WO2019019033A1

WO2019019033A1 - 3d printer and printing method therefor

Info

Publication number: WO2019019033A1
Application number: PCT/CN2017/094410
Authority: WO
Inventors: 张帆; 刘青
Original assignee: 北京阿迈特医疗器械有限公司
Priority date: 2017-07-26
Filing date: 2017-07-26
Publication date: 2019-01-31
Also published as: CN110139741A

Abstract

A 3D printer (1) and a printing method therefor. The 3D printer (1) comprises a stand (11); a head (12) mounted on the stand (11), the head comprising a nozzle (122); a receiving device (13) positioned opposite to the nozzle (122); a grounding electrode (16) aligned with the nozzle (122); and a driving device (17), which is used for driving the receiving device (13) to move. The 3D printer (1) can precisely control landing points of fibres of a printing material, improving the printing accuracy and precision.

Description

3D printer and its printing method

Technical field

The present invention relates to 3D printing, and in particular to a 3D printer and a printing method thereof.

Background technique

3D printing (3D printing), also known as additive processing technology, is based on three-dimensional digital model files, including metals, polymers, ceramics, biomaterials (including natural biomaterials, synthetic biomaterials, cell solutions), etc. Materials are printed layer by layer by means of powder, melt, solution, etc. to produce a technique with precise three-dimensional structures.

At present, 3D printers using Fused Deposition Modeling (FDM) have the advantages of compact equipment, low price, simple structure and wide application, and can be applied to industrial production on a large scale. The modified FDM printer can not only print polymer materials, but also print biomaterials (including natural biomaterials, synthetic biomaterials, cell solutions).

As the nozzle diameter of the 3D printer decreases, the required extrusion pressure will also increase dramatically. And because of the extrusion swell effect of the material, the printing precision of the finished product is not high.

In order to reduce the diameter of the nozzle, the application of electrospinning technology to 3D printing equipment is one of the ideal choices to solve the current bottleneck. The basic principle of electrospinning technology is that the melt or solution gradually deforms under the action of high-voltage electrostatic field. When the electric field force is greater than the surface tension of the melt or solution, the melt or solution will break away from its surface tension to form a fiber jet to receive. electrode. The diameter of the fibers ejected by electrospinning is 40-2000 nm, which can be used to print 3D printed filaments with a diameter of 40-2000 nm, thus greatly expanding the application of 3D printing technology in tissue engineering.

However, in the conventional electrospinning collection process, it is impossible to precisely control the landing point of the fiber on the surface of the receiving electrode, thereby reducing the printing accuracy.

Summary of the invention

In view of the above technical problems existing in the prior art, an embodiment of the present invention provides a 3D printer, including:

support;

a handpiece mounted on the bracket, comprising a spray head;

a receiving device disposed opposite the shower head;

a ground electrode aligned with the showerhead;

a driving device for driving the receiving device to move.

Preferably, the 3D printer further includes a power source for generating a high voltage electrostatic field, the two stages of the power source being respectively connected to the shower head and the ground electrode.

Preferably, the receiving device is a receiving tube, the grounding electrode is located inside the receiving tube, and the driving device is further configured to drive the receiving tube to rotate.

Preferably, the 3D printer further includes a fixing rod, one end of the fixing rod is located inside the receiving tube and connected to the ground electrode, and the other end of the fixing rod is fixedly connected with the bracket.

Preferably, the ground electrode is spherical or ellipsoidal.

Preferably, the driving device comprises a single-axis slide table and a stepping motor mounted on the single-axis slide table, and an output shaft of the stepping motor is connected to one end of the receiving tube.

Preferably, the 3D printer further includes an annular heater sleeved at both ends of the receiving tube, and the annular heater is mounted on the single-axis slide table.

Preferably, the receiving device is a receiving board, and the receiving board is located between the head and the ground electrode and is close to the ground electrode.

Preferably, the 3D printer further includes a synchronization device for causing the nozzle and the ground electrode to move in synchronization.

Preferably, the inside of the receiving plate has a receiving space for accommodating the heating liquid, and the side wall has a liquid port and a liquid outlet connected to the receiving space; the 3D printer further includes A heated pump that pumps the heated liquid to the inlet.

Preferably, the handpiece further comprises a syringe disposed at an exit of the syringe.

Preferably, the 3D printer further includes an insulating sleeve sleeved on the barrel, and an electric heating sleeve sleeved on the insulating sleeve.

Preferably, the 3D printer further includes a nozzle heater that is sleeved on the nozzle.

An embodiment of the present invention also provides a printing method using the 3D printer as described above, comprising the following steps:

S1): applying a predetermined DC voltage between the nozzle of the 3D printer and the ground electrode;

S2): controlling a driving device of the 3D printer to drive the receiving device to move.

Preferably, the receiving device is a receiving tube, and in the step S2), further comprising controlling the driving device to drive the receiving tube to rotate.

Preferably, the 3D printer further includes a synchronizing device, and in the step S2), further comprising controlling the synchronizing device to cause the nozzle and the ground electrode to move synchronously.

Preferably, the handpiece further comprises a syringe for filling the printing material, and the 3D printer further An electric heating sleeve including the sleeve is included, and before the step S1), the electric heating sleeve is turned on to heat the printing material to a molten state or a solution state.

Preferably, the 3D printer further includes a head heater that is sleeved on the head, and further includes turning on the head heater before the step S1).

The 3D printer of the invention can precisely control the landing point of the printing material fiber, and improves the printing accuracy and precision.

DRAWINGS

The embodiments of the present invention are further described below with reference to the accompanying drawings, wherein:

1 is a perspective view of a 3D printer in accordance with a first embodiment of the present invention.

2 is a perspective view of the receiving tube and the ground electrode in the 3D printer shown in FIG. 1 as seen in the direction indicated by the arrow A1.

Figure 3 is a cross-sectional view of Figure 2 .

4 is an exploded view of the receiving tube and the ground electrode shown in FIG. 2.

Figure 5 is a plan view showing the receiving tube and the ground electrode shown in Figure 4 in the direction indicated by the arrow A2.

Figure 6 is an exploded view of the handpiece shown in Figure 1.

Figure 7 is a cross-sectional view of the handpiece shown in Figure 1.

Figure 8 is a perspective view of a 3D printer in accordance with a second embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings.

1 is a perspective view of a 3D printer in accordance with a first embodiment of the present invention. As shown in FIG. 1, the 3D printer 1 includes a bracket 11 including a rectangular base 117, and

support columns

111, 112 vertically fixed on the base 117 and disposed in parallel, between the

support columns

111, 112 And a lifting rod 113 perpendicular to the

supporting columns

111, 112; the two ends of the lifting rod 113 are respectively connected to the supporting

columns

111, 112 by two L-

shaped sliders

115, 116, and the

sliders

115, 116 are configured to be adapted Movement along the axial direction of the

support columns

111, 112. The bracket 11 further includes a slider 114 that fits over the lifter 113 and a handpiece 12 that is fixedly mounted to the slider 114. The slider 114 is configured to move along the length of the lift bar 113.

A receiving tube 13 opposite to the head 12 is disposed on the base 117, and is sleeved at both ends of the receiving tube 13. The

ring heaters

151, 152, and the stepper motor 17. The output shaft 171 of the stepping motor 17 is connected to one end of the receiving tube 13 for driving the rotational movement of the receiving tube 13. The receiving tube 13 is internally provided with a ground electrode 16 (see FIG. 3), and the fixing rod 14 is connected to the ground electrode 16 (described in detail below in conjunction with FIG. 3).

The 3D printer 1 further includes a two-axis slide table and a single-axis slide table (not shown in Fig. 1), wherein the two-axis slide table and the single-axis slide table can be selected from manual or numerically operated slide tables known in the market. For convenience of description, the axial direction of the lifting rod 113 is defined as the x direction, the axial direction of the receiving tube 13 is the y direction, and the axial direction of the supporting column 111 is the z direction. It will be apparent to those skilled in the art that the x, y, and z directions in the specification are not specifically referring to three coordinate axes in a three-dimensional Cartesian coordinate system.

The

sliders

114, 115, 116 are fixed on the two-axis slide table, and the position of the sliders 115 in the x direction is controlled by manually or numerically operating the two-axis slide to control the position of the

sliders

115, 116 in the z direction, thereby The head 122 of the handpiece 12 is aligned with the receiving tube 13 and in the z-direction of the receiving tube 13. The stepping motor 17, the

ring heaters

151, 152 are fixed on the single-axis slide table, and the single-axis slide table is operated by manual or numerical control, thereby moving the stepping motor 17, the

ring heaters

151, 152 and the receiving tube 13 in the y direction. .

2 is a perspective view of the receiving tube and the ground electrode in the 3D printer shown in FIG. 1 as seen in the direction indicated by the arrow A1, and FIG. 3 is a cross-sectional view of FIG. 2, wherein the sectional plane is parallel to the y direction and the z direction. The plane passes through the axis of the receiving tube 13. As shown in Figures 2 and 3,

annular heaters

151, 152 are sleeved on both ends of the receiving tube 13 and fixed to the single-axis slide table for heating the receiving tube 13 so that the surface of the receiving tube 13 has the desired The temperature, in turn, causes the fibers on the outer sidewall of the receiver tube 13 to have a desired viscosity. The ground electrode 16 is located inside the receiving tube 13. The fixing rod 14 is an elongated conductive rod having one end inserted into the receiving tube 13 and connected to the ground electrode 16, and the other end extending from the receiving tube 13 and fixedly coupled to the bracket 11.

4 is an exploded view of the receiving tube and the ground electrode shown in FIG. 2, and FIG. 5 is a plan view schematically showing the receiving tube and the grounding electrode shown in FIG. 4 in the direction indicated by the arrow A2. As shown in FIGS. 4 and 5, the receiving tube 13 has a cylindrical shape and is made of an insulating material. The ground electrode 16 is spherical in shape and is made of a conductive material. The diameter of the fixing rod 14 is smaller than the diameter of the ground electrode 16.

The 3D printer 1 further includes a high voltage electrostatic power source (not shown in FIGS. 1 to 4), the positive electrode of the high voltage electrostatic power source is electrically connected to the shower head 122, and the negative electrode is electrically connected to the fixed rod 14, so that the potential difference between the shower head 122 and the ground electrode 16 is The voltage output from the high voltage electrostatic power supply.

6 is an exploded view of the handpiece shown in FIG. 1, and FIG. 7 is a cross-sectional view of the handpiece shown in FIG. 1, wherein the sectional plane is parallel to the plane defined by the y direction and the z direction, and passes through the axis of the handpiece 12. As shown in Figures 6 and 7, the handpiece 12 includes a generally cylindrical syringe 121 and a showerhead 122 disposed at the exit of the syringe, and a metal sleeve 123 over the syringe 121 that is sleeved over the metal. An insulating sleeve 124 on the sleeve 123 and a thermostated electric sleeve 125 over the insulating sleeve 124. The syringe 121 for containing the printing material is made of a stainless steel material. The insulating sleeve 124 is a Teflon sleeve made of polytetrafluoroethylene, which is used to electrically isolate the syringe 121 from the outermost thermostated heating sleeve 125, thereby avoiding the risk of electric shock and improving safety performance. The heat generated by the thermostat heating sleeve 125 is transmitted to the barrel 121 through the insulating sleeve 124 and the metal sleeve 123 for heating the printing material in the barrel 121. The handpiece 12 also includes a showerhead heater 126 disposed on the showerhead 122 for heating the printed material at the showerhead 122. A high pressure nitrogen pump (not shown in Figs. 6 and 7) is filled with high pressure gas through the inlet 1211 of the barrel 121 to the inside of the barrel 121, and the printing material in the barrel 121 is extruded to the head 122.

The four printing functions of the 3D printer 1 according to an embodiment of the present invention will be briefly described below.

1) Melt extrusion mode: The heating temperature of the thermostat heating jacket 125 is set such that the printing material in the cylinder 121 is in a molten state, and the heating temperature of the nozzle heater 126 is set. The pressure valve of the high pressure nitrogen pump is turned on to deliver the melt to the showerhead 122. The melt fibers extruded from the head 122 are directly adhered to the outer side wall of the receiving tube 13. The stepping motor 17 drives the rotational movement of the receiving tube 13, while operating the single-axis slide so that the receiving tube 13 moves in the y direction, thereby forming a porous tubular structure. In the melt extrusion mode, the wall thickness of the porous tubular structure can be varied by changing the rotational speed of the receiving tube 13 or the speed of movement along its axial direction.

2) Solution extrusion mode: it is basically the same as the above-described melt extrusion mode, except that the printed material after heating is in a solution state, and details are not described herein again.

3) The molten electrospinning mode: the polylactic acid (PLA) material is filled in the syringe 121, and the heating temperature of the thermostat heating jacket 125 is adjusted so that the printing material in the syringe 121 is in a molten state, and the nozzle heater 126 is additionally The temperature was adjusted to 230 °C. The pressure valve of the high pressure nitrogen pump is turned on to deliver the polylactic acid melt to the showerhead 122. The high-voltage electrostatic power source is turned on and the voltage is adjusted to 8 kV, and the stepping motor 17 drives the receiving tube 13 to rotate, while operating the single-axis slide table to move the receiving tube 13 in the y direction. The melt extruded from the head 122 forms a Taylor cone under the action of a high voltage electrostatic field, from which fibers are formed and ejected toward the ground electrode 16, and finally adhered to the outer side wall of the receiving tube 13. When a high voltage DC voltage is applied between the head 122 and the ground electrode 16, since the head 122 is always aligned with the ground electrode 16 inside the receiving tube 13, the uniformity of the electric field between the head 122 and the ground electrode 16 is ensured to the utmost extent, In turn, the targeting and stability of the fibers ejected by the nozzle 122 during the electrospinning process are ensured, thereby precisely controlling the landing of the fibers on the receiving tube 13. Points improve print accuracy. In the melt electrospinning mode, it is also possible to change the wall thickness of the porous tubular structure by changing the voltage value of the high voltage electrostatic power source and the distance between the head 122 and the ground electrode 16.

4) Solution electrospinning mode: it is basically the same as the above-described molten electrospinning mode, except that the printed material after heating is in a solution state, and details are not described herein again.

Figure 8 is a perspective view of a 3D printer in accordance with a second embodiment of the present invention. It is basically the same as FIG. 1 except that the 3D printer 2 further includes a guide rail 2132 near the base 217, the

sliders

2142, 2152, 2162, the guide rail 2132 and the

sliders

2142, 2152, 2162 are mounted in the manner of the lifting rod 213 and The

sliders

214, 215, and 216 are installed in the same manner, and are not described herein again. The 3D printer 2 further includes a ground electrode 284 fixed to the slider 2142. The ground electrode 28 is disposed coaxially with the shower head 222, and is made of a metal rod made of a metal material. The 3D printer 2 also includes a synchronizing device (not shown in Fig. 8) for causing the ground electrode 284 and the head 222 to move in synchronization in the X direction. The 3D printer 2 also includes a receiving plate 282 between the ground electrode 284 and the showerhead 222. The receiving plate 282 is secured to the platform 281 by posts 283 adjacent the ground electrode 284 and at a predetermined distance. The driving device (not shown in Fig. 8) of the 3D printer 2 is used to drive the stage 281, the stay 283, and the receiving plate 282 to move in the Y direction, whereby the printing material can be received anywhere on the plane of the receiving plate 282.

In other embodiments of the present invention, the inside of the receiving plate 282 has an accommodating space for accommodating the heating liquid, and the side wall of the receiving plate 282 has a liquid inlet and a liquid outlet connected to the accommodating space, and the heat pump will The heated liquid is pumped to the inlet port to effect heating of the receiving plate 282.

The 3D printer 1 of the invention can realize four printing functions of melt extrusion, solution extrusion, melt electrospinning, and solution electrospinning, thereby realizing polymer melt, polymer solution, precursor cells, biological factors, and the like. 3D printing greatly improves the design and application range of the product, and thus enables printing of single or composite structures such as porous tubes, stents, films, and biomaterials.

The above four printing modes of the present invention do not relate to the voltage value of the high voltage electrostatic power source, the heating temperature of the constant temperature heating jacket 125, the heating temperature of the head heater 126, the pressure value of the high pressure nitrogen pump, and the distance between the head 122 and the receiving tube 13. And the rotation speed of the receiving tube 13 and the like are limited. Depending on the printing material selected, suitable printing parameters can be selected to cause the nozzle to eject a predetermined thickness of fiber.

In other embodiments of the invention, the ground electrode is ellipsoidal. At the same voltage, the electric field distribution near the spherical or ellipsoidal ground electrode is denser than that of the flat electrode, and the electric field strength is stronger, which is more favorable for the fiber to be accurately deposited on the receiving tube.

The thermostat heating jacket 125 and the showerhead heater 126 in the above embodiment can independently heat the syringe 121 and the showerhead 122, while maintaining the temperature of the showerhead 122 while ensuring that the printing material is molten or solution and not degraded. In the best condition.

In other embodiments of the present invention, the handpiece 12 of the 3D printer 1 of the present invention may not have heating means for heating the syringe 121 and the showerhead 122 when the printing material is in a molten state at room temperature.

In another embodiment of the invention, the 3D printer 1 further includes a second handpiece that carries other printed materials, the second handpiece and the handpiece 12 being arranged in parallel along the x-direction. The handpiece is mounted on the slider 114 or on another slider on the lifter 113. During the printing process, two different printing materials are deposited on the receiving tube by controlling the dual-axis slide such that the head of the second handpiece and the head 122 of the handpiece 12 are aligned with the receiving tube at different times.

In other embodiments of the invention, the negative pole of the high voltage electrostatic power source is electrically coupled to the showerhead 122, the positive pole of which is electrically coupled to the ground electrode 16.

The receiving tube 13 in the above embodiment may be made of a material such as glass, ceramic material, polytetrafluoroethylene, polyimide, etc., and a receiving tube with a varying diameter may be used depending on the product requirements.

While the present invention has been described in its preferred embodiments, the invention is not limited to the embodiments described herein, and various changes and modifications may be made without departing from the scope of the invention.

Claims

A 3D printer, comprising:

support;

a handpiece mounted on the bracket, comprising a spray head;

a receiving device disposed opposite the shower head;

a ground electrode aligned with the showerhead;

a driving device for driving the receiving device to move.
The 3D printer of claim 1 further comprising a power source for generating a high voltage electrostatic field, the two stages of the power source being coupled to the showerhead and the ground electrode, respectively.
The 3D printer according to claim 1, wherein the receiving device is a receiving tube, the ground electrode is located inside the receiving tube, and the driving device is further configured to drive the receiving tube to rotate.
A 3D printer according to claim 3, wherein said 3D printer further comprises a fixing rod, one end of said fixing rod is located inside said receiving tube and connected to said ground electrode, and said fixing rod is further One end is fixedly connected to the bracket.
The 3D printer of claim 3 wherein said ground electrode is spherical or ellipsoidal.
A 3D printer according to claim 3, wherein said driving means comprises a single-axis slide table and a stepping motor mounted on said single-axis slide table, an output shaft of said stepping motor and said receiving One end of the tube is connected.
A 3D printer according to claim 6, wherein said 3D printer further comprises an annular heater disposed at both ends of said receiving tube, said annular heater being mounted on said single-axis slide.
The 3D printer of claim 1 wherein said receiving means is a receiving plate, said receiving plate being located between said head and said ground electrode and adjacent said ground electrode.
A 3D printer according to claim 8, wherein said 3D printer further comprises synchronization means for causing said head and said ground electrode to move in synchronism.
The 3D printer according to claim 8, wherein the receiving plate has an accommodating space for accommodating the heating liquid, and the side wall has a liquid port and a liquid outlet communicating with the accommodating space; The 3D printer also includes a heat pump for pumping the heated liquid to the liquid inlet.
A 3D printer according to any one of claims 1 to 10, wherein the handpiece further comprises a syringe disposed at an exit of the syringe.
The 3D printer of claim 11 wherein said 3D printer further comprises an insulative sleeve over said barrel and an electric sleeve overlying said insulative sleeve.
A 3D printer according to any one of claims 1 to 10, wherein the 3D printer further comprises a head heater that is sleeved on the head.
A printing method using the 3D printer of claim 1, comprising the steps of:

S1): applying a predetermined DC voltage between the nozzle of the 3D printer and the ground electrode;

S2): controlling a driving device of the 3D printer to drive the receiving device to move.
The printing method according to claim 14, wherein the receiving device is a receiving tube, and in the step S2), further comprising controlling the driving device to drive the receiving tube to rotate.
The printing method according to claim 14, wherein the 3D printer further comprises synchronizing means, and in the step S2), further comprising controlling the synchronizing means to cause the head and the ground electrode to move in synchronization.
The printing method according to claim 14, further comprising a syringe for filling the printing material, the 3D printer further comprising an electric heating sleeve sleeved on the cylinder, before the step S1) Also included is turning on the electric heating sleeve to heat the printing material to a molten state or a solution state.
The printing method according to claim 14, wherein the 3D printer further comprises a head heater that is sleeved on the head, and further comprising turning on the head heater before the step S1).