Cross-modulus material gradient printing feeding system

Abstract

The invention discloses a cross-modulus material gradient printing feeding system. An ultrasonic oscillator is fixed to the outer portion of a mixing barrel. The mixing barrel is communicated with the gradient feeding system, the gradient feeding system is communicated with the screw extrusion system, and the gradient feeding system comprises a discharging pipe, a liquid pipeline, a one-way switch valve and a multi-port communicating vessel; the multiple discharging pipes are sequentially arranged in the vertical height direction of the mixing barrel, and the arrangement height of each discharging pipe corresponds to one layered material; each discharge pipe is connected with a liquid pipeline, and each liquid pipeline is provided with a one-way switch valve; and the multi-port communicating vessel is mounted at the lateral upper part of the screw extrusion system, is connected with all the liquid pipelines and is used for feeding materials in the liquid pipelines into the screw extrusion system. In the whole printing process, the printing process does not need to be stopped for material replacement, material switching in the printing process is achieved through gradient feeding, the work period is short, and efficiency is high.

Description

Technical Field

[0001] The present invention belongs to the field of extrusion biological 3D printing, and in particular relates to a cross-modulus material gradient printing feeding system. Background Art

[0002] With the gradual maturity of 3D printing technology, a variety of biomedical related printing equipment has emerged in recent years, such as: 3D printing equipment based on the molding principles of melt deposition, extrusion, photocuring, laser sintering, etc., using metals, alloys, ceramics, plastics, hydrogels, etc. as printing inks, and applied to bone implants, dental implants, bone guides, medical teaching instruments, etc. For example, when using inorganic substances as printing inks to construct bionic bone structures, when printing structures with different density requirements such as cortical bone and cancellous bone, the conventional solution is to use multiple nozzles to print multiple groups of inks. On the one hand, it is necessary to switch nozzles back and forth to achieve gradient printing of cross-modulus materials with different particle sizes. On the other hand, when configuring materials, it is necessary to screen bone powders of various particle sizes separately and configure separate inks. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention proposes a cross-modulus material gradient printing and feeding system to solve the problem of continuous gradient printing of cross-modulus materials in the existing extrusion biological 3D printing technology, completely abandon the existing cross-modulus material gradient printing method that relies on multiple nozzles, and realize fast, granularity-controllable gradient distribution printing.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A cross-modulus material gradient printing feeding system, comprising a mixing barrel, a material pool, a screw feeding system, a gradient feeding system, a screw extrusion system, an extrusion head and an ultrasonic oscillator;

[0006] Among them, a feed port is opened on one side of the top of the mixing barrel, the material pool is fixedly connected to the feed port of the mixing barrel, and the material pool is used to accommodate the cross-modulus material; the piston rod of the screw feeding system penetrates into the material pool, and is used to push the cross-modulus material in the material pool into the mixing barrel; the ultrasonic oscillator is fixed on the outside of the mixing barrel; the mixing barrel is connected to the gradient feeding system, the gradient feeding system is connected to the screw extrusion system, and the extrusion head is located in the screw extrusion system;

[0007] The gradient feeding system includes a discharge pipe, a liquid pipeline, a one-way switch valve and a multi-port communicating vessel; the plurality of discharge pipes are opened in sequence along the vertical height direction of the mixing barrel, and the opening height of each discharge pipe corresponds to one of the layered materials; each of the discharge pipes is connected to a liquid pipeline, and each of the liquid pipelines is provided with a one-way switch valve; the multi-port communicating vessel is installed on the upper side of the screw extrusion system, and the multi-port communicating vessel is connected to all the liquid pipelines, and is used to deliver the material in the liquid pipeline into the screw extrusion system.

[0008] Furthermore, a one-way valve is provided at the bottom of the material pool to control the material to flow from the material pool into the mixing barrel in one direction.

[0009] Furthermore, an air hole is provided on the top of the mixing barrel to balance the air pressure in the mixing barrel.

[0010] Furthermore, the gradient feeding system has at least one discharge pipe.

[0011] Furthermore, the extrusion head is fixed on a three-axis motion mechanism, and other parts of the cross-modulus material gradient printing and feeding system are fixed on an extrusion printer frame.

[0012] The beneficial effects of the present invention are as follows:

[0013] The cross-modulus material gradient printing feeding system of the present invention utilizes the characteristics of static stratification of cross-modulus materials. Only by oscillating the mixing barrel containing bone powder of various particle sizes through an ultrasonic oscillator, the materials will be automatically stratified, and then the bone powder of different particle sizes is fed into the extruder through a liquid pipeline connecting different layers of materials, and a cross-modulus material gradient structure can be formed. Compared with conventional extrusion printing, it is suitable for integrated printing and molding of multiple materials with the same nozzle, greatly improving the efficiency of multi-material extrusion printing; compared with the conventional printing method of switching material pools or extruder heads, the present invention does not need to stop the printing process to replace materials during the entire printing process, and realizes the switching of materials during the printing process through gradient feeding, especially for cross-modulus materials such as bone powder + hydrogel, with a short working cycle, high efficiency and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a cross-modulus material gradient printing and feeding system according to an embodiment of the present invention.

[0015] Figure 2 Schematic diagram of gradient feeding system 4. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] like Figure 1 As shown, the cross-modulus material gradient printing feeding system of this embodiment includes a mixing barrel 1, a material pool 2, a screw feeding system 3, a gradient feeding system 4, a screw extrusion system 5, an extrusion head 6 and an ultrasonic oscillator 8. Among them, the material pool 2 is fixedly installed at the feed port on one side of the top of the mixing barrel 1, and the material pool 2 is used to accommodate the cross-modulus material. A one-way valve is set at the bottom of the material pool 2 to control the material to flow from the material pool 2 to the mixing barrel 1 in one direction.

[0018] The piston rod of the screw feeding system 3 penetrates into the material pool 2 to push the cross-modulus material in the material pool 2 into the mixing barrel 1. The top of the mixing barrel 1 is also provided with an air hole 7 to balance the air pressure in the mixing barrel 1. The ultrasonic oscillator 8 is fixed to the outside of the mixing barrel 1 to provide vibration drive for the cross-modulus material in the mixing barrel 1. The mixing barrel 1 is connected to the gradient feeding system 4, the gradient feeding system 4 is connected to the screw extrusion system 5, and the extruder head 6 is located in the screw extrusion system 5.

[0019] Among them, Figure 2 As shown, the gradient feeding system 4 includes a discharge pipe 401, a liquid pipeline 402, a one-way switch valve 403 and a multi-port communication vessel 404. Multiple discharge pipes 401 are opened in sequence along the vertical height direction of the mixing barrel 1, and the opening height of each discharge pipe 401 corresponds to one of the layered materials. Each discharge pipe 401 is connected to a liquid pipeline 402, and a one-way switch valve 403 is arranged on each liquid pipeline 402. The multi-port communication vessel 404 is installed on the upper side of the screw extrusion system 5, and the multi-port communication vessel 404 is connected to all the liquid pipelines 402, and is used to send the material in the liquid pipeline 402 into the screw extrusion system 5. By real-time switching on and off the one-way switch valve 403, it is possible to extract ink from different vertical heights of the mixing barrel 1 into the extruder head 6, and then extrude the ink into shape through the screw extrusion system 5.

[0020] The cross-modulus material gradient printing and feeding system of this embodiment is mounted on an extrusion printer frame. The extrusion printer frame mainly consists of a frame and a conventional three-axis motion mechanism, including but not limited to a Cartesian coordinate system motion mechanism, which can be stably placed on the ground or platform surface by fixing feet. Except for the extrusion head 6 mounted on the three-axis motion mechanism, other components are fixed on the extrusion printer frame.

[0021] This embodiment takes bone powder hydrogel as an example, and describes the working principle of the cross-modulus material gradient printing feeding system of this embodiment with a gradient feeding system 4 having 5 discharge pipes 401. There is no need to manually separate bone powder of different particle sizes. The bone powder hydrogel is mixed and placed in the material pool 2. The screw feeding system 3 drives the push rod to push the material in the material pool 2 into the mixing barrel 3, and the ultrasonic oscillator 8 is started. The bone powder of different particle sizes is layered in the mixing barrel 1 after ultrasonic oscillation. The five one-way switch valves 403 of the gradient feeding system 4 are opened and closed according to demand, and the screw extrusion system 5 is started. As the screw extrusion system 5 rotates, negative pressure is generated at the discharge port of the one-way switch valve 403, and the bone powder hydrogel material at the open valve is sucked out and enters the extruder 6. As the screw extruder system 5 rotates, the material is pushed out of the needle tip of the extruder 6 to form an extruded wire. By switching the five one-way switch valves 403 of the gradient feeding system 4, the hydrogel ink containing bone powder of different particle sizes is formed into a cross-modulus material gradient structure.

[0022] The cross-modulus material gradient printing and feeding system of the present invention can realize the free and high-precision distribution of various materials in space according to the designed structure, support the continuous printing of materials with a large modulus span, especially the on-demand mixed printing of low modulus hydrogels and high modulus bone powder, and support the three-dimensional spatial density gradient distribution of heterogeneous multi-particle size bone powder, and can realize automatic, rapid, and controllable gradient distribution printing.

[0023] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. A cross-modulus material gradient printing feeding system, characterized in that: It comprises a mixing barrel (1), a material pool (2), a screw feeding system (3), a gradient feeding system (4), a screw extrusion system (5), an extrusion head (6) and an ultrasonic oscillator (8); Wherein, a feed port is provided on one side of the top of the mixing barrel (1); the material pool (2) is fixedly connected to the feed port of the mixing barrel (1); the material pool (2) is used to contain the cross-modulus material; the piston rod of the screw feeding system (3) penetrates into the material pool (2) to push the cross-modulus material in the material pool (2) into the mixing barrel (1); the ultrasonic oscillator (8) is fixed on the outside of the mixing barrel (1); the mixing barrel (1) is connected to the gradient feeding system (4), the gradient feeding system (4) is connected to the screw extrusion system (5), and the extrusion head (6) is located in the screw extrusion system (5); The gradient feeding system (4) comprises a discharge pipe (401), a liquid pipeline (402), a one-way switch valve (403) and a multi-port communicating vessel (404); a plurality of the discharge pipes (401) are opened in sequence along the vertical height direction of the mixing barrel (1), and the opening height of each of the discharge pipes (401) corresponds to one of the layered materials; each of the discharge pipes (401) is connected to a liquid pipeline (402), and each of the liquid pipelines (402) is provided with a one-way switch valve (403); the multi-port communicating vessel (404) is installed on the upper side of the screw extrusion system (5), and the multi-port communicating vessel (404) is connected to all the liquid pipelines (402) for feeding the material in the liquid pipeline (402) into the screw extrusion system (5).

2. The cross-modulus material gradient printing and feeding system according to claim 1, characterized in that: A one-way valve is arranged at the bottom of the material pool (2) for controlling the material to flow from the material pool (2) into the mixing barrel (1) in one direction.

3. The cross-modulus material gradient printing and feeding system according to claim 1, characterized in that: The top of the mixing barrel (1) is also provided with an air hole (7) for balancing the air pressure in the mixing barrel (1).

4. The cross-modulus material gradient printing and feeding system according to claim 1, characterized in that: The gradient feeding system (4) has no less than three discharge pipes (401).

5. The cross-modulus material gradient printing and feeding system according to claim 1, characterized in that: The extrusion head (6) is fixed on a three-axis motion mechanism, and the other parts of the cross-modulus material gradient printing and feeding system are fixed on an extrusion printer frame.

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