CN109732899B

CN109732899B - Polymer matrix composite high-resolution 3D printing device and working method thereof

Info

Publication number: CN109732899B
Application number: CN201910204502.9A
Authority: CN
Inventors: 兰红波; 杨昆; 赵佳伟; 许权
Original assignee: Qingdao Wuwei Zhizao Technology Co ltd
Current assignee: Qingdao Wuwei Zhizao Technology Co ltd
Priority date: 2019-03-18
Filing date: 2019-03-18
Publication date: 2023-07-07
Anticipated expiration: 2039-03-18
Also published as: CN109732899A

Abstract

The utility model provides a polymer matrix composite high resolution 3D printing device and method of operation thereof utilizes the printing shower nozzle for adopting single screw rod melt extrusion formula shower nozzle and conductive nozzle integrated configuration, and is provided with multistage heating, can accurate regulation and control printing temperature, and whole printing device can realize polymer matrix composite and complicated three-dimensional structure integration manufacturing, prints the piece and mixes evenly, and the performance is good, and prints the material unlimited, has high accuracy, macroscopically/little integration printing, and production efficiency is high, with low costs, characteristics and advantage of simple structure, especially it can realize mixed material and three-dimensional structure integration manufacturing simultaneously.

Description

Polymer matrix composite high-resolution 3D printing device and working method thereof

Technical Field

The disclosure belongs to the technical field of additive manufacturing and composite material manufacturing, and relates to a polymer matrix composite material high-resolution 3D printing device and a working method thereof.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

The 3D printing technology is a rapid additive manufacturing technology for generating three-dimensional entities by adding stacked materials layer by layer, so that the problem of material waste in traditional material reduction manufacturing is solved, and the product manufacturing is more intelligent, accurate and efficient. In particular, high-end fabrication involving complex shapes, 3D printing techniques show great advantages. The polymer (comprising ABS, PCL, PLA, nylon, resin and the like) is widely applied to the field of 3D printing due to the advantages of low manufacturing cost, easy molding of raw materials and the like, but is limited by the physical characteristics of chemical polymers, the plastic 3D printing part cannot be directly used as a mechanical part or a functional device, and a brand new solution is provided for the 3D printing polymer by the composite material preparation and printing technology developed in recent years.

The nano metal powder, ceramic powder, graphene, carbon nano tube, carbon fiber powder and other materials are added into the polymer, so that the mechanical property and physical property of the polymer can be effectively improved, the polymer composite material also has excellent electric conduction, heat conduction, static resistance, seepage prevention, electromagnetic shielding, electromagnetic absorption and other properties, antistatic plastics, electromagnetic shielding materials, digital temperature control heating materials and the like can be manufactured, and the polymer composite material has important application value in the fields of new material development, electronic devices, biomedicine and aerospace, and greatly expands the application field of the polymer material.

The present inventors have appreciated that the current methods of preparing polymers and powders mainly include three types: solution mixing, melt mixing and in-situ polymerization, wherein the solution mixing method is the simplest and feasible, but the solvent is difficult to remove and recover, and pollutes the environment; the interaction force between the matrix and the powder by the in-situ polymerization method is strong, but the polymerization reaction process is complex and is not easy to operate; the melting mixing method does not need to use a solvent, has less environmental pollution and simple operation, and at present, the melting mixing method mostly adopts a screw stirring method, comprises single screw stirring, double screw stirring and multi-screw stirring, and mainly utilizes shearing mixing to uniformly disperse powder in a matrix to prepare the composite material.

The processes of applying the prepared composite material to 3D printing mainly comprise processes of ink jet printing forming (Inkjet), fused deposition Forming (FDM), three-dimensional light curing forming (SLA), selective Laser Sintering (SLS) and the like, however, the inventor knows that certain defects and defects exist in the processes, particularly, the viscosity of printing ink based on the Inkjet method is limited, and the strength of a product is not high; printing material shape (mainly using wires) based on FDM method is limited, and forming precision is not high; SLA and SLS based methods are expensive and SLA is mainly suitable for photosensitive resins, SLS has extremely high requirements (10-100 microns) on the particle size and shape of the shaped powder.

In summary, the 3D printing polymer has certain defects in the preparation and printing processes of the composite material, meanwhile, the existing process for 3D printing the polymer-based composite material has relatively harsh requirements on the performance, shape and size of the material, the types and the shapes of the material are limited, and the printing material needs to be processed into the required size in advance; the processing precision is low, the manufacturing of the micro-scale structure cannot be realized by all the existing processes, the minimum feature resolution is difficult to realize below 100 micrometers, the equipment and the process are complex, and the production cost is high.

Disclosure of Invention

In order to solve the problems, the disclosure provides a high-resolution 3D printing device for a polymer matrix composite and a working method thereof, and the disclosure can realize integrated manufacturing of the polymer matrix composite and a three-dimensional structure, and can realize integrated printing of a macro/micro scale structure, thereby realizing high-precision and high-resolution printing.

High resolution in this disclosure means that the resolution can reach below 100 microns.

According to some embodiments, the present disclosure employs the following technical solutions:

the utility model provides a polymer matrix composite high resolution 3D printing device, includes the bottom plate, is provided with three-dimensional workstation on the bottom plate, installs the printing shower nozzle on the Z axle workstation of three-dimensional workstation, is provided with the printing bed on the X/Y axle workstation, the printing shower nozzle includes actuating mechanism, single screw rod, churn, conductive nozzle, feed arrangement, multistage churn heater and conductive nozzle heater, actuating mechanism is connected with single screw rod, can drive single screw rod carries out axial motion, the churn cover is established in single screw rod outside, conductive nozzle installs in the bottom of churn, is connected with high-voltage pulse power supply, the upper end of churn is provided with the feed arrangement that can carry the material to its inside, multistage churn heater includes a plurality of independent heaters, the heater is cladding in proper order along axial on the churn, conductive nozzle periphery is provided with conductive nozzle heater, be provided with the heater on the printing bed, form the segmentation heating in the printing process;

the 3D printing device is further provided with a control system for controlling triaxial movement of the three-dimensional workbench, heating temperatures of the stirring cylinder, the conductive nozzle and the printing bed, and printing actions of the driving mechanism and the printing spray head.

According to the technical scheme, the printing spray head adopts the single-screw melt extrusion spray head, so that mixed printing materials can be further and uniformly mixed in the stirring barrel, meanwhile, extrusion of the materials can be accurately controlled by utilizing extrusion force generated by the single screw, and forming in the printing process is assisted; different from the traditional air pressure and the like, the single screw extrusion force is stable and simple to regulate and control, and continuous and stable printing is ensured. In addition, by utilizing the extrusion effect of a single screw, the printing material can be formed in an unlimited shape, and any mixed materials such as particles, powder, wires and the like can be finally extruded and molded in a single screw active mixing nozzle through melt shearing.

Secondly, the conductive nozzle of the printing spray head is also connected with a high-voltage pulse power supply, and an electric field driving spray deposition 3D printing process can be adopted, so that on one hand, the printing resolution is very high, printing of micro-nano scale characteristic structures can be realized, and particularly, the printing capability of large-area macro/micro/nano trans-scale 3D printing is also realized; on the other hand, the available printing materials are also very wide-ranging in variety and are particularly suitable for printing high-viscosity polymer materials (polymer matrix composites).

In addition, through setting up a plurality of heaters, form multistage heating on churn and conductive nozzle, the shaping performance of assurance material that can be better.

As a further limitation, the conductive nozzle is a metal nozzle or a nozzle coated with a conductive material, and the inner diameter of the nozzle is 1-1000 micrometers.

Through theoretical analysis and actual experiments, the definition of the nozzle inner diameter parameter range can be found, and high-resolution printing and microscale printing can be realized.

As a further limitation, the heating temperature of the multi-stage mixer drum heater and the conductive nozzle heater ranges from 0 to 450 ℃.

As a further limitation, the print bed has a heating temperature in the range of 0-120 ℃.

Through theoretical analysis and actual experiments, the parameter ranges can be found to be helpful for temperature control and material molding in the printing process.

As a further limitation, the base plate is provided with a frame, and the three-dimensional table includes a X, Y and Z-axis table, wherein the X, Y-axis table is orthogonal, and the Z-axis table is provided on the frame.

Of course, the specific structure of the three-dimensional workbench is variable, so long as the requirement that the printing nozzle can move in three dimensions relative to the printing bed is met.

As a further limitation, the stirring barrel comprises three sections which are in sealing connection, namely a metal material section, an insulating heat conducting material section and a metal material section in sequence.

By providing the insulating and heat conducting material segments between the metal material segments, conduction with the electrically conducting nozzle can be prevented from affecting other electronic devices of the device.

As a further limitation, the high voltage pulse power supply can output direct current, alternating current and pulse voltage, and can set bias voltage; the set bias voltage range is continuously adjustable, the DC voltage is 0-5KV, the output pulse DC voltage is 0- +/-4 KV, the output pulse frequency is 0-3000 Hz, and the AC high voltage is 0- +/-4 KV.

As a further limitation, the multi-stage mixing drum heater comprises at least three annular heaters which are respectively arranged at the positions corresponding to the feeding section, the compression section and the metering section of the single screw in the mixing drum.

As a further limitation, the printing spray head is connected with the Z-axis workbench through a spray head clamp, the spray head clamp comprises an upper layer and a lower layer, the upper layer is used for fixing the stepping motor, the lower layer is used for fixing the stirring barrel, and the back surface of the clamp is fixed with the Z-axis workbench through a fixing piece.

The printing method based on the device specifically comprises the following steps:

mixing materials according to the component proportion of the composite material, starting all heaters to reach a set temperature, enabling the printing spray heads to be in a standby state, and enabling all the work tables to be in an enabling state;

placing the mixed composite material into a feeding device, enabling the material to move downwards under the action of self gravity or external force, enabling the material to be heated and softened initially at a feeding hole, enabling the material to move downwards continuously under the action of screw extrusion of a single screw, enabling the material at a gap between the single screw and a cylinder wall to be sheared and extruded to finish mixing and conveying, and finally conveying the uniformly mixed composite material to a conductive nozzle;

and according to different printing geometric characteristics, respectively adopting different printing modes to print layer by layer.

Specifically, the printing mode includes: for macroscopic structures, the single screw of the printing nozzle is directly utilized to extrude and deposit the printing material onto the substrate or the formed structure; for the micro-scale characteristic structure, a high-voltage pulse power supply is started, a printing material is sprayed and deposited on a substrate or a formed structure by utilizing an electric field driven spray deposition 3D printing process, and the geometric structure forming is realized by combining the movement of a X, Y axis workbench.

According to the technical scheme, two printing modes are arranged, the first printing mode (extrusion molding) is directly single-screw extrusion molding and is used for printing a macrostructure and a characteristic structure with low precision requirements, and the mode has high printing efficiency; the second mode employs an electric field driven jet deposition 3D printing process (jet forming) for micro-nano feature structure printing, particularly with which micro-structure based fabrication is achieved. The two printing modes can simultaneously give consideration to printing efficiency and printing precision, and ensure the realization of large-area macro/micro/nano trans-scale 3D printing.

Compared with the prior art, the beneficial effects of the present disclosure are:

(1) The preparation of the polymer and powder composite material and the 3D printing forming are integrally completed, the process is simple, the device is particularly suitable for the development and research fields of new materials, the performance of the prepared composite material can be directly tested in the aspects of mechanics, thermal performance and the like after 3D forming by using the device, and the device is simple and reliable.

(2) The printing precision is high, and the electric field is adopted to drive the jet deposition 3D printing, so that the manufacturing of the micro-scale characteristic structural member can be realized, and particularly, the manufacturing of the large-area micro-nano trans-scale functional structural member can be realized.

(3) Two printing modes are set, extrusion molding and spray molding. The printing efficiency and the printing precision can be simultaneously considered, and the realization of large-area macro/micro/nano cross-scale 3D printing and the efficient manufacture of large-size high-precision functional structural members are ensured.

(4) The printing polymer raw material does not need to be molded by secondary processing, so that the manufacturing process is simplified, and the universality of the material is improved. The printing material has wide variety of suitable materials, can realize the printing of various polymer materials such as granular, powdery, filiform, flaky and the like and inorganic reinforcing materials, is especially suitable for the printing of high-viscosity materials, and has strong universality.

(5) Simple structure, the precision is high, and equipment cost is low, efficient. The single-screw melt extrusion type spray head can be directly installed on a triaxial motion platform for printing, and has strong portability.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application.

FIG. 1 is a schematic view showing the structure of a high-resolution 3D printing device for polymer matrix composite materials according to the embodiment;

fig. 2 is a schematic diagram of the structure of the printing head according to the present embodiment.

Fig. 3 is a schematic view of the structure of the stirring cylinder of this embodiment.

Fig. 4 is a schematic diagram of the printing principle of the present embodiment.

Fig. 5 (a) and (b) are a high-resolution 3D structure physical photograph and SEM image of the chopped carbon fiber PCL composite material printed in this example, respectively.

The device comprises a printing nozzle 1, a stepping motor 101, a coupling 102, a single screw 103, a stirring cylinder 104, a feeding port 10401, a metal material section 10402, an insulating heat conducting material section 10404, a metal material section 105, a feeding device 106, a stirring cylinder heater I, a stirring cylinder heater II, a stirring cylinder heater III, a conducting nozzle 109, a conducting nozzle heater IV of 1010, a nozzle 1011, a nozzle clamp, a 2Z-axis workbench, a 3-frame, a 4Y-axis workbench, a 5X-axis workbench, a 6-base plate, a 7-printing bed, an 8-high-voltage pulse power supply and a 9-control module.

901 temperature control unit, 902 motor control unit, 903 triaxial motion control unit, 904 print control unit, 905 auxiliary unit.

The specific embodiment is as follows:

the disclosure is further described below with reference to the drawings and examples.

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "side", "bottom", and the like indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, are merely relational terms determined for convenience in describing structural relationships of the various components or elements of the present disclosure, and do not denote any one of the components or elements of the present disclosure, and are not to be construed as limiting the present disclosure.

In the present disclosure, terms such as "fixedly coupled," "connected," and the like are to be construed broadly and refer to either a fixed connection or an integral or removable connection; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the terms in the disclosure may be determined according to circumstances, and should not be interpreted as limiting the disclosure, for relevant scientific research or a person skilled in the art.

As described in the background art, the existing process for printing polymer-based composite materials in 3D has relatively severe requirements on the properties, shape and size of the materials, the types and shapes of the materials are limited, and the printed materials need to be processed into required sizes in advance; the processing precision is low, the manufacturing of the micro-scale structure cannot be realized by all the existing processes, the minimum feature resolution is difficult to realize below 100 micrometers, the equipment and the process are complex, and the production cost is high.

To solve the above problems, the present disclosure adopts the following technical improvements:

1. the printing spray head adopts a single-screw melt extrusion spray head, and has the following remarkable functions by utilizing the single-screw melt extrusion spray head:

(1) The printing materials after mixing can be further evenly mixed;

(2) Extrusion of the material is precisely controlled by using extrusion force generated by a single screw, and shaping in the printing process is assisted. Different from the traditional air pressure and the like, the single screw extrusion force is stable and simple to regulate and control, and continuous and stable printing is ensured.

(3) The shape of the printing material is not limited. The mixed materials such as particles, powder, wires and the like can be finally extruded and molded in a single-screw active mixing nozzle through melting and shearing;

2. the printing spray head adopts a single-screw melt extrusion type spray head and conductive nozzle combined structure, the conductive nozzle of the printing spray head is connected with the positive electrode of a high-voltage pulse power supply, and the structural part is printed and molded by adopting an electric field driven spray deposition 3D printing process. The electric field driven jet deposition 3D printing process has high printing resolution on one hand, can realize printing of micro-nano scale feature structures, and particularly has the capability of large-area macro/micro/nano trans-scale 3D printing; on the other hand, the available printing materials are very wide in variety, and are particularly suitable for printing high-viscosity polymer materials (polymer matrix composite materials);

3. the printing nozzle adopts four-stage heating, and can accurately regulate and control the printing temperature. The design of screw rod divides sectional designs such as charging section, compression section and measurement section to adopt a plurality of annular heaters to heat corresponding position respectively, and conductive nozzle adopts the heating block to heat alone, and the material is heated evenly in printing the shower nozzle inside, risees gradually, guarantees the material.

4. Setting two printing modes, wherein the first printing mode (extrusion molding) is directly single-screw extrusion molding and is used for printing a macrostructure and a characteristic structure with low precision requirements, and the mode has higher printing efficiency; the second mode employs an electric field driven jet deposition 3D printing process (jet forming) for micro-nano feature structure printing, particularly with which micro-structure based fabrication is achieved. The two printing modes can simultaneously give consideration to printing efficiency and printing precision, and ensure the realization of large-area macro/micro/nano trans-scale 3D printing.

In a first embodiment, a high-resolution 3D printing device for polymer matrix composite is provided, as shown in fig. 1, and mainly includes a printing nozzle 1, a Z-axis table 2, a frame 3, a Y-axis table 4, an X-axis table 5, a base plate 6, a printing bed 7, a high-voltage pulse power supply 8, a control module 9, and the like.

The printing spray head 1 is installed on the Z-axis workbench 2, the Z-axis workbench 2 is fixed on the frame 3, the frame 3 is fixed on the bottom plate 6, the X-axis workbench 5 is perpendicular to the printing spray head and is fixed on the bottom plate 6, the Y-axis workbench 4 is fixed on the X-axis workbench 5, the printing bed 7 is fixed on the Y-axis workbench 4, and the high-voltage pulse power supply 8 is connected with the conductive nozzle 109 of the printing spray head 1 through a wire. The X-axis workbench 4 and the Y-axis workbench 5 are orthogonally arranged by adopting a high-precision displacement workbench X, Y, and a servo motor, a stepping motor, a linear motor or the like can be adopted.

In this embodiment, the working stroke of the X-axis is 0-1000 mm, the repeated positioning accuracy is not lower than + -1 micron, the absolute positioning accuracy is not lower than + -2 microns, the maximum speed is 700mm/s, and the maximum acceleration is 500m/s 2. The working stroke of the Y-axis is 0-1000 mm, the repeated positioning precision is not lower than +/-1 micron, the absolute positioning precision is not lower than +/-2 microns, the maximum speed is 700mm/s, and the maximum acceleration is 500m/s ² 。

Of course, in other embodiments, one skilled in the art may modify the body structure of the printing apparatus, such as the structure of a three-dimensional table, or use existing equipment, provided that the print head is capable of three-dimensional movement relative to the print bed.

Or modifying the motion parameters or precision parameters of the three-dimensional/triaxial worktable.

The foregoing is a simple alternative and is intended to be within the scope of the present disclosure.

The printing bed 7 is a platform with vacuum adsorption and electric heating functions, a round table or other structural shapes, the temperature of the heating bed is controlled by the heater V, the heating temperature of the printing bed ranges from 0 ℃ to 120 ℃, the printing bed has high flatness, a substrate can be placed on the printing bed 7 during printing, and if the surface of an existing object is printed, the object can be fixed on the printing bed 7 for reprinting.

The high-voltage pulse power supply 8 has the following functions of outputting direct-current high voltage; outputting alternating-current high voltage; the output pulses are high voltage and can be set with a bias voltage. In the embodiment, the set bias voltage range is continuously adjustable, the DC high voltage is 0-5KV, the output pulse DC voltage is 0- + -4 KV, the output pulse frequency is 0-3000 Hz, and the AC high voltage is 0- + -4 KV.

In other embodiments, the parameters may be adaptively selected or modified by those skilled in the art based on the printing materials and the specific printing requirements.

As a printing head which can be commonly used in various embodiments, as shown in FIG. 2, a stepping motor 101, a coupling 102, a single screw 103, a stirring cylinder 104, a feeding device 105, a stirring cylinder heater I106, a stirring cylinder heater II107, a stirring cylinder heater III108, a conductive nozzle 109, a conductive nozzle heater IV1010, and a head clamp 1011 are specifically included. Step motor 101 and single screw 103 pass through shaft coupling 102 interconnection, single screw 103 installs in the inside of churn 104, conductive nozzle 109 installs in the bottom of churn 104, feed arrangement 105 passes through the screw thread realization and is connected with churn 104, churn heater I106, churn heater II107, churn heater III108 and conductive nozzle heater IV1010 cladding are at churn 104 and conductive nozzle 109 periphery respectively, shower nozzle anchor clamps 1011 include the fixed plate, and the fixed plate divide into upper and lower two-layer, the upper strata is used for fixed step motor 101, the lower floor is used for fixed churn 104, screw hole is opened at the anchor clamps 1011 back, realize the fixed with Z axle workstation 2 through the screw thread.

In some embodiments, the feeding device 105 is funnel-shaped and forms an angle of 45 degrees with the stirring cylinder 104, so that the installation, the fixation and the blanking are convenient.

Of course, in other embodiments, the feeding device 105 may be modified to other shapes, such as spherical, cylindrical, columnar, etc. And the included angle with the stirring barrel and the setting position can be adjusted adaptively.

The heating temperatures of the stirring cylinder heater I106, the stirring cylinder heater II107, the stirring cylinder heater III108 and the conductive nozzle heater IV1010 range from 0 to 450 ℃. The amount of heat required and generated by the material in different areas of the mixing drum 104 is different, and different temperature values are set according to plasticization and pressure requirements. Typically, the nozzle 109 temperature is slightly higher than the mixing drum 104 temperature, facilitating accurate regulation of the material injection temperature.

The conductive nozzle 109 is a metal nozzle or a nozzle coated with conductive material, the inner diameter of the nozzle is 1-1000 micrometers, and the nozzle is connected with the positive electrode of the high-voltage pulse power supply 8 through a wire.

As a mixing drum that may be used in common in various embodiments, as shown in fig. 3, the mixing drum specifically includes a feed inlet 10401, a metal material section 10402, an insulating and heat conducting material section 10403, and a metal material section 10404, where the mixing drum 104 is designed in three sections of metal material section-insulating and heat conducting material section-metal material section, and sealing connection is implemented by threads, and the purpose of the insulating and heat conducting material is to prevent conduction with the electric conduction nozzle 109 to affect other electronic devices of the apparatus. The feed inlet 10401 is communicated with the feed device 105, the material is heated and softened at the feed inlet, and the material continues to move downwards under the action of screw extrusion of the screw 103.

In some embodiments, as shown in FIG. 4, the conductive nozzle 109 employs a gun needle having an inside diameter of 200 μm, mounted at the lowermost end of the mixing drum 104 and connected to the positive electrode of the high voltage power supply 8 by a wire. The conductive nozzle 104 forms a strong electric field with the substrate 701 placed on the print bed 7, driving the spray deposition of material on the substrate.

Of course, in other embodiments, the size and configuration of the conductive nozzle may be adapted.

In the above embodiments, the connection relationship between the parts, such as threaded connection, may be replaced by other connection manners, which will not be described herein.

As a commonality, in the device using the above embodiment, the working method for realizing the integrated manufacturing of the mixed material and the molding structure specifically includes:

(1) Data preparation. Drawing a three-dimensional model, importing model files (STL, AMF, 3MF and the like) into slicing software (a printing control unit), setting printing parameters, and generating a printing path G code;

(2) And initializing printing. The preparation work before printing is finished, specifically comprises the steps of manually finishing mixing according to the component ratio (volume ratio or mass ratio) of the composite material, starting all heating units to reach a set temperature, enabling each moving platform to be in a standby state, and finishing the preparation and initialization of the whole printing equipment;

(3) Printing the structural member. Mainly comprises feeding, melt mixing and conveying extrusion, and 3D printing of a geometric forming structure. Placing the mixed composite material into a feeding device, enabling the material to move downwards under the action of self gravity or external force, enabling the material to be heated and softened initially at a feeding hole, enabling the material to move downwards continuously under the action of screw extrusion of a single screw, enabling the material at a gap between the single screw and a cylinder wall to be sheared and extruded to finish mixing and conveying, and finally conveying the uniformly mixed composite material to a conductive nozzle; and then adopting different printing modes according to different printing geometric characteristics.

Specifically, for a macroscopic structure, a single screw of a printing spray head is directly utilized to extrude and deposit a printing material onto a substrate or a formed structure, if a microscale characteristic structure is printed, a high-voltage pulse power supply is started, an electric field driving spray deposition 3D printing process is utilized to spray and deposit the printing material onto the substrate or the formed structure, and the geometric structure forming is realized by combining the movement of a X, Y workbench.

After each layer of printing is finished, the Z-axis workbench is lifted by one layer of thickness, then printing of the next layer of structure is finished, and the processes are repeated until printing of all layers of structures is finished;

(4) Printing is completed. And the heaters, the motor control units and the high-voltage power supply are turned off, the X, Y, Z workbench returns to the initial printing position (triaxial motion control unit) of the workbench, and the printed composite structural member is taken down.

Taking the first embodiment as an example, the specific description of the printing process steps includes:

step 1: print data file preparation. Drawing a three-dimensional model, importing model files (STL, AMF, 3MF and the like) into slicing software (a printing control unit 904), setting printing parameters (parameters such as layer thickness, filling and the like), and generating a printing path G code;

step 2: and initializing printing. Taking thermoplastic polymer particles and modified powder blending as an example, mixing materials A and B according to a proportion (volume ratio of 20%), starting all heating units 901 to reach a set temperature, enabling each moving

platform

2, 4 and 5 to complete the preparation and initialization of the whole printing equipment, wherein the printing nozzle 1 is in a standby state;

step 3: printing the structural member. (1) Feeding, namely placing the mixed composite material into a feeding device 105, enabling the material to move downwards under the action of self gravity or external force, and (2) mixing, namely enabling thermoplastic polymer particle materials to be heated and softened initially at a feeding hole 10401, enabling the materials at a gap between a single screw 103 and a cylinder wall 104 to be sheared and extruded to finish mixing and conveying under the action of screw extrusion of the screw 103, and finally conveying the uniformly mixed composite material to a conductive nozzle 109; (3) Printing a first layer structure, extruding printing materials by using a single screw 103 of a printing nozzle according to a working mode required to be used for printing the layer, and driving X and Y working tables 4 and 5 to move according to the geometric information of the layer to finish printing the layer structure if the working mode is an extrusion forming mode; if the forming is the spray forming, a high-voltage pulse power supply 8 is started, printing materials are sprayed, and the Y-axis workbench 4 and the X-axis workbench 5 are driven to move according to the geometric information of the layer, so that the printing of the layer structure is completed; (4) The Z-axis workbench 2 rises by one layer thickness, and the operation is repeated to finish the printing of the second layer structure; (5) repeating the above operation to complete the printing of all layers.

Step 4: and (5) post-treatment. After the printing is completed, the heating units 901, the motor control units 902, the high-voltage power supply 8,Z, the Y-axis table 4 and the X-axis table 5 are turned back to the table initial printing positions (the triaxial motion control units 903), the printed composite structural member is taken down, and the corresponding post-processing and the like such as support removal, surface finishing and the like are performed as needed.

The foregoing description is only of the preferred embodiments of the present application and is not intended to limit the same, but rather, various modifications and variations may be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

While the specific embodiments of the present disclosure have been described above with reference to the drawings, it should be understood that the present disclosure is not limited to the embodiments, and that various modifications and changes can be made by one skilled in the art without inventive effort on the basis of the technical solutions of the present disclosure while remaining within the scope of the present disclosure.

Claims

1. The utility model provides a polymer matrix combined material high resolution 3D printing device, includes the bottom plate, is provided with three-dimensional workstation on the bottom plate, installs the printing shower nozzle on the Z axle workstation of three-dimensional workstation, is provided with the printing bed on the X/Y axle workstation, characterized by: the printing spray head comprises a driving mechanism, a single screw, a stirring barrel, a conductive nozzle, a feeding device, a multistage stirring barrel heater and a conductive nozzle heater, wherein the driving mechanism is connected with the single screw and can drive the single screw to axially move, the stirring barrel is sleeved outside the single screw, the conductive nozzle is arranged at the bottom of the stirring barrel and is connected with a high-voltage pulse power supply, the feeding device capable of conveying materials to the inside of the stirring barrel is arranged at the upper end of the stirring barrel, the multistage stirring barrel heater comprises a plurality of independent heaters, the heaters are sequentially coated on the stirring barrel along the axial direction, the conductive nozzle heater is arranged at the periphery of the conductive nozzle, and the heater is arranged on a printing bed to form segmented heating in the printing process;

the 3D printing device is further provided with a control system for controlling triaxial movement of the three-dimensional workbench, heating temperatures of the stirring cylinder, the conductive nozzle and the printing bed, and printing actions of the driving mechanism and the printing spray head;

the conductive nozzle is a metal nozzle or a nozzle coated with a conductive material, and the inner diameter of the nozzle is 1-1000 microns;

the heating temperature of the multistage stirring cylinder heater and the conductive nozzle heater ranges from 0 ℃ to 450 ℃;

the multistage stirring cylinder heater comprises at least three annular heaters, and the annular heaters are respectively arranged at positions corresponding to a feeding section, a compression section and a metering section of a single screw in the stirring cylinder;

the stirring cylinder comprises three sections which are connected in a sealing way, namely a metal material section, an insulating heat-conducting material section and a metal material section in sequence; the feeding device is connected with the stirring cylinder through threads.

2. A polymer matrix composite high resolution 3D printing device according to claim 1, wherein: the heating temperature of the printing bed is in the range of 0-120 ℃.

3. A polymer matrix composite high resolution 3D printing device according to claim 1, wherein: the machine frame is arranged on the bottom plate, the three-dimensional workbench comprises a X, Y workbench and a Z-axis workbench, wherein the X, Y workbench is orthogonal, and the Z-axis workbench is arranged on the machine frame.

4. A polymer matrix composite high resolution 3D printing device according to claim 1, wherein: the high-voltage pulse power supply can output direct current, alternating current and pulse voltage and can set bias voltage; the set bias voltage range is continuously adjustable, the DC voltage is 0-5KV, the output pulse DC voltage is 0- +/-4 KV, the output pulse frequency is 0-3000 Hz, and the AC high voltage is 0- +/-4 KV.

5. A polymer matrix composite high resolution 3D printing device according to claim 1, wherein: the printing spray head is connected with the Z-axis workbench through a spray head clamp, the spray head clamp comprises an upper layer and a lower layer, a stepping motor is fixed on the upper layer, a stirring barrel is fixed on the lower layer, and the back of the clamp is fixed with the Z-axis workbench through a fixing piece.

6. A printing method based on the device of any one of claims 1-5, characterized by: comprising the following steps:

7. The printing method of claim 6, wherein: the printing mode includes: for macroscopic structures, the single screw of the printing nozzle is directly utilized to extrude and deposit the printing material onto the substrate or the formed structure; for microscale features, a high-voltage pulsed power supply is turned on, and an electric field driven spray deposition 3D printing process is used to spray deposit a printing material onto a substrate or already shaped structure.