KR20230064068A - Apparatus for additive manufacturing - Google Patents

Abstract

One aspect of the present invention provides an apparatus for additive manufacturing, which comprises: a first unit which is fixed to a housing; and a second unit which includes a substrate provided to move horizontally and vertically within the housing. The first unit includes: an extrusion part which melts and kneads raw materials to produce a melt; a storage part which stores the melt transferred from the extrusion part; and a nozzle part which discharges the melt transferred from the storage part toward the substrate to manufacture a molded product.

Description

Additive Manufacturing Equipment {APPARATUS FOR ADDITIVE MANUFACTURING}

The present invention relates to an additive manufacturing apparatus, and more particularly, to an additive manufacturing apparatus based on a fused deposition modeling (FDM) method.

A 3D printer is a device that prints (molds) the three-dimensional shape of a real object based on a three-dimensional drawing (data). That is, after completing a 3D drawing using a CAD or 3D modeling program, the data is transmitted to the printer through a predetermined data interface, and the 3D printer performs the process of making the molded product based on the transmitted drawing data will do Specifically, after creating a virtual cross section based on the corresponding drawing data, a material such as metal or polymer is sprayed through a nozzle to create and fuse a continuous layer, thereby manufacturing a corresponding molded article.

3D printing is applied to various manufacturing fields such as architecture, structure (AEC), industrial design, automobile, aerospace industry, engineering, medical industry, biotechnology, fashion, and footwear.

3D printing technology includes the SLA (stereolithography) method of partially sintering a liquid-based material to produce a molded product, the SLS (selective laser sintering) method of producing a molded product by sintering a powder-based material, and the ejection of a solid-based material to produce a molded product. There are various methods such as fused deposition modeling (FDM).

In particular, there is an urgent need to improve the quality of FDM-type 3D printers, which are widely spread due to their low price and small size. FDM-type 3D printer refers to a 3D printer that creates a three-dimensional model by melting plastic filaments with the heat of a nozzle to turn them into a liquid and then stacking them layer by layer. Due to the nature of this technology, the layers are inevitably revealed on the surface of the completed three-dimensional model. The layered surface is exposed to the outside as it is, like a staircase. When stacking three-dimensional models, this problem can be solved by setting the thickness of one layer as thin as possible, but if the layers are stacked too thin, the strength of the finished model may be weakened. In addition, there is a limit to making the thickness of the layer thin because it is a method of extruding and stacking a liquid in which a plastic resin is dissolved. Most recently released FDM-type 3D printers can print with a thickness of about 0.1mm or support settings that are thinner than this, but if the thickness is set too thin, the printing speed becomes remarkably slow.

A method of manufacturing a molded article by molding a conventional thermoplastic resin into a solid filament and then applying the filament to an FDM type 3D printer is generalized. The filament can be stably fed to the nozzle of an FDM-type 3D printer, is convenient to store or store, and has the advantage of being able to manufacture a molded product that meets the purpose and purpose by mounting two or more filaments required in a cartridge.

However, since the process of manufacturing a filament and the process of manufacturing a molded product using the filament are separated, and the filament and the molded product are sold as products having independent added value by different manufacturers along the value chain, It is a factor that increases the manufacturing cost.

In this regard, attempts have been made to extrude raw materials such as thermoplastic resins from raw materials such as FDM without passing through filaments, which are intermediate materials for manufacturing molded products, and directly apply them to FDM-type 3D printers, but raw materials melted in the extruder Since the flowability of the 3D printer cannot be properly controlled, raw materials are randomly discharged from the nozzle of the 3D printer during the movement of the nozzle and/or substrate, which may reduce the precision of the molded product, and the surface of the substrate other than the molded product is contaminated. there is. In addition, when the molten raw material is rapidly discharged from the nozzle, productivity may be lowered because a shortage of raw material occurs and an excessive amount of raw material must be injected into the extruder.

The present invention is to solve the problems of the prior art described above, and an object of the present invention is to improve economy, productivity, workability, and sophistication of molded products without applying a solid filament made of thermoplastic resin to an FDM-type 3D printer. It is to provide an additive manufacturing device that can be implemented in a balanced way.

One aspect of the present invention includes a first part fixed to a housing and a second part including a substrate provided to move horizontally and vertically inside the housing, wherein the first part melts and kneads raw materials Provides an additive manufacturing apparatus including an extrusion unit generating a melt, a storage unit storing the melt transported from the extrusion unit, and a nozzle unit discharging the melt transported from the storage unit toward the substrate to manufacture a molded product. do.

In one embodiment, the raw material may include a thermoplastic resin.

In one embodiment, the storage unit may include a pressurizing means for providing pressure for transferring the melt to the nozzle unit.

In one embodiment, the storage unit may include a first heat exchange means for maintaining the melt viscosity of the melt.

In one embodiment, the nozzle unit may include a second heat exchange means for maintaining the melt viscosity of the melt.

In one embodiment, the nozzle unit may include a path through which the melt is transported, and a screw provided in the path to control at least one of a speed and an amount of the melt being discharged.

In one embodiment, the substrate may move horizontally and vertically in the housing along a path designed based on a three-dimensional model.

In one embodiment, the melt may not be solidified in the reservoir and the nozzle.

In one embodiment, the storage unit may have an empty space of a predetermined volume on top of the melt.

In one embodiment, the volume of the empty space may be 5 to 30% of the total volume of the storage unit.

An additive manufacturing apparatus according to an aspect of the present invention includes a first part fixed to a housing and a second part including a substrate provided to move horizontally and vertically inside the housing, wherein the first part includes a raw material By including an extrusion unit for generating a melt by melting and kneading, a storage unit for storing the melt transferred from the extrusion unit, and a nozzle unit for discharging the melt transferred from the storage unit toward the substrate to manufacture a molded product , Economic feasibility, productivity, workability, and sophistication of a molded product can be realized and improved in a balanced manner without applying a conventionally generalized solid filament.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 shows an additive manufacturing apparatus according to an embodiment of the present invention.
2 shows an additive manufacturing apparatus according to another embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and, therefore, is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected" to another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with another member interposed therebetween. . In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows an additive manufacturing apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , an additive manufacturing apparatus according to an aspect of the present invention includes a first part fixed to a housing and a second part including a substrate 400 provided to move horizontally and vertically inside the housing. The first part includes an extrusion part 100 for melting and kneading raw materials to generate a melt, a storage part 200 for storing the melt transferred from the extrusion part 100, and the storage part 200 ) may include a nozzle unit 300 for manufacturing a molded product by discharging the melt transferred from the substrate 400 toward the substrate 400.

The housing may be a body of an additive manufacturing apparatus or a case surrounding it, and the first part including the extrusion part 100, the storage part 200, and the nozzle part 300 may be inside the housing, preferably Preferably, it may be fixed to the top of the housing. Specifically, the extrusion part 100, the storage part 200, and the nozzle part 300 are all fixed to the housing so that their movement may be restricted. Since the first part is heavier than the second part, which will be described later, it is preferable to fix the first part to the housing in consideration of equipment, power, and the like required to move it.

When the additive manufacturing is performed while moving the heavy first part, in particular, the nozzle part 300, the precision of the molded article may be reduced. In addition, when the nozzle part 300 of the first part is separated and designed to move only the nozzle part 300, the melt generated and stored in the extrusion part 100 and the storage part 200, respectively, Since a separate configuration for transferring to the nozzle is required, two or more of the extrusion unit 100, the storage unit 200, and the nozzle unit 300 are directly connected to each other without a separate configuration to connect them to the extrusion unit. It is preferable to ensure that the melt generated in (100) is stably transferred to the nozzle part (300).

The second part may include a substrate 400 provided to move horizontally and vertically inside the housing. For example, the second part includes a moving means provided to move horizontally and vertically at the lower part of the housing and a substrate 400 fixed to the moving means in a horizontal direction and moved horizontally and vertically by the moving means. can include The moving means may include a known member capable of moving in three axis directions (horizontal and vertical directions) such as an arm, a rail, and a slide, and the type, structure, and driving method thereof are not particularly limited.

The substrate 400 included in the second part may be provided as a flat panel, and the panel may be made of a material such as plastic, glass, ceramic, or metal (including alloy), preferably. , In order to reduce the weight of the substrate 400 and thereby improve the mobility and sophistication of molded products, it may be made of plastic, glass, light metal, and/or light alloy, but is not limited thereto.

The moving unit may horizontally and vertically move the substrate 400 inside the housing along a path designed based on a three-dimensional model (virtual and/or real) of a molded article to be manufactured. Unlike the conventional apparatus, the additive manufacturing apparatus, in a state in which the nozzle part 300 is not moved but fixed, relative to the first part along a path designed based on a three-dimensional model (virtual and/or real) of a molded product. By moving the light substrate 400, it is possible to sufficiently secure workability and sophistication of molded products.

The first part includes an extrusion unit 100 for melting and kneading raw materials to generate a melt, a storage unit 200 for storing the melt transferred from the extrusion unit 100, and transported from the storage unit 200. It may include a nozzle unit 300 for manufacturing a molded article by discharging the melted material toward the substrate 400.

The extrusion unit 100 may generate a melt by melting and kneading the raw material. Specifically, the extruding unit 100 includes a raw material inlet 110 into which the raw material is introduced, a cavity in which the raw material is melted, kneaded, and transported, and is built along the central axis of the cavity to increase the uniformity of the melt and simultaneously to increase the uniformity of the melt. It may include a screw 120 for transferring to the storage unit 200. The extrusion unit 100 may be a single-screw, twin-screw, or multi-screw extruder, depending on the number of screws 120 . The temperature of the extrusion part 100 may be preheated and heated to a temperature suitable for melting and kneading of the raw material by a separate heat exchanging means, preferably, a heating means.

The raw material may include a thermoplastic resin. The thermoplastic resin is a soft or hard polyolefin elastomer, an ethylene-based copolymer, a styrenic copolymer, polyethylene, polypropylene, polyurethane, polyester, nylon, polybutylene terephthalate, polycarbonate, polylactic acid, polyvinyl alcohol, It may be one selected from the group consisting of polymethyl methacrylate, polyoxymethylene, epoxy, and a combination of two or more of these.

In particular, each of the thermoplastic resins may be a thermoplastic elastomer, preferably a polyurethane and/or an ethylene-based copolymer. For example, the ethylene-based copolymer may be one selected from the group consisting of ethylene vinyl acetate, ethylene butyl acrylate, ethylene ethyl acrylate, and a combination of two or more thereof, preferably, may be ethylene vinyl acetate, More preferably, the content of vinyl acetate may be 10 to 20% by weight of ethylene vinyl acetate, but is not limited thereto.

The raw material may further include a thermosetting resin. As used herein, the term "thermosetting resin" may be interpreted as including elastic resins such as rubber and elastomer, and in particular, "thermosetting" refers to the elasticity of an elastic resin when exposed to a predetermined heat source or thermal energy equivalent thereto. It can be interpreted as meaning that the polymers included in the resin are mutually cross-linked, polymerized, and/or vulcanized to cause the elastic resin to solidify.

At least a part of the raw material, the melt, and the molded article manufactured therefrom may be made of a thermosetting resin. The thermosetting resin may provide a curable material that exhibits elastomer properties when exposed to thermal energy.

The thermosetting resin may be provided as a composition or mixture including an elastic polymer, an initiator, a crosslinking agent, and the like. If necessary, the composition or mixture may further include a process oil that facilitates mixing and processing, and may further include various additives such as a coupling agent, a titanium or zirconium compound, an antioxidant, an anti-ozone agent, and the like.

The elastic polymer is, for example, polyisoprene and natural rubber (NR) including hevea and guayule rubber, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer ( NBR or nitrile butadiene), butadiene-propylene copolymer, butadiene-ethylene copolymer, butadiene-isoprene copolymer, isobutylene-isoprene copolymer (butyl rubber or IIR), brominated isobutylene-isoprene copolymer (bromobutyl rubber), ethylene-propylene-cyclopentadiene terpolymer, ethylene-propylene-5-ethylidene-norbornene terpolymer, ethylene-propylene-1,4-hexadiene terpolymer Polymer, isoprene-isobutylene copolymer, ethylene vinyl acetate (EVA), ethylene-propylene copolymer (EPR or EPM), chlorinated and chlorosulfonated polyethylene (CM, CSM), silicone elastomer, fluorocarbon elastomer, acrylic rubber And it may be one selected from the group consisting of a combination of two or more of them, but is not limited thereto.

The initiator may be, for example, one selected from the group consisting of dialkyl peroxide, diacyl peroxide, peroxyester, peroxyketal, peroxydicarbonate, peroxymonocarbonate, hydroperoxide, and a combination of two or more thereof It may, but is not limited thereto. Suitable organic peroxides are, for example, di-tert-amyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5- Di(tert-butylperoxy)hexyne-3, tert-butyl peroxybenzoate, tert-amyl peroxyacetate, tert-amylperoxy 2-ethylhexyl carbonate, 1,1-(di(t -butylperoxy)-3,3,5-trimethylcyclohexane), 1,1-di(tert-amylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, tert t-butyl peroxyisobutyrate, tert-butyl peroxydiethyl acetate, tert-butyl peroxy-2-ethylhexanoate, tert-amyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(ethylhexanoylperoxy)hexane, didecanoylperoxide and two or more of these It may be one selected from the group consisting of good, but is not limited thereto.

The crosslinking agent may be, for example, metal salts of ethylenically unsaturated acids such as zinc diacrylate and magnesium dimethacrylate; polyacrylates and polymethacrylates such as polybutadiene diacrylate, ethylene glycol dimethacrylate and trimethylolpropane triacrylate; triallylsyanuate; triallyl isocyanurate; And it may be one selected from the group consisting of a combination of two or more of them, but is not limited thereto.

The raw material may be a pellet that includes the thermoplastic resin and, if necessary, further includes the thermosetting resin, and the pellet may be manufactured by further including a filler, a pigment, and the like.

The filler (or filler) may be, for example, silica, carbon black, clay, talc, calcium sulfate, calcium silicate, graphite, glass, mica, calcium metasilicate, barium sulfate, zinc sulfide, aluminum hydroxide, diatomaceous earth, carbonate ( Calcium carbonate, magnesium carbonate, etc.), metals (titanium, tungsten, zinc, aluminum, bismuth, nickel, molybdenum, iron, copper, brass, boron, bronze, cobalt, beryllium and their alloys, etc.), metal oxides (zinc oxide, iron oxide, aluminum oxide, titanium oxide, magnesium oxide, zirconium oxide, etc.), particulate synthetic plastics (high molecular weight polyethylene, polypropylene, polystyrene, polyethylene ionomer resin, polyamide, polyester, polyurethane, polyimide, etc.), cotton flock, It may be one selected from the group consisting of cellulose floc, cellulose pulp, leather fiber, and a combination of two or more of them, but is not limited thereto.

The pigments include, for example, carbon black, titanium dioxide, iron oxide pigments such as black iron oxide and red iron oxide, zinc oxide, monoazo and diazo pigments, cobalt blue, ultramarine blue, bismuth vanadate yellow, azo metal complexes, copper phthalocyanine , anthraquinone, quinacridone, dioxazine, perylene pigment, thioindigo pigment, and may be one selected from the group consisting of a combination of two or more of these, but is not limited thereto.

The storage unit 200 may store the melt transported from the extrusion unit 100, and the amount of the melt discharged through the nozzle unit 300 is appropriately based on the structure and shape of the molded product to be manufactured. can be regulated. For example, the melt stored in the storage unit 200 may supply additional melt to the nozzle unit 300 according to the structure and shape of a molded product when the amount of the melt detected by the nozzle unit 300 is insufficient. can

The storage unit 200 may include a pressurizing means 210 providing pressure to transfer the melted material to the nozzle unit 300 . The pressing means 210 may be based on a physical method such as air pressure, hydraulic pressure, or a piston, but is not limited thereto. The pressing means 210 may provide a driving force for transferring the melt stored in the storage part 200 to the nozzle part 300 . Even without the pressurizing means 210, the melt may be transferred to the nozzle part 300 by gravity and/or an orifice effect according to a difference in inner diameter between the storage part 200 and the nozzle part 300, but in this case The additive manufacturing speed may be significantly lowered, and the above-described shortage of the melt may occur frequently.

The storage unit 200 may have an empty space (V) of a predetermined volume on top of the melt. A predetermined empty space (V) is formed at the top of the storage unit 200 by controlling and designing the surface of the melt filled in the storage unit 200 and the top of the storage unit 200 to be separated by a predetermined distance. The empty space V may provide a space in which gas or fluid injected by the pressurizing means 210 stays or a physical means such as a piston can reciprocate.

The volume of the empty space V may be 5 to 30% of the total volume of the storage unit 200 . If the volume of the empty space (V) is less than 5% of the total volume of the storage unit 200, the space in which the pressurizing means 210 can stay or reciprocate is narrowed, and the nozzle unit is removed from the storage unit 200. The amount of the melt that can be transported to 300 may be limited, and if it exceeds 30%, the pressurizing means 210 fills the empty space (V) or moves along the empty space (V) to form the melt A delay may occur until pushing out, and the additive manufacturing speed may decrease.

The storage unit 200 may further include a separate means for adjusting the height of the surface of the melt, so-called water level, in order to adjust the volume of the empty space V within a predetermined range.

The storage unit 200 may include a first heat exchange means 220 for maintaining the melt viscosity of the melt. When the manufacture of the molded article is completed or the molded article has a hollow and/or porous structure, the discharge of the molten material from the nozzle unit 300 must be stopped temporarily or for a long period of time. As such, when the discharge of the melt is stopped, the residence time of the melt in the storage unit 200 may be increased, and in order to prevent denaturation of the melt and maintain the dispersibility of each component included in the melt, the It is necessary to control the melt viscosity of the melt within a predetermined range. The first heat exchange means 220 may increase the melt viscosity by lowering the temperature of the storage unit 200 when the melt viscosity is lower than a preset range, and conversely, when the melt viscosity is higher than a preset range, the storage The melt viscosity may be lowered by increasing the temperature of the part 200 . That is, the first heat exchanging means 220 may be involved in both cooling and overheating of the storage unit 200 .

The nozzle part 300 may include a second heat exchange means 310 for maintaining the melt viscosity of the melt. The first heat exchange means 220 may adjust the melt viscosity of the melt stored in the storage unit 200 to a predetermined range, but after the melt is transferred to the nozzle unit 300, the melt viscosity of the melt can't affect In contrast, the second heat exchange means 310 adjusts the melt viscosity of the melt transported and discharged through the nozzle unit 300 within a predetermined range so that the melt is arbitrarily modified or the dispersibility of the melt is reduced. can prevent it from happening. The second heat exchanging means 310 may increase the melt viscosity by lowering the temperature of the nozzle unit 300 when the melt viscosity is lower than a predetermined range, and conversely, when the melt viscosity is higher than a predetermined range, the nozzle The melt viscosity may be lowered by increasing the temperature of the part 300 . That is, the second heat exchanging means 310 may be involved in both cooling and overheating of the nozzle unit 300 .

The melt is not solidified in the storage part 200 and the nozzle part 300 by the first and/or second heat exchange means 220 and 310 and is stored, transported, can be ejected.

2 shows an additive manufacturing apparatus according to another embodiment of the present invention.

Referring to FIG. 2 , the nozzle unit 300 may include a path along which the melt is transported, and a screw 320 provided in the path to adjust at least one of a speed and an amount of the melt discharged.

The screw 320 may maintain and improve dispersibility and uniformity of the melt transported along the path. In addition, the discharge speed and/or the discharge amount of the melt is controlled through the rotational speed of the screw 320, and, if necessary, the rotation of the screw 320 is stopped so that the melt is not discharged from the nozzle unit 300. By doing so, it is possible to improve the sophistication of molded products manufactured by the additive manufacturing apparatus. The size and number of the screws 320 provided in the path may be appropriately changed as needed.

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

Example 1

As shown in FIG. 1, a first part composed of an extrusion part (built-in screw), a storage part (including a pressurizing means and a heat exchange means), and a nozzle part (without a screw) is fixed to the upper part of the housing of the FDM type 3D printer, and the lower part of the housing A second part including an arm provided to move in horizontal and vertical directions and a substrate fixed in the horizontal direction to an upper end of the arm was installed.

Raw material pellets containing thermoplastic polyurethane were put into the main hopper of the extrusion unit, and the raw material pellets were melted, kneaded, and transferred to the storage unit. The input amount of the raw material pellets was adjusted so that an empty space of 5% by volume of the total volume of the storage unit was formed on top of the melt transferred to the storage unit, and the extrusion speed was controlled through the rotational speed of the screw built into the extrusion unit. .

The melt was transported to the nozzle unit by injecting air (or inert gas) into the empty space, and the melt passing through the nozzle unit moved horizontally and vertically along a path designed based on a preset model on the substrate. to prepare a molded product specimen corresponding to the model.

Example 2

The input amount of the raw material pellets was adjusted so that an empty space of 30% by volume of the total volume of the storage unit was formed on top of the melt transferred to the storage unit, and the extrusion speed was adjusted through the rotational speed of the screw built into the extrusion unit. Except for the above, a molded article specimen was prepared in the same manner as in Example 1.

Example 3

As shown in FIG. 2, a first part composed of an extrusion part (with a built-in screw), a storage part (including a pressurizing means and a heat exchange means), and a nozzle part (with a built-in screw) is fixed to the upper part of the housing of the FDM type 3D printer, and the lower part of the housing A second part including an arm provided to move in horizontal and vertical directions and a substrate fixed in the horizontal direction to an upper end of the arm was installed.

Raw material pellets containing thermoplastic polyurethane were put into the main hopper of the extrusion unit, and the raw material pellets were melted, kneaded, and transferred to the storage unit. The input amount of the raw material pellets was adjusted so that an empty space of 10% by volume of the total volume of the storage unit was formed on the top of the melt transferred to the storage unit, and the extrusion speed was controlled through the rotational speed of the screw built into the extrusion unit. .

While injecting air (or inert gas) into the empty space, a screw built into the nozzle part was rotated to transport the melt to the nozzle part, and the melt passing through the nozzle part followed a path designed based on a preset model. A molded article specimen corresponding to the model was prepared by ejecting onto the substrate moving in horizontal and vertical directions.

Comparative Example 1

A molded article specimen was manufactured in the same manner as in Example 1, except for omitting the storage part among the first parts according to Example 1.

Comparative Example 2

A molded article specimen was manufactured in the same manner as in Example 2, except for omitting the storage part among the first parts according to Example 2.

Comparative Example 3

The input amount of the raw material pellets was adjusted so that an empty space of 3% by volume of the total volume of the storage unit was formed on top of the melt transferred to the storage unit, and the extrusion speed was controlled through the rotational speed of the screw built into the extrusion unit. Except for the above, a molded article specimen was prepared in the same manner as in Example 1.

Comparative Example 4

The input amount of the raw material pellets was adjusted so that an empty space of 40% by volume of the total volume of the storage unit was formed on top of the melt transferred to the storage unit, and the extrusion speed was controlled through the rotational speed of the screw built into the extrusion unit. Except for the above, a molded article specimen was prepared in the same manner as in Example 1.

Experimental example

In the Examples and Comparative Examples, the ejection speed (printing speed) of the melt from the nozzle part and workability thereof were evaluated, and the results are shown in Table 1 below.

division Printing speed (mm/s) printing characteristics Example 1 10 ◎ Example 2 8 ○ Example 3 50 ◎ Comparative Example 1 10 X Comparative Example 2 50 X Comparative Example 3 15 X Comparative Example 4 5 X

(◎: Excellent, ○: Good, X: Bad)

Referring to Table 1, in the case of the embodiment, the raw materials are uniformly mixed and kneaded in the extrusion part, and the melt stored in the storage part is smoothly exposed through the nozzle part, so that any projections, irregularities, pores, etc. No defects or damage were observed.

On the other hand, in Comparative Examples 1 and 2 in which the storage unit was omitted, the melt viscosity of the melt generated in the extruder cannot be adjusted to meet the target physical properties of the molded product, and the printing speed cannot be controlled in addition to controlling the extrusion unit. Not only was there a significant difference in the appearance of the molded product specimen and the manufactured specimen, but a number of defects or damages such as random protrusions, irregularities, and pores were observed on the surface of the molded specimen.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

100: extrusion unit 110: raw material inlet
120: screw 200: storage unit
210: pressurization means 220: first heat exchange means
300: nozzle unit 310: second heat exchange means
320: screw 400: substrate

Claims (10)

A first part fixed to the housing and a second part including a substrate provided to move horizontally and vertically inside the housing,
The first part,
An extrusion unit that melts and kneads raw materials to produce a melt;
A storage unit for storing the melt transferred from the extrusion unit, and
Including a nozzle unit for manufacturing a molded product by discharging the melt transferred from the storage unit toward the substrate,
additive manufacturing equipment. According to claim 1,
The raw material includes a thermoplastic resin,
additive manufacturing equipment. According to claim 1,
The storage unit includes a pressurizing means for providing pressure to transfer the melt to the nozzle unit,
additive manufacturing equipment. According to claim 1,
The storage unit includes a first heat exchange means for maintaining the melt viscosity of the melt,
additive manufacturing equipment. According to claim 1,
The nozzle unit includes a second heat exchange means for maintaining the melt viscosity of the melt,
additive manufacturing equipment. According to claim 1,
The nozzle unit includes a path through which the melt is transported, and a screw provided in the path to adjust at least one of a speed and an amount at which the melt is discharged.
additive manufacturing equipment. According to claim 1,
The substrate moves horizontally and vertically inside the housing along a path designed based on a three-dimensional model,
additive manufacturing equipment. According to claim 1,
The melt is not solidified in the reservoir and the nozzle,
additive manufacturing equipment. According to claim 1,
The storage unit having an empty space of a predetermined volume on top of the melt,
additive manufacturing equipment. According to claim 9,
The volume of the empty space is 5 to 30% of the total volume of the storage unit,
additive manufacturing equipment.

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