CN113103585A

CN113103585A - 3D printer head capable of laying continuous fiber web and printing method

Info

Publication number: CN113103585A
Application number: CN202110436807.XA
Authority: CN
Inventors: 姚胜南
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-04-22
Filing date: 2021-04-22
Publication date: 2021-07-13
Anticipated expiration: 2041-04-22
Also published as: CN113103585B

Abstract

The invention belongs to the technical field of 3D printing, and discloses a 3D printer head capable of laying continuous fiber nets and a printing method. The invention can meet the social development requirements of multifunction, high performance parameters, stable size, complexity and customization.

Description

3D printer head capable of laying continuous fiber web and printing method

Technical Field

The invention belongs to the technical field of 3D printing, and particularly relates to a 3D printer head capable of laying a continuous fiber web and a printing method.

Background

Currently, Fused Deposition Modeling (FDM) technology has achieved a large market share in recent years due to its lower cost and superior realizability. However, in the process, a thermoplastic resin consumable material which can be melted by heating is used as a forming material, the material does not have continuity, the distance between molecular groups in a layer is larger, and poor interlayer binding force is caused by the process characteristics of layer-by-layer stacking, which all cause high brittleness, low impact strength, easy deformation and poor bearing performance of parts.

The mechanical properties of parts are usually optimized in the design process of parts in international and domestic manners by adopting a structural topology optimization manner, or the mechanical properties of components formed by a high-melting deposition process cannot be fundamentally improved by adding reinforcing bodies such as particles and chopped fibers into a thermoplastic base material. Especially for complex components in the aerospace field, the requirements for light weight and high strength are increasingly strict, and although additive manufacturing processes such as fused deposition and the like can greatly save raw materials and reduce the difficulty of part manufacturing, the poor mechanical properties of the product are also the main reasons for limiting the development in the industry.

At present, some institutes and enterprises at home and abroad develop a 3D printing method of a continuous fiber reinforced resin matrix composite material, but the method also has the following main problems:

for example, CN 209492172U, an FDM-3D printing extrusion head of a continuous fiber reinforced component, which discloses an FDM-3D printing extrusion head of a continuous fiber reinforced component, comprising a wire feeding device, a shearing device, an extrusion cavity and a nozzle which are arranged in sequence from top to bottom, wherein the wire feeding device is provided with a first feeding end and a feeding hole for continuous fibers, the extrusion cavity is provided with a second feeding end which is communicated with the extrusion cavity and is used for feeding photosensitive resin so as to realize synchronous feeding of the continuous fibers and the photosensitive resin, the wire feeding device comprises a frame, and a driving wheel, a driving motor and a driven wheel which are arranged on the frame, the driving wheel is connected with an output shaft of the driving motor through a coupler, the continuous fibers are clamped and clamped between the driving wheel and the driven wheel, the driving wheel rotates under the control of the driving circuit to drive the continuous fibers to feed forwards, so as to synchronize the material compounding process and the forming.

Nanjing aerospace university invented a 3D printing method of continuous fiber reinforced thermoplastic resin matrix composite material. The rotary blending 3D printing head for the continuous fiber reinforced thermoplastic resin matrix composite is developed and characterized in that: the extrusion head is connected with the melting cavity and can rotate around the central shaft, and the rotating direction is opposite to that of the melting cavity; stirring toothed rings are arranged on the inner sides of the melting cavity and the extrusion head, the fiber bundle and the molten thermoplastic resin are uniformly blended under the stirring action of two stages of spiral toothed rings rotating in opposite directions, a blending body is tightly wound into a cylindrical strand in a spiral manner, and the resin is uniformly distributed along the fiber orientation; the extrusion head extrudes material to a forming area and cures into a fiber reinforced resin matrix composite material.

The invention adopts the two-stage rotary cavity to stir and wind the blend of the fiber and the resin, is suitable for fiber tows with larger size, optimizes the adaptability of the printing head to the original state of the fiber, improves the printing efficiency and improves the surface quality of the component at the same printing speed; under the action of stirring and blending, the fibers and the resin are fully infiltrated, the fibers in the blend are in a tight spiral winding shape, the bearing capacity of the reinforcement is improved, the resin is uniformly distributed in each part of the fibers, and the mechanical property of the printing component is improved; the rotating action of the extrusion head can ensure that the fibers and the resin are uniformly distributed after the blended body is extruded, and the fiber volume content is high due to the adoption of the fiber tows with larger sizes.

Some patents also teach the application of a fibrous web to the surface to improve interlaminar bonding.

However, the prior art generally has certain problems and defects, which are mainly expressed as follows:

(1) in the prior art, the connection among resins is increased only by the chopped fibers in a mode of adding the chopped fibers, but the mechanical parameters of a printed body cannot be improved by fully utilizing the mechanical properties of the fibers;

(2) the mechanical properties of the printing body added with the continuous fibers in the length direction of the adding are really improved greatly, but the fiber bundles are only singly laid along the length direction, so that the fiber bundles among printing tracks and printing layers are not effectively strengthened, and the mechanical parameters in the width direction, particularly among layers (height direction) are increased very limitedly.

(3) At present, the continuous fiber 3D printing can only add one fiber bundle at a time, so that the fiber adding amount is limited, and the improvement range of the strength of a printing body is limited.

(4) If the surface of the outer surfaces of the printing bodies needs to be strengthened, only one layer of strengthening material can be added on the surface of the outer surfaces of the printing bodies, the strengthening material is often combined with the surface of a printing piece through a coating material, even if a fiber net is adhered on the surface, the adhering process can be completed only by consuming a large amount of labor, the bonding quality of the adhering layer and the printing layer is difficult to guarantee, and the adhering fiber net layer and the coating strengthening layer have the risk of peeling.

The difficulty in solving the above problems and defects is: to solve the above problems, firstly, the problems of adding and adding amount in the spatial direction of the fibers of the printing body need to be solved, secondly, the problems that the high-viscosity resin is difficult to completely permeate the dry fibers and the internal quality and the appearance quality of the product are influenced need to be solved, and furthermore, the problem of how to realize the automatic adding in the spatial direction of the high-content fibers is solved.

The significance of solving the problems and the defects is as follows:

according to the invention, interlayer automatic lapping is realized on 3D printing, the fiber nets are distributed in mortise and tenon structure space in the printing part, so that the fiber nets can be automatically and uniformly distributed in the printing part in a three-dimensional distribution, and the fiber nets with wider printing channels are selected during printing, so that the fiber net cover is formed on the outer surface of the printing part, and the surface of the printing part forms compressive stress when the fiber nets on the outer surface are rolled into the printing part, so that the surface quality of the printing part is greatly improved, particularly the tensile strength in the height direction, the fatigue strength of the printing part and the overall mechanical property of the printing part are improved, and the mechanical property of pure aluminum can be achieved.

The continuous fiber web is introduced into 3D printing, so that a multifunctional, high-strength, physical and chemical-property-excellent 3D printing product of the continuous fiber web can be obtained, and the product can be made into products such as aerospace, military and national defense, marine ships, automobiles, high-speed rail vehicles, machinery, buildings, wind power generation and the like;

according to the invention, one or more continuous fibers of aramid fiber, polyethylene fiber, Kevlar fiber, glass fiber, nylon fiber, ceramic fiber, carbon fiber, graphite fiber, graphene fiber, carbon nanotube fiber, metal fiber, quartz fiber and the like can be combined and woven into a net, and by applying the continuous fiber net 3D printing method, a 3D printing model, a part or a product containing continuous fibers with excellent mechanical properties, high electric conductivity, high heat conductivity, corrosion resistance and wear resistance can be obtained, the performance of the product is far better than that of a short fiber and continuous fiber reinforced composite material product, and the product can be suitable for one or more complicated working conditions of high strength, impact resistance, heat conductivity, electric conductivity, corrosion resistance, wear resistance and the like;

the 3D printing method of the continuous fiber web realizes the 3D printing of the continuous fiber web reinforced composite material, does not need a pre-customized die, can automatically compound the fiber web into a printed product, is easier to obtain a composite material product with customized performance, and can realize the rapid manufacturing of composite material parts with complex structures and different performance requirements;

the equipment provided by the invention integrates multiple functions of automatic lapping, 3D printing, upper rolling, outer surface rolling flattening, outer surface automatic coating and the like, is high in production efficiency, good in product performance parameters, suitable for single piece or small batch production, suitable for production of large-batch high-strength 3D printed pieces by a large number of printers, and wide in application prospect.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a 3D printer head capable of laying a continuous fiber web and a printing method.

The invention is realized in such a way that a printing method of a 3D printer head capable of laying a continuous fiber web comprises the following steps:

the external control system controls the rotary support to drive the fiber web and the printing head system to correspondingly rotate, so that the top part of the protrusion of the groove-shaped pressure head is always positioned on the center line of the printing track, and the first fiber web or the second fiber web is always positioned on the normal line position of the printed curve;

in the 3D printing process, the first fiber net and the second fiber net are laid and are driven by a fiber net feeding and cutting mechanism to rotate and feed a fiber net disc; in the printing process, a first fiber net is laid on the upper surface of a printed layer, printing materials enter through a rotary joint at the top of a lifting rod and are fed to a printing head through a feeding pipe, the current printed layer is printed on the first fiber net, and meanwhile, the fiber nets extending out of the printing materials on the first printed layer and the side surfaces of the printed layer are rolled together by rolling mechanisms on the two sides of the printing head. Secondly, laying a second fiber net on the current printing layer, pressing one or more grooves in the center of the printing track by the convex part of the groove-shaped pressure head in the advancing process of the printing head, and pressing the laid second fiber net into the grooves to enable the printing layers to be in mortise and tenon similar structures; meanwhile, the first fiber net is pressed into the middle of the groove, so that the first fiber net and the second fiber net enter the printing layer and are combined with the printing material, and the fiber nets are staggered in the height direction;

when 3D printing is to the break position, the cutting device can delay cutting the web for a period of time, while the web feed device feeds the web a period of time in advance before entering the next printing segment, so that the web can completely cover the printing segment and have proper drooping coverage at the break position and in the length direction of the tip.

When the printing is carried out at the turning position, the external control system controls the rotary support to drive the fiber web and the printing head system to correspondingly rotate, so that the first fiber web or the second fiber web is always positioned in the normal direction of the position of the printed curve;

after the printing of one layer is finished, the printing head drives the lifting rod to move upwards by a printing layer height through the lifting mechanism, and the printing of the next layer is continued;

further, a first fiber net is laid on the upper surface of the printed layer, the printing layer is printed on the first fiber net, and then a second fiber net is laid on the printing layer; the first fiber net and the second fiber net are laid through a fiber net feeding and cutting mechanism to drive a first fiber net disc and a second fiber net disc to be fed and laid;

3. drive the lifter up-and-down motion through elevating system and realize beating the high lift of printer head, the rotary joint who prints the material through the lifter top gets into, send into again through the conveying pipe and beat printer head, the bulge of beating printer head marching in-process cell type pressure head can impress the current layer of printing with the second fibre web, and can push out one or more recess in printing the orbit, also impress first fibre web simultaneously among the recess of printing the layer, thereby make and print and be similar mortise and tenon structure between layer and the layer, make first, two fibre webs get into and print the in situ portion and combine together with the printing material, and the fibre web has also realized crisscross in the direction of height.

At the same time, the rolling rollers at both sides of the printing channel roll the fiber web hanging out of the printing channel into both sides of the printing channel.

Furthermore, except that the rotary support is fixed on the fixed frame, the first fiber net disk, the second fiber net disk, the fiber net tray, the first fiber net, the second fiber net, the fiber net steering mechanism, the linear bearing, the feeding pipe, the rotary joint, the fiber net guide plate, the lifting mechanism, the fiber net feeding mechanism, the cutting mechanism and the like all rotate around the lifting rod freely through the rotary support axis.

Further, the first fiber net and the second fiber net can be made of two fiber net materials with different materials and different model specifications.

Further, the first fiber and the second fiber net can be woven by fibers made of different materials.

The printing material is made of liquid, wire, strip or particle, powder and the like.

Another object of the present invention is to provide a 3D printer head that can lay down a continuous web, including a print head, the 3D printer head that can lay down a continuous web including:

the device comprises a first fiber net disc, a second fiber net disc, a fiber net tray, a fixing frame, a first fiber net, a second fiber net, a rotary support, a fiber net direction changing mechanism, a lifting and material conveying rod, a linear bearing, a feeding pipe, a rotary joint, a fiber net guide plate, a lifting mechanism, a fiber net feeding and cutting mechanism, a groove-shaped pressure head and a rolling mechanism;

except that the rotary support is fixed on the fixed frame, the first fiber net disc, the second fiber net disc, the fiber net tray, the fixed frame, the first fiber net, the second fiber net, the rotary support, the fiber net turning mechanism, the linear bearing, the lifting and material conveying rod, the rotary joint, the fiber net guide plate, the lifting mechanism, the fiber net feeding and cutting mechanism, the groove-shaped pressure head and the rolling mechanism can rotate freely through the rotary support axis;

when printing is carried out, the first fiber net is converted from horizontal rotation motion to vertical downward motion through the fiber net turning mechanism, then the first fiber net is sent to a position to be printed through the fiber net feeding and cutting mechanism, a printing material is sent through the lifting and material conveying rod, the second fiber net is sent through the fiber net feeding and cutting mechanism, the second fiber net is pressed into the center position of the printing head through the groove-shaped pressing head of the groove-shaped pressing head to form a groove shape, and the first fiber net, the second fiber net and the lifting and material conveying rod are driven by the rotary support to be always located at the normal position of a printed curve. The rolling mechanisms on two sides of the printing channel roll the fiber nets extending out of the two sides of the printing channel into the two sides of the printing channel, and in order to improve the groove rolling and rolling quality, the two mechanisms can be added with a working mode of combining ultrasonic vibrator, motor vibration and battery vibration static load rolling to process the surface of a product. The working head applies ultrasonic frequency mechanical vibration with a certain amplitude along the normal direction of the surface of the workpiece, and under a certain feeding condition, the working head transmits static pressure and impact vibration to the surface to be processed to generate impact extrusion action so as to enable the metal material to generate large-amplitude elastic-plastic deformation. After processing, the generated plastic flow fills or partially fills the 'valley' on the surface of the workpiece with the 'peak', thereby greatly reducing the surface roughness, generating a surface strengthening layer, wherein the strengthening layer and the interior of the material are in continuous transition, improving the comprehensive performance index of the surface, and achieving the purposes of improving the fatigue strength and the fatigue life of the product.

When 3D prints to the interrupt position, control system control fibre web feed, shutdown mechanism postpones a period and cuts off the fibre web, and before entering next section and printing, fibre web feed, shutdown mechanism can advance a period and send the fibre web into for the fibre web can cover completely and print the section and have suitable flagging to cover in interrupt position end length direction.

In particular for the second web, after cutting the web, the groove press of the channel press will be retracted a distance to be able to press the previously fed sagging web two into the printing layer when entering the next printing section.

In addition, when the printing head prints at the juncture of the printing channels inside and outside the printing body, the controller can control the roller pressing heads on one side or two sides of the rolling mechanism to ascend, so that the roller pressing heads can not roll the printing channels any more, and the interference phenomenon of the printing channels is avoided.

After one layer of printing is finished, the controller controls the lifting and material conveying rod to move upwards by one printing layer height, and then the next printing layer is printed.

Another object of the present invention is to provide an application of the printing method of the 3D printer head capable of laying the continuous fiber web in 3D printing of non-arc heat sources such as thermoplastic resin, thermosetting resin, light-cured resin, concrete, and ceramics which are melted by heating.

By combining all the technical schemes, the invention has the advantages and positive effects that:

compared with the prior art that short fibers are added into printing materials at home and abroad, fibers are pasted on the surface of a printed piece, and long fibers or continuous fibers are blended into a printed body, the existing continuous fiber printing is only carried and printed in the axial direction, and the fibers between printing channels are not mutually connected, so that the strength of the printed body can be improved only by depending on the fiber strength in the printing length direction, and the strength cannot be increased basically in the printing height direction and the printing width direction due to the increase of the fibers.

The invention adopts a drooping structure formed by laying fiber nets between printing layers at intervals and even extending out of a printing channel, considers the problems of matching of material and specification models of the fiber nets, conveying of the fiber nets, adaptation of conveying positions and printing direction changes of the fiber nets, combination and distribution of the fiber nets and the inner and outer surfaces, and the like, and better solves the problems of conveying direction change, matching of the printing process and the moving direction of one or more fiber nets, and the like. The fiber net is integrated with the printing material in three dimensions of length, width and height, and all the printing materials are connected together in the three-dimensional direction, so that the printed part not only has the strength of the printing material, but also increases the strength of the fiber net added into the printing material, and the strength and the anti-seismic performance of the printed part are improved in an all-round manner, and particularly, the improvement on the external surface strength, the surface crack resistance, the falling resistance, the interlayer bonding strength, the toughness, the fatigue strength and the interlayer bonding quality of the printed part is more remarkable.

Compared with the prior art, the invention has the advantages that:

the laying direction of the fiber web can change along with the change of the printing direction, and the printing head can be always positioned at the center line of the fiber web and the fiber web is positioned in the normal direction of the printing direction;

the conveying and laying of one or more fiber nets with the same or different materials and specifications can be realized;

the recess pressure head of cell type pressure head can put the central point who prints the way and extrude one or multichannel recess to make and print and form similar mortise and tenon structure between the layer, and the fibre web content of printing internal portion obtains improving by a wide margin, the bulk strength of the improvement printing body that can be very big, print bonding strength and bonding quality between the layer.

The inner and outer compression rollers of the rolling mechanism can not only roll the inner and outer surfaces of the printing channel smoothly, but also roll the fiber web which is intentionally extended out of the inner and outer surfaces into the printing material, so that the fiber web is paved on the inner and outer surfaces of the printing channel simultaneously.

The recess pressure head all installs the anterior segment at ultrasonic vibrator with inside and outside compression roller, has all improved the compound quality of fibre web and printing material under high frequency vibration's effect when pressing recess and interior external surface to roll, can reach ultrasonic bonding's combination quality between layer to organic material to improve the effect of rolling of interior external surface by a wide margin, and made interior external surface form compressive stress, improved the fatigue strength of printing the body by a wide margin.

The invention can also compound the printing material and the fiber net to form a compound net belt with the fiber net, and then the whole net belt is sent by the printing head to be printed.

Compared with the addition of continuous fibers, the addition of the fiber web can increase the fiber addition amount of the printing body by at least more than 400% compared with the addition of the continuous fibers (a plurality of fibers can be simultaneously paved in the length direction, only one fiber can be paved in the continuous fiber paving process, the fiber web can also bring about the fiber bundle paving in the width direction, and in addition, the surface pressure groove brings about the further increase of the fiber bundle in the length direction), so that the strength of the printing body in the printing length direction is increased by more than 30% compared with the continuous fibers, and the strength of the printing body in the width direction can be increased by more than 60%. In addition, as the printing layers and the inner and outer surfaces of the printing channels are subjected to ultrasonic rolling treatment and the fiber nets are embedded in the height direction, the interlayer bonding quality is greatly improved compared with the existing 3D printing technology, and the strength in the height direction can be improved by at least over 150 percent compared with the continuous fiber 3D printing technology.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained from the drawings without creative efforts.

Fig. 1 is a schematic view of a 3D printer head on which a continuous web may be laid down according to an embodiment of the present invention.

Fig. 2 is a side view of a 3D printer head on which a continuous web may be laid down, provided by an embodiment of the present invention.

Fig. 3 is a schematic view of a web direction change in a printing process provided by an embodiment of the present invention.

In fig. 1-3: 1. a second fiber mesh tray; 2. a fiber mesh tray base; 3. a fixed mount; 4. a second web; 5. a rotation support mechanism; 6. a web turning mechanism; 7. a lifting and material conveying rod; 8. a linear bearing; 9. a rotary joint; 10. a first fiber web tray; 11. a web guide plate; 12. a first web; 13. a web feed and cut-off mechanism; 14. a print head; 15. an internal and external rolling mechanism; 16. a printed layer; 17. a current print layer; 18. an ultrasonic vibrator; 19. a groove-shaped pressure head telescopic mechanism; 20. a groove-shaped pressure head; 21. a cylinder; 22. a lifting mechanism; 23. the trace is printed outside the print volume. 24. Printing an internal track of the body; 25. stop position in printing section, 26, start position of next printing section.

Fig. 4 is a schematic view of a portion of a printed body showing the distribution of the web.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In view of the problems in the prior art, the present invention provides a 3D printer head capable of laying a continuous web and a printing method thereof, and the present invention is described in detail below with reference to the accompanying drawings.

The invention comprises a 3D printing head which is driven by a rotary support and can rotate around the center of the printing head, a lapping device, a lifting mechanism, a plurality of fiber net discs and the like, fiber nets are alternately paved between printing layers, one or more grooves are pressed out at the center of a printing track by a groove-shaped pressure head arranged at the end part of the printing head, so that different fiber nets and printing layers form a mortise and tenon structure in the printing height direction and are fused into a whole, the combination between the layers is more compact due to the function of the groove-shaped pressure head, in the printing structure, different fiber nets are added in the plane of the printing layer, and the printing structure also forms the superposition of various fiber nets in the height direction by the groove form, thereby obtaining a continuous fiber net 3D printing product with multiple functions, high strength, specific rigidity, high specific strength, good impact performance, excellent fatigue resistance and high forming precision, the requirements of social development on multiple functions, high performance parameters, stable size, complexity and customization are better met.

Specifically, the invention provides a printing method of a 3D printer head capable of laying a continuous fiber web, which comprises the following steps:

the external control system controls the rotary support to drive the printing head and the fiber net system to correspondingly rotate, so that the first fiber net or the second fiber net is always positioned at the normal line position of the printed curve;

and laying a first fiber net on the upper surface between the printed layers, feeding printing materials into the printing head through a rotary joint at the top of the lifting rod, feeding the printing materials to the printing head through a feeding pipe, printing the current printed layer on the first fiber net, and laying a second fiber net on the current printed layer. The first fiber net and the second fiber net are laid and are driven by a fiber net feeding and cutting mechanism to feed a first fiber net disc and a second fiber net disc in a rotating manner; the groove-shaped pressure head presses the second fiber net and the current printing layer to form a groove structure, so that a connection form of a mortise and tenon structure is formed between the printing layers, the ultrasonic vibrator driving the groove-shaped pressure head enables the current printing layer and the printed layer to realize the combination quality similar to ultrasonic welding, and the compactness of the printing body is greatly improved. The rolling mechanisms on two sides of the printing channel not only roll the fiber web which is intentionally extended out of the printing channel into the printing body, but also add ultrasonic vibrators to the rolling mechanisms for rolling, thereby greatly improving the strength and surface quality of the inner and outer surfaces of the printing channel.

When 3D printing is to the interrupt location 25, the control system controls the web feed and cut mechanism to delay cutting the web for a period of time, and before printing into the next print station 26, the web feed and cut mechanism can advance the web for a period of time so that the web can completely cover the print station and have proper sag coverage in the length direction of the end at the interrupt location. In particular for the second web, after reaching the interruption position 25, the groove press of the channel press will recover a distance to be able to press the previously fed sagging second web into the printing layer when entering the next printing section 26.

In addition, when the printing head is at the junction 24 of the inner printing channel and the outer printing channel of the printing body, the controller can control the rolling heads on one side or both sides of the rolling mechanism to ascend, so that the rolling heads can not be rolled on the printing channels any more, and the interference phenomenon of the printing channels is avoided.

After printing on a printing layer is finished, the lifting mechanism can be controlled to drive the lifting rod to move up and down to realize that the printing head is lifted by one printing layer height, and then the printing on the next printing layer is carried out.

Preferably, except that the rotary support is fixed on the fixed frame, the first fiber net disk, the second fiber net disk, the fiber net tray, the first fiber net, the second fiber net, the fiber net steering mechanism, the linear bearing, the feeding pipe, the rotary joint, the fiber net guide plate, the lifting mechanism, the fiber net feeding mechanism, the cutting mechanism and the like can rotate around the rotary support axis at will.

Preferably, the first fiber net and the second fiber net are made of two different fiber net materials with different material and model specifications.

The printing material is liquid, wire, strip or particle or powder material.

As shown in fig. 1-4, the present invention provides a 3D printer head for laying down a continuous web, comprising 1, a second web tray; 2. a fiber mesh tray base; 3. a fixed mount; 4. a second web; 5. a rotation support mechanism; 6. a web turning mechanism; 7. a lifting and material conveying rod; 8. a linear bearing; 9. a rotary joint; 10. a first fiber web tray; 11. a web guide plate; 12. a first web; 13. a web feed and cut-off mechanism; 14. a print head; 15. an internal and external rolling mechanism; 16. a printed layer; 17. a current print layer; 18. an ultrasonic vibrator; 19. a groove-shaped pressure head telescopic mechanism; 20. a groove-shaped pressure head; 21. a cylinder; 22. a lifting mechanism; 23. the trace is printed outside the print volume. 24. Printing an internal track of the body; 25. stop position in printing section, 26, start position of next printing section.

Except that the rotary support 5 is fixed on the fixed frame 3, all other parts or materials can rotate around the lifting rod freely through the rotary support axis, when some curves are printed, the external control system can control the rotary support 5 to drive the fiber net system to rotate correspondingly, so that the first fiber net 4 or the second fiber net 14 is always in the normal position of the printed curve (see fig. 3, the arrow in the middle part shows the moving direction, 23 is the printing track, and 14 is the printing head). In the 3D printing process, a first fiber net 12 is laid on the upper surface of a printed interlayer 16, then a current printing layer 17 is printed on the fiber net, the second fiber net 4 can be laid on the current printing layer 17 in order to improve the use amount of fibers in a printed piece and improve the strength of a printed body during printing, and in order to achieve the purposes of improving the strength, realizing different functions and reducing the cost, the first fiber net 4 and the second fiber net 14 can be made of two fiber net materials with different materials and types and specifications. The fiber net is laid by driving the fiber net disc to rotate and feed through the fiber net feeding mechanism 13. Wherein fig. 1 is a front view, fig. 2 is a side view, and fig. 3 is a schematic view of a web direction change during printing.

This high lift of printer head drives through elevating system 22 and goes up and down and material transport pole 7 up-and-down motion realizes, and its printing material can adopt materials such as liquid, wire rod, strip or granule, powder, and the material gets into through the rotary joint 9 at lifter top, and the pole 7 is carried to the printer head of sending into through going up and down again and material. In the printing process, a groove is pressed out of the printing track by the groove-shaped pressure head (see fig. 1 and 2), and meanwhile, the fiber net is pressed into the middle of the groove, so that the printing layers are of similar mortise and tenon structures, the fiber net can be overlapped in the height direction, and the combination quality and the combination strength between the 3D printing layers are greatly improved.

In addition, the fiber mesh laid by printing can be woven by adopting two different fiber meshes, and each fiber mesh can be woven by adopting different fiber bundles, and can be combined with copper or aluminum wires, nano materials, optical fibers, conductive ink or other materials which are beneficial to realizing a multifunctional structure. The fiber net not only has the purpose of improving the strength, but also has the special functions of other fiber bundles, such as the functions of electric conduction, heat dissipation, monitoring and the like.

The technical solution of the present invention is further described below with reference to specific application examples.

Application example

The continuous fiber system developed by mark forging, usa, uses two printheads, one for the matrix resin and the other for the thermoplastic resin prepreg tows. The emphasis on technical improvement is reliability and repeatability. Companies are working to achieve a complete closed loop of the process and are developing a range of functions for this, such as fully integrated material tracking and full automatic reporting functions. An important application of the system is in printing tooling fixtures and components, 3D printed thermoplastic products are as strong but lighter than machined aluminum components, do not damage parts as metal components, and can be prepared within the same day, which can facilitate the development of aerospace composite manufacturing molds.

Assuming that a V-shaped groove with the width of 10mm, the thickness of a printing layer of 5mm, the middle of the printing layer of 3mm and the width of 6mm is pressed, a fiber net with two sides extending 8mm outside a printing channel is laid between each two layers, the diameter of the fiber is 0.2mm (shown in figure 4), the hole of the fiber net is 1 x 1, the tensile strength of the fiber bundle is 2000MPa (the tensile strength of the carbon fiber is 3500MPa), a section of printing body with 10 x 10 is taken out for analysis, two layers are required to be printed, and three layers of fiber nets (bottom, middle and upper) are laid for the bottom fiber net, because the middle part of the bottom fiber net is pressed into a groove structure, the fiber net only has two fiber bundles with the size of 2 x 10 on two sides, the fiber bundle usage amount of 10 fiber bundles with the width direction of 10mm and the length direction of 6 fiber bundles with the length of 10 mm; for the middle part of the printing layer, the size of the fiber web is 10 × 22.4, the used amount of the fiber bundles is 10 fiber bundles with the width direction of 22.4mm and 22 fiber bundles with the length direction of 10 mm; the size of the web was 10 × 28.4 for the top of the print layer, the amount of fiber bundles used was 10 bundles of 28.4mm in the width direction and 28 bundles of 10mm in the length direction, 30 bundles were added in the width direction and 56 bundles were added in the length direction for the entire print body, and the amounts of fiber bundles added were: 6 × 10 × 4+10 × 22.4+22 × 10+28 × 10+10 × 28.4 ═ 1108 mm. In the 3D printing method with continuous fibers added, only 3 fiber bundles of 10mm are added in the middle and lower layers in the longitudinal direction, no fibers are added in the width direction, and the overall fiber adding length is 30 mm.

Adding a fiber net: the increase in strength in the longitudinal direction of the fiber bundle (area of fiber bundle filament) and the number of fiber bundles (tensile strength/cross-sectional area of printed body) were 3.14 (0.2/2)²*2000*56/(10*10)＝35.2MPa；

The increase in strength in the width direction (area of fiber bundle filament) and the number of fiber bundles (tensile strength/cross-sectional area of printed body) were 3.14 (0.2/2)²*2000*30/(10*10)＝18.8MPa；

Adding continuous fibers: the increase in strength in the longitudinal direction of the fiber bundle (area of fiber bundle filament) and the number of fiber bundles (tensile strength/cross-sectional area of printed body) were 3.14 (0.2/2)²2000 × 3/(10 × 10) ═ 1.884MPa, the increase in strength in the longitudinal direction, i.e., the area of the tow filaments, the number of the tow filaments, the tensile strength of the tow, and the cross-sectional area of the printed body, i.e., 3.14 × 3.2/2)²*2000*0/(10*10)＝0MPa。

From the above calculations, the following conclusions can be drawn: by laying the fiber web, the total adding length of the fiber bundles reaches 1108mm, the continuous fibers are only 30mm, and in addition, the strength of the laid fiber web can be increased by 18 times in the length direction compared with that of the laid continuous fibers, so that the strength reaches 35.2 MPa; the strength in the width direction cannot be increased by laying continuous fibers, but the strength in the width direction of the printing track can be increased by more than 18.8MPa by only laying one layer of fiber net every 5 mm.

A single layer of web was laid per 5mm with a volume percentage of 10 x 10 cubes of 3.47%, and if two layers of web were laid according to the invention, the web percentage would reach 6.94%, at which point the increase in strength in the length direction would reach 70.4 MPa.

If two layers of fiber webs are laid every 2mm, the proportion of the fiber webs reaches 13.88 percent, and the strength increase in the length direction reaches 140.8MPa, which exceeds the strength of industrial pure aluminum.

Therefore, the laying of the web can greatly increase the fiber content in the printing lane and the strength in each direction.

The above description is only for the purpose of illustrating the present invention and the appended claims are not to be construed as limiting the scope of the invention, which is intended to cover all modifications, equivalents and improvements that are within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A printing method of a continuous web-layable 3D printer head, the method comprising:

in the 3D printing process, the first fiber net and the second fiber net are laid and are driven by a fiber net feeding and cutting mechanism to rotate and feed a fiber net disc; in the printing process, a first fiber net is laid on the upper surface of a printed layer, printing materials enter through a rotary joint at the top of a lifting rod and are fed to a printing head through a feeding pipe, the current printed layer is printed on the first fiber net, and then the second fiber net is laid on the current printed layer.

after the printing of one layer is finished, the printing head drives the lifting rod to move upwards by a printing layer height through the lifting mechanism, and the printing of the next layer is continued.

2. The method of claim 1, wherein the raised portion of the groove-type press head presses the second web into the current printing layer during the printhead travel, and presses one or more grooves in the printing track, and presses the first web into the grooves of the printed layer, thereby forming a mortise and tenon-like structure between the printing layers, so that the first and second webs enter the printing layer and are combined with the printing material, and the webs are staggered in height.

And the press rollers of the rolling mechanisms arranged at the two sides of the printing head can roll the fiber web extending out of the printing channel into the side surface of the printing channel, so that the fiber web can be covered at the side surface of the printing channel.

3. The method for printing by a 3D printer head capable of laying down a continuous web according to claim 1, wherein the first web and the second web are made of two different types of web materials, and even the same web can be woven by fibers made of different materials, and the width of the web can exceed one side or both sides of the printing track.

4. The method of printing with a continuous web layup 3D printer head of claim 1, wherein the printing material is a wire, tape, granule, powder or liquid material.

5. A3D printer head capable of laying a continuous fiber web, comprising a printing head and a control system, wherein the 3D printer head capable of laying the continuous fiber web comprises:

the device comprises a first fiber net disc, a second fiber net disc, a fiber net tray, a fixing frame, a first fiber net, a second fiber net, a rotary support, a fiber net direction changing mechanism, a lifting rod, a linear bearing, a feeding pipe, a rotary joint, a fiber net guide plate, a lifting mechanism, a fiber net feeding and cutting mechanism, a press-rolling mechanism, a groove-shaped pressure head and a rolling mechanism;

except that the rotary support is fixed on the fixing frame, the first fiber net disc, the second fiber net disc, the fiber net tray, the fixing frame, the first fiber net, the second fiber net, the rotary support, the fiber net turning mechanism, the linear bearing, the feeding pipe, the rotary joint, the fiber net guide plate, the lifting mechanism, the fiber net feeding and cutting mechanism, the groove-shaped pressure head and the rolling mechanism can rotate freely around the axis of the rotary support.

6. The 3D printer head capable of laying continuous fiber web as claimed in claim 6, wherein the groove type press head and the rolling mechanism can be driven by vibration mechanism such as ultrasonic vibrator, motor vibration, electromagnetic vibration, etc. to perform groove pressing and rolling.

7. A printing method of a 3D printer head capable of laying a continuous fiber web according to any one of claims 1 to 6 is applied to 3D printing.