CN104690960A - 3d printing system - Google Patents

Abstract

The present application discloses a 3D printing system, including: a workbench; an ink cartridge storing cured material; a nozzle; a drive pump to deliver the cured material in the ink cartridge to the nozzle; a high-voltage generator connected to the nozzle to make the nozzle The cured material is charged. In the present invention, a high-voltage generator is connected to the nozzle so that the liquid droplets are positively charged. The droplet is placed in the electric field, which provides another driving force for the droplet besides gravity, which makes the drop trajectory of the droplet more accurate, and enables liquid materials with greater viscosity to be ejected from the nozzle.

Description

3D printing system

technical field

This application belongs to the field of 3D printing, and in particular relates to a 3D printing system provided with a high-voltage generator.

Background technique

3D printing technology is a kind of manufacturing technology based on digital technology, establishing a digital model for the target object through software, and dividing the model into a series of 2D printing slices, relying on the numerical control molding system to print layer by layer, and finally accumulating into physical objects. Unlike the traditional manufacturing industry that processes raw materials through mechanical processing such as moulds, turning and milling, 3D printing manufacturing technology can manufacture products of any configuration without complex processes and various equipment, which can reduce mold loss and avoid artificial Mistakes, reduce production costs and labor intensity. Therefore, 3D manufacturing technology has received widespread attention in recent years.

The current 3D manufacturing technologies mainly include: (1) Fused deposition modeling technology (FDM), which heats and melts hot-melt raw materials, extrudes them continuously from the nozzle, and the extruded part of the material cools and solidifies, and is fused with the previous material to form In fact, in theory, this technology can print all thermoplastics and metals, but because the melting point of metal materials is generally high, considering the heat resistance and cost of 3D printing equipment itself, FDM is currently mainly used as a molding technology for plastic materials. (2) Selective laser sintering technology (SLS), the powder material is flattened on the workbench and scraped, and the high-intensity laser is used to scan the part section on the freshly laid powder layer, and the material powder is processed by the high-intensity laser It is sintered together under irradiation to obtain the cross section of the part, lower the workbench, repeat the process of powder spreading and sintering, and accumulate the real object. The high-intensity laser generator is a necessary part of the 3D printing equipment based on SLS technology, resulting in these Equipment is more expensive. (3) Inkjet technology, one is the SLS-like production method adopted by Voxeljet in Germany. The material powder is spread on the workbench, and the adhesive droplets are sprayed from the nozzle to cover the cross section of the part, and the powder material is adsorbed and solidified; the other One is the Polyjet technology of Israel Objet (now acquired by Stratasys of the United States), which directly sprays liquid photosensitive polymer materials from the nozzle to the build tray layer by layer. Immediately after being jetted, it is cured with UV light until the part is complete.

Compared with the previous two technologies, inkjet technology has simple equipment, and can directly use existing 2D inkjet printer nozzles and main transmission components; it has low energy consumption, and adhesives or photosensitive materials can be cured and formed at room temperature. However, the development of inkjet technology is also restricted by some factors. For example, the high viscosity of the liquid material is easy to block the nozzle and cause equipment loss, and the droplet volume formed by the liquid with high viscosity at the nozzle is also large, and the pattern resolution is reduced. The viscous adhesive is not easy to penetrate the flat powder layer; and the viscosity of the droplet is too small, the shape of the spread after dripping is not easy to control, and the physical structure is loose. The volume of the droplet also affects the object printed by inkjet. The larger the droplet volume, the worse the precision and the rougher the object; on the contrary, the smaller the droplet volume, the higher the resolution of the printer, the more detailed the object, but the faster the printing speed. Slow, the resolution of most current 3D inkjet printing equipment is 600dpi, and the diameter of the "ink droplet" is about tens of microns, which still cannot meet the needs of high-precision processing. In addition, the traditional inkjet technology only relies on gravity to control the drop of ink droplets. External factors such as air flow and interface wettability will affect the accuracy of the cross-sectional pattern and cause unpredictable effects on the performance of the object.

Contents of the invention

The purpose of the present invention is to provide a 3D printing system to solve the problems of low pattern resolution and slow printing speed in the prior art.

To achieve the above object, the present invention provides the following technical solutions:

The invention discloses a 3D printing system, comprising:

workbench;

an ink cartridge storing a cured material;

Nozzle;

Drive the pump to deliver the cured material in the ink cartridge to the nozzle;

A high-voltage generator is connected to the spray head and makes the sprayed cured material charged.

Preferably, in the above-mentioned 3D printing system, the working voltage of the high voltage generator is greater than 0kV and less than or equal to 60kV.

Preferably, in the above 3D printing system, the cured material is an adhesive.

Preferably, in the above-mentioned 3D printing system, the 3D printing system further includes a servo mechanism, the servo mechanism is connected to the workbench and controls the three-dimensional movement of the workbench, and there is also a powder coating above the workbench. roll. .

Preferably, in the above 3D printing system, the curing material is a liquid photosensitive material, and the 3D printing system further includes an ultraviolet light generator that causes the photosensitive material to be cured.

Preferably, in the above 3D printing system, the 3D printing system further includes a servo mechanism, the servo mechanism is connected to the nozzle and controls the three-dimensional movement of the nozzle.

Preferably, in the above 3D printing system, the 3D printing system further includes an electric field system that drives the charged solidified material to move downward.

Preferably, in the above 3D printing system, the cured material is positively charged, and the workbench is grounded.

Preferably, in the above 3D printing system, the 3D printing system further includes a positioning system for determining the horizontal and vertical positions of the nozzle relative to the worktable.

Preferably, in the above 3D printing system, the 3D printing system further includes a controller connected to the driving pump.

Compared with the prior art, the present invention has the advantages of: a high-voltage generator is connected to the nozzle to make the droplets positively charged, and the droplets are split under the action of an electric field, so that the volume of the droplets becomes smaller, and 3D inkjet printing The resolution of the system is improved; the inkjet droplet is placed in the electric field, which provides another driving force for the droplet besides gravity, which makes the droplet trajectory more accurate, and can make liquids with greater viscosity Material is also ejected from the spray head.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in this application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 shows the structural representation of the 3D printing system in the first embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a 3D printing system in a second embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1

1, in the first embodiment of the present invention, the 3D printing system includes an ink cartridge 11, a driving pump 12, a nozzle 13, a high-voltage generator 14, a workbench 15, a powder spreading roller 16, a controller and a positioning system.

The ink cartridge 11 is used to store the adhesive required for 3D inkjet printing. The adhesive is an acrylic adhesive adjusted with butyl acetate, and the viscosity is between 0.4~0.5 Pa ^● s.

A connecting pipe 17 is connected between the ink cartridge 11 and the drive pump 12 , and the drive pump 12 is used to deliver the adhesive stored in the ink cartridge 11 to the nozzle 13 .

An adjustable high-voltage generator 14 is connected to the spray head 13, so that the sprayed adhesive droplets are positively charged. The working voltage range of the adjustable high voltage generator 14 is +12kV~+15kV.

The size of the adhesive is controlled by controlling the flow rate of the driving pump and the voltage of the high voltage generator.

The powder spreading roller 16 is used to spread the powder raw material on the workbench 15 . The raw material is nano-ZnO powder with a particle size of about 80-150nm.

The workbench 15 can realize three-dimensional movement under the action of the servo mechanism, and the surface of the workbench 15 is used for laying powdery raw materials required for physical molding, and is connected to the ground through wires.

The distance between the shower head 13 and the workbench 15 is about 10-15cm.

The positioning system is used to determine the horizontal and vertical position of the spray head 13 relative to the worktable 15 .

The controller is used to control the flow rate of the drive pump 12 and the operation of the servo mechanism.

The controller may include a microprocessor (MCU), and the MCU may include a central processing unit (Central Processing Unit, CPU), a read-only memory module (read-only memory, ROM), a random access memory module (random access memory, RAM), Timing module, digital-to-analog conversion module (A/D converter), and complex input/output ports. Of course, the controller can also use other forms of integrated circuits, such as Application Specific Integrated Circuit (ASIC) or Field Programmable Gate Array (Field Programmable Gate Array, FPGA).

Example 2

2, in the second embodiment of the present invention, the 3D printing system includes an ink cartridge 21, a drive pump 22, a nozzle 23, a high voltage generator 24, a workbench 25, an ultraviolet light generator 26, a controller and a positioning system.

The ink cartridge 21 is used to store the liquid photosensitive material required for 3D inkjet printing. The liquid photosensitive material is an epoxy photosensitive material adjusted with acetone, and its viscosity is between 0.65 and 0.7.

A connecting pipe 27 is connected between the ink cartridge 21 and the driving pump 22 , and the driving pump 22 is used to deliver the liquid photosensitive material stored in the ink cartridge 21 to the nozzle 23 .

The spray head 23 is connected with a servo mechanism, and the servo mechanism controls the three-dimensional movement of the spray head 23 .

The adjustable high-voltage generator 24 is connected with the spray head 23, so that the sprayed photosensitive material droplets are positively charged. The working voltage range of the adjustable high voltage generator 14 is +10kV~+13kV.

The size of the liquid photosensitive material droplet is controlled by controlling the flow rate of the driving pump and the voltage of the high voltage generator.

The ultraviolet light generator 26 is used to initiate the photocuring reaction of the photosensitive material.

The surface of the workbench 25 is used to carry the photosensitive material sprayed by the nozzle and the solidified objects, and is connected to the ground through wires.

The distance between the nozzle 13 and the three-dimensional workbench 15 is about 10-12 cm.

The positioning system is used to determine the horizontal and vertical position of the spray head 23 relative to the worktable 25 .

The controller is used to control the flow rate of the drive pump 22 and the operation of the servo mechanism.

The controller may include a microprocessor (MCU), and the MCU may include a central processing unit (Central Processing Unit, CPU), a read-only memory module (read-only memory, ROM), a random access memory module (random access memory, RAM), Timing module, digital-to-analog conversion module (A/D converter), and complex input/output ports. Of course, the controller can also use other forms of integrated circuits, such as Application Specific Integrated Circuit (ASIC) or Field Programmable Gate Array (Field Programmable Gate Array, FPGA).

It is easy to imagine that in order to exert a downward electric field force on the ejected droplets, the droplets can also be negatively charged, as long as the direction of the external electric field is changed.

In summary, a high-voltage generator is connected to the nozzle to make the droplets positively charged, and the droplets are split under the action of the electric field, so that the volume of the droplets becomes smaller, and the resolution of the 3D inkjet printing system is improved; The inkjet droplet is placed in the electric field, which provides another driving force for the droplet besides gravity, makes the droplet trajectory more accurate, and enables liquid materials with greater viscosity to be ejected from the nozzle.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The above description is only the specific implementation of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present application, some improvements and modifications can also be made. It should be regarded as the protection scope of this application.

Claims (10)

1. A 3D printing system, characterized in that, comprising: workbench; an ink cartridge storing a cured material; Nozzle; Drive the pump to deliver the cured material in the ink cartridge to the nozzle; A high-voltage generator is connected to the spray head and makes the sprayed cured material charged. 2. The 3D printing system according to claim 1, wherein the working voltage of the high voltage generator is greater than 0kV and less than or equal to 60kV. 3. The 3D printing system according to claim 1, wherein the curing material is an adhesive. 4. The 3D printing system according to claim 3, characterized in that: the 3D printing system further comprises a servo mechanism, the servo mechanism is connected to the workbench and controls the three-dimensional movement of the workbench, and the workbench There is also a powder spreading roller on the top. 5 . The 3D printing system according to claim 1 , wherein the curing material is a liquid photosensitive material, and the 3D printing system further comprises an ultraviolet light generator that causes photocuring of the photosensitive material. 6. The 3D printing system according to claim 5, wherein the 3D printing system further comprises a servo mechanism, the servo mechanism is connected to the nozzle and controls the three-dimensional movement of the nozzle. 7. The 3D printing system according to claim 1, characterized in that: the 3D printing system further comprises an electric field system that drives the charged solidified material to move downward. 8. The 3D printing system according to claim 7, characterized in that: the cured material is positively charged, and the workbench is grounded. 9. The 3D printing system according to claim 1, characterized in that: the 3D printing system further comprises a positioning system for determining the horizontal and vertical positions of the nozzle relative to the worktable. 10. The 3D printing system according to claim 1, characterized in that: the 3D printing system further comprises a controller connected to the driving pump.