CN110435132B

CN110435132B - 3D printer of continuous fiber reinforced composite material and printing method thereof

Info

Publication number: CN110435132B
Application number: CN201910641807.6A
Authority: CN
Inventors: 于旻; 乔宇杰; 葛正浩; 孙立新
Original assignee: Shaanxi University of Science and Technology
Current assignee: Shaanxi University of Science and Technology
Priority date: 2019-07-16
Filing date: 2019-07-16
Publication date: 2021-07-09
Anticipated expiration: 2039-07-16
Also published as: CN110435132A

Abstract

The invention discloses a 3D printer of a continuous fiber reinforced composite material and a printing method thereof, wherein the 3D printer comprises a heating block, wherein a heating element is arranged in the heating block; set up the first passageway in the heating block, the second is branched the passageway, the third is branched the passageway, the first passageway, the second is branched the passageway, the third is branched the passageway and is the Y type setting, set up the shower nozzle in the first passageway, the second is branched the passageway, the third is branched the passageway and is connected with the choke respectively, every choke communicates in proper order has the cooling tube, quick connector, the passageway has still been seted up in the heating block, the passageway is located the second and branches the passageway, between the third is branched the passageway, passageway and first passageway intercommunication, still including being used for sending into the silk material feeding unit of quick connector. The continuous fibers are oriented and controllable in the composite material through the conduit, the channel and the first channel, and the comprehensive performance of the 3D printing part is effectively improved.

Description

3D printer of continuous fiber reinforced composite material and printing method thereof

Technical Field

The invention belongs to the technical field of printers, and relates to a 3D printer of a continuous fiber reinforced composite material and a printing method of the 3D printer.

Background

The 3D printer is based on extruding raw material, using 3D design software to print the drawn product to its 3D model. The 3D printing technology is additive manufacturing technology and has the advantages of low manufacturing cost, short production period and the like. However, the existing 3D printer product has poor mechanical properties such as strength and rigidity, cannot be well used in the engineering field, and needs to adopt a filler reinforced modified composite material. The invention patent (patent number 2015107817291, named as a reinforced PLA material for 3D printing) discloses that chopped carbon fiber reinforced PLA is adopted as a 3D printing material, and the invention patent (patent number 2018109685159, named as a lignin/microcrystalline cellulose compound, a reinforced polylactic acid 3D printing material and a preparation method thereof) firstly carries out chemical pretreatment on short fibers or powder, then adopts the methods of melt extrusion blending and wire drawing forming to prepare the reinforced polylactic acid 3D printing material, the orientation distribution of the fillers has larger randomness, and the fillers are easy to generate and disperse unevenly in the blending process, so that the mechanical property of the fillers is far from meeting the requirement of the expected performance index due to the defect of an agglomerated structure.

The current patents for continuous fiber reinforced modified 3D printing material devices are not yet mature. The invention patent (patent number 201811374788.7, named as a continuous fiber reinforced composite material 3D printer and printing method) discloses a continuous fiber reinforced composite material 3D printing method, which mainly comprises the following steps: soaking the continuous fibers by sizing agent, and then curing the sizing agent (light-cured resin) on the surfaces of the continuous fibers under the irradiation of an ultraviolet light source to generate a crosslinking reaction on the surfaces of the continuous fibers; and finally, extruding the continuous fiber reinforced composite material from the spray head, and printing and forming according to the preset model information of the 3D printer. However, this production method has the following disadvantages: (1) the method has the advantages that the steps are complex, wires need to be pre-soaked in the light-cured resin before production and are subjected to crosslinking reaction under the irradiation of ultraviolet light, the production efficiency is low, and the process is complex; (2) the photocuring resin has high cost and low bonding strength with a plastic matrix interface, and is easy to strip (3). The photocuring resin often has certain corrosivity and toxicity, and has the dissolution of mercury, silver, copper and zinc, and organic volatile exists in the crosslinking reaction process, so that the energy is saved and the environment is protected.

The invention patent (patent number 201810422931.9, named as a continuous fiber reinforced composite 3D printer) discloses that the main structure of the continuous fiber reinforced composite 3D printer is as follows: the printing nozzle consists of a wire extruding device, a feeding pipeline, a heating device, a temperature measuring device, a wire feeding pipeline, a gear and a power device. A cavity for accommodating resin materials is arranged inside the feeding pipeline; the filament extruding device is used for feeding the resin material into the cavity and extruding the resin material; a wire cavity through which fiber yarns penetrate is arranged inside the wire feeding pipeline, the wire feeding pipeline is fixed on a gear, and the gear is rotationally connected to the feeding pipeline; the outlet end of the wire feeding pipeline is positioned at the outlet end of the feeding pipeline; the power device is used for driving the gear to rotate, and the wire feeding pipe is controlled to rotate around the axis of the wire feeding pipe through the gear, so that the extruded resin material covers the fiber wires. However, the printer head structure has the following disadvantages: (1) the fiber is positioned at the outer end of the feeding pipeline, only half of the fiber is wrapped by the resin, and the fiber cannot be completely soaked by the molten resin, so that the bonding strength of the fiber and a resin matrix interface is low, and the fiber is easy to peel; (2) the fibers which are not soaked by the resin cannot be bonded with the cooled resin material on the upper layer, so that the interlayer bonding strength of a printed part is low, and the mechanical property of the part is poor; (3) the printing nozzle in the patent must control the motion of the wire feeding pipe at any time to ensure that the fiber is under the molten resin, otherwise, the fiber cannot be coated, but the angle control of the wire feeding pipe is very difficult, the rotation angle of the wire feeding pipe cannot be flexibly and accurately controlled, the shape of a printing part is necessarily limited, and therefore a three-dimensional model with a complex modeling cannot be printed.

Disclosure of Invention

The invention aims to provide a 3D printer of a continuous fiber reinforced composite material, which can improve the mechanical property of a printed part.

The invention adopts the technical scheme that the 3D printer of the continuous fiber reinforced composite material comprises a heating block, wherein a heating element is arranged in the heating block; set up the first passageway in the heating block, the second is branched the passageway, the third is branched the passageway, the first passageway, the second is branched the passageway, the third is branched the passageway and is the Y type setting, set up the shower nozzle in the first passageway, the second is branched the passageway, the third is branched the passageway and is connected with the choke respectively, every choke communicates in proper order has the cooling tube, quick connector, the passageway has still been seted up in the heating block, the passageway is located the second and branches the passageway, between the third is branched the passageway, passageway and first passageway intercommunication, still including being used for sending into the silk material feeding unit of quick connector.

The invention is also characterized in that:

the feeding device comprises a motor, two feeding rollers are sleeved on an output shaft of the motor, and each feeding roller corresponds to the quick-connection connector in position.

A conduit is arranged in the channel, and one end of the conduit extends out of the channel and is fixed on the heating block.

The connecting frame is attached to the surface of the heating block, a boss is arranged on the outer wall of the guide pipe, and the guide pipe is fixed on the heating block through the boss by the connecting frame; the throat pipe passes through the connecting frame and is connected with the second branch channel or the third branch channel.

The two side walls of the heating block form inclined planes, the outlet ends of the second branch channel and the third branch channel are respectively positioned on the inclined planes of the heating block, and the connecting frame is provided with the inclined planes matched with the heating block.

The heating device is characterized by further comprising a fixing frame, wherein the fixing frame comprises a first connecting plate and a second connecting plate which are perpendicular to each other, the middle of the second connecting plate is recessed inwards, the heating block is located in the recessed portion of the second connecting plate, and two ends of the connecting frame are fixed on the second connecting plate.

Another object of the present invention is to provide a printing method of a 3D printer of a continuous fiber reinforced composite material.

The invention adopts another technical scheme that the printing method of the 3D printer of the continuous fiber reinforced composite material comprises the following steps of:

the continuous fibers sequentially pass through the guide pipe, the channel and the spray head, two plastic wires are clamped on the feeding rollers respectively, the motor drives the two feeding rollers to enable each wire to sequentially pass through the quick-connection connector, the throat pipe and the heating block, the wires are heated and melted in the heating block and enter the spray head through the second branch channel and the third branch channel, and the wires wrap the continuous fibers at the spray head and move downwards to be extruded from the outlet of the spray head, so that the continuous fiber reinforced composite material is formed.

The continuous fiber is stainless steel wire with diameter of 0.016-0.07mm, and the wire is X60 resin.

The continuous fiber is Kevlar fiber, and the wire material is PLA wire material.

The continuous fiber is inorganic non-metal wire, and the wire is nylon plastic wire.

The invention has the beneficial effects that: according to the 3D printer, the continuous fibers are oriented and controllable in the composite material through the guide pipe, the channel and the first channel, so that the comprehensive performance of a 3D printing workpiece is effectively improved; the distribution of the second branch channel and the third branch channel in the heating block can ensure that the wire material uniformly coats the continuous fiber, improve the mechanical property of a printed part and is not easy to peel; the fixing frame and the connecting frame are arranged according to the structure of the heating block, so that the flexibility of the printer is improved; the construction is simple, the control is easy, and the energy is saved and the environment is protected; according to the printing method of the 3D printer, the continuous fiber types, the fiber diameters and the fiber brands are replaced according to the performance requirements of different printed workpieces, so that the 3D printed workpiece which is excellent in comprehensive performance, strong in functionality and capable of being customized is obtained; changing the color of the wire to further change the color of the product; the printing product has the characteristics of richer and stronger functionality by adopting wires with flame retardance, aging resistance, corrosion resistance and other functionalities and by optimally combining plastic wires with different characteristics and continuous fibers.

Drawings

Fig. 1 is a schematic structural diagram of a 3D printer of a continuous fiber reinforced composite material of the present invention.

In the figure, 1, a heating block, 2, a first channel, 3, a second branch channel, 4, a third branch channel, 5, a spray head, 6, a throat pipe, 7, a radiating pipe, 8, a quick connector, 9, a channel, 10, a motor, 11, a feeding roller, 11-1, a driving feeding roller, 11-2, a driven feeding roller, 11-3, a spring, 12, a guide pipe, 13, a connecting frame, 14, a boss, 15, a through hole, 16, a heating rod, 17, a fixing frame, 17-1, a first connecting plate, 17-2, a second connecting plate, 18, a driving part, 19, a thin pipe, 20, a fan frame and 21, a thermistor.

Detailed Description

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

The invention discloses a 3D printer of a continuous fiber reinforced composite material, which comprises a heating block 1 as shown in figure 1, wherein a heating element 16 is arranged in the heating block 1; first passageway 2 has been seted up in heating block 1, second branch passageway 3, third branch passageway 4, first passageway 2, second branch passageway 3, third branch passageway 4 is the Y type setting, set up shower nozzle 5 in the first passageway 2, second branch passageway 3, third branch passageway 4 is connected with choke 6 respectively, every choke 6 communicates in proper order has cooling tube 7, quick connector 8, 6 one end of choke stretches into in third branch passageway 4, the other end stretches into in cooling tube 7, 8 one end of quick connector stretches into in cooling tube 7, 6 both ends of choke are passed through the screw thread and are connected with third branch passageway 4 and cooling tube 7 respectively. The heating block 1 is also internally provided with a channel 9, the channel 9 is positioned between the two second branch channels 3 and the third branch channel 4, the channel 9 is communicated with the first channel 2, and the heating block also comprises a feeding device for feeding wires into the quick-connect plug 8.

The heating element comprises a heating rod 16 and a thermistor 21, the heating rod 16 and the thermistor 21 are electrically connected, holes are formed below the second branch channel 3 and the third branch channel 4 of the heating block 1, the heating rod 16 is located in the hole below the second branch channel 3, and the thermistor 21 is located in the hole below the third branch channel 4.

The last joint of the fin heat dissipation grid of cooling tube 7 has fan board 20, is provided with the fan on the fan board 20, can be used to adjust the temperature of silk material, can choose for use the 3D printer fan that has now on the market.

The feeding device comprises a motor 10, two feeding rollers 11 are sleeved on an output shaft of the motor 10, each feeding roller 11 corresponds to the position of the quick-connection plug 8, each feeding roller 11 comprises a driving feeding roller 11-1 and a driven feeding roller 11-2 which are used for clamping wires and conveying the wires downwards, the driving feeding roller 11-1 and the driven feeding roller 11-2 are connected through a spring 11-3, the driving feeding roller 11-1 and the driven feeding roller 11-2 clamp the wires under the tensioning action of the spring 11-3, and the plastic wires are fed to the spray head 5. The motor 10 is any one of a 42-series stepping motor and a 57-series stepping motor.

A conduit 12 is arranged in the channel 9, and one end of the conduit 12 extends out of the channel 9 and is fixed on the heating block 1. The boss 14 is arranged outside the conduit 12, the conduit 12 is clamped on the upper surface of the heating block 1 through the boss 14, the lower end of the conduit 12 is connected with the thin tube 19, and the thin tube 19 is positioned in the channel 9 and communicated with the first channel 2.

The heating device further comprises a connecting frame 13 matched with the heating block 1, the connecting frame 13 is attached to the surface of the heating block 1, a through hole 15 matched with the guide pipe 12 is formed in the connecting frame 13, the guide pipe 12 penetrates through the through hole 15, the connecting frame 13 is sleeved on the guide pipe 12 and compresses the boss 14, the guide pipe 12 is fixed on the heating block 1, and the throat pipe 6 penetrates through the connecting frame 13 and is connected with the second branch channel 3 or the third branch channel 4. The shape of the connecting frame 13 is changed along with the shape of the heating block 1, as long as the connecting frame can fix the heating block 1 and the guide pipe 12.

Inclined planes are formed on two side walls of the heating block 1, and outlet ends of the second branch channel 3 and the third branch channel 4 are respectively positioned on the inclined planes of the heating block 1. The connecting frame 13 is provided with an inclined plane matched with the heating block 1, and the connecting frame 13 is tightly attached to the heating block 1. The throat pipe 6 sequentially penetrates through the inclined surface of the connecting frame 13 and the inclined surface of the heating block 1 to be connected with the second branch channel 3 or the third branch channel 4, and the connecting frame 13 and the heating block 1 are further fixed.

The continuous fiber reinforced composite material printer further comprises a fixing frame 17, wherein the fixing frame 17 is used for fixing the heating block 1 on a driving part 18, and the driving part 18 comprises an X-direction driving stepping motor, a Y-direction driving stepping motor, a Z-direction driving stepping motor and corresponding transmission devices, so that the movement in the X direction, the Y direction and the Z direction required by the continuous fiber reinforced composite material printer is realized. The fixing frame 17 comprises a first connecting plate 17-1 and a second connecting plate 17-2 which are perpendicular to each other, the middle part of the second connecting plate 17-2 is recessed inwards, the heating block 1 is positioned in the recessed part of the second connecting plate 17-2, and two ends of the connecting frame 13 are fixed on the second connecting plate 17-2. The heating block 1 is fixed on a fixing frame 17 through a connecting frame 13.

The invention relates to a printing method of a 3D printer for a continuous fiber reinforced composite material, which comprises the following steps:

continuous fibers sequentially pass through a guide pipe 12, a channel 9 and a spray head 5, two plastic wires are respectively clamped on feeding rollers 11, a motor 10 drives the two feeding rollers 11 to enable each wire to sequentially pass through two lateral flow channels consisting of a quick connection plug 8, a throat pipe 6 and a heating block 1, due to the heating effect of a heating rod 16 and a thermistor 21, the wires are heated and melted in the heating block 1 and enter the spray head 5 through a second branch channel 3 and a third branch channel 4, the viscosity of the wires is reduced and the fluidity of the wires is enhanced along with the heating of the heating rod and the friction heat of the wires in the flow channels, and the wires are converged with the continuous fibers at the lower end conical flow channel of the spray head 5, so that the molten wires on the two sides cover and move downwards, and are extruded from an outlet of the spray head 5 to form a continuous fiber reinforced composite material which is deposited on a working platform of a driving part 18.

Example 1

When the core layer continuous fiber is soft superfine metal wire, such as superfine stainless steel metal wire, the diameter is 0.016-0.07 mm; the wire is made of a flexible printing wire, X60 resin of Diabase Engineering is selected in the embodiment, the wire is strong in toughness and has excellent tensile strength and wear resistance, and the elongation at break exceeds 7 times of the elongation at break. The printing method can fully infiltrate and wrap the superfine stainless steel wire with the melted X60 resin, continuously extrude the resin through the nozzle, and print out the composite material with the core layer reinforced by the continuous superfine stainless steel wire; in addition, the fashionable dress fabric formed by printing and weaving the composite material has the functional effects of antimagnetic radiation protection, static resistance, shielding, natural memory wrinkle and other health concepts, particularly when the plastic wire is a transparent material, the fabric woven by the continuous superfine stainless steel wire reinforced composite material has a very good light reflection effect after being worn, and is more obvious in sunlight and light.

Example 2

When the PLA is selected for use to the plastics silk material, it is fragile to print the finished piece texture, the easy rupture, and PLA in the past prints the finished piece and generally can only be used for the model show, and can not use, has restricted its application greatly. In order to better improve and improve the toughness of the printed product, continuous aramid fiber can be selected as the reinforcing fiber, in this embodiment, kevlar fiber of dupont is selected, the diameter is 0.2mm, and the continuous fiber has the characteristics of low density, high tensile strength and high elastic modulus. The printing method can enable the molten PLA wire to completely and fully infiltrate the aramid fiber, continuously extrude the PLA composite material with the continuous aramid fiber reinforced core layer through the nozzle, and the 3D model workpiece printed by the method can play a good toughening role by exerting the characteristic of high tensile strength of the aramid fiber of the core layer, effectively improve the defect of high brittleness of pure PLA and improve impact toughness; in addition, the structure of the composite material is changed from isotropy of pure PLA to anisotropy due to the addition of the continuous fibers, the mechanical property of the printed part in the continuous fiber orientation direction is greatly improved, and a three-dimensional weaving effect is formed by combining the reciprocating motion and the layer-by-layer overlapped printing mode in the 3D printing process, so that the comprehensive performance of the printed part in all directions is improved.

Example 3

When the core layer continuous fiber is an inorganic nonmetal wire material, such as carbon fiber, glass fiber, basalt fiber and the like, the continuous fiber has high strength, but has high brittleness, and is easy to break when the fiber length is too long, so that the conventional reinforcing mode usually adopts short fiber reinforcement, and the effect of short fiber reinforcement is not as good as that of long fiber. The nylon 3D printing material is good in toughness, but compared with ABS, nylon is not hard enough, and the rigidity requirement of parts cannot be met. According to the printer nozzle structure, nylon 3D printing wires with good toughness can be used as plastic wire materials, so that molten nylon plastics are fully infiltrated and wrapped with inorganic continuous fibers, the inorganic continuous fibers are continuously extruded through the nozzle, and a nylon-based composite material with a continuous inorganic fiber reinforced core layer is printed.

Example 4

The two silk materials are selected to be different in color, for example, one silk is white, the other silk is blue, and the composite material which is alternate in blue and white and reinforced by the continuous fibers can be printed by the printer.

Through the mode, the 3D printer enables the continuous fibers to be directionally controllable in the composite material through the guide pipe 12, the channel 9 and the first channel 2, and the comprehensive performance of a 3D printing part is effectively improved; the distribution of the second branch channel 3 and the third branch channel 4 in the heating block 1 can ensure that the wire material uniformly coats the continuous fiber, improve the mechanical property of a printed part and is not easy to peel; the fixing frame 17 and the connecting frame 13 are arranged according to the structure of the heating block 1, so that the flexibility of the printer is improved; according to the printing method of the 3D printer, the continuous fiber types, the fiber diameters and the fiber brands are replaced according to the performance requirements of different printed workpieces, so that the 3D printed workpiece which is excellent in comprehensive performance, strong in functionality and capable of being customized is obtained; changing the color of the wire to further change the color of the product; the printing product has the characteristics of richer and stronger functionality by adopting wires with flame retardance, aging resistance, corrosion resistance and other functionalities and by optimally combining plastic wires with different characteristics and continuous fibers.

Claims

1. The 3D printer for the continuous fiber reinforced composite material is characterized by comprising a heating block (1), wherein a heating element is arranged in the heating block (1); a first channel (2), a second branch channel (3) and a third branch channel (4) are arranged in the heating block (1), the first channel (2), the second branch channel (3) and the third branch channel (4) are arranged in a Y shape, a spray head (5) is arranged in the first channel (2), the second branch channel (3) and the third branch channel (4) are respectively connected with a throat (6), each throat (6) is sequentially communicated with a radiating pipe (7) and a quick connector (8), a channel (9) is further arranged in the heating block (1), the channel (9) is located between the second branch channel (3) and the third branch channel (4), the channel (9) is communicated with the first channel (2), and the feeding device is used for feeding wires into the quick connector (8);

a guide pipe (12) is arranged in the channel (9), and one end of the guide pipe (12) extends out of the channel (9) and is fixed on the heating block (1);

the heating device is characterized by further comprising a connecting frame (13) matched with the heating block (1), wherein the connecting frame (13) is attached to the surface of the heating block (1), a boss (14) is arranged on the outer wall of the guide pipe (12), and the guide pipe (12) is fixed on the heating block (1) through the boss (14) by the connecting frame (13); the throat pipe (6) penetrates through the connecting frame (13) to be connected with the second branch channel (3) or the third branch channel (4);

inclined planes are formed on two side walls of the heating block (1), outlet ends of the second branch channel (3) and the third branch channel (4) are respectively positioned on the inclined planes of the heating block (1), and the connecting frame (13) is provided with an inclined plane matched with the heating block (1);

the heating device is characterized by further comprising a fixing frame (17), wherein the fixing frame (17) comprises a first connecting plate (17-1) and a second connecting plate (17-2) which are perpendicular to each other, the middle of the second connecting plate (17-2) is recessed inwards, the heating block (1) is located in the recessed portion of the second connecting plate (17-2), and two ends of the connecting frame (13) are fixed on the second connecting plate (17-2).

2. The 3D printer of continuous fiber reinforced composite material according to claim 1, wherein the feeding device comprises a motor (10), two feeding rollers (11) are sleeved on an output shaft of the motor (10), and each feeding roller (11) corresponds to the position of the quick connector (8).

3. A method of printing with a 3D printer of continuous fiber reinforced composite material, comprising the 3D printer of claim 2, comprising the steps of:

the continuous fibers sequentially pass through a guide pipe (12), a channel (9) and a spray head (5), two plastic wires are clamped on a feeding roller (11) respectively, a motor (10) drives the two feeding rollers (11) to enable each wire to sequentially pass through a quick-connection connector (8), a throat (6) and a heating block (1), the wires are heated and melted in the heating block (1) and enter the spray head (5) through a second branch channel (3) and a third branch channel (4), and the wires coat and move downwards at the spray head (5) to be extruded out of an outlet of the spray head (5) to form the continuous fiber reinforced composite material.

4. The printing method of a 3D printer of continuous fiber reinforced composite material according to claim 3, wherein the continuous fiber is Kevlar fiber and the filament is a PLA filament.

5. The printing method of a 3D printer of continuous fiber reinforced composite material according to claim 3, wherein the continuous fiber is inorganic nonmetallic wire, and the wire is nylon plastic wire.