CN112848278A

CN112848278A - Passive mixed functional gradient material 3D printing nozzle suitable for ink-jet printing

Info

Publication number: CN112848278A
Application number: CN202110005176.6A
Authority: CN
Inventors: 郭鑫; 刘也琪; 于淼; 赵武; 张凯; 陈领
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2021-01-05
Filing date: 2021-01-05
Publication date: 2021-05-28

Abstract

The invention discloses a passive mixing functional gradient material 3D printing nozzle suitable for ink-jet printing, which comprises a mixing barrel, a feeding pipe arranged at the upper part of the mixing barrel and a nozzle arranged at the bottom of the mixing barrel; more than one mixing unit is arranged in the mixing cylinder along the axial direction; each mixing unit is formed by splicing a plurality of corrugated plates; the inclination angle directions of two adjacent corrugated plates in the mixing unit are mutually vertical. Firstly, liquid raw materials are added into a mixing cylinder through a feeding pipe in an opposite direction, so that the primary mixing effect of the liquid raw materials just entering the mixing cylinder is improved; the mixing units spliced by the corrugated plates form a passive mixing structure, and the flowing direction of the liquid is disordered continuously when the mixed liquid raw material passes through the mixing units, so that the mixing effect of the liquid raw material is further improved; this mixing method can mix liquids uniformly with a viscosity of 110cP or less, and is applicable to mixing of all inkjet-based coating materials.

Description

Passive mixed functional gradient material 3D printing nozzle suitable for ink-jet printing

Technical Field

The invention belongs to the technical field of 3D printing, relates to a 3D printing nozzle, and particularly relates to a passive mixed functional gradient material 3D printing nozzle suitable for ink-jet printing.

Background

The 3D printing technique is one of the rapid prototyping techniques, which constructs an object by printing layer by layer. This rapid prototyping technique enables the manufacture of objects of almost any complex geometry. Traditional 3D printing technique is used for the 3D of single material to print more, and the 3D of present many materials prints and adopts the multiinjector mode, and the wire rod mixes after the heating melting again, and the material is difficult for misce bene, and needs external power source to increased the complexity of 3D printing apparatus structure, also can't guarantee the positioning accuracy after trading the material.

Especially for inkjet 3D printer, the domestic start is late, and the printing material is liquid viscosity material, and most shower nozzles on the market can not be used for being suitable for.

In addition, although the inkjet-based 3D printing is the only 3D printing technology that can realize voxel-level printing at present, the nozzle diameter is small, the spraying material is single, the structure of the spray head is complex, and the nozzle is used as the only outlet of the spraying material, so that the problems of blockage and the like are easily caused.

Disclosure of Invention

Aiming at the technical problems of uneven mixing, easy blockage, difficulty in realizing a multi-material three-dimensional structure and the like existing in the existing 3D printing technology, the invention aims to provide a passive mixing functional gradient material 3D printing nozzle suitable for ink-jet printing, which realizes uniform mixing of materials by improving the structure of a rotating blade, and is further beneficial to realizing high-precision and functional gradient material printing of 3D ink-jet printing.

The invention provides a passive mixing functional gradient material 3D printing nozzle suitable for ink-jet printing, which comprises a mixing barrel, a feeding pipe arranged at the upper part of the mixing barrel and a nozzle arranged at the bottom of the mixing barrel;

the mixing cylinder is of a cylindrical structure with an opening at the upper end; and the open end of the mixing cylinder is provided with a sealing cover;

the feeding pipes are at least two in number and are uniformly arranged at the upper part of the mixing port along the axial direction of the mixing barrel;

more than one mixing unit is arranged in the mixing cylinder along the axial direction; each mixing unit is of a cylindrical structure formed by splicing a plurality of corrugated plates, and the shape of each mixing unit is matched with the inner wall of the mixing cylinder; the inclination angle directions of two adjacent corrugated plates in the mixing unit are mutually vertical.

Above-mentioned passive mixed functional gradient material 3D prints shower nozzle suitable for inkjet printing, the liquid raw materials that need mix gets into mixing barrel through the inlet pipe respectively in proportion, and each liquid raw materials proportion can carry out accurate control through the solenoid valve of installing on the inlet pipe in getting into mixing barrel. In the mixing cylinder, the flow direction of liquid can be disturbed continuously through the arranged mixing units, so that a good fluid mixing effect is realized. The uniformly mixed liquid raw materials are sprayed out through a nozzle, and 3D printing is completed.

Above-mentioned passive mixed functional gradient material 3D prints shower nozzle suitable for inkjet printing, the liquid inlet that is connected with the inlet pipe on the compounding section of thick bamboo is mutually perpendicular with compounding section of thick bamboo axial (liquid inlet is 90 degrees with compounding section of thick bamboo axial promptly), can make like this that the liquid raw materials contained angle that enters into the compounding section of thick bamboo of spraying with certain velocity of flow is the biggest, and the counterpulsation effort is the biggest, and the shearing action that liquid produced when the convection current is the biggest, and the turbulent phenomenon in the compounding section of thick bamboo is the biggest to make the mixed effect best. In a preferred embodiment, the feed tube is L-shaped with a horizontal portion connected to the mixing bowl liquid inlet to further ensure maximum included angle of liquid feedstock entering the mixing bowl. When only two printing raw materials exist, the number of the feeding pipes is two, and the feeding pipes are symmetrically arranged on two sides of the mixing barrel.

According to the passive mixed functional gradient material 3D printing nozzle suitable for ink-jet printing, the diameter of the mixing unit is the same as the inner diameter of the mixing cylinder; the aspect ratio of the mixing unit is 1.5: 1; when the number of the mixing units is more than two, the spacing distance between two adjacent mixing units is equal to the length of the mixing units; mixing unit constantly plays cutting, rotation effect to the liquid that flows through like this and makes its dispersion, obtains converging again between two mixing unit afterwards, cuts apart many times, joins and makes liquid raw materials mix more evenly, and the contrast does not have the mixing unit of interval distance, and the liquid viscosity scope of being suitable for is wider. In a preferred implementation, the number of mixing units is three. The angle between the inclined direction and the vertical direction of the corrugated plates forming the mixing unit is 30-60 degrees, so that the liquid raw materials can be mixed more uniformly. In a preferred implementation, the corrugated sheet has a crest height of 5mm and a corrugation pitch of 45 °. Through the mixing unit arranged above, the mixing effect of two liquids with the viscosity of less than or equal to 110cP can be optimized. The viscosity of the ink-jet ink used by the ink-jet based 3D printing technology is below 20cP, and the mixing unit provided by the invention has wide application range and covers all spraying materials used by the ink-jet based 3D printing material.

Above-mentioned passive mixed functional gradient material 3D printing nozzle suitable for inkjet printing, the nozzle is conductive nozzle, and the electric field force that forms between conductive nozzle and the electrically conductive base plate of setting on the print table draws out the liquid in the compounding section of thick bamboo from the nozzle and forms the taylor cone, realizes voxel level 3D and prints. Since the nozzle is extremely fine (inner diameter 20 μm to 40 μm), the nozzle is easily clogged if the liquid viscosity is too high. According to the invention, the high-voltage pulse power supply is applied between the conductive nozzle and the conductive substrate, and the liquid is pulled out from the nozzle by using the electric field force formed between the nozzle and the substrate to form the Taylor cone, so that the sprayed liquid drop is sprayed from the nozzle by overcoming the surface tension to form the superfine cone jet flow, the nozzle blockage is avoided, the applicable liquid viscosity range of 3D printing is expanded, and the voxel-level 3D printing is further realized.

Compared with the prior art, the passive mixed functional gradient material 3D printing nozzle suitable for ink-jet printing provided by the invention has the following outstanding advantages and beneficial technical effects:

1. firstly, liquid raw materials are added into a mixing cylinder through a feeding pipe in an opposite direction, so that the primary mixing effect of the liquid raw materials just entering the mixing cylinder is improved; the mixing units spliced by the corrugated plates form a passive mixing structure, and the flowing direction of the liquid is disordered continuously when the mixed liquid raw material passes through the mixing units, so that the mixing effect of the liquid raw material is further improved; by adopting the mixing mode, the liquid with the viscosity of less than or equal to 110cP can be uniformly mixed, and the method is suitable for mixing all spray materials based on ink jet;

2. the inclination angles of two adjacent corrugated plates forming the mixing unit are mutually vertical, so that the liquid mixing unit is more favorable for disturbing the flowing direction of liquid, is more favorable for passively mixing liquid raw materials and provides a liquid raw material mixing effect;

3. according to the invention, a plurality of mixing units are axially arranged in the mixing cylinder at intervals, the distance between two adjacent mixing units is the length of one mixing unit, and the two adjacent mixing units relatively rotate for 90 degrees, so that the mixing effect of liquid raw materials is further improved;

4. the nozzle used in the invention is a conductive nozzle, a high-voltage pulse power supply is applied between the conductive nozzle and the conductive substrate, and the liquid is pulled out from the nozzle by using the electric field force formed between the nozzle and the substrate to form a Taylor cone, so that the sprayed liquid drop can be sprayed from the nozzle by overcoming the surface tension to form a superfine cone jet flow, thereby avoiding the nozzle from being blocked.

Drawings

Fig. 1 is a schematic perspective view of a passive mixed functionally graded material 3D printing head suitable for inkjet printing according to the present invention.

Fig. 2 is an exploded view of a passive mixed functionally graded material 3D printing head suitable for inkjet printing according to the present invention.

Fig. 3 is an exploded view of the mixing unit.

Fig. 4 is a schematic diagram illustrating the principle of using the 3D printing head and the conductive substrate in combination.

In the figure, 1, a mixing cylinder, 2, a feeding pipe, 3, a sealing cover, 4, a nozzle, 5, a fixing plate, 6, a mixing unit, 61, a corrugated plate, 7, a printing piece, 8, a high-voltage power supply, 9, a conductive substrate, 10 and a printing workbench.

Detailed Description

The embodiments of the present invention will be given below with reference to the accompanying drawings, and the technical solutions of the present invention will be further clearly and completely described by the embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the disclosure of the invention without any inventive step, are within the scope of the invention.

Examples

The passive mixing functionally graded material 3D printing nozzle suitable for inkjet printing in the present embodiment, as shown in fig. 1 and fig. 2, includes a mixing barrel 1, a feeding pipe 2 installed on the upper portion of the mixing barrel, and a nozzle 4 installed on the bottom of the mixing barrel.

As shown in fig. 1 and 2, the mixing cylinder 1 is a cylindrical structure with an open upper end, and a sealing cover 3 is arranged at the open end of the mixing cylinder; a convex part provided with an external thread extends from one side of the sealing cover; the sealing cover is connected with the mixing cylinder through threads. The sealing cover is further connected with the fixing plate 5 by bolts.

In this embodiment, as shown in fig. 1 and 2, the number of the feeding pipes 2 is two, and the two feeding pipes are not in an L-shaped structure and are symmetrically arranged at the upper part of the mixing opening along the axial direction of the mixing drum; the horizontal part of the feed pipe 2 is connected with a liquid inlet of the mixing cylinder, and the liquid inlet connected with the feed pipe on the mixing cylinder is axially vertical to the mixing cylinder.

In this embodiment, as shown in fig. 1 to 2, three mixing units 6 are fixedly mounted in the mixing drum along the axial direction thereof, and the three mixing units are spaced apart by the length of one mixing unit. The aspect ratio of the mixing unit was 1.5: 1. Every mixing unit is the cylindricality structure that is formed by the concatenation of a plurality of buckled plate 61 (five buckled plates in this embodiment), and its appearance and compounding section of thick bamboo inner wall phase-match, and mixing unit's diameter is the same with compounding section of thick bamboo internal diameter. The wave crest height of the corrugated plate is 5mm, and the inclination angle of the corrugated plate is 45 degrees. In order to make the liquid raw materials be better disturbed, as shown in fig. 3, the inclination angles of two adjacent corrugated plates in the mixing unit are perpendicular to each other, and the two adjacent mixing units rotate 90 degrees relatively, so that the adjacent liquid raw materials are disturbed again when flowing into the adjacent mixing units from one mixing unit, and the passive mixing effect is further improved.

As shown in fig. 1 and 2, the nozzle 4 is fixedly mounted to the bottom of the mixing cylinder by a screw cap having a through hole. A gasket for improving the sealing performance is further sleeved on the screw cap. The nozzle used in this example was a conductive nozzle having an inner diameter of 30 μm. In order to form a uniform electric field around the conductive nozzles, as shown in fig. 4, the 3D printer provided by the present embodiment further includes a conductive substrate 9 mounted on the printing table 10. The conductive nozzle 4 is connected to the positive electrode of the high voltage power supply 8, and the conductive substrate 9 is connected to the negative electrode of the high voltage power supply 8 and grounded.

The above-mentioned passive mixed function gradient material 3D who is applicable to the inkjet and prints the shower nozzle, installs the relevant position of 3D printer through the fixed plate 5 that links firmly with sealed lid 3.

The above-mentioned passive mixed functional gradient material 3D who is applicable to inkjet printing prints shower nozzle's theory of operation does: liquid raw materials to be mixed respectively enter the mixing barrel through the feeding pipe in proportion. In the mixing cylinder, the flow direction of liquid can be disturbed continuously through the arranged mixing units, so that a good fluid mixing effect is realized. The uniformly mixed liquid raw materials are sprayed out through the nozzle, liquid is pulled out from the nozzle by utilizing the electric field force formed between the nozzle and the substrate to form a Taylor cone, so that sprayed liquid drops can be sprayed from the nozzle by overcoming the surface tension to form superfine cone jet flow, 3D printing is further completed according to a program set by 3D printing, and a printing piece 7 is obtained.

It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

Claims

1. A3D printing nozzle suitable for passively mixing functionally graded materials for ink-jet printing is characterized by comprising a mixing barrel (1), a feeding pipe (2) arranged at the upper part of the mixing barrel and a nozzle (4) arranged at the bottom of the mixing barrel;

the mixing cylinder (1) is of a cylindrical structure with an opening at the upper end; and the open end of the mixing cylinder is provided with a sealing cover (3);

the number of the feeding pipes (2) is at least two, and the feeding pipes are uniformly distributed on the upper part of the mixing opening along the axial direction of the mixing barrel;

more than one mixing unit (6) is arranged in the mixing barrel along the axial direction; each mixing unit is a cylindrical structure formed by splicing a plurality of corrugated plates (61), and the shape of each mixing unit is matched with the inner wall of the mixing cylinder; the inclination angle directions of two adjacent corrugated plates in the mixing unit are mutually vertical.

2. 3D print head for passively mixing functionally graded material suitable for inkjet printing according to claim 1 characterised in that the liquid inlet on the mixing bowl (1) connected to the feed tube (2) is axially perpendicular to the mixing bowl.

3. 3D print head for passively mixing functionally graded material suitable for inkjet printing according to claim 2 characterised in that the feed pipe (2) is L-shaped with its horizontal part connected to the liquid inlet of the mixing bowl.

4. 3D print head for passively mixing functionally graded material suitable for inkjet printing according to claim 2 or 3 characterized in that the feed pipes (2) are two in number and symmetrically arranged on both sides of the mixing bowl when there are only two printing materials.

5. The passive mixing functionally graded material 3D print head suitable for inkjet printing according to claim 1 wherein the diameter of the mixing unit is the same as the inner diameter of the mixing barrel; the aspect ratio of the mixing unit is 1.5: 1.

6. The passive mixing functionally graded material 3D print head suitable for inkjet printing according to claim 5 wherein when the number of mixing units is two or more, the distance between two adjacent mixing units is equal to the length of the mixing unit.

7. The passively mixed functionally graded material 3D print head according to claim 5 or 6, wherein the corrugated plates forming the mixing unit are inclined at an angle of 30 ° to 60 ° from the vertical.

8. The passive hybrid functionally graded material 3D print head suitable for inkjet printing according to claim 7 wherein the corrugated plate has a peak height of 5mm and a corrugation pitch of 45 °.

9. The passive mixing functionally graded material 3D print head suitable for inkjet printing according to claim 1 wherein the nozzle is a conductive nozzle, and the electric field force formed between the conductive nozzle and a conductive substrate disposed on the printing table pulls the liquid in the mixing cylinder out of the nozzle to form a Taylor cone, thereby realizing voxel-level 3D printing.