CN108297404B - Continuous fiber 3D printing device and method - Google Patents

Abstract

The invention provides a continuous fiber 3D printing device and method, comprising a fiber roller, a dipping part and a printing part, the dipping part has a shell filled with a resin solution, and a tension roller, The dipping split roll and the pulling roll, the tensioning roll is placed above the liquid level of the resin solution, and is used to provide partial pre-tensioning force for the "dry" fibers under the action of friction, and the dipping split roll It is placed below the resin liquid level and at an angle with the tensioning roller, and the traction roller is placed above the resin liquid level to provide traction; wherein, the "dry" fibers enter the dip through the fiber roller. The glue part is dipped in sequence through the tension roller, the glue-dipping split roller and the traction roller, and then the printing part is used for printing. The strength of the parts obtained by the invention is more than 4 times higher than that of the existing resin 3D printing, which lays a foundation for the high-performance printing parts to be used in the aerospace field.

Description

A continuous fiber 3D printing device and method

technical field

The invention relates to a continuous fiber 3D printing device and method, belonging to the technical field of composite material manufacturing.

Background technique

3D printing technology, also known as additive manufacturing, is a technology that creates three-dimensional objects by adding materials layer by layer through a printing device based on a pre-designed three-dimensional model. This technology integrates cutting-edge technologies in the fields of digital modeling technology, electromechanical control technology, information technology, material science and chemistry. It is a kind of rapid prototyping technology and is known as the core technology of the "third industrial revolution". Among them, the printing technology of thermoplastic resin is the main component, which has been developed and applied in the fields of automobile, medicine, food, etc., and has become one of the hot directions sought after by domestic and foreign counterparts.

At this stage, thermoplastic resin printing technology is still mainly based on pure resin or thermoplastic resin with reinforcing particles. The material has high toughness, low modulus and low strength, which cannot meet the requirements of parts in the aerospace field. In order to improve the mechanical load of the material, domestic and foreign research institutions have developed melt-printed continuous fiber parts; however, during this process, it is difficult for the high-viscosity resin to fully penetrate the "dry" fibers, which affects the internal quality and appearance quality of the product; at the same time , and some resins that are easily oxidized and degradable are also not suitable for fusion printing methods.

SUMMARY OF THE INVENTION

The following presents a brief summary of the present invention in order to provide a basic understanding of certain aspects of the invention. It should be understood that this summary is not an exhaustive overview of the invention. It is not intended to identify key or essential parts of the invention nor to limit the scope of the invention. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

In order to solve the above problems, the present invention provides a continuous fiber 3D printing device and method. The strength of the parts obtained by using the device and method of the present invention is more than 4 times higher than that of pure resin 3D printing, and it also directly reduces the technical difficulty and cost. cost.

Technical solution of the present invention:

In one aspect, the present invention provides a continuous fiber 3D printing device, comprising:

The fiber roller, the dipping part and the printing part, the dipping part has a shell filled with resin solution, and the inside of the shell is sequentially provided with a tensioning roller, a dipping split roller and a traction roller. The rollers are placed above the resin solution level to provide partial preload for the "dry" fibers under the action of friction. Arranged at an angle, the traction roller is placed above the resin liquid surface to provide traction; wherein, the "dry" fibers enter the dipping part through the fiber roller, and then pass through the tensioning roller, dipping The split roller and traction roller are dipped and then printed through the printing section.

Further, the resin solution is preferably a solvent-based thermoplastic resin solution;

Further, the viscosity of the resin solution is preferably not higher than 1 Pa·s;

Further, the tension roller is a metal roller that can rotate along the central axis;

Further, the dipping roll is composed of two metal rolls that can rotate along the central axis;

Further, the traction roller is composed of two oppositely rotating metal rollers;

Further, the printing part includes a spinneret and a platform, wherein the spinneret is placed on a movable part, so that the spinneret can be moved; Deposition is carried out on the platform;

Further, the printing part further includes a hot air supply part, and the hot air supply part is arranged on the movable part to provide a heat source for the dipped fibers after they exit the spinneret;

Further, both the platform and the hot air supply part can be temperature controlled, and the maximum temperature does not exceed 80°C;

On the other hand, the present invention also provides a continuous fiber 3D printing method, characterized in that the above-mentioned device is used for printing from "dry" fibers.

The present invention has the beneficial effects compared to the prior art:

A new type of continuous fiber 3D printing device and method provided by the present invention is different from the existing offline dipping (that is, the raw fiber used is the fiber wire after dipping) printing, but uses "dry" fiber as the raw material The method of printing while dipping glue saves the steps of preparing difficult wires, and also overcomes the defects of easy oxidation, easy degradation and high viscosity of the existing offline dipping collagen materials. On the one hand, the present invention utilizes the characteristics of rapid pre-impregnation of solvent-based thermoplastic resins to provide a precondition for full infiltration of fibers, and also provides an application approach for some thermoplastic resins that are refractory and susceptible to thermal decomposition; on the other hand, the present invention uses " The infiltration method of "three sets of rollers", after the fiber passes through the "tension roller, dipping roller, and active traction roller", the traction force on the fiber can be reduced to zero, and the subsequent migration force comes from the bonding of the prepreg fiber tow. It can effectively reduce the probability of fiber damage during the printing process, and can also effectively control the problem of "force migration after in-situ placement" caused by excessive force on the fiber; moreover, the present invention does not involve high heat sources. , there is only a hot air flow device and a thermal platform that is not higher than 80 °C, which can effectively avoid chemical reactions such as molecular chain crosslinking and molecular chain scission of the thermoplastic resin when heated, maintain the original structure and performance of the thermoplastic resin, and reduce the thermoplastic resin. The risk of molecular degradation, and the present invention adopts the form of rapid drying of hot air flow and thermal platform, and the solvent is quickly volatilized by the action of the hot air flow, which ensures the rapid bonding of the wire.

The device and method of the present invention provide a new way for continuous fiber 3D printing, and the strength of the obtained part is more than 4 times higher than that of the existing resin 3D printing, laying a foundation for the high-performance printing parts to be used in the aerospace field , and at the same time, the invention saves the steps of preparing high-difficulty wires, directly applies the "dry" fibers to the printing technology, and reduces the technical difficulty and cost.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a schematic structural diagram of an embodiment of a continuous fiber 3D printing device provided by the present invention;

FIG. 2 is a schematic structural diagram of an embodiment of the dipping part in the continuous fiber 3D printing device provided by the present invention.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, for purposes of explanation and not limitation, specific details are set forth in order to assist in a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details.

It should be noted here that, in order to avoid obscuring the present invention due to unnecessary details, the accompanying drawings only show the device structure and/or processing steps closely related to the solution according to the present invention, and omit the details related to the present invention. Invent other details that are less relevant.

Referring to Figure 1, this embodiment provides a continuous fiber 3D printing device, including:

Fiber roll 1, dipping part and printing part, including:

The dipping part has a shell 10 filled with a resin solution. Inside the shell 10, a tensioning roller 4, a dipping half-rolling roller 6 and a pulling roller 5 are sequentially arranged. The tensioning roller 4 is placed in the resin. Above the liquid level of the solution, it is used to provide partial pre-tensioning force for the "dry" fibers under the action of friction. Angle setting, the traction roller 5 is placed above the resin liquid level to provide traction; wherein, the "dry" fibers enter the dipping part through the fiber roller 1, and then pass through the tensioning roller 4, the dipping The glue split roller 6 and the traction roller 5 are dipped and then printed by the printing part.

In the continuous fiber 3D printing device provided in this embodiment, in order to ensure that the fiber can minimize the dipping tension, the dipping part will be divided into three parts, namely the tension roller, the dipping split roller, and the active traction roller. , Under the action of the pulling roller, the fiber bundle is spread and unfolded, and the resin solution is rapidly migrated to the inside of the fiber bundle under the pressure of the conveying roller during the movement process of the fiber unfolding and migration. The pre-impregnated fiber bundles are moved out of the equipment under the action of force. In this example, "dry" fibers are used as raw materials, and the printing is performed while dipping, which saves the steps of preparing difficult wires and overcomes the existing offline dipping process. Collagen material is easy to be oxidized, easy to degrade and has high viscosity and other defects. On the other hand, the infiltration method of "three sets of rollers" is used. It is reduced to zero, and the subsequent migration force comes from the bonding force of the prepreg fiber tow, which can effectively reduce the probability of fiber damage during the printing process, and can also effectively control the "in-situ" caused by excessive force on the fiber. The problem of force migration after laying”.

As an embodiment of the present invention, the resin solution is preferably a solvent-based thermoplastic resin solution, and its viscosity is not higher than 1 Pa·s;

The application of this configuration method utilizes the characteristics of rapid pre-impregnation of solvent-based thermoplastic resins to provide a prerequisite for full fiber infiltration, and also provides an application approach for some thermoplastic resins that are refractory and susceptible to thermal decomposition.

As an embodiment of the present invention, in the dipping part:

The tension roller 4 is configured as a metal roller that can rotate along the central axis; partial pre-tightening force is provided under the action of friction force;

Further, the described dipping split roll 6 is composed of two metal rolls that can be rotated along the central axis, and the two metal rolls are arranged up and down, and the described dipping split roll 6 is below the resin liquid level. ; Using this configuration, set up and form a certain angle with the tension roller 4 to form a tension-unfolding force, so that the fibers are spread out when running to the surface of the dipping roller 6, while the dipping roller 6 The opposite rotation tendency of resin moves to form a pressurized zone, which accelerates resin infiltration of fibers;

Further, the traction roller 5 is composed of two metal rollers that rotate in opposite directions, and the two metal rollers are arranged up and down; using this configuration, the traction roller 5 is set as a driving roller with adjustable rotational speed, which can be The external motor adjusts the rotation speed to provide the power for fiber pulling, and the pulling power after passing through the pulling roller 5 is provided by the adhesive force of the workpiece.

As an embodiment of the present invention, the casing 10 is connected with a resin injection pipe, and if the liquid level of the resin in the casing 10 is too low, the resin solution can be added through the pipe;

As an embodiment of the present invention, the device further includes a conveying pipe 2, and the conveying pipe 2 is respectively placed between the fiber roller 1 and the dipping part, and between the dipping part and the printing part, for " Delivery of "dry" fibers as well as pre-impregnated fibers;

Further, the conveying pipe is preferably a PE pipe with an inner diameter not greater than 5 mm.

As an embodiment of the present invention, the printing part is configured to include a spinneret 8 and a platform 9, and the spinneret 8 is placed on a movable part, so that the spinneret 8 can move; The final fibers are deposited on the platform 9 after passing through the spinneret 8; wherein, the configuration of the movable parts is a well-known technology in the art;

Further, the printing part further includes a hot air supply part 7, and the hot air supply part 7 is arranged on the movable part to provide a heat source for the dipped fibers after they exit the spinneret 8;

Further, both the platform and the hot air supply part can be temperature controlled, and the maximum temperature does not exceed 80°C.

Applying the above configuration method, the prepreg fibers are placed in a hot air environment after passing through the spinneret; the solvent is accelerated to volatilize under the action of the hot air, and the resin rapidly increases in viscosity and adheres to the platform or the resin deposited on the platform. Splicing, consolidation, thereby fixing the position of the fiber and providing the traction force of the prepreg fiber, and so on, and finally forming a part.

As an embodiment of the present invention, there is a small channel and a nozzle on the spinneret 8, the diameter of the channel is not less than the diameter of the nozzle, and the diameter of the nozzle is generally 0.2-1mm;

As an embodiment of the present invention, the hot air supply part may be a hot fan.

Therefore, an embodiment of the present invention also provides a continuous fiber 3D printing method, which is characterized in that: the "dry" fiber is printed by using the above-mentioned device.

The device and method provided by the embodiments of the present invention provide a new way for continuous fiber 3D printing, and the strength of the obtained part is more than 4 times higher than that of the existing resin 3D printing, which lays a solid foundation for the high-performance printing parts used in the aerospace field. At the same time, the invention saves the steps of preparing difficult wires, and directly applies the "dry" fibers to the printing technology, which reduces the technical difficulty and cost.

Features described and/or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and/or in combination with or instead of features in other embodiments Features in use.

It should be emphasized that the term "comprising/comprising" as used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps, components or combinations thereof .

The numerous features and advantages of these embodiments are apparent from this detailed description, and the appended claims are therefore intended to cover all such features and advantages of these embodiments as fall within their true spirit and scope. Furthermore, since many modifications and changes will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise construction and operation illustrated and described, but are to cover all suitable modifications and equivalents falling within the scope thereof thing.

The parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims (4)

1. A continuous fiber 3D printing device, comprising: a fiber roller, a dipping part and a printing part, wherein,

the impregnation part is provided with a shell filled with resin solution, a tensioning roller, an impregnation split roller and a traction roller are sequentially arranged in the shell, the tensioning roller is arranged above the liquid level of the resin solution and used for providing partial pre-tightening force for dry fibers under the action of friction force, the impregnation split roller is arranged below the liquid level of the resin and forms an included angle with the tensioning roller, and the traction roller is arranged above the liquid level of the resin and used for providing traction force; the dry fiber enters a glue dipping part through a fiber roller, the glue dipping is completed through the tensioning roller, the glue dipping split roller and the traction roller in sequence, and then printing is performed through a printing part, the resin solution is a solvent type thermoplastic resin solution, and the tensioning roller is a metal roller capable of rotating along a central shaft; the gumming split roller consists of two metal rollers which can rotate along a central shaft; the traction roller consists of two metal rollers which rotate in opposite directions; the printing part comprises a spinneret and a platform, wherein the spinneret is arranged on a movable part so that the spinneret can move; depositing the impregnated fiber on the platform after passing through a spinneret; the printing part also comprises a hot air flow supply part which is arranged on the movable part and is used for providing a heat source for the impregnated fiber after the fiber is discharged out of the spinneret.

2. The continuous fiber 3D printing apparatus according to claim 1, wherein the viscosity of the resin solution is not higher than 1 Pa-s.

3. The continuous fiber 3D printing device according to claim 1, wherein: the platform and the hot air flow supply part can be controlled in temperature, and the highest temperature is not more than 80 ℃.

4. A continuous fiber 3D printing method is characterized in that: printing from "dry" fibres using the apparatus of any one of claims 1 to 3.

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