3D PRINTER FILAMENT COMPOSITION CONTAINING METAL POWDER, AND FILAMENT USING SAME

Abstract

The present invention provides a 3D printer composition, a 3D printer filament using same, and a method for manufacturing a metal steel product by using the filament, the composition including: 10 wt % to 30 wt % of a polymer binder including 3.5 wt % to 10 wt % of polyacetal, 3.5 wt % to 10 wt % of a polyolefin elastomer, 2 wt % to 6 wt % of a plasticizer, and 1 wt % to 4 wt % of a lubricant; and 70 wt % to 90 wt % of a metal powder.

Claims

1. A 3D printer filament composition containing a metal powder, comprising: 10 wt % to 30 wt % of a polymer binder including 3.5 wt % to 10 wt % of polyacetal, 3.5 wt % to 10 wt % of a polyolefin elastomer, 2 wt % to 6 wt % of a plasticizer, and 1 wt % to 4 wt % of a lubricant; and wt % to 90 wt % of a metal powder.

2. The 3D printer filament composition of claim 1, wherein the polyacetal is an oxymethylene homopolymer containing an oxymethylene (OCH.sub.2).sub.n group as a repeating unit and capped at both ends by an ester or ether group, or a polyacetal copolymer or terpolymer in which oxyalkylene units having 2 to 10 carbon atoms are randomly inserted in a polymer chain composed of oxymethylene monomer units, and both ends of the polymer are blocked by ester or ether groups.

3. The 3D printer filament composition of claim 1, wherein the polyolefin elastomer is a polymer resin in the form of a linear, branched, grafted, or composite type composed of 2 to 12 carbon atoms.

4. The 3D printer filament composition of claim 1, wherein the metal powder includes stainless, titanium, a nickel alloy, an amorphous alloy, or a mixture thereof.

5. The 3D printer filament composition of claim 1, wherein the plasticizer includes paraffin wax, carnauba wax, microcrystalline wax, beeswax, montan wax, fatty acid wax, natural wax, or a mixture thereof.

6. The 3D printer filament composition of claim 1, wherein the lubricant includes stearic acid, Zn-stearate, Ca-stearate, ethylene bis steramide (EBS), or a mixture thereof.

7. A 3D printer filament manufactured by extruding the 3D printer filament composition containing a metal powder of claim 1.

8. The 3D printer filament of claim 7, wherein the 3D printer filament has a diameter of 1.5 to 3.0 mm.

9. A method of manufacturing a metal steel product, comprising melting the 3D printer filament of claim 7 to form a semi-finished product in which print layers are continuously laminated in a three-dimensional shape of an object to be printed, degreasing for 6 hours to 10 hours at 110 C. to 120 C. and under conditions of 98% or more nitric acid in order to remove the polymeric binder component from the semi-finished product, sintering at a high temperature of 1350 C. to 1380 C. to prepare a metal sintered body, and cooling the metal sintered body to room temperature.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

Examples

[0042] Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not to be construed as being limited by these examples.

Examples and Comparative Examples: Preparation of 3D Printer Filament Composition and Filament

[0043] Each composition containing the metal powder, polyacetal, polyolefin elastomer, plasticizer (paraffin wax), and lubricant (stearic acid) of Table 1 was prepared.

[0044] Each prepared composition was kneaded and extruded by using a single screw extruder (a screw diameter: 30 mm) and then cooled and wound in a cooling water bath, preparing a 3D printer filament with a length of 3 m and a diameter of 1.75 mm.

TABLE-US-00001 TABLE 1 Examples Comparative Examples 1 2 3 1 2 3 4 5 6 7 8 A 90 85 70 65 92 80 85 85 85 85 85 B 3.5 5.5 10 12.5 2.5 5 7 11 0 5.5 5.5 C 3.5 5.5 10 12.5 2.5 5 7 0 11 5.5 5.5 D 2 3 6 6 2 10 0 3 3 3 3 E 1 1 4 4 1 0 1 1 1 1 1 A: Metal powder (Apson Atmix SUS316L PF-15F) B: Polyacetal copolymer (Kolon Plastic K300) C: polyolefin elastomer (LG Chem LC180) D: plasticizer (Seiro paraffin wax) E: lubricant (LG Chem stearic acid)

Experimental Example 1: Evaluation of Characteristics of 3D Printer Filament

[0045] The manufactured filaments were evaluated with respect to characteristics by winding each filament on a cylinder with a diameter of 45 mm at room temperature under a normal pressure to check whether or not they would be broken, wherein when neither broken nor cut, it was evaluated as good, but when broken or cut, it was evaluated as inferior, and the results are shown in Table 2.

Experimental Example 2: Evaluation of Characteristics of 3D Sculptures Using 3D Printer Filaments

[0046] The 3D printer filaments according to the examples and the comparative examples were used in a 3D printer (ALMOND, OpenCreators) to print out a sculpture (width: 50 mm, length: 50 mm, height: 20 mm) and then evaluated with respect to properties, and the results are shown in Table 2. The sculpture was printed by setting a printing speed: 10 mm/s to 100 mm/s, a nozzle temperature: 170 C. to 220 C., a nozzle diameter: 0.4 mm to 0.6 mm, a bed temperature: 0 C. to 60 C., and internal filling: 100%.

[0047] The sculpture was put in a dedicated degreasing furnace and degreased for 6 to 10 hours in total including cooling time at 120 C. to check whether or not a shape thereof was deformed, wherein when there was a crack, it was evaluated as inferior, but when there was no crack, it was evaluated as good. In the examples, the degreasing was performed at 120 C. under nitric acid of 98% or more for 8 hours.

[0048] A sculpture of Comparative Example 7 was manufactured by performing the degreasing at 100 C. or less under nitric acid of 98% or more for 6 hours to hours, the sintering at a high temperature of 1350 C. to 1380 C., and the cooling to room temperature.

[0049] A sculpture of Comparative Example 8 was manufactured by performing the degreasing at 130 C. or higher under nitric acid of 98% or more for 6 to 10 hours, the sintering at a high temperature of 1350 C. to 1380 C., and the cooling to room temperature.

[0050] Sintering characteristics were evaluated by heating the sculptures to 1000 C. under a vacuum atmosphere and to 1350 C. under an argon gas atmosphere, and then cooling them by checking whether or not there was a crack, wherein when there was a crack, it was evaluated as inferior but when there was no change, it was evaluated as good.

[0051] Bed adhesion was evaluated by checking whether or not the sculptures were well adhered to a floor but did not fall off during the 3D printing, wherein when well adhered, it was evaluated as good, but when it fell off or was deformed, it was evaluated as inferior.

[0052] 3D printing characteristics were evaluated as inferior when the sculptures were excited at the edges after the printing or when the nozzle was clogged during the printing but as good when the printing smoothly proceeded.

TABLE-US-00002 TABLE 2 Examples Comparative Examples 1 2 3 1 2 3 4 5 6 7 8 Filament Good Good Good Good Inferior Good Good Inferior Inferior Good Good characteristics Degreasing Good Good Good Inferior Inferior Inferior Inferior Inferior characteristics Sintering Good Good Good Inferior Inferior Inferior Inferior Inferior characteristics Bed Good Good Good Inferior Inferior Inferior Good Good adhesion Printing Good Good Good Inferior Inferior Good Good Good characteristics

[0053] Referring to Table 2, the filaments according to the examples of the present invention turned out to be not broken when wound on a cylinder with a diameter of 45 mm, but the filaments of the comparative examples exhibited slightly deteriorated properties when out of the composition range of the present invention.

[0054] In addition, when comparing properties of the 3D sculptures manufactured by using the 3D printer filaments, the 3D sculptures manufactured by using the filaments of the examples of the present invention exhibited excellent properties through degreasing, sintering, bed adhesion, and printing characteristics.

[0055] However, in the case of the 3D sculptures using the filaments manufactured according to the comparative examples, overall properties of the degreasing, the sintering, the bed adhesion, and the printing characteristics were deteriorated.

[0056] In particular, as for Comparative Examples 2, 5, and 6 using metal powder or polyacetal and polyolefin elastomer out of the content ranges of the present invention, since a filament itself was impossible to manufacture, properties such as degreasing, sintering, bed adhesion, printing characteristics, and the like were impossible to measure.

[0057] In addition, Comparative Examples 7 and 8, in which the degreasing and sintering processes were different from those of the present invention, turned out to exhibit inferior degreasing and sintering characteristics.

[0058] As above, a specific part of the contents of the present invention has been described in detail, and for a person of ordinary skill in the art, this specific description is only a preferred embodiment, and thereby the scope of the present invention is not limited. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

[0059] The present invention relates to a 3D printer composition containing metal powder and a filament using the same, wherein the filament is flexible and thus wound on a cylindrical bobbin with an interior diameter 45 mm or more without being broken at room temperature under a normal pressure to optimize degreasing conditions and sintering conditions, effectively manufacturing a metal steel product through a generally widely used extrusion 3D printer (FDM method).