KR102344434B1 - Carbon fiber-polymer composites mulit-joint robot 3D printer including filament cutting devices - Google Patents

Abstract

The present invention relates to a carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device, and has a nozzle for heating and spraying a filament supplied from a filament supply unit for supplying a carbon fiber-polymer composite filament and a plurality of joints. The nozzle is combined to include an articulated robot that adjusts the height and position of the nozzle in multiple angles, and the nozzle includes a hollow case, a mounting plate horizontally coupled within the case, and a power supply module disposed between the mounting plate and the case. , a filament supply module vertically arranged on the upper side of the mounting plate to supply a filament while being spaced apart from the power supply module in the horizontal direction, a sliding block slidably arranged in a horizontal direction below the filament supply module, and a lower portion of the sliding block and a filament cutting module including a lower cutter fixedly coupled to the lower cutter and an upper cutter sliding with respect to the lower cutter. sliding motion at regular time intervals, and the upper cutter returns to its original state through an elastic member disposed between the case and the upper cutter when the external force applied through the power supply module is released.

Description

Carbon fiber-polymer composites mulit-joint robot 3D printer including filament cutting devices

The present invention relates to a carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device, and more particularly, a polymer composite material manufactured including carbon fiber can be cut to an appropriate size for use on a 3D printer. It includes a carbon fiber filament cutting device, and a carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device capable of forming nozzles at various angles through the articulated robot.

The use of 3D printers capable of forming three-dimensional objects is increasing. The product molding method of this 3D printer is a method of injecting a laser beam into a photocurable material and molding the light-scanned part into an object, a method of cutting and molding a molding material, a method of melting and laminating a thermoplastic polymer composite (FDM method) etc.

Among these methods, 3D printers that melt and laminate a polymer composite material have a lower production cost compared to other types of 3D printers.

On the other hand, the polymer composite material for a 3D printer is made of a thermoplastic resin, and polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) may be used as the thermoplastic resin.

ABS is easy to purchase, has high tensile strength, is strong in heat, and is easier to make smaller parts than PLA, but it is somewhat difficult to form due to heat shrinkage.

Nowadays, PLA, which is harmless to the human body and the environment, is in the spotlight as a polymer composite material instead of ABS. However, due to the disadvantage of low tensile strength, it is used only for the production of simple prototypes such as sculptures and figures.

Therefore, in order to be applied to high-strength parts at present, it is necessary to develop a composite material with improved strength in a state in which carbon fibers and the like are combined.

Referring to the existing Korean Patent No. 10-1774941 (composite filament composition for 3D printer and manufacturing method thereof), 3D printer technology is introduced to provide a composite filament composition for a 3D printer for manufacturing lightweight automobile parts. , a predetermined amount of carbon fiber is mixed with the thermoplastic resin to improve mechanical properties and formability, and to reduce the cost and time required for manufacturing lightweight parts for automobiles or electronic products, multi-type, multi-structured It provides technical details about a composite filament composition optimized for a small-volume production system.

Republic of Korea Patent Registration No. 10-1774941

It is an object of the present invention to include a carbon fiber filament cutting device capable of cutting a polymer composite material manufactured including carbon fiber to an appropriate size for use on a 3D printer, and can form various angles of the nozzle through an articulated robot It is to provide a carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device.

The object of the present invention is not limited to the object mentioned above, and other objects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description.

In order to achieve the above object, the carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device according to an embodiment of the present invention is a carbon fiber-polymer composite material by heating the filament supplied from the filament supply unit for supplying the filament. a nozzle for spraying (10); and a multi-joint robot 20 having a plurality of joints to which the nozzle is coupled to adjust the height and position of the nozzle in multiple angles, wherein the nozzle includes a hollow case 110 and the case 110 The mounting plate 113 horizontally coupled to the inside, the power supply module 120 disposed between the mounting plate 113 and the case, and the upper side of the mounting plate in a state spaced apart from the power supply module 120 in the horizontal direction The filament supply module 130 arranged vertically to supply a filament, the sliding block 141 and the sliding block 141 that are slidably arranged in the horizontal direction at the lower part of the filament supply module 130 in the lower part A filament cutting module 140 including a fixed lower cutter 143 and an upper cutter 142 sliding with respect to the lower cutter 143 is provided, and the carbon fiber filament is passed through the filament supply module 130 . In the process of being supplied, the power supply module 120 slides the upper cutter 142 with respect to the lower cutter 143 at regular time intervals, and the upper cutter 142 moves the power supply module 120 When the external force applied through the ) is released, it is returned to its original state through the elastic member 150 disposed between the case 110 and the upper cutter 142 .

Here, the articulated robot 20 includes a support 210; a rotation support part 220 rotatably coupled to the support part; A first joint part 230 having one end rotatably coupled to the rotation support part and extending in one direction; and a second joint portion 240 having one end rotatably coupled to the other end of the first joint portion to extend in one direction, and to which the nozzle 10 is coupled to the other end.

Here, the case 110 supports the filament cutting module 140 on the bottom surface of the upper cover 111 and the lower case 112 forming the outside of the case 110 , and the lower case 112 inside. and a base plate 114 , a support block 115 disposed on each of both upper sides of the base plate 114 , and the mounting plate 113 disposed on the upper end of the support block 115 .

Here, the power supply module 120 includes a drive motor 121 fixed to the mounting plate 113 , a rotation cam 122 rotatably coupled to a drive shaft constituting the drive motor 121 , and the base plate 114 . ) includes a cam support block 123 for rotatably fixing the cam shaft of the rotation cam 122 in the disposed state.

Here, the upper cutter 142 is inserted and fixed inside the sliding block 141 , and the upper cutter 142 and the lower cutter 143 are disposed to face each other in the upper and lower directions.

Here, the carbon fiber-polymer composite filament is 95 to 99.9 parts by weight of a thermoplastic resin; and 0.1 to 5 parts by weight of the carbon fiber, wherein the carbon fiber has a reinforcing interfacial phase of 10 to 1,000 nm thickness, and 0.5 to 30 parts by weight of an interface material to 100 parts by weight of the carbon fiber. A reinforcing interfacial phase is formed on the surface, and the interfacial material includes a toughening agent and a transfer agent.

Here, the thermoplastic resin is characterized in that the polylactic acid (Poly lactic Acid, PLA) or acrylonitrile butadiene styrene (Acrylonitrile Butadien Styrene, ABS).

Carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device according to the present invention is continuous for 3D printing by stably cutting the continuous carbon fiber filament for laminating use of the supplied continuous carbon fiber filament on the 3D printer It is possible to solve the problem of quality deterioration in the process of laminating carbon fiber filaments.

In addition, the height and position of the nozzle can be variously set through the articulated robot, so 3D printing can be implemented more precisely.

In addition, by using a filament with improved mechanical properties such as tensile strength, tensile modulus, flexural strength, and flexural modulus by mixing a thermoplastic resin and carbon fiber having a reinforced interfacial phase, it is possible to manufacture a finished product with high durability.

1 is a perspective view of a carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device according to an embodiment of the present invention.
FIG. 2 is a side view showing the rotational state of FIG. 1 .
3 is a view showing a perspective view of a nozzle according to an embodiment of the present invention.
4 is a perspective view illustrating a state in which the upper cover is separated so that the inside of the nozzle is visible in FIG. 3 according to an embodiment of the present invention.
5 is a perspective view illustrating a state in which the sliding motion of the upper cutter is progressed by the rotation cam in FIG. 4 according to an embodiment of the present invention;
FIG. 6 is a view showing a cross-sectional state of FIG. 4 .
FIG. 7 is a view showing a cross-sectional state of FIG. 5 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this case, it should be noted that in the accompanying drawings, the same components are denoted by the same reference numerals as much as possible. Detailed descriptions of well-known functions and configurations that may obscure the gist of the present invention will be omitted. For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. In addition, throughout the specification, "on" means to be located above or below the target part, and does not necessarily mean to be located above the gravitational direction.

Carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device according to an embodiment of the present invention is a nozzle 10 and a plurality of carbon fiber-polymer composites for heating and spraying the filament supplied from the filament supply unit supplying the filament The nozzle 10 is coupled to the end of the joint and includes an articulated robot 20 that adjusts the height and position of the nozzle 10 in multiple angles, and the nozzle 10 is a hollow case 110 and, The mounting plate 113 horizontally coupled to the case 110 , the power supply module 120 disposed between the mounting plate 113 and the case, and the mounting plate in a horizontally spaced apart state from the power supply module 120 . The filament supply module 130 disposed vertically on the upper side to supply the filament, the sliding block 141 and the sliding block 141 that are slidably arranged in the horizontal direction at the lower part of the filament supply module 130 are fixed to the lower part. A filament cutting module 140 including a lower cutter 143 coupled to and an upper cutter 142 sliding with respect to the lower cutter 143 is provided, and carbon fiber filaments are supplied through the filament supply module 130 In the process, the power supply module 120 slides the upper cutter 142 with respect to the lower cutter 143 at regular time intervals, and the upper cutter 142 releases the external force applied through the power supply module 120 . In this case, it is returned to its original state through the elastic member 150 disposed between the case 110 and the upper cutter 142 .

Hereinafter, a carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 7 .

The case 110 may be formed in a box shape by being coupled to the lower case 112 constituting the outer surface of the case 110 and the upper cover 111 coupled to the upper end of the lower case. And, the base plate 114 for supporting the filament cutting module 140 on the bottom surface of the lower case 112, the support blocks 115 disposed at both ends between the base plate 114 and the base plate 114 ), and a mounting plate 113 disposed on the upper end of the support block 115 .

The upper cover 111 has a cover through hole 1111 such that the upper cover 111 exposes the upper portion of the filament supply module 130 . On the other hand, both upper sides of the lower case 112 are cut in a chamfered shape, and at the same time, the upper end is formed with a bent portion 116 that forms a coupling portion with the upper cover 111 . In the process of combining the upper cover 111 and the lower case 112 , the upper cover 111 and the bent portion 116 are mutually penetrated while the bent portion 116 is overlapped with the upper side of the upper cover 111 . It can be fastened using a coupling bolt or the like.

The base plate 114 may employ AL6061 made of aluminum. A plurality of fastening grooves for bolting are formed in the base plate 114 to enable coupling of the upper cover 111 and the lower case 112 .

The support block 115 includes a first support block 1151 disposed on one side of the upper surface of the base plate 114 and a second support block disposed on the other upper surface of the base plate 114 to face the first support block 1151 . includes a block 1152 . The support block 130 may also employ AL6061 made of aluminum.

An elastic member 150 is disposed between any one of the first and second support blocks 115 and the filament cutting module 140 . As an example, one side of the elastic member 150 is fixed on the spring groove formed on the side surface of the second support block 134 , and the other side of the elastic member 150 is a sliding block 141 constituting the filament cutting module 140 . is connected to

The power supply module 120 is disposed on the drive motor 121 fixed to the mounting plate 113 , the rotation cam 122 rotatably coupled to the drive shaft constituting the drive motor 121 , and the base plate 114 . It includes a cam support block 123 for rotatably fixing the camshaft of the rotating cam 122 in the state.

The rotation cam 122 has a structure in which a plurality of rotation blades having different lengths are alternately formed along the outer periphery of the edge. That is, the plurality of rotary blades are formed with rotary blades having different distances from the central axis of the rotary cap. As an example, the plurality of rotary blades includes a long-axis blade that enables a sliding motion by pressing the side of the filament cutting module 140 and a short-axis blade that enables restoration of the slidably moved filament cutting module 140 .

The filament cutting module 140 is a sliding block 141 that is slidably disposed in the horizontal direction from the lower portion of the filament supply module 130, a lower cutter that is fixedly coupled to the case 110 on the lower portion of the sliding block 141 ( 143) and a guide block 144 disposed on both sides of the sliding block 141.

The sliding block 141 includes an upper cutter 142 inserted and fixed therein. The upper cutter 142 and the lower cutter 143 are disposed to face each other in the upper and lower directions.

The sliding block 141 has a rectangular parallelepiped shape, and at the same time a cutter groove in which the upper cutter 142 can be inserted and mounted is formed at the lower portion, and a filament supply hole to which the lower end of the filament supply module 130 is connected is formed in the upper portion. . The cutter groove may be a rectangular groove matching the shape of the upper cutter 142 , and the filament supply hole may have a circular shape.

The sliding block 141 is capable of position change through periodic direct contact with the filament supply module 130 . When the rotation cam 122 rotatably coupled to the drive shaft constituting the drive motor rotates, when the long shaft wing is positioned on one side of the sliding block 141, the sliding block compresses the elastic member 150. will do Through the process, the upper cutter 142 disposed on the upper part of the lower cutter 143 is displaced by sliding. That is, the upper cutter 142 slides together with the sliding block 141 in a state inserted and fixed therein through the lower end of the sliding block 141 .

The guide block 144 enables a stable linear motion along the base plate 114 when the sliding block 141 moves. That is, a pair of guide blocks 144 are fixed to the base plate 114 on both sides of the sliding block 141, and through this, the sliding block 141 slides repeatedly without departing from a straight path. work out. On the other hand, in order to prevent friction between the guide block 144 and the sliding block 141, a guide rail and a bearing interpolated into the guide rail are provided on the inner surface of the guide block 144, and friction is reduced through rolling motion through the bearing. can be minimized On the other hand, a material that prevents friction between the guide block 144 and the sliding block 141 may be selected.

The upper cutter 142 and the lower cutter 143 are formed to face each other in the upper and lower directions. The upper and lower cutters have the shape of a rectangular parallelepiped hollow block, and a through hole of a predetermined diameter is formed to enable movement of the filament required to be cut along the upper and lower directions. A predetermined cutting blade is disposed on the through hole of the upper and lower cutters to enable transverse cutting of the supplied filament.

When the upper cutter 142 is slid through the sliding block 141 in a state in which the carbon fiber filaments are supplied at predetermined intervals in the lower direction through the filament supply module 130 , the filament fillets cut in the lower cutter 143 are In this remaining state, it is discharged to the outside through the discharge passage 1131 formed on the base plate 114 .

One side of the elastic member 150 is fixedly installed in the spring groove formed on the side surface of the second support block 134 , and the other side is connected to the sliding block 141 constituting the filament cutting module 140 . A pair of elastic members 150 may be symmetrically arranged side by side along the sliding block 141 .

On the other hand, on one side of the cam support block 123, a damper unit 160 is disposed to function to reduce the shock and vibration to the cam support block 123 in the process of restoring the sliding block 141. The damper unit 160 may have a structure arranged on the sliding block 141 .

In the process in which the carbon fiber filament is supplied through the filament supply module 130 , the power supply module 120 slides the sliding block 141 and the upper cutter 142 with respect to the lower cutter 143 at regular time intervals. When the external force applied by the external force is applied and the external force applied by the power supply module 120 is released, the sliding block 141 to which the external force is applied has an original shape through the elastic member 150 disposed between the case 110 and the upper cutter 142. is returned

The articulated robot 20 is provided with a plurality of joints and the nozzle 10 is coupled to serve to adjust the height and position of the nozzle 10 in multiple angles. It is configured to include a first joint part 230 and a second joint part 240 .

The support 210 serves to support and fix the articulated robot 20 at a preset position.

The rotation support 220 is rotatably coupled to the support 210 . A driving motor is provided inside the rotation support 220 so as to be rotated in both directions by 360 degrees in the support 210 . At this time, the rotation support 220 is formed with a first joint groove 211 of a concave shape from the upper side to the lower side so that the first joint portion 230 can be rotationally coupled.

One end of the first joint portion 230 is rotatably coupled to the joint groove 211 of the rotation support unit 220, and the other end is concave from the upper side to the lower side so that the second joint portion 240 can be rotatably coupled. of the second joint groove 231 is formed.

The second joint portion 240 has one end rotatably coupled to the second joint groove 231 of the first joint portion 230 to extend in one direction, and the nozzle 10 is coupled to the other end. And, the second joint portion 240 may be formed to extend along the filament supply module 130 in one direction.

In this way, 3D printing can be implemented at various angles by dispersing the height and position of the nozzle 10 at various angles through the articulated robot 20 that can be formed at multiple angles.

The carbon fiber-polymer composite filament supplied in the present invention improves mechanical properties such as tensile strength, tensile modulus of elasticity, flexural strength, and flexural modulus by mixing a thermoplastic resin and carbon fiber having a reinforcing interfacial phase.

The carbon fiber-polymer composite filament preferably includes 0.01 to 5 parts by weight of the carbon fiber in 95 to 99.99 parts by weight of the thermoplastic resin, and more preferably 0.07 to 0.1 parts by weight of the carbon fiber. When the range of use of the thermoplastic resin and carbon fiber is exceeded or less than the range of use, there may be problems in that the carbon fiber oozes out or mechanical properties decrease when the polymer composite is extruded. In addition, it is preferable that the carbon fiber contains 1000 to 7000 strands, preferably 2000 to 4000 strands per filament unit length (1 cm). When it contains less than 1000 strands, it cannot be expected to improve physical properties by carbon fibers, and when it contains more than 7000 strands, the filament may be exposed to the surface of the fiber, or malleability and ductility may be deteriorated.

The thermoplastic resin means a polymer such as polyethylene or polyvinyl chloride that becomes soft when heated and hardens again when cooled. These materials can be changed into various shapes by heating. Even after molding by applying heat, the shape can be deformed by applying heat again, so that it can be efficiently processed by extrusion or injection molding. Thermoplastic resins include crystalline thermoplastic resins and amorphous thermoplastic resins, and crystalline thermoplastic resins include polyethylene, nylon, polyacetal resin, and the like, and are milky white. There are many transparent amorphous thermoplastic resins such as vinyl chloride resin, polystyrene, ABS (Acrylonitrile Butadien Styrene) resin, and acrylic resin.

The thermoplastic resin is polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), high-density polyethylene (HDPE), low-density polyethylene (LDPE), styrene (Styrene), polypropylene (PP), And it may include one or more selected from the group consisting of polycarbonate (PC). PLA (Poly Lactic Acid) is a polymer of low-molecular-weight compounds (monomers) present in the living body called lactic acid, which does not exist in nature. In general, it is known that it is hydrolyzed by water, reduced to a molecular weight, and then decomposed by microorganisms.

In other words, the biggest advantage of PLA is that it can be decomposed on the ground, unlike general plastics and synthetic fibers. For this reason, it has recently been spotlighted as an alternative material for plastic yogi. In the field of 3D printing materials, PLA material has the advantage of hardly shrinking because it takes a long time to cool down again after melting. ABS (Acrylonitrile Butadien Styrene) is an amorphous styrene-based thermoplastic resin. It has excellent impact resistance, rigidity, fluidity, etc., and also has excellent properties such as dimensional stability, molding processability, and chemical resistance.

The carbon fiber preferably has a reinforcing interfacial phase with a thickness of 10 to 1,000 nm, and it is preferable to form the reinforcing interfacial phase by including 0.5 to 30 parts by weight of an interface material in 100 parts by weight of the carbon fiber.

When the amount of the interfacial material is less than 0.5 parts by weight, it is difficult to form a reinforcing interfacial phase, and when it exceeds 30 parts by weight, the thickness of the reinforcing interfacial phase may exceed 1,000 nm.

When the thickness of the reinforcing interfacial phase is less than 10 nm, the mechanical properties of the polymer composite are reduced, and when the thickness of the reinforcing interfacial phase exceeds 1,000 nm, the carbon fiber and the thermoplastic resin may not be mixed well.

The interfacial material may be a toughening agent or a mixture of toughening agents containing one or more components that are incompatible with the transfer agent. The toughening agent is an elastomer, branched polymer, hyperbranched polymer, dendrimer, rubbery polymer, rubbery copolymer, block copolymer, core-shell particle, oxide or inorganic material such as clay, polyhedral oligomersilsesquioxane ( POSS), carbon black, carbon nanotubes, carbon nanofibers, carbonaceous materials such as fullerenes, ceramics, and silicon carbide.

Examples of block copolymers having a composition described in US 6894113 (Court et al., Atofina, 2005) include "Nanostrength (registered trademark)" SBM (polystyrene-polybutadiene-polymethacrylate) and MBM (polymethacrylic rate-polybutylacrylate-polymethacrylate), both of which are manufactured by Arkema. Other block copolymers include Fortegra® and amphiphilic block copolymers (described in US 7820760B2 to Dow Chemical). Examples of known core-shell particles are core-shell (dendrimer) particles whose composition is described in US 20100280151A1 (Nguyen et al., Toray Corporation, 2010) and has an unsaturated carbon-carbon bond. an amine branching polymer is grafted as a shell to a polymerized core polymer from a polymerizable monomer]; Core-shell rubbery particles whose composition is described in EP 1632533A1 and EP 2123711A1 of Kaneka, Ltd., the "KaneAce MX" product line of such particle/epoxy blends is that the particles contain polymerizable monomers, such as butadiene , a polymer core polymerized from styrene, other unsaturated carbon-carbon bonding monomers, or combinations thereof, and a polymer shell corresponding to an epoxy, usually polymethylmethacrylate, polyglycidylmethacrylate, polyacrylonitrile or equivalent with water and the like]; "JSR SX" series of carboxylated polystyrene/polydivinylbenzene manufactured by JSR Corporation; "Kureha paraloid" EXL-2655 which is a butadiene alkyl methacrylate styrene copolymer (made by Kureha Corporation); "Stafiloid" AC-3355 and TR-2122 which are acrylate methacrylate copolymers, respectively (both manufactured by Takeda Yakuhin Kogyo Co., Ltd.); "PARALOID" EXL-2611 and EXL-3387 (both manufactured by Rohm & Haas), respectively, which are butyl acrylate methyl methacrylate copolymers. Examples of known oxide particles include Nanopox (registered trademark) manufactured by nanoresins AG. It is a master blend of functionalized nanosilica particles and epoxy.

Toughening agents used as interfacial materials include core-shell particles (eg, MX416, MX125, MX156) found in the Kane Ace MX product line by Kaneka, Ltd.; or a material having a shell composition or surface chemistry similar to the Kane Ace MX material; or a rubber-like material such as a material having a surface chemistry compatible with the surface chemistry of the adherend (this enables the material to migrate in the vicinity of the adherend and have a higher concentration than that of the bulk adhesive composition). These core-shell particles are generally sufficiently dispersed in the epoxy base material at a typical addition amount of 25%, and can be directly used in the adhesive composition for high-performance bonding to an adherend.

The ratio of transfer agent to interfacial material may be from about 0.1 to about 30 or from about 0.1 to about 20. Examples of the transfer agent include polyvinyl formal, polyamide, polycarbonate, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyarylate, polyester, polyamideimide, polyimide, polyetherimide, and phenyltrimethylindane structure. polyimide, polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, polyaramid, polyethernitrile, polybenzimidazole, derivatives thereof, and mixtures thereof having

The reinforcing interfacial phase is a mechanical application method such as a pump, a control system, a dosing gun assembly, a swirl technology using a remote supply device and an application gun, a steaming method, or a hot melt method. It may be formed on the carbon fiber.

When the thermoplastic resin and the carbon fiber are mixed, the rotation speed of the mixing screw may be 15 to 17 RPM. When the rotation speed of the mixing screw is less than 15 RPM, the thickness of the polymer composite material becomes thick, and there may be a problem of clogging during printing.

The carbon fiber-polymer composite filament is (a) immersing the carbon fiber in a pretreatment agent; (b) drying the pretreated carbon fiber; and (c) mixing the dried carbon fiber and the thermoplastic resin.

The step (a) is a step of surface-treating the carbon fiber and is performed by immersing the carbon fiber in a point treatment agent. The pretreatment agent can be used without limitation as long as it is a pretreatment agent capable of reducing the roughness by etching the carbon fiber surface and increasing the number of oxygen functional groups, but preferably hydrochloric acid, nitric acid, phosphoric acid, acetic acid, hydrofluoric acid, ammonium bicarbonate ( It may include at least one selected from the group consisting of NH4HCO3) and ammonium carbonate ((NH4)2CO3), more preferably hydrogen carbonate or ammonium carbonate, and most preferably ammonium hydrogen carbonate.

In addition, the acid radical pretreatment agent can be used by selecting an appropriate concentration according to the type and pH of the pretreatment agent used, but preferably by selecting a concentration of 0.1 to 1M, more preferably 0.2 to 0.5M, and most preferably 0.3M. can be used If the pretreatment agent has a concentration of less than 0.1M, the pretreatment agent treatment time is prolonged, or the effect of reducing surface roughness and increasing oxygen functional groups by the pretreatment agent cannot be expected. Agitation time may be lengthened during manufacturing, and the bond between carbon and thermoplastic polymer may be weakened by the pretreatment agent remaining during washing.

In addition, the step (a) is carried out under a current density of 0.7 ~ 7.0A / ㎡ and may be performed for 50 ~ 120 seconds, preferably it may be carried out for 80 ~ 110 seconds under a current density of 0.75 ~ 6.82A / ㎡ . If the current density is less than 0.7A/m2 or if the surface treatment is performed for less than 50 time, the effect of reducing the surface roughness and increasing the oxygen functional group cannot be expected due to poor surface treatment, and the current density exceeds 7.0A/m2 or 120 If the surface treatment is carried out for more than a second, the amount of current used increases and the production time of carbon fiber increases, resulting in lower economic feasibility.

Step (c) is a step of mixing the carbon fiber and the thermoplastic resin, and if it is a condition capable of mixing the thermoplastic resin, it may be performed by selecting an appropriate condition, but preferably at 230 to 310°C. When the step (c) is performed at less than 230°C, the viscosity is lowered because the resin is not sufficiently liquefied. Therefore, the resin in the extruder is hardened and the carbon fiber is wound, so that the carbon fiber is subjected to high tension and is broken. In addition, when the temperature is low as described above, the surface of the filament may become non-uniform due to a decrease in viscosity. In addition, when step (c) is carried out at more than 310° C., the viscosity of the resin may increase, so that the diameter of the carbon fiber-polymer composite filament may decrease than the specified value, and discoloration of the surface may occur.

In addition, step (c) may have 2 to 10 temperature sections. When the step (c) is performed at a constant temperature, a temperature difference between the inside and the outside of the filament may occur, which may cause non-uniformity on the surface during extrusion of the thermoplastic resin. Therefore, it is preferable to heat to a constant temperature using the temperature section of the extruder 2 to 10 steps. At this time, the temperature section may have a temperature of 230 ~ 310 ℃, preferably may have a temperature of 260 ~ 280 ℃. In addition, the temperature section starts at a temperature of 260 ° C., rises by 5 to 10 ° C. to reach the maximum temperature section of 280 ° C., and then decreases by 5 to 10 ° C. to reach 260 ° C. It is most preferable.

As described above, the present invention provides a carbon fiber-polymer composite filament for 3D printing in order to solve the problem of quality deterioration in the process of laminating the carbon fiber-polymer composite filament for use on a 3D printer. The inclusion of a device makes it possible to cut carbon fiber-polymer composite filaments.

The filament supply part is a part that supplies the wound filament to the filament supply module 130, and is preferably located in the vertical direction of the filament supply module 130 for a smooth supply of the filament, but the factory layout and raw material supply situation It may be located in a right-angled direction. When positioned at a right angle in this way, an additional supply means capable of changing the supply direction of the filament may be installed inside for supplying the filament, and this supply means uses a pipe bent in a curve, or by using a pulley or rotation of a bearing. A means for changing the direction of the filament may be used.

The nozzle is a device for heating and spraying the filament supplied from the supply unit, and as described above, includes the filament cutting device, and includes a heater to melt and spray the filament. In this case, the heater is preferably installed so as to heat the nozzle to 200 ~ 400 ℃. When heated to less than 200 ° C, printing may not be possible because the melting of the carbon fiber-polymer composite filament is not complete. In addition, the nozzle may have a nozzle of 1 to 5 mm. The injection port is a place through which the filament is injected, and it is preferable to prepare various nozzles according to the diameter of the filament and replace it according to the thickness of each filament. However, if the diameter of the nozzle is less than 1mm, it takes a lot of time for printing, so economical efficiency is lowered.

The carbon fiber-polymer composite 3D printer may further include a chamber heater module. The chamber heater module is installed to maintain the inside of the printing chamber at a constant temperature, and it is preferable to maintain the inside of the chamber at 40 to 80° C. to maintain the printing object and the filament at a constant temperature. When the temperature inside the chamber is less than 40 ℃, the temperature of the printing object is lowered, so the pre-printed layer is cured quickly, so that the adhesion between the newly printed layers may decrease. Poetry may collapse.

Hereinafter, preferred embodiments of the present invention will be described so that those of ordinary skill in the art can easily implement them with reference to the accompanying drawings. In addition, in the description of the present invention, if it is determined that a detailed description of a related known function or a known configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, certain features presented in the drawings are enlarged, reduced, or simplified for ease of explanation, and the drawings and components thereof are not necessarily drawn to scale. However, those skilled in the art will readily understand these details.

Example

Preparation of polymer composites and evaluation of mechanical properties

An example was prepared by mixing 5 parts by weight of carbon fiber having a reinforcing interfacial phase of 100 nm to 95 parts by weight of ABS at 16 rpm, and as Comparative Example 1, a product from Stratasys of the United States, which is currently the world's highest level of polymer composite material for 3D printers, was used. As 2, the same filament as in Example 1 was used, but it was output using an FDM 3D printer.

In order to evaluate the mechanical properties of Examples and Comparative Examples, tensile specimens (ASTM D 638) and bent specimens (ASTM D 790) were prepared using the printer shown in FIG. 6 of the present invention with the polymer composites of Examples and Comparative Examples. Table 1 below shows the experimental results of tensile strength, tensile modulus of elasticity, flexural strength and flexural modulus.

Item (unit) Example Comparative Example 1 Comparative Example 2 Assessment Methods Tensile strength (MPa) 49 35 41 ATSM D 638 Tensile modulus (GPa) 3.4 2.4 2.8 ATSM D 638 Flexural strength (MPa) 83 63 78 ATSM D 790 Flexural Modulus (GPa) 2.9 2.2 2.6 ATSM D 790

As shown in Table 1, Comparative Example 2 was found to have high tensile strength, tensile modulus, flexural strength and flexural modulus compared to Comparative Example 1, and in the case of Example according to the present invention, higher than Comparative Example 1 It was found to have physical properties. This is judged to be the result of printing by appropriately cutting carbon fibers by the filament cutter of the present invention.

On the other hand, the embodiments of the present invention disclosed in the present specification and drawings are merely presented as specific examples to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

10: nozzle 110: case
120: power supply module 130: filament supply module
140: filament cutting module 150: elastic member
160: damper 20: articulated robot
210: support 220: rotation support
230: first joint 240: second joint

Claims (7)

a nozzle 10 for heating and spraying the filament supplied from the filament supply unit for supplying the carbon fiber-polymer composite filament; and
A multi-joint robot 20 provided with a plurality of joints and coupled to the nozzle to adjust the height and position of the nozzle in multiple angles; includes,
The nozzle is
A hollow case 110, a mounting plate 113 horizontally coupled in the case 110, a power supply module 120 disposed between the mounting plate 113 and the case, the power supply module ( 120) in a state spaced apart in the horizontal direction, the filament supply module 130 is vertically disposed on the upper side of the mounting plate to supply the filament, the sliding disposed slidably along the horizontal direction at the lower part of the filament supply module 130 A filament cutting module 140 including a block 141 and a lower cutter 143 fixedly coupled to a lower portion of the sliding block 141 and an upper cutter 142 sliding with respect to the lower cutter 143 is provided. do,
In the process in which the carbon fiber filament is supplied through the filament supply module 130, the power supply module 120 slides the upper cutter 142 with respect to the lower cutter 143 at regular time intervals, and The upper cutter 142 is returned to its original state through the elastic member 150 disposed between the case 110 and the upper cutter 142 when the external force applied through the power supply module 120 is released,
The carbon fiber-polymer composite filament,
95 to 99.9 parts by weight of a thermoplastic resin; and
The carbon fiber includes; 0.1 to 5 parts by weight;
The carbon fiber has a reinforced interfacial phase with a thickness of 10 to 1,000 nm, and 0.5 to 30 parts by weight of an interface material is included in 100 parts by weight of the carbon fiber to form a reinforced interfacial phase on the surface of the carbon fiber, and the interface material is strong including topical and transitional agents;
The power supply module 120,
In a state in which a drive motor 121 fixed to the mounting plate 113, a rotation cam 122 rotatably coupled to a drive shaft constituting the drive motor 121, and a base plate 114 are disposed, the rotation cam ( 122) including a cam support block 123 for rotatably fixing the camshaft,
The rotary cam 122 is formed alternately with a plurality of rotary blades having different lengths along the outer periphery of the edge,
The carbon fiber-polymer composite filament,
It is made by immersing the carbon fiber in a pretreatment agent, drying the pretreated carbon fiber, and then mixing the dried carbon fiber and a thermoplastic resin,
The pretreatment agent is at least one selected from the group consisting of hydrochloric acid, nitric acid, phosphoric acid, acetic acid, hydrofluoric acid, ammonium bicarbonate (NH4HCO3) and ammonium carbonate ((NH4)2CO3) capable of reducing roughness by etching the carbon fiber surface Carbon fiber having a filament cutting device, characterized in that it comprises: a polymer composite articulated robot 3D printer.
According to claim 1,
The articulated robot 20,
support 210;
a rotation support part 220 rotatably coupled to the support part;
a first joint part 230 having one end rotatably coupled to the rotation support part and extending in one direction; and
One end is rotatably coupled to the other end of the first joint portion to extend in one direction, and a second joint portion 240 to which the nozzle 10 is coupled to the other end. Robot 3D printer.
delete delete According to claim 1,
The upper cutter 142 is
Inserted and fixed in the inside of the sliding block (141),
The upper cutter 142 and the lower cutter 143 are carbon fiber-polymer composite articulated robot 3D printer having a filament cutting device, characterized in that they are disposed to face each other in the upper and lower directions.
delete According to claim 1,
Carbon fiber having a filament cutting device, characterized in that the thermoplastic resin is poly lactic acid (PLA) or acrylonitrile butadiene styrene (ABS) - polymer composite articulated robot 3D printer.

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