KR20210156488A - 3D printing method for metal product output and nozzle - Google Patents

Abstract

The present invention relates to an FFDM-type metal 3D printing method that prints and laminates a thermoplastic resin containing a metal filler through a heated nozzle and, at the same time, degreases a thermoplastic polymer resin with a laser beam of a proper temperature, so as to omit a degreasing process, thereby reducing processing time and increasing work efficiency.

Description

3D printing method for metal product output and nozzle thereof

The present invention belongs to the field of 3D printers for outputting metal products, and more particularly, to a technology for outputting metal products using a 3D filament containing a metal filler in a thermoplastic polymer resin.

In general, a 3D printer is a manufacturing device that creates an article based on a three-dimensional drawing as if it was printed in a chamber, which is a three-dimensional space. In the past, 3D printers were used limitedly for the purpose of printing plastic products, but with the advent of various 3D printing techniques and materials, the field of application is expanding. is a trend that is becoming

These 3D printers use a variety of materials ranging from plastic materials to silicon, carbon, iron, tungsten, and titanium materials. can do.

As an example of a 3D printer that outputs such metal products, there are a selective laser sintering (SLS) method and a selective laser melting (SLM) method, which are typical processing methods using fine metal powder.

In the selective laser sintering (SLS) method, individual layers are manufactured by sintering metal powder by irradiating a laser, but the individual layers are sequentially laminated to manufacture a final dimensional metal body.

Selective Laser Melting (SLM) method uses a laser with a higher intensity than the selective laser sintering (SLS) method to completely melt metal powder and completely compress the material. characteristics

It is a method of manufacturing the final three-dimensional metal body by creating and manufacturing individual layers so as to have, but sequentially stacking and manufacturing individual layers.

However, the existing metal powder 3D printer reflects a high-temperature laser beam with a reflector and at the same time adjusts the irradiation angle of the laser beam through angle control of the reflection angle to determine the sintering position. The powder located far from the reflector has difficulty in complete sintering because the intensity of the laser beam is weakened. For this reason, there is a limitation in that it is difficult to manufacture a product with a large output size.

In addition, a 3D printer that sinters and fuses metal powder with a laser requires processing of nanometer-level metal powder particles and requires very precise uniformity of metal particles, so the material price is very expensive.

In addition, the cost of the laser beam irradiation device is high, and the price of the 3D printer rises because a lot of precise and expensive parts are required for the continuous supply of powder. A new type of 3D printer was needed.

In order to solve this problem, metal 3D printing method of Bound Metal Deposition (BMD) method and metal 3D printing method of Fused Deposition Metal Modeling (FDMM) method appeared.

The metal 3D printing method of the BMD method inserts a bar material mixed with metal powder, wax, and a polymer binder, and at the same time extrudes it and melts it using the heat of the nozzle to print it layer by layer, just like the FDM method. Metal 3D printing is a method of printing metal products by melting filaments containing metal fillers with heat and performing additive manufacturing.

The above BMD and FDMM 3D printers have the advantages of simple components, relatively large particle size of metal powder and low cost of equipment and materials, but remain in the product printed from the nozzle. The second step of sintering at high heat using a calcination chamber after additionally going through the process of degreasing the thermoplastic polymer resin to be degreased with a degreasing device is further required, which complicates the post-processing process and reduces work efficiency. have.

Hereinafter, in the metal 3D printing method of the FFDM method according to the present invention, the degreasing process is performed by outputting and laminating a thermoplastic polymer resin containing a metal filler with a heated nozzle, and at the same time degreasing the thermoplastic polymer resin with a laser beam at an appropriate temperature. It has the advantage of reducing processing time and increasing work efficiency.

The problem to be solved in the present invention is to output and laminate a filament composed of a metal filler and a thermoplastic polymer resin with a nozzle, and at the same time degreasing the thermoplastic polymer resin with a laser beam at an appropriate temperature, thereby omitting the degreasing process and reducing processing time It is to provide a 3D printing method and a nozzle device with high work efficiency at the same time.

A solution of the present invention is to provide a metal filament output and degreasing through a laser at the same time. Through this, in the case of additive manufacturing method metal printer using FDM type filament, unlike existing products, 3D printer outputs in a degreased state, so there is no need for a separate degreasing process, reducing work time and cost due to additional degreasing process provide so that

The metal 3D printing method and nozzle according to the present invention include a metal filler in a thermoplastic polymer resin, output it with a heated nozzle, and laminate it, and at the same time degreasing the thermoplastic polymer resin with a laser beam at an appropriate temperature, thereby omitting the degreasing process, resulting in processing time There is an effect of increasing the efficiency of the operation at the same time as this is reduced.

In addition, the FDM-type 3D printing method using a 3D filament containing a metal filler has the effect of having a simple configuration of parts and low cost of equipment and materials.

1 is a process diagram of a metal product through laser degreasing at the same time as outputting a metal filament according to an embodiment of the present invention;
2 is a filament composed of a thermoplastic polymer resin and a metal filler.
3 to 4 are process diagrams of metal products through laser degreasing at the same time as outputting metal filaments in another embodiment of the present invention;
5 is a block diagram of a rotary metal printer nozzle capable of degreasing with a laser while simultaneously outputting a metal filament according to an embodiment of the present invention.
6 is a block diagram of a metal printer nozzle having a reflector capable of degreasing with a laser at the same time as outputting a metal filament according to an embodiment of the present invention.
7 is a block diagram of a fixed metal printer nozzle capable of degreasing with a laser while simultaneously outputting a metal filament according to an embodiment of the present invention.
8 is a diagram schematically illustrating a metal 3D printer according to an embodiment of the present invention.

In a method for providing the present invention, a step of mixing a thermoplastic polymer resin (S) and a metal filler (F) with a mixer to prepare a master medium, wherein the thermoplastic polymer resin (S) is a thermoplastic polymer resin (S) ) Materials include polylactide [PLA], polyvinyl acetate [PVA], polycarbonate [PC], polyethylene terephthalate glycol [PETG], polyvinyl alcohol [PVA], [PCLA], poly(glycolide) [PGA] ], poly(dioxanone) [PDO], polymethacrylic acid [PMA], poly(caprolactone-lactide), poly(DL-lactide-co-L-lactide) [LDLPLA], poly(DL-lactide-co-glycolide) [DLPLG], poly(glycolide-co-trimethylene carbonate) [PGATMC], poly(L-lactide-co-glyco Ride) [PLGA], poly(ε-caprolactone) [PCL], poly(glycolide-co--L-lactide) [PGLA], poly(glycolide-co)-DL-lactide ) [PGDLLA], poly-L-lactide [PLLA], poly-D-lactide [PDLA], poly-DL-lactide [PDLLA], poly(L-lactide-co-ε-capro lactone) [LCL], acrylonitrile butadiene styrene [ABS], nylon [nylon], and impact-resistant polystyrene [HIPS] may be provided, and one or more of these may be selected and may be composed of complexes thereof

As a material of the metal filler (F), iron, brass, copper, gold, silver, titanium, aluminum, tungsten, a nickel alloy, a titanium alloy, and a cobalt alloy may be provided, and at least one of them and complexes thereof may be made of

In addition, as the filler included in the thermoplastic polymer resin (S), various materials other than metallic materials may be used, which are limited to a variety of materials having a melting point of at least 500 ° C. This is because, in the process of degreasing with a laser, the filler is melted together by the high heat of the laser beam, and the filler flows down in the direction of gravity, making it difficult to maintain the shape of the printed product.

Representative filler materials that can replace the metal filler (F) include ceramics and glass fibers.

Additives such as derivatives and plasticizers may be additionally added here to improve mixing performance. Examples of additives include polyacrylamide, polyvinyl alcohol (PVA), polyamide, and combinations thereof. Polyacrylic acid (PAA), polyvinyl pyrrolidone (PVP), polymethyl methacrylate (PMMA), polyvinyl methyl ether-maleic anhydride (PVME-MA) at least one selected and their may be provided in complexes.

The size of the prepared master medium is suitable within 3 to 10 mm, and the closer to a spherical shape, the more suitable for forming a uniform filament (P).

Here, as for the mixing ratio of the thermoplastic polymer resin (S) and the metal filler (F), 80 wt% of the thermoplastic polymer resin (S) and 20 wt% of the metal filler (F) are most suitable, but the thermoplastic polymer resin (S) And depending on the type of material of the metal filler (F), the thermoplastic polymer resin (S) is 60 wt% to 90 wt%, the metal filler (F) may be provided in a mixing ratio of 40 wt% to 10 wt% .

If the mixing ratio is exceeded or less than this, the production of the filament (P) is difficult, and the output from the 3D printing nozzle is not easy.

Hereinafter, the examples in Table 1 relate to the optimal mixing ratio for each material of the plastic polymer resin (S) and the metal filler (F).

PLA ABS PVA PC PETG pp steel 80% 20% 80% 20% 81% 19% 80% 20% 80% 20% 80% 20% brass 79% 21% 79% 21% 80% 20% 79% 21% 79% 21% 79% 21% copper 82% 18% 82% 18% 83% 17% 82% 18% 82% 18% 81% 19% gold 81% 19% 81% 19% 82% 18% 81% 19% 79% 19% 80% 20% silver 78% 22% 78% 22% 79% 21% 78% 22% 78% 22% 78% 22% titanium 79% 21% 79% 21% 80% 20% 79% 21% 79% 21% 79% 21% aluminum 82% 18% 78% 18% 83% 17% 81% 18% 82% 18% 81% 19% tungsten 79% 21% 79% 21% 80% 20% 79% 21% 79% 21% 79% 21%

※The left column is the mixing ratio of the thermoplastic polymer resin (S), and the right column is the mixing ratio of the metal filler (F).

In addition, the size of the metal filler (F) is suitable for a size of around 0.001 to 0.2 mm, and if it is 0.5 mm or more, it is not suitable because the precision of the output of the final product through the 3D printer is lowered.

The tensile strength of the filament (P) is weakened, the filament may be broken during output from the nozzle, and problems such as clogging of the nozzle (1) may occur.

Next, the master medium is extruded with an extruder to manufacture a long and thin filament (P) through injection molding. can be

The following process is a characteristic technique of the present invention, and a 3D printing nozzle device of the FDM method for laminating through melting using heat for outputting a metal product is provided, and the filament (P) is outputted with the extrusion nozzle (1) At the same time, the step of outputting a metal product by degreasing the thermoplastic polymer resin with the laser nozzle 2 at an appropriate temperature is a feature of the present invention.

The laser nozzle 2 having an appropriate temperature is preferably a laser nozzle 2 that outputs a beam having a temperature between 100° C. and 800° C., representatively, a plasma pulse laser nozzle and an excimer. and an eximer laser nozzle.

If degreasing is performed simultaneously with lamination through the laser nozzle 2 at an appropriate temperature, the thermoplastic polymer resin (S) remains in a small amount in the portion directly facing between the metal filler (F) and the metal filler (F) even after the degreasing process. It is possible to maintain the shape of the output product by acting as an adhesive between the fillers (F). Thereafter, a complete metal product can be manufactured by sintering through a firing machine.

Through this, there is no degreasing process unlike the existing 3D printing manufacturing process method, so the product output time and work efficiency are improved.

After that, the finally printed metal product is put into the firing machine, and the thermoplastic polymer resin remaining between the metal fillers (F) is burned and sintered through plastic processing at high temperature, and the metal filler (F) particles are hardened through melting and cooling. proceeds

<Example 1>

Hereinafter, an embodiment of outputting a metal product is

1 and 2, mixing the thermoplastic polymer resin (S) and the metal filler (F) to prepare a master medium (M1) and extruding the master medium with an extruder to prepare a filament (P) (M2) and a 3D printing nozzle (1) device for outputting metal products, outputting a filament (P) with an extrusion nozzle (1) and degreasing a thermoplastic polymer resin with a laser nozzle (2) to output a metal product A 3D printing method for outputting a metal product is provided, characterized in that it is provided as a step (M3) and a step (M4) of sintering and finally curing the metal product output in the following process using a firing equipment.

Here, in FIG. 3, the step (M3) of outputting a metal product by degreasing the thermoplastic polymer resin with the laser nozzle (2) while outputting the filament (P) with the extrusion nozzle (1) is, the extrusion nozzle ( 1) and the laser nozzle 2 are provided in a state fixed to the plate T (M1), and the filament P is outputted to the extrusion nozzle 1 and laminated in one or more layers (M32) Next, along the output path of the extrusion nozzle (1), the degreasing step (M33) with the laser nozzle (2) was repeatedly laminated to manufacture.

Another method of outputting a metal product by degreasing the thermoplastic polymer resin with a laser nozzle 2 at the same time as outputting the filament P with the extrusion nozzle 1,

In Figure 4, the step (M311) of providing equipment configured to rotate the laser nozzle (2) in conjunction with the extrusion nozzle (1) and first output the filament (P) through the extrusion nozzle (1) for lamination at the same time The laser nozzle 2 is manufactured in a step (M312) of degreasing the filament (P) while rotating along the stacked output path.

On the other hand, the present invention provides a nozzle device for outputting a metal product.

In the 3D printing nozzle device of the present invention, the filament (P) contains a metal filler (F) in the thermoplastic polymer resin (S), and outputs the filament (P) to the extrusion nozzle (1) by using the filament (P) and simultaneously laser A 3D printing nozzle for printing metal products, characterized in that the nozzle 2 is configured to degrease the thermoplastic polymer resin, was constructed.

Hereinafter, it will be described in detail through embodiments of the present invention.

<Example 2>

Hereinafter, as shown in Figure 5 and provided with an extrusion nozzle (1) and a laser nozzle (2), the laser nozzle (2) is a rotary plate (ST) configured to be rotatable to the extrusion nozzle (1) is connected and , the rotary plate ST is configured to have a rotation angle adjusted by the gear module 31 connected to the step motor 3 so as to be able to change the divergence position of the laser beam while rotating the laser nozzle 2 . In addition, a cooling device 12 is provided between the extrusion nozzle 1 and the laser nozzle 2 to rapidly cool the filament P output from the extrusion nozzle 1 to maintain its shape after lamination. Next, the device was configured so that the laser nozzle 2 was rotated along the stacking path in response to the stacked layers of the filaments P while simultaneously undergoing the degreasing process.

Through this, by laminating the filament (P) in the 3D printer (4) and degreasing at the same time, there is an advantage in that the post-process of reprocessing the output product using a degreasing device can be reduced.

<Example 3>

Hereinafter, as shown in FIG. 6 and having an extrusion nozzle 1 and a laser nozzle 2, the laser nozzle 2 is a laser beam emitted from the laser nozzle 2 is one or more condensing lenses 31 The light collected by passing through is reflected by the reflector 3 and configured to irradiate the stacked filaments.

Here, the reflector 3 is configured to rotate at an angle of 180° or more up, down, left and right to control the irradiation angle of light. At this time, it is interlocked with the gear module 22 connected to the step motor 21 to rotate the step motor 21 . It was configured to change the angle of the reflector 3 according to the direction.

<Example 4>

Hereinafter, as shown in Figure 7 and the extrusion nozzle (1) and the laser nozzle (2) is configured to be integrally fixed to a single fixed plate (T) at a predetermined interval.

Here, a device for rapidly cooling the filament P output from the extrusion nozzle 1 by further including a cooling device 12 may be further provided.

Specifically, when the filament P is extruded with the extrusion nozzle 1 to complete lamination of one or more layers, and then cooled with a cooling device 12 to produce a cured layer, then it is properly It was configured to undergo a process of degreasing the thermoplastic polymer resin (S) by irradiating the layer beam while the temperature laser moved along the path corresponding to the path of the cured layer.

By continuously repeating the above method to stack the output layers and output the shape of the object, a metal product was finally manufactured.

1: Extrusion nozzle
11: Heating chamber
12: cooling device
2: Laser nozzle
21: step motor
22: gear module
3: reflector
31: condensing lens
P: filament
S: Thermoplastic polymer resin
F: metal filler
T: fixed plate
ST: Rotary plate
4: 3D printer

Claims (11)

In the nozzle for outputting a metal product,
The filament (P) contains a metal filler (F) in a thermoplastic polymer resin (S),
To output the filament (P) with the extrusion nozzle (1) and at the same time to degrease the thermoplastic polymer resin with the laser nozzle (2)
3D printing nozzle for metal product output, characterized in that it is configured. The method of claim 1,
The extrusion nozzle (1) and the laser nozzle (2) are coupled in a fixed state integrally to a single fixed plate (T),
3D printing nozzle for metal product output, characterized in that it is configured. The method of claim 1,
The extrusion nozzle 1 and the laser nozzle 2 are spaced apart from each other so that the laser nozzle 2 rotates in a direction corresponding to the output path of the extrusion nozzle 1 .
3D printing nozzle for metal product output, characterized in that it is configured. The method of claim 1,
The laser light emitted from the extrusion nozzle (1) and the laser nozzle (2) is configured to be reflected by the reflecting mirror (3) configured to enable adjustment of the reflection angle, and the direction corresponding to the output path of the extrusion nozzle (1) to control the angle of the reflector 3 so that the laser beam is irradiated according to the
3D printing nozzle for metal product output, characterized in that it is configured. In the method of outputting a metal product,
Preparing a master medium by mixing a thermoplastic polymer resin (S) and a metal filler (F);
Extruding the master medium with an extruder to prepare a filament (P);
A 3D printing nozzle (1) device for outputting a metal product is provided, and the filament (P) is outputted with the extrusion nozzle (1) and at the same time the thermoplastic polymer resin is degreased with the laser nozzle (2) to output the metal product step;
a step of finally hardening the output metal product by sintering it using a firing equipment;
A 3D printing method for outputting metal products, characterized in that it is provided as 6. The method of claim 5,
In the filament (P), the mixing ratio of the thermoplastic polymer resin (S) to the metal filler (F) is provided in an amount of 60 wt% to 90 wt% of the thermoplastic polymer resin (S), and the metal filler (F) ) is a mixing ratio of 40 wt% to 10 wt%
3D printing method for outputting metal products, characterized in that provided. 6. The method of claim 5,
The metal filler (F) is made of iron, brass, copper, gold, silver, titanium, aluminum, tungsten, nickel alloy, titanium alloy, cobalt alloy or one or more selected from ceramic and glass fiber and composites thereof.
3D printing method for outputting metal products, characterized in that provided. 6. The method of claim 5,
Thermoplastic polymer resin (S) is polylactide [PLA], polyvinyl acetate [PVA], polycarbonate [PC], polyethylene terephthalate glycol [PETG], polyvinyl alcohol [PVA], [PCLA], poly(glycolide) ) [PGA], poly(dioxanone) [PDO], polymethacrylic acid [PMA], poly(caprolactone-lactide), poly(DL-lactide-co-L-lactide)[ LDLPLA], poly(DL-lactide-co-glycolide) [DLPLG], poly(glycolide-co-trimethylene carbonate) [PGATMC], poly(L-lactide-co )-glycolide) [PLGA], poly(ε-caprolactone) [PCL], poly(glycolide-co(co)-L-lactide) [PGLA], poly(glycolide-co(co)-DL -lactide) [PGDLLA], poly-L-lactide [PLLA], poly-D-lactide [PDLA], poly-DL-lactide [PDLLA], poly(L-lactide-co)- ε-caprolactone) [LCL], acrylonitrile butadiene styrene [ABS], nylon [nylon], impact-resistant polystyrene [HIPS] at least one selected and a complex thereof
3D printing method for outputting metal products, characterized in that provided. 6. The method of claim 5,
In the step of producing a filament (P) by extruding the master medium with an extruder,
An additive is further added to increase the miscibility, and among the additives, the derivatives are polyacrylamide, polyvinyl alcohol (PVA), polyamide derivatives thereof, and combinations thereof, and the polymer strand is polyacrylic acid (PAA). , polyvinyl pyrrolidone (PVP), polymethyl methacrylate (PMMA), polyvinyl methyl ether-maleic anhydride (PVME-MA) at least one selection and composites thereof
3D printing method for outputting metal products, characterized in that provided. 6. The method of claim 5,
The step of outputting a metal product by degreasing the thermoplastic polymer resin,
The extrusion nozzle (1) and the laser nozzle (2) are equipped with equipment in a state integrally fixed to the fixed plate (T), and then output the filament (P) to the extrusion nozzle (1) to form one or more layer layers Degreasing with a laser nozzle (2) along the layered layer corresponding to the output path of the extrusion nozzle (1) after laminating;
A 3D printing method for outputting metal products, characterized in that it is provided as 6. The method of claim 5,
The step of degreasing the thermoplastic polymer resin (S) to output a metal product,
The laser nozzle (2) is connected to the rotary plate (ST) and the extrusion nozzle (1) is provided with a rotary laser nozzle (2) capable of rotation, and outputting a filament (P) through the extrusion nozzle (1) When stacked, the laser nozzle (2) degreasing the filament (P) along the stacked output path;
A 3D printing method for outputting metal products, characterized in that it is provided as

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