is used as a free radical inhibitor to stabilize the ink formula, triallyl isocyanurate is used as a co-crosslinking agent for free radical reaction crosslinking, pentaerythritol tetramercaptopropionate is used as one of the monomers for the crosslinking reaction, dipentaerythritol hexa(3-mercaptopropionate) is used as one of the monomers for the crosslinking reaction, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is used as a photoinitiator for the crosslinking reaction.

[0086] 1.2) Dissolve the weighed pyrogallol in triallyl isocyanurate, and then dissolve it in pentaerythritol tetramercaptopropionate, dipentaerythritol hexa(3-mercaptopropionate) and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and mix well to obtain ink.

[0087] Step 2: Direct bubble writing process to form a multi-bubble fusion foaming structure:

[0088] 2.1) According to the determined structural morphology of the foaming structure, a corresponding three-dimensional model is established; along the height direction of the three-dimensional model, the three-dimensional model is sliced ​​to form a plurality of parallel slice layers. Then, a single-layer printing path of each geometric shape is determined according to the shape characteristics of the plurality of parallel slice layers in the three-dimensional model.

[0089] 2.2) Write the single-layer printing path of each geometric shape in the form of a Gcode script, and load the data corresponding to the written Gcode script into the 3D printer through the SD card.

[0090] 2.3) This embodiment uses 4 Figure 4 The core-shell nozzle shown is used as a forming nozzle 1, and each forming nozzle 1 includes a core flow channel 11 and an external flow channel 12; the diameter of the core flow channel 11 is 0.6mm, the diameter of the external flow channel 12 is 0.8mm, and the distance between the output end of the core flow channel 11 and the output end of the external flow channel 12 is 1mm. The four forming nozzles 1 are centrally symmetrically distributed on the same horizontal plane, and the output end of each forming nozzle 1 points to the axial direction of the central symmetry axis, and the angle between the output end of each forming nozzle 1 and the axial direction of the central symmetry axis is 30°. The position of the forming nozzle 1 is adjusted so that the bubbles extruded from each nozzle mouth can intersect at a coalescence point to complete the fusion of the bubbles, and the vertical distance between the position of the fusion point and the nozzle mouth is 10mm.

[0091] 2.4) Connect the prepared ink to the input end of the external flow channel 12, and connect the air to the input end of the core flow channel 11 to control the ink flow rate to be stable at 3mL / min, and continuously adjust the gas pressure range of 22kPa until the bubbles form the desired fusion form, place the substrate 10cm below the nozzle, and start printing layer by layer according to the printing path of each layer. Apply ultraviolet light at the bubble fusion point to make the fused bubbles at 200mW / cm -2 ~300mW / cm -2 The sample was cured under a light intensity of 100 nm. Within 5 minutes after the cured fused bubbles were deposited on the substrate, they were irradiated with unfiltered UV light for 30 s to ensure that the sample was completely cured to form the first single-layer porous foam structure.

[0092] 2.5) After controlling the distance between the surface of the first single-layer porous foam structure and the bottom of the nozzle to 10 cm, repeat the operation of the above step 2.4) to form a second single-layer porous foam structure on the surface of the first single-layer porous foam structure, and repeat multiple times until the desired structure is formed, that is, a multi-bubble fused foam structure is obtained.

[0093] 2.6) Take out the prepared multi-bubble fusion foaming structure, tidy up the equipment, turn off the power, and disconnect and tidy up the pipes connecting the two ends of the molding nozzle 1.

[0094] Example 4

[0095] This embodiment provides a method for forming a multi-bubble fused foaming structure based on direct bubble writing, comprising the following steps:

[0096] Step 1, ink preparation:

[0097] 1.1) Weigh the raw materials for ink preparation according to the following mass percentage ratio:

[0098] Pyrogallol 0.2wt%, triallyl isocyanurate 40wt%, pentaerythritol tetrakismercaptopropionate 28wt%, dipentaerythritol hexa(3-mercaptopropionate) 28wt%, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide 3.8wt%.

[0099] In this embodiment, pyrogallol is used as a free radical inhibitor to stabilize the ink formula, triallyl isocyanurate is used as a co-crosslinking agent for free radical reaction crosslinking, pentaerythritol tetramercaptopropionate is used as one of the monomers for the crosslinking reaction, dipentaerythritol hexa(3-mercaptopropionate) is used as one of the monomers for the crosslinking reaction, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide is used as a photoinitiator for the crosslinking reaction.

[0100] 1.2) Dissolve the weighed pyrogallol in triallyl isocyanurate, and then dissolve it in pentaerythritol tetramercaptopropionate, dipentaerythritol hexa(3-mercaptopropionate) and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and mix well to obtain ink.

[0101] Step 2: Direct bubble writing process to form a multi-bubble fusion foaming structure:

[0102] 2.1) According to the determined structural morphology of the foaming structure, a corresponding three-dimensional model is established; along the height direction of the three-dimensional model, the three-dimensional model is sliced ​​to form a plurality of parallel slice layers. Then, a single-layer printing path of each geometric shape is determined according to the shape characteristics of the plurality of parallel slice layers in the three-dimensional model.

[0103] 2.2) Write the single-layer printing path of each geometric shape in the form of a Gcode script, and load the data corresponding to the written Gcode script into the 3D printer through the SD card.

[0104] 2.3) This embodiment uses 4 Figure 4The core-shell nozzle shown is used as a forming nozzle 1, and each forming nozzle 1 includes a core flow channel 11 and an external flow channel 12; the diameter of the core flow channel 11 is 0.6mm, the diameter of the external flow channel 12 is 0.8mm, and the distance between the output end of the core flow channel 11 and the output end of the external flow channel 12 is 1mm. The four forming nozzles 1 are centrally symmetrically distributed on the same horizontal plane, and the output end of each forming nozzle 1 points to the axial direction of the central symmetry axis, and the angle between the output end of each forming nozzle 1 and the axial direction of the central symmetry axis is 30°. The position of the forming nozzle 1 is adjusted so that the bubbles extruded from each nozzle mouth can intersect at a coalescence point to complete the fusion of the bubbles, and the vertical distance between the position of the fusion point and the nozzle mouth is 10mm.

[0105] 2.4) Connect the prepared ink to the input end of the external flow channel 12, and connect the air to the input end of the core flow channel 11 to control the ink flow rate to be stable at 3mL / min, and continuously adjust the gas pressure range of 24kPa until the bubbles form the desired fusion form, place the substrate 10cm below the nozzle, and start printing layer by layer according to the printing path of each layer. Apply ultraviolet light to the bubble fusion point to make the fused bubbles at 200mW / cm -2 ~300mW / cm -2 The sample was cured under a light intensity of 100 nm. Within 5 minutes after the cured fused bubbles were deposited on the substrate, they were irradiated with unfiltered UV light for 30 s to ensure that the sample was completely cured to form the first single-layer porous foam structure.

[0106] 2.5) After controlling the distance between the surface of the first single-layer porous foam structure and the bottom of the nozzle to 10 cm, repeat the operation of the above step 2.4) to form a second single-layer porous foam structure on the surface of the first single-layer porous foam structure, and repeat multiple times until the desired structure is formed, that is, a multi-bubble fused foam structure is obtained.

[0107] 2.6) Take out the prepared multi-bubble fusion foaming structure, tidy up the equipment, turn off the power, and disconnect and tidy up the pipes connecting the two ends of the molding nozzle 1.

[0108] Example 5

[0109] See also Figure 5 This embodiment provides a multi-bubble fusion foaming structure forming device based on direct bubble writing. The multi-bubble fusion foaming structure forming device of this embodiment is constructed according to the multi-bubble fusion foaming structure forming method based on direct bubble writing of the present invention, and is used in the multi-bubble fusion foaming structure forming method based on direct bubble writing of any one of the above embodiments 1 to 4. Figure 5As shown, the multi-bubble fusion foaming structure molding device of this embodiment includes a plurality of molding nozzles 1, a gas storage tank 2, a gas pressure controller 3, a syringe 4, an injection pump 5, a UV curing device 7, a high-speed camera 8, a substrate moving device 9 and a control device 10.

[0110] In this embodiment, a plurality of molding nozzles 1 are circumferentially arranged on the same horizontal plane, and each molding nozzle 1 is respectively provided with a core flow channel 11 and an external flow channel 12. The core flow channel 11 is connected to the output end of the gas storage tank 2 through the gas delivery pipe 21, so as to facilitate the introduction of the regulated gas into the molding nozzle 1 through the core flow channel 11. The external flow channel 12 is connected to the output end of the injector 4 through the delivery pipe 41, so as to introduce the prepared ink into the molding nozzle 1 through the external flow channel 12, so as to make the regulated gas as the core gas and the ink as the liquid shell to form a bubble flow.

[0111] In this embodiment, the gas storage tank 2 stores a regulated gas to provide the regulated gas to each of the forming nozzles 1 for supplying the core gas for forming bubbles. The gas storage tank 2 can be a gas storage tank 2 storing one or more of air, oxygen, nitrogen, helium and argon according to actual needs.

[0112] In this embodiment, the gas pressure controller 3 is disposed between the gas storage tank 2 and the molding nozzle 1, so as to adjust the gas pressure of the regulating gas entering the molding nozzle 1. In order to facilitate adjusting the gas pressure of the core gas by adjusting the gas pressure controller 3, the gas pressure controller 3 of this embodiment is connected to the control device 10 by electrical signals, so as to realize the control of the electronic pressure controller by the control device 10, thereby realizing the adjustment of the gas pressure.

[0113] In this embodiment, the syringe 4 is used to fill the prepared ink to provide ink to the plurality of molding nozzles 1, and to supply the liquid shell ink for forming bubbles. In order to facilitate the adjustment of the flow rate of the ink in the syringe 4, the syringe pump 5 is connected to the syringe 4 by signal in this embodiment, so as to realize the control of the output flow rate of the ink in the syringe 4 through the syringe pump 5, so as to realize the adjustment of the output flow rate of the ink and the gas pressure of the regulating gas through the syringe pump 5 and the gas pressure controller 3, respectively, so as to realize the adjustment of the shape and size of a single bubble.

[0114] In this embodiment, the ultraviolet curing device 7 is disposed below a plurality of the forming nozzles 1 , and is used for real-time curing of the fused deformed single bubble flows ejected from the forming nozzles 1 .

[0115] In this embodiment, the high-speed camera 8 is arranged below the molding nozzle 1, and the high-speed camera 8 is electrically connected to the control device 10 to monitor and observe in real time the shape and bubble fusion of the bubbles generated at the molding nozzle 1 and the lower end of the nozzle adjustment device, thereby facilitating the adjustment of the corresponding gas pressure and ink flow rate according to the shape and bubble fusion to ensure the desired bubble fusion effect.

[0116] In a preferred embodiment of the present invention, the multi-bubble fusion foaming structure molding device also includes a substrate moving device 9, which is arranged below the plurality of molding nozzles 1 and below the ultraviolet curing device 7, and is used to place a substrate and move the substrate relative to the plurality of molding nozzles 1, so that the solidified bubble flow is deposited on the substrate placed on the substrate moving device 9 and forms the multi-bubble fusion foaming structure.

[0117] In a preferred embodiment of the present invention, the control device 10 used is a MATLAB control system, and the electronic pressure controller used is an Alicat Scientific electronic pressure controller.

[0118] In a preferred embodiment of the present invention, the syringe 4 used is a 30 mL syringe 4 with a Luer lock, the injection pump 5 used is NE-8000, and the output end of the syringe 4 is connected to the input end of the external flow channel 12 of the PEEK tube into the molding nozzle 1 by using a standard Luerlok assembly.

[0119] In a preferred embodiment of the present invention, the high-speed camera 8 is an Olympus i-speed 2CDU high-speed camera, which is set to a 50 μs shutter time to monitor a series of bubbles in real time during the printing process. The high-speed video is run at a speed of 2000 frames per second and uses a bright light source LA vision for bright field illumination.

[0120] In a preferred embodiment of the present invention, Figure 6As shown, the multi-bubble fusion foaming structure forming device of this embodiment also includes a nozzle control device 6, and the nozzle control device 6 includes a mounting bracket 61; the mounting bracket 61 is provided with a plurality of guide rails 62 along a circumferential array; each of the guide rails 62 is slidably connected with a slider 63, and each of the sliders 63 is connected with an adjustable connector 64 by bolts, and each slider 63 is connected to the control device 10 by signal. And the ultraviolet curing device 7 includes a plurality of ultraviolet curing units 71 and a plurality of ultraviolet curing unit mounting parts 72, and each of the ultraviolet curing unit mounting parts 72 is provided with a card slot for mounting the ultraviolet curing unit 71, and the structure of the card slot matches the peripheral structure of the ultraviolet curing unit 71, so that the plurality of ultraviolet curing units 71 are respectively connected to the card slots of the corresponding ultraviolet curing units 71. Among them, the plurality of ultraviolet curing units 71 are used to provide a light intensity of 200mW / cm -2 ~300mW / cm -2 A UV light source is used to achieve the curing of deformed single bubbles.

[0121] The adjustable connector 64 of this embodiment is set as a T-shaped structure, that is, the adjustable connector 64 of this embodiment has three connection ends, one of which is set on the corresponding slider 63 by bolts, one connection end is used for the corresponding molding nozzle 1 to be installed by bolts, and the other connection end is used for the corresponding UV curing unit mounting member 72 to be connected by bolts. Therefore, by adjusting to the required angles and tightening the bolts, the molding nozzle 1 and the UV curing unit 71 can be installed, the angles adjusted and the angles fixed. For example, the angle between the output end of the molding nozzle 1 and the axis direction of the central symmetry axis is adjusted to 20°~40°, and the angle of the UV curing unit 71 is adjusted so that the angle between the illumination direction of the UV light source and the falling direction of the deformed single bubble is 10°~30°. In addition, the corresponding parts can be installed or disassembled according to the number of molding nozzles 1 actually required, and the operation is simple and convenient.

[0122] In the printing process, the present embodiment can realize the printing of a single-layer porous foam structure by adjusting the position of the substrate through the substrate moving device. The control device 10 can also drive the position of the slider in each guide rail to drive the slider to move the plurality of molding nozzles, thereby realizing the printing of a single-layer porous foam structure.

[0123] Experimental Section

[0124] The present invention takes the multi-bubble fused foaming structure prepared in Example 1 to Example 4 as an example, and tests the density and Young's modulus thereof respectively, and the test results are shown in Table 1.

[0125] Among them, the density test is carried out according to the immersion method in the national standard GB / T 1033.1-2008.

[0126] Young's modulus is tested according to the dynamic resonance method in the national standard GB / T2105-91.

[0127] Table 1 Test results of density and Young's modulus

[0128]

[0129] It can be seen from the test results in Table 1 that with the gradual increase of gas pressure, the density and Young's modulus of the prepared multi-bubble fused foaming structure gradually decrease. This may be because when the gas pressure increases, the bubble combination and fusion increase, from the sticky state of the bubble with the smallest pressure at the beginning, that is, two bubbles stick together, to the bubble coalescence, and the bubble coalescence amount gradually increases with the increase of pressure. At the maximum pressure, the bubbles are emptied to form larger bubbles. Due to the increase of gas, the performance of the structure is reflected in the decrease of density and Young's modulus.

[0130] The above test results indicate that the present invention is capable of controlling the bubble morphology and bubble fusion mode of a single layer by adjusting the gas pressure and ink flow rate in real time, so as to realize control over the degree of continuous bubble generation and fusion and real-time solidification and molding, thereby being able to realize control over the morphology of the porous structure, thereby realizing control over the performance of the final porous structure through control over the morphology of the porous structure, and realizing the manufacture of the desired porous structure with high molding quality.

[0131] In summary, the molding method of the present invention can realize the manufacture of a porous foaming structure with controllable bubble morphology. The present invention determines the material and morphology of the required foaming structure, configures the ink material for forming the bubble shell, and adopts a direct bubble writing process to realize the fusion of the porous bubbles. After obtaining a single-layer porous foaming structure, it is stacked and connected layer by layer, and the second layer of the required foaming structure is stacked on the first layer of the foaming structure. Through controllable bubble regulation and continuous manufacturing, the problems of disordered and uncontrollable bubble morphology and uneven material performance and quality in the traditional porous structure manufacturing process are solved.

[0132] Obviously, the above embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for forming a multi-bubble fusion foaming structure based on direct bubble writing, characterized in that: The following steps are involved: Determine the material and structural form of the foaming structure according to the performance requirements of the desired foaming structure; prepare the corresponding ink according to the determined material of the foaming structure; The ink is passed into a plurality of forming nozzles (1), and a direct bubble writing process is used to print layer by layer from bottom to top according to the structural form of the determined foaming structure, so that the single-layer porous foaming structures corresponding to each layer are stacked and connected layer by layer to obtain the multi-bubble fused foaming structure; The printing of a single-layer porous foam structure is specifically performed through the following steps: A regulating gas is simultaneously introduced into each of the molding nozzles (1), so that the ink introduced into each of the molding nozzles (1) is continuously output in the form of a single bubble under the gas pressure provided by the regulating gas to form a bubble stream; a plurality of single bubbles in the bubble streams simultaneously output from different molding nozzles (1) merge during the falling process and are continuously output in the form of deformed single bubbles; The continuously output deformed single bubbles are subjected to a curing process, so that after the deformed single bubbles are cured, they are sequentially deposited on a substrate that moves relative to the forming nozzle (1), and after curing, a single-layer porous foam structure is formed; The plurality of shaping nozzles (1) are centrally symmetrically distributed on the same horizontal plane, and the output end of each shaping nozzle (1) points in the axial direction of the central symmetry axis.

2. The method for forming a multi-bubble fusion foaming structure based on direct bubble writing as claimed in claim 1, characterized in that: The regulating gas is one or more of air, oxygen, nitrogen, helium and argon.

3. The method for forming a multi-bubble fusion foaming structure based on direct bubble writing as claimed in claim 1, characterized in that: Each of the molding nozzles (1) is a core-shell nozzle, comprising a core flow channel (11) and an outer flow channel (12); The input end of the core flow channel (11) is connected to a gas source for conveying regulating gas; The input end of the external flow channel (12) is connected to an ink source for conveying ink; The output end of the external flow channel (12) is arranged outside the output end of the core flow channel (11), so that the regulated gas forms a gas core, and after the ink contacts the gas core, a liquid shell covering the gas core is formed at the gas-liquid contact surface, and is ejected from the nozzle of the forming nozzle (1) in the form of a single bubble.

4. The method for forming a multi-bubble fusion foaming structure based on direct bubble writing as claimed in claim 3, characterized in that: The inner diameter ratio of the core flow channel (11) to the outer flow channel (12) is 0.5-1.5:0.

8.

5. The method for forming a multi-bubble fusion foaming structure based on direct bubble writing as claimed in claim 4, characterized in that: The distance between the output end of the external flow channel (12) and the output end of the core flow channel (11) is 1 mm.

6. The method for forming a multi-bubble fusion foaming structure based on direct bubble writing as claimed in claim 1, characterized in that: The curing treatment is performed by ultraviolet light irradiation, and the ultraviolet light irradiation conditions are provided by a plurality of ultraviolet light sources.

7. A multi-bubble fusion foaming structure forming device based on direct bubble writing, used in the multi-bubble fusion foaming structure forming method based on direct bubble writing according to any one of claims 1 to 6, characterized in that: The multi-bubble fusion foaming structure forming device comprises a plurality of forming nozzles (1), a gas storage tank (2), a gas pressure controller (3), a syringe (4), a syringe pump (5) and a UV curing device (7); A plurality of the molding nozzles (1) are arranged on the same horizontal plane and are centrally symmetrically distributed, and the output end of each molding nozzle (1) points to the axial direction of the central symmetry axis; and each molding nozzle (1) is respectively provided with a core flow channel (11) and an external flow channel (12); The gas storage tank (2) stores regulated gas inside, and the output end of the gas storage tank (2) is in communication with the core flow channel (11) of each molding nozzle (1) so as to provide regulated gas to each molding nozzle (1); The gas pressure controller (3) is arranged between the gas storage tank (2) and the molding nozzle (1) to regulate the gas pressure of the regulating gas entering the molding nozzle (1); The syringe (4) is used to introduce ink; and the output end of the syringe (4) is connected to the external flow channel (12) of each molding nozzle (1) through a delivery tube, so as to provide ink to each molding nozzle (1); The injection pump (5) is connected to the syringe (4) by a signal and is used to adjust the output flow rate of the ink in the syringe (4); The ultraviolet curing device (7) is arranged below a plurality of the molding nozzles (1) and is used to perform real-time curing on the bubble flow ejected from the nozzles of the molding nozzles (1).

8. The multi-bubble fusion foaming structure forming device based on direct bubble writing as claimed in claim 7, characterized in that: It also includes a nozzle control device (6), wherein the nozzle control device (6) includes a mounting bracket (61); The mounting bracket (61) is provided with a plurality of guide rails (62) in a circumferential array; A slider (63) is slidably connected in each guide rail (62), and an adjustable connecting member (64) is connected to each slider (63) via a bolt, and each adjustable connecting member (64) is T-shaped; A plurality of the forming nozzles (1) are respectively arranged at one end of the corresponding adjustable connecting member (64) via bolts.

9. The multi-bubble fusion foaming structure forming device based on direct bubble writing as claimed in claim 8, characterized in that: The ultraviolet curing device (7) comprises a plurality of ultraviolet curing units (71) and a plurality of ultraviolet curing unit mounting parts (72); The plurality of UV curing unit mounting members (72) are respectively arranged at the other end of the corresponding adjustable connecting member (64) by means of bolts, and the plurality of UV curing units (71) are respectively arranged on the corresponding plurality of UV curing unit mounting members (72).

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