CN106626358A - Multi-material 3D printer and liquid matter accumulation 3D printing method - Google Patents

Abstract

The invention discloses a multi-material 3D printer and a liquid object accumulation 3D printing method. A print head switching mechanism and a print head frame are installed on the 3D printer frame, and a plurality of print heads are arranged, and different print heads are placed in each print head. materials, and at the same time, a material post-processing device is installed on the print head frame to reprocess the printed materials. Using the technical solution of the present invention, thermoplastic materials can be used to build a container with a complex spatial structure, and liquids are filled in the container while the container is being constructed, thereby precisely controlling the spatial configuration of the liquid. The multi-material 3D printer and liquid object accumulation printing method described in the present invention expand the single-material 3D printing technology to the field of multi-material 3D printing; the multi-material 3D printer operates reliably and has high precision; materials can be reprocessed while 3D printing ; 3D printing of low-viscosity liquids can be realized, which has a good market prospect.

Description

A kind of multi-material 3D printer and liquid object accumulation 3D printing method

technical field

The present invention relates to the field of 3D printing, in particular to a multi-material 3D printer and a method for accumulating and printing liquid objects, which is a technique for mixing 3D printing of multi-materials by accumulating liquid objects.

Background technique

With the improvement of the precision of industrial products and the development of personalization, 3D printing technology has emerged as the times require. Compared with the traditional model construction technology, 3D printing can complete the three-dimensional structure by printing layer by layer. Because the printing of a single layer is similar to two-dimensional printing technology, this technology is called three-dimensional printing. The technology can be used to quickly build personalized models, including sophisticated model building and converting them into outputable signals for 3D printers. During the 3D printing process, the printed properties are determined by software design, the composition of the structure is determined by changing the material, and the final shape is determined by the control of physical conditions such as extrusion, laser or high temperature. It can not only quickly print complex 3D structures but also meet individual needs. Therefore, 3D printing technology has been applied in many fields.

Currently commonly used 3D printing methods include stereo-lithography (SLA), fused deposition modeling (FDM), selective laser sintering (SLS), and digital light processing (digital light). processing, DLP), three-dimensional printing (three dimensional printing, 3DP). No matter which technology is used, the principle is to solidify, condense, sculpt or shape a single layer first, and then make another layer, and the layers are gradually combined.

After searching the existing technical literature, it was found that the Chinese invention application number: CN201410669660.9, publication number: CN104667344A, name: "3D printing technology for producing tissue engineering scaffolds", the invention application discloses the 3D printing of tissue engineering scaffolds technology, wherein there are two embodiments, one is to use a printer to print the first layer of scaffold fibers onto the basic gel substrate, and the other is to place the first gel layer on the printed first layer. The invention takes advantage of 3D printing technology in constructing three-dimensional scaffolds. However, the printing method proposed in this invention is limited to the preparation of tissue engineering scaffolds, and the application field is too narrow. And, for the liquid solution, the treatment mode wherein is to carry out by spraying through the nozzle, so only can spray liquid droplet, if need the solution of larger dosage, so the technical scheme of this invention just is not applicable.

Another Chinese invention application number: CN201610122318.6, publication number: CN105643939A, name: "Silicone 3D Printer and Silicone Product Printing Method", which discloses a silicone 3D printer and a silicone 3D printing method. This invention mainly uses a pneumatic extrusion cylinder with a heating device to 3D print silicone products. However, the invention does not specify the composition and specific heating temperature of the silicone raw material available for printing. The silicone raw material is limited to one with shear thinning properties. Silicone, so this method greatly limits the types of silicone available for 3D printing. In fact, silicone rubber has a raw rubber vulcanization process before it becomes an elastomer. According to the vulcanization temperature, silicone rubber is divided into heat vulcanization type (HTV) and room temperature vulcanization type (RTV). All in all, the vulcanization process of silica gel with different raw rubber components is completely different, and the performance of the polymerized silicone rubber varies greatly. Generally, raw rubber is gel-like and has good fluidity. If a relatively rapid vulcanization and reprocessing step can be performed during the 3D printing process, the range of silicone raw materials available for 3D printing will be greatly expanded.

At present, no matter what principle of 3D printer is used, only one raw material can be used for printing in the process of printing a model. The current 3D printers cannot reprocess the materials after printing out the materials, resulting in the inability of some types of materials to be processed by 3D printing methods. Due to its fluidity, low-viscosity liquids are difficult to form a stable spatial structure. If extrusion is used to print low-viscosity liquid compounds/mixtures, the shape of the liquid cannot be precisely controlled, or the initial shape of the liquid is controlled, and the final shape cannot be maintained due to fluidity.

Therefore, those skilled in the art are devoting themselves to developing a multi-material 3D printer and a method for accumulating liquid objects, which have the characteristics of being able to use multiple materials for printing, being able to use low-viscosity liquid objects, and being able to reprocess printed materials.

Contents of the invention

In view of the above-mentioned defects of the prior art, the technical problems to be solved by the present invention are how to use various materials for printing, how to use low-viscosity liquid materials for printing and how to reprocess the printed materials.

To achieve the above object, the present invention provides a multi-material 3D printer, including a frame, a stage, a single-axis moving module, and a print head module, wherein the single-axis moving module includes an X-axis single-axis moving module, a Y axis single-axis movement module, Z-axis single-axis movement module; the Y-axis single-axis movement module is installed on the frame, and the X-axis single-axis movement module is installed across the Y-axis single-axis movement module and On the frame, the Z-axis single-axis moving module is vertically installed on the frame; the print head module is fixedly arranged on the X-axis single-axis moving module.

Further, one end of the stage is fixed on the Z-axis single-axis moving module, the other end is fixed on a spline, and both ends of the guide rail sliding the spline are fixed on the frame.

Further, the print head module includes a print head switching mechanism, a print head frame and one or more print heads.

Further, the print head is installed on the print head frame, and the print head switching mechanism is configured to rotate the print head frame; the print head frame is provided with fixing holes or clamps, and the print head is configured to be fixed through the fixing hole or the clamp.

Further, the printing head is a device for ejecting or extruding printing materials, or a device for post-processing materials.

Further, the way of ejecting or extruding printing materials is one of electromagnetic ejection, piezoelectric ejection, air pressure ejection, piston extrusion or spiral extrusion; the post-processing The preferred device is a laser or a blast gun.

Further, the multi-material 3D printer also includes an upper control system and an automatic control module, the upper control system is configured to take the computer as the core, preprocess the model file, generate machining code information of the model to be printed, and The data is transmitted to the automatic control module through the data line; the automatic control module is configured to control the movement and data collection of the various mechanisms of the entire multi-material 3D printer.

Further, the automatic control module includes a controller, a print head module motion control module, a stage motion control module, a print head switching mechanism control module and a print head control module.

Further, the print head module motion control module is configured to control the moving position of the print head module in the two directions of the X axis and the Y axis according to the machining code information of the model to be printed generated by the host control system, Moving speed and moving acceleration; the print head module motion control module also includes a position sensor, and the position sensor communicates with the controller in real time.

Further, the motion control module of the stage is configured to control the moving position, speed and acceleration of the stage in the Z-axis direction according to the machining code information generated by the model to be printed; the motion control module of the stage The module also includes a position sensor in real-time communication with the controller.

Further, the print head switching mechanism control module is configured to control the movement of the print head switching mechanism according to the printing materials required by the model to be printed, including rotating the print head frame to move the required print head to the working position; the printing The head switching mechanism control module also includes a position sensor in real-time communication with the controller.

Further, the print head control module is configured to collect sensor data and control the movement of the actuator of the print head at the desired moment.

Further, the data communication mode of the automatic control module adopts the RS485 communication bus under the Modbus protocol.

The present invention also provides a liquid object accumulation 3D printing method, comprising the following steps:

S100, providing a multi-material 3D printer according to any one of claims 1-13;

S101. The upper control system first divides the model into several layers according to the information of the model to be printed and the accuracy requirements of the user, and then selects the corresponding print head according to the material and processing needs, and plans the corresponding movement path of the print head;

S102. The automatic control module executes corresponding actions according to the data generated by the host control system, and collects measurement data of sensors installed on the 3D printer.

Further, the step S101 further includes the following steps:

S101A. The host control system designs the working parameters of the printing head, the feeding rate of the printing head, the time and the rotation angle of starting the switching mechanism of the printing head according to the requirements of the printing process.

Further, the step S102 further includes the following steps:

S102A. Control the Z-axis single-axis moving module to drive the stage to the corresponding position of each layer of the product according to the layer data; drive the print head switching mechanism to rotate the print head frame to the specified angle according to the required print head data, so that the required print The head reaches the working position;

S102B. When the print head is in place, control the X-axis single-axis movement module and the Y-axis single-axis movement module to drive the print head module to the designated position according to the planned motion control information, and at the same time control the print head to execute the material in the designed way Jetting/extrusion operations or controlling post-processing processing devices to reprocess printed materials;

S102C, repeatedly driving the movement of the printing head switching mechanism for the next printing head, driving the movement of the X-axis single-axis moving module and the Y-axis single-axis moving module, and controlling the printing head to perform material ejection/extrusion or reprocessing steps;

S102D. Repeat the foregoing steps for all layers.

Further, the liquid substance refers to a thermoplastic material with a melting temperature between 50°C and 400°C.

Further, the liquid substance refers to a liquid compound or a liquid mixture.

The present invention provides a multi-material 3D printer, which realizes multi-material mixed 3D printing, thereby realizing a more free printing combination mode and expanding the selection range of raw materials for models. The basic printing method adopted by the printer of the present invention is a liquid accumulation printing method.

The multi-material 3D printer provided by the present invention includes a frame, an object stage, an X-axis single-axis moving module, a Y-axis single-axis moving module, a Z-axis single-axis moving module, a print head switching mechanism, a print head frame, a print head, Host control system, automatic control module.

The Y-axis single-axis moving module is installed on the frame and can move along the Y-axis direction to realize the degree of freedom in the Y-axis direction of the 3D printer print head module (the combination of the print head switching mechanism, the print head frame and the print head). The X-axis single-axis moving module is installed across the Y-axis single-axis moving module and the frame, and can move along the X-axis direction to realize the degree of freedom of the 3D printer print head module in the X-axis direction. The Z-axis single-axis moving module is installed on the frame and can move along the Z-axis direction to realize the degree of freedom of the 3D printer stage in the Z-axis direction. The X-axis, Y-axis and Z-axis form a Cartesian space Cartesian coordinate system, giving the print head module three degrees of freedom.

One end of the stage is fixed on the Z-axis single-axis moving module, the other end is fixed on a spline that can slide up and down, and the two ends of the guide rail of the sliding spline are fixed on the frame. By fixing both ends of the stage, the deflection is reduced, and the stability of the stage and the movement precision of the Z axis are improved. The general 3D printer stage is designed to be fixed at one end. When the stage itself is heavy or the printed model is heavy, the resulting deflection is large, resulting in a decline in printing accuracy and printing stability. The mechanisms connected with the frame are fixedly connected with bolts through grooves.

In the multi-material 3D printer of the present invention, the print head module includes: a print head switching mechanism, a print head frame and a print head. It is fixedly arranged on the X-axis single-axis moving module.

In the multi-material 3D printer of the present invention, the print head switching mechanism is driven by a stepping motor, and the motor shaft drives the print head frame to rotate through a pulley.

In the multi-material 3D printer of the present invention, multiple print heads can be installed on the print head frame, and the print head switch mechanism is used to rotate the print head frame to switch the working print heads. There are fixed holes on the print head frame, and the print head can be fixed by a clamp.

In the multi-material 3D printer of the present invention, different/same printing materials can be placed in the different printing heads according to printing requirements, so as to realize multi-material 3D printing. The characteristics of the material to be printed require the use of print heads based on different principles or special specifications.

Preferably, the printing head is not limited to a device for ejecting/extruding materials, but also a device for post-processing materials.

In the multi-material 3D printer of the present invention, the host control system takes a computer as the core, and can preprocess the model file to generate machining code information of the model to be printed, and transmit it to the automatic control module through the data line.

In the multi-material 3D printer of the present invention, the automatic control module is used to systematically control the movement and collect data of each mechanism of the entire multi-material 3D printer. Classified according to the control objects, the entire automatic control module is divided into five sub-modules: controller, print head module motion control module, stage motion control module, print head switching mechanism control module and print head control module. Wherein, the controller, as the core of the entire automatic control module, performs operations on all data and communicates with all control objects. The print head module motion control module controls the moving position, moving speed and moving acceleration of the printing head module in the two directions of the X axis and the Y axis according to the machining code information of the model to be printed generated by the host control system; at the same time, the control The module also includes a position sensor to communicate with the controller in real time to improve the accuracy of motion control. The movement control module of the stage controls the moving position, moving speed and moving acceleration of the carrying stage in the Z-axis direction according to the processing code information generated by the model to be printed; meanwhile, the control module also includes a position sensor and a real-time communication to improve the accuracy of motion control. The print head switching mechanism control module controls the movement of the print head switching mechanism according to the printing materials required by the model to be printed, thereby rotating the print head frame and moving the required print head to the working position; at the same time, the control module also includes position The sensor communicates with the controller in real time to improve the positional accuracy of the print head. The print head control module is used to control the print head, and the control method depends on the type of the print head. Examples of materials ejected/extruded by the print head include but are not limited to electromagnetic ejection, piezoelectric ejection, air pressure ejection, etc. Extrusion type, piston extrusion type, screw extrusion type; if post-processing of materials is required, examples of print heads here include but not limited to ultraviolet lasers, infrared lasers, powerful air spray guns. Either way, the printhead control module collects relevant sensor data (if any) and controls the movement of the printhead's actuators at the desired moment.

Preferably, the data communication mode of the automatic control module of the present invention adopts the RS485 communication bus under the Modbus protocol.

The present invention also provides a method for accumulating and printing liquid objects, where the liquid objects refer to two types of printing materials: thermoplastic materials with a melting temperature between 45°C and 400°C; and liquid compounds/liquid mixtures (including: turbid liquid , solution, colloid). The printing method includes the following steps:

S101, the host control system first divides the model into several layers according to the information of the model to be printed and the accuracy requirements of the user, and then designs the printing path according to the process requirements: select the corresponding print head according to the material and processing needs, and plan the print head corresponding movement path. Finally, the generated data is transmitted to the automatic control module;

S102, the automatic control module executes corresponding actions according to the data generated by the host control system. First, control the Z-axis single-axis moving module to drive the stage to the corresponding position of each layer of the product according to the layer data; drive the print head switching mechanism to rotate the print head frame to the specified angle according to the required print head data, so that the required print The head reaches the working position; when the print head is in place, control the X-axis single-axis movement module and the Y-axis single-axis movement module to drive the print head module to the specified position according to the planned motion control information (position, speed and acceleration), and at the same time Control the print head to execute material ejection/extrusion in the designed way or control the post-processing device to reprocess the printed material; repeatedly drive the movement of the print head switching mechanism for the next print head, and drive the X-axis single-axis movement Module and Y-axis single-axis movement Module movement, control of the print head to perform material ejection/extrusion or reprocessing three steps to complete the printing of this layer; repeat the above steps for all layers to complete the printing of this product .

In the method for accumulating and printing liquid objects according to the present invention, in the step S101, the following steps are further included:

The upper control system designs the working parameters of the print head according to the printing process requirements (processing characteristics of the material to be printed);

The upper control system designs the feed rate of the print head according to the printing process requirements (material thickness);

The host control system designs the time and rotation angle for starting the print head switching mechanism according to the printing process requirements (when and which print head should be selected to work).

In the method for accumulating and printing liquid objects according to the present invention, in the step S102, the following steps are further included:

Collect the measurement data of various sensors installed on the 3D printer, including the XYZ three-axis position sensor, the position sensor of the print head switching mechanism, and various sensors installed on the print head.

Based on the multi-material 3D printer and liquid accumulation printing method proposed by the present invention, the following printing operations can be performed to break through the two major bottlenecks encountered by the current 3D printing technology:

First, by using thermoplastic materials to print out a container with a complex spatial structure, after the construction of each layer of container is completed, the low-viscosity liquid is filled in it, and then layer by layer, layer by layer, so as to precisely control the low-viscosity liquid The spatial configuration of objects.

Second, by setting the material post-processing print head on the print head frame, after each layer of material that needs post-processing is printed, the print head frame is switched to the post-processing print head to further process the material, thereby solving the problem of 3D printing. The post-processing problems in the material printing process effectively broaden the types of 3D printing materials that can be printed.

The multi-material 3D printer and liquid object accumulation printing method described in the present invention expand the single-material 3D printing technology to the field of multi-material 3D printing; the multi-material 3D printer operates reliably and has high precision; materials can be reprocessed while 3D printing ; 3D printing of low-viscosity liquids can be realized.

The idea, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings, so as to fully understand the purpose, features and effects of the present invention.

Description of drawings

Fig. 1 is a schematic diagram of the three-dimensional structure of a multi-material 3D printer according to a preferred embodiment of the present invention;

Fig. 2 is a schematic diagram of the processing of PCL materials in the first embodiment of the liquid object accumulation printing method of the present invention;

Fig. 3 is a schematic diagram of the processing of the hydrogel material in the first embodiment of the liquid object accumulation printing method of the present invention;

Fig. 4 is a schematic diagram of the processing of the culture mixture in the first embodiment of the liquid object accumulation printing method of the present invention;

Fig. 5 is a schematic diagram of the printing of the silica gel support material in the second embodiment of the liquid object accumulation printing method of the present invention;

Fig. 6 is a schematic diagram of the printing of the silica gel material in the second embodiment of the liquid object accumulation printing method of the present invention;

Fig. 7 is a schematic diagram of the processing of the ultraviolet emitter in the second embodiment of the liquid object accumulation printing method of the present invention;

Fig. 8 is the printed product after removing the support material in the second embodiment of the liquid object accumulation printing method of the present invention.

detailed description

The following descriptions of the various embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present invention can be practiced. The directional terms mentioned in the present invention, such as [top] [bottom] [front] [back] [left] [right] [inside] [outside] [side], etc., are only referring to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and understand the present invention, but not to limit the present invention.

As shown in Figure 1, the multi-material 3D printer of the preferred embodiment of the present invention includes a frame 109, an object stage 107, an X-axis single-axis movement module 102, a Y-axis single-axis movement module 103, and a Z-axis single-axis movement module 101 , the print head switching mechanism 105, the power source 104 of the print head switching mechanism, the print head frame 106, the print heads 110 and 111 and 112, the host control system (not shown), the automatic control module (not shown). X-axis single-axis moving module 102, Y-axis single-axis moving module 103, and Z-axis single-axis moving module transmission parts adopt threaded screws, driven by stepping motors, and the moving accuracy reaches 0.1mm. The whole equipment structure is simple and reliable, and the printing accuracy is high. . The Y-axis single-axis moving module 103 is installed on the frame 109 to realize the degree of freedom in the Y-axis direction of the 3D printer print head module (the combination of the print head switching mechanism 105, the print head frame 106 and the print head 110). The print head module includes a fixed X-axis single-axis moving module 102, the print head switching mechanism 105 is driven by a stepping motor 104, and the motor shaft drives the print head 106 to rotate through a pulley. The X-axis single-axis moving module 102 is installed across the Y-axis single-axis moving module 103 and the frame 109 to realize the degree of freedom of the 3D printer print head module in the X-axis direction. The Z-axis single-axis movement module 101 is installed on the frame 109 to realize the degree of freedom of the 3D printer stage 107 in the Z-axis direction. The X-axis, Y-axis and Z-axis form a Cartesian space Cartesian coordinate system, giving the print head module three degrees of freedom. One end of the stage 107 is fixed on the Z-axis single-axis moving module 101 , the other end is fixed on a spline 108 that can slide up and down, and the two ends of the guide rail of the sliding spline 108 are fixed on the frame 109 . By fixing both ends of the object stage 107, the deflection is reduced, and the stability of the object stage 107 and the Z-axis movement precision are improved.

In this embodiment, three printheads 110 , 111 and 112 are installed on the printhead frame 106 , and the printhead switching mechanism 105 is used to rotate the printhead frame 106 to switch the working printheads. There are fixing holes on the print head frame 106, and the print head is fixed by hexagon socket head screws. As shown in Figure 1, the print head 112 is an FDM print head, and the printing material used is a PCL wire; the print head 111 is a motor-driven piston extrusion print head, and the printing material used is a hydrogel embedded with living cells ; The print head 110 is an air pressure ejection type print head (the air pressure adjustment module is not shown), and the printing material used is a medium containing biochemical environment regulators and nutrients. Print heads with different materials and different principles jointly realize multi-material 3D printing. These three print heads will use the liquid object accumulation printing method to print, and also constitute the first embodiment of the liquid object accumulation printing method. If the print head 112 adopts an FDM print head, the material used is changed to the Infinity ^TM Rinse-Away water-soluble support material of 3DSystems; the print head 111 adopts a pneumatic extrusion print head, and the printing material is liquid silica gel containing a photoinitiator; If the print head 110 is changed to an ultraviolet emitter, then printing by using the liquid accumulation printing method constitutes the second embodiment of the liquid accumulation printing method.

The host control system (not shown) takes the computer as the core, and can preprocess the model file to generate the machining code information of the model to be printed, and transmit it to the automatic control module (not shown) through the data line.

Wherein, the automatic control module (not shown) can systematically control the movement and collect data of each mechanism of the entire multi-material 3D printer. Classified according to the control objects, the entire automatic control module is divided into five sub-modules: controller, print head module motion control module, stage motion control module, print head switching mechanism control module and print head control module. As the core of the entire automatic control module, the controller performs operations on all data and communicates with all control objects. The print head module motion control module controls the motors on the X-axis single-axis moving module 102 and the Y-axis single-axis moving module 103 according to the machining code information of the model to be printed generated by the upper control system, and drives the lead screw in the module to move to drive The moving positions, moving speeds and moving accelerations of the print head modules 105, 106, 110, 111, and 112 in the two directions of the X-axis and the Y-axis; at the same time, the control module also collects the X-axis single-axis moving module 102 and the Y-axis The data of the position sensor on the single-axis movement module 103 is communicated with the controller in real time to improve the accuracy of motion control. The stage motion control module controls the motor on the Z-axis single-axis movement module 101 according to the processing code information generated by the model to be printed, and drives the lead screw in the module to move, thereby controlling the moving position of the stage 107 in the Z-axis direction , moving speed and moving acceleration; at the same time, the control module will also collect the data of the position sensor on the Z-axis single-axis moving module 101, and communicate with the controller in real time so as to improve the accuracy of motion control. The print head switching mechanism control module controls the power source 104 motor of the print head switching mechanism 105 to rotate according to the printing material required by the model to be printed, and drives a shaft connected to the print head frame 106 to rotate with a belt pulley, thereby rotating the print head frame 106, Make the required print head 110 or 111 or 112 rotate to the working position, where the shaft is connected with the bearing fixed on the bracket; at the same time, a position sensor is installed on the print head frame 106, which communicates with the controller in real time to collect the print head The rotation position information of the frame 106 improves the position accuracy of the print head.

The print head control module will carry out the motion control and data collection of the print head when needed according to the processing code information generated by the host control system. As shown in Figure 1, in the first embodiment of the method for accumulating and printing liquid objects, the print head 112 is an FDM print head, and the print head control module will control the movement of a stepping motor to send the desired printed thermoplastic PLC wire to the Entering the high-temperature melting chamber, the melting chamber reaches a high temperature (60°C) under the heating of the electric heating wire, changing the filament from solid to fluid state, and extruding from the nozzle through the pressure of the motor. During this process, the print head control module continuously collects and melts The data of the thermal resistance temperature sensor installed in the room constitutes a PID closed-loop control to improve the temperature control accuracy; the print head 111 is a motor-driven piston extrusion print head, and the print head control module will control the movement of the stepping motor to push a piston to print The material container moves to extrude the hydrogel. The heating wire is evenly distributed on the container wall, and four temperature sensors are symmetrically distributed around the container wall. The print head control module continuously collects the temperature sensor data to control the heating wire on and off, so that The container maintains a certain temperature to ensure the fluidity and temperature environment of the gel; the print head 110 is an air pressure ejection type print head (the air pressure adjustment module is not shown), and an electronically controlled air pressure adjustment device is housed on it. The air outlet is connected to the container containing the printing material, and the print head control module controls the air pressure in the container to realize the ejection of the material. In the second embodiment of the liquid accumulation printing method, the print head 112 is an FDM print head, and the structure, printing principle and control mode of the print head are as described above, and will not be repeated here; the print head 111 is a motor-driven piston squeezer. The output type print head, the print head structure, printing principle and control method are as mentioned above, and will not be repeated here; the print head 110 is an ultraviolet emitter, and the print head control module controls the power on and off of the emitter.

Preferably, the data communication mode of the automatic control module adopts the RS485 communication bus under the Modbus protocol.

The present invention also provides a method for accumulating and printing liquid objects, where the liquid objects refer to two kinds of printing materials: 1. thermoplastic materials, the melting temperature of which is between 45°C and 400°C. Second, liquid compounds/liquid mixtures (including: turbid liquid, solution, colloid).

The printing method includes the following steps:

S101, the upper control system first divides the model into several layers according to the information of the model to be printed and the accuracy requirements of the user, and then designs the printing path according to the process requirements: select the corresponding print head 110, 111 or 112 according to the material and processing needs, And plan the motion path corresponding to this print head. Finally, the generated data is transmitted to the automatic control module;

S102, the automatic control module executes corresponding actions according to the data generated by the host control system. First, control the Z-axis single-axis moving module 101 to drive the stage 107 to the corresponding position of each layer of the product according to the layer data; drive the print head switching mechanism 105 to rotate the print head frame 106 according to the required print head 110, 111 or 112 data To the specified angle, so that the required print head 110, 111 or 112 reaches the working position; when the print head is in place, control the X-axis single-axis movement module 102 and Y according to the planned motion control information (position, speed and acceleration) The single-axis moving module 103 drives the print head module to the designated position, and at the same time controls the print head to perform material ejection/extrusion operations in the designed way or controls the post-processing device to reprocess the printed materials; for the next The printing head repeatedly drives the movement of the printing head switching mechanism, drives the movement of the X-axis single-axis moving module and the Y-axis single-axis moving module, and controls the printing head to perform three steps of material ejection/extrusion or reprocessing, so as to complete the printing of this layer ;repeat the preceding steps for all layers to complete the print for this product.

In the method for accumulating and printing liquid objects according to the present invention, in the step S101, the following steps are further included:

The host control system designs the working parameters of the print head 110, 111 or 112 according to the printing process requirements (processing characteristics of the material to be printed);

The host control system designs the feed rate of the print head 110, 111 or 112 according to the printing process requirements (material thickness);

The host control system designs the time and rotation angle for starting the print head switching mechanism 105 according to the requirements of the printing process (when and which print head should be selected to work).

In the method for accumulating and printing liquid objects according to the present invention, in the step S102, the following steps are further included:

Collect the measurement data of various sensors installed on the 3D printer, including the XYZ three-axis position sensor, the position sensor of the print head switching mechanism, and various sensors installed on the print head.

Based on the multi-material 3D printer and liquid accumulation printing method proposed by the present invention, the following printing operations can be performed to break through the two major bottlenecks encountered by the current 3D printing technology:

First, by using thermoplastic materials to print out a container with a complex spatial structure, after the construction of each layer of container is completed, the low-viscosity liquid is filled in it, and then layer by layer, layer by layer, so as to precisely control the low-viscosity liquid The spatial configuration of objects. The first embodiment of the liquid object accumulation printing method is proposed here for illustration, as shown in FIG. 2 , FIG. 3 , and FIG. 4 . In this embodiment, three materials are used for printing, PCL, hydrogel embedded with living cells, and culture medium containing biochemical environmental regulators and nutrients. First use the FDM print head 991 to print the zeroth layer 001, which is completely composed of PCL, to form the bottom of the container, and then start to print the first layer, the second layer, the third layer of the multi-material layer layer by layer... until the end. In the printing process of each single layer, the PCL material is used to print first, the periphery is closed, and the interior is filled with other materials. Take the printing of the third layer as an example, as shown in Figure 2, after the printing of the PCL material 031 is completed on this layer, use the print head switching mechanism 105 in Figure 1 to switch the working print head to the hydrogel print head 992, as As shown in Figure 3, the hydrogel material starts to be printed, and the hydrogel 032 is filled in the space structure 031 controlled by the PCL. After the printing of the hydrogel material is completed on this layer, use the printing head switching mechanism 105 in Fig. 1 to switch the working printing head to the medium printing head 993, as shown in Fig. Medium 033 containing biochemical environmental regulators and nutrients is uniformly printed in the glue. In addition, it can be seen in Figure 2 that the 011 of the first layer, the 021 of the second layer and the 031 of the third layer are printed with PCL materials, the periphery is closed, and other materials are printed with other print heads inside. The inside of the third layer is also filled with PCL 031, which is used as an inner container to control the spatial configuration of the hydrogel and the medium. It can also be seen in Figure 2 that the structure of the second layer printed before: PLC controls the spatial configuration 021 of the second layer, fills the hydrogel 022 in the gap, and sprays the medium 023 on the hydrogel.

Second, by setting the material post-processing print head on the print head frame, after each layer of material that needs post-processing is printed, the print head frame is switched to the post-processing print head to further process the material, thereby solving the problem of 3D printing. The post-processing problems in the material printing process effectively broaden the types of 3D printing materials that can be printed. A second embodiment of the method for accumulating and printing liquid objects is proposed here for illustration, as shown in FIG. 5 , FIG. 6 , FIG. 7 , and FIG. 8 . In this embodiment, the Infinity ^TM Rinse-Away water-soluble support material of 3DSystems company, raw rubber [ingredients are: methyl vinyl silicone oil, silane coupling agent, photoinitiator benzophenone (BP), MQ Silicone resin, cross-linking agent triallyl isocyanurate (TAIC)] two materials for printing, and use UV emitter for cross-linking of silicone. First use the FDM print head 991 to print the zeroth layer 001, which is completely composed of water-soluble support materials, to form the bottom of the product, and then start printing the first layer, the second layer... until the end. In the printing process of each single layer, the water-soluble support material is first printed to control the spatial configuration of the raw rubber before cross-linking, then the raw rubber is printed, and finally the UV light emitter is used to cross-link and cure the raw rubber. glue. Taking the printing of the second layer as an example, as shown in Figure 5, after the printing of the water-soluble support material 021 is completed on this layer, the working printing head is switched to the raw rubber printing head 992 by using the printing head switching mechanism 105 in Figure 1 , As shown in FIG. 6 , the raw rubber material is printed, and the raw rubber 032 is filled in the space structure 021 controlled by the water-soluble support material. After the raw rubber material is printed on this layer, use the print head switching mechanism 105 in Figure 1 to switch the working print head to the UV emitter print head 993, as shown in Figure 7, to irradiate the raw rubber with ultraviolet light, thereby realizing Cross-linking of raw rubber to realize reprocessing during 3D printing. Finally, the water-soluble support material is washed away with water to obtain the desired silica gel product, as shown in FIG. 8 . In addition, it can be seen in FIG. 5 that the first layer 011 and the second layer 021 are printed using water-soluble support materials. It can also be seen in Figure 5 that the structure of the first layer printed before: the water-soluble support material controls the spatial configuration 011 of the first layer, and raw rubber 012 is filled in the gaps.

The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make many modifications and changes according to the concept of the present invention without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art shall be within the scope of protection defined by the claims.

Claims (18)

1. A kind of multi-material 3D printer, it is characterized in that, comprises frame, stage, uniaxial movement module, printing head module, wherein, described uniaxial movement module comprises X-axis uniaxial movement module, Y-axis uniaxial A mobile module, a Z-axis single-axis mobile module; the Y-axis single-axis mobile module is installed on the frame, and the X-axis single-axis mobile module is installed across the Y-axis single-axis mobile module and the machine The Z-axis single-axis movement module is vertically installed on the frame; the print head module is fixedly arranged on the X-axis single-axis movement module. 2. The multi-material 3D printer according to claim 1, wherein one end of the stage is fixed on the Z-axis single-axis moving module, the other end is fixed on a spline, and the spline slides The ends of the key rails are secured to the rack. 3. The multi-material 3D printer according to claim 1, wherein the print head module comprises a print head switching mechanism, a print head frame and one or more print heads. 4. The multi-material 3D printer according to claim 3, wherein the print head is mounted on the print head frame, and the print head switching mechanism is configured to rotate the print head frame; the printing Fixing holes or clamps are provided on the head frame, and the printing head is configured to be fixed through the fixing holes or the clamps. 5. The multi-material 3D printer according to claim 3, wherein the print head is a device for ejecting or extruding printing materials, or a device for post-processing materials. 6. The multi-material 3D printer according to claim 5, wherein the method of ejecting or extruding printing materials is electromagnetic ejection, piezoelectric ejection, air pressure ejection, or piston extrusion Or one of the screw extrusion type; the post-processing device is a laser or an air spray gun. 7. The multi-material 3D printer according to claim 1, wherein the multi-material 3D printer also includes a host control system and an automatic control module, and the host control system is configured to use a computer as the core to process model files Perform preprocessing to generate machining code information of the model to be printed, and transmit it to the automatic control module through the data line; the automatic control module is configured to control the movement and data collection of the various mechanisms of the entire multi-material 3D printer. 8. The multi-material 3D printer according to claim 7, wherein the automatic control module comprises a controller, a print head module motion control module, a stage motion control module, a print head switching mechanism control module, and a print head control module. 9. The multi-material 3D printer according to claim 8, wherein the print head module motion control module is configured to control the printing according to the machining code information of the model to be printed generated by the host control system. The moving position, moving speed and moving acceleration of the head module in the two directions of X-axis and Y-axis; the motion control module of the printing head module also includes a position sensor, and the position sensor communicates with the controller in real time. 10. The multi-material 3D printer according to claim 8, wherein the stage motion control module is configured to control the movement of the stage in the Z-axis direction according to the machining code information generated by the model to be printed position, moving speed and moving acceleration; the stage motion control module also includes a position sensor, and the position sensor communicates with the controller in real time. 11. The multi-material 3D printer according to claim 8, wherein the print head switching mechanism control module is configured to control the movement of the print head switching mechanism according to the printing materials required by the model to be printed, including rotating the print head frame , so that the required print heads are moved to the working position; the control module of the print head switching mechanism further includes a position sensor, and the position sensor communicates with the controller in real time. 12. The multi-material 3D printer according to claim 8, wherein the print head control module is configured to collect sensor data and control the movement of the actuators of the print head at the desired moment. 13. The multi-material 3D printer according to claim 7, wherein the data communication mode of the automatic control module adopts the RS485 communication bus under the Modbus protocol. 14. A method for accumulating 3D printing of liquid objects, comprising the following steps: S100, providing a multi-material 3D printer according to any one of claims 1-13; S101. The upper control system first divides the model into several layers according to the information of the model to be printed and the accuracy requirements of the user, and then selects the corresponding print head according to the material and processing needs, and plans the corresponding movement path of the print head; S102. The automatic control module executes corresponding actions according to the data generated by the host control system, and collects measurement data of sensors installed on the 3D printer. 15. The method for accumulating and printing liquid objects according to claim 14, characterized in that the step S101 further comprises the following steps: S101A. The host control system designs the working parameters of the printing head, the feeding rate of the printing head, the time and the rotation angle of starting the switching mechanism of the printing head according to the requirements of the printing process. 16. The method for accumulating and printing liquid objects according to claim 14, characterized in that the step S102 further comprises the following steps: S102A. Control the Z-axis single-axis moving module to drive the stage to the corresponding position of each layer of the product according to the layer data; drive the print head switching mechanism to rotate the print head frame to the specified angle according to the required print head data, so that the required print The head reaches the working position; S102B. When the print head is in place, control the X-axis single-axis movement module and the Y-axis single-axis movement module to drive the print head module to the designated position according to the planned motion control information, and at the same time control the print head to execute the material in the designed way Jetting/extrusion operations or controlling post-processing processing devices to reprocess printed materials; S102C, repeatedly driving the movement of the printing head switching mechanism for the next printing head, driving the movement of the X-axis single-axis moving module and the Y-axis single-axis moving module, and controlling the printing head to perform material ejection/extrusion or reprocessing steps; S102D. Repeat the foregoing steps for all layers. 17. The method for accumulating and printing liquid objects according to claim 14, wherein the liquid objects refer to thermoplastic materials with a melting temperature between 50°C and 400°C. 18. The method for accumulating and printing liquid objects according to claim 14, wherein the liquid objects refer to liquid compounds or liquid mixtures.