3D printing piece structure enhancing process based on continuous fiber prepreg filaments

Abstract

The invention discloses a 3D printed piece structure enhancement process based on continuous fiber prepreg filaments, and relates to the technical field of 3D printed piece structure enhancement, and the 3D printed piece structure enhancement process comprises the following steps: step 1, determining a direction and a region needing to be enhanced in a 3D printed piece; 2, digging or reserving a hole channel or a channel in an area needing to be reinforced along the direction needing to be reinforced so as to insert continuous fiber prepreg filaments; and 3, inserting the continuous fiber prepreg filaments into the pore channels or the channels, and then fixing the continuous fiber prepreg filaments. According to the method, the structure of the 3D printing piece can be efficiently enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printed part structure reinforcement, and in particular to a 3D printed part structure reinforcement process based on continuous fiber prepreg. Background Art

[0002] Due to its process, 3D printing has high porosity and anisotropy after printing, and its part performance cannot meet industrial requirements. In order to overcome the above defects, in the prior art, relevant personnel in this field have conducted some research, such as using reinforcing materials such as short fibers and continuous fiber prepregs to reinforce parts. However, although these studies can improve the performance of printed parts to a certain extent, the effect is often limited, and the reinforcement effect on printed parts with complex structures is limited. Summary of the invention

[0003] The purpose of the present invention is to provide a 3D printed part structure reinforcement process based on continuous fiber prepreg yarn to solve the problems existing in the above-mentioned prior art and achieve efficient reinforcement of the 3D printed part structure.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides a 3D printed part structure reinforcement process based on continuous fiber prepreg, comprising:

[0006] Step 1: Determine the direction and area that needs to be enhanced in the 3D print;

[0007] Step 2: drilling or reserving holes or channels in the area to be reinforced along the direction to be reinforced so as to insert the continuous fiber prepreg;

[0008] Step 3: Insert the continuous fiber prepreg into the hole or channel and fix it.

[0009] Preferably, in step one, the directions and areas that need to be strengthened are determined according to the stress characteristics of the 3D printed part.

[0010] Preferably, in step three, the continuous fiber prepreg is fixed to the hole or channel by glue.

[0011] Preferably, in step three, before inserting the continuous fiber prepreg, glue is applied to the continuous fiber prepreg.

[0012] Preferably, in step three, before inserting the continuous fiber prepreg, glue is poured into the hole or channel.

[0013] Preferably, the continuous fiber prepreg has a certain stiffness.

[0014] Preferably, after the continuous fiber prepreg is inserted, the glue is cured so that the glue is cured and firmly bonds the continuous fiber prepreg and the inner wall of the pore or channel.

[0015] Preferably, before step three, the continuous fiber prepreg needs to be prepared, and the step of preparing the continuous fiber prepreg includes: selecting a continuous fiber prepreg of a shape and specification that matches the specification and curvature of the pore or channel.

[0016] Preferably, when the 3D printed part is a thermoplastic plastic, in step three, the two ends of the continuous fiber prepreg are electrically heated, the thermoplastic plastic is melted by the heat and fills the gaps in the pores or channels, and then solidified by a cooling process, so that the continuous fiber prepreg and the 3D printed part form a firm bond.

[0017] Preferably, the continuous fiber prepreg is a carbon fiber prepreg, a glass fiber prepreg, a Kevlar fiber prepreg or a basalt fiber prepreg.

[0018] Preferably, the cross-sectional shape of the continuous fiber prepreg includes circular and rectangular.

[0019] Compared with the prior art, the present invention has achieved the following technical effects:

[0020] High laying accuracy: The present invention achieves high laying accuracy and ensures the uniformity and reliability of the reinforcement effect by accurately controlling the laying direction and position of the prepreg by drilling or reserving holes or channels.

[0021] Strong adaptability: Prepreg filaments can be flexibly selected according to the shape and specifications of the printed parts, and the path laying is not limited by the material of the printed parts, whether it is metal or plastic, and is suitable for printed parts of various complex shapes and sizes.

[0022] High operational flexibility: The stiffness of the prepreg yarn itself can provide the feeding force during the laying process, and the path is controllable, which improves the operational flexibility.

[0023] Simultaneous enhancement of mechanical properties in multiple directions: The present invention achieves simultaneous enhancement in different directions by inserting prepreg filaments in specific directions, thus overcoming the limitations of traditional reinforcement methods in terms of anisotropy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1This is a schematic diagram of the structure of a 3D printed part after the structure is enhanced by using the 3D printed part structure enhancement process based on continuous fiber prepreg provided by the present invention in implementation case 1;

[0026] Figure 2 In implementation case 2, Figure a→Figure b→Figure c are schematic diagrams of the process of inserting continuous fiber prepreg into the three-way pipe;

[0027] Figure 3 This is the stress analysis diagram of the truss structure;

[0028] Figure 4 It is a schematic diagram of the opening at the connection of the truss structure, and Figure a→Figure b→Figure c→Figure d→Figure e→Figure f are schematic diagrams of the process of inserting continuous fiber prepreg into each rod that intersects at one point;

[0029] In the figure: 1-Continuous fiber prepreg. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Carbon fiber has excellent mechanical properties with high specific strength and specific stiffness, so the addition of continuous carbon fiber is of great significance to improving the strength and stiffness of 3D printed parts.

[0033] In the related technology, one solution proposes to use FDM-based continuous fiber 3D printing to enhance part performance. However, due to problems such as laying accuracy and laying limitations, it is difficult to use continuous fibers to reinforce industrial parts, especially cage-shaped parts and topology-optimized parts.

[0034] Another solution proposed a continuous fiber injection molding process (CFIP) by combining continuous fiber precursor with thermosetting resin. However, this process uses precursors that have not been pre-impregnated, and the process uses airflow extrusion, which cannot achieve a higher fiber volume fraction.

[0035] Another solution proposed an interlayer strengthening method of a Z-pin structure to achieve enhancement in the Z-axis direction. However, the actual working conditions are complicated, and the FDM process cannot achieve simultaneous enhancement in all directions, so its flexibility is not high.

[0036] Although the above research has improved the performance of 3D printed parts to a certain extent, the effect is often limited. The inventors found that the main reason is that it is difficult to achieve the optimal arrangement of fibers in three-dimensional space with the existing technology, resulting in unsatisfactory reinforcement effect, especially in complex structural parts.

[0037] In principle, the performance improvement of 3D printed parts is limited by the bonding effect between the fiber and the matrix and the distribution of the fiber in the matrix. The current research status shows that although certain progress has been made in the industry, there are still technical limitations on how to achieve efficient reinforcement of fibers in complex structures. This application can solve this defect well.

[0038] Note: The prepreg in this manual refers to continuous fiber prepreg.

[0039] Combine the following Figures 1 to 4 , describing an embodiment of the present invention.

[0040] The present invention provides a 3D printed part structure reinforcement process based on continuous fiber prepreg, comprising:

[0041] Step 1: Determine the direction and area that needs to be enhanced in the 3D print;

[0042] Step 2: drilling or reserving a hole or channel in the area to be reinforced along the direction to be reinforced so as to insert the continuous fiber prepreg 1;

[0043] Step 3: Insert the continuous fiber prepreg 1 into the hole or channel and fix it, preferably manually.

[0044] The 3D printed structure reinforcement process provided by this embodiment has high laying accuracy, strong adaptability and can simultaneously enhance the mechanical properties in multiple directions. Specifically, the high laying accuracy is due to the fact that the present invention accurately controls the laying direction and position of the prepreg by drilling or reserving holes or channels, thereby achieving high laying accuracy and ensuring the uniformity and reliability of the reinforcement effect.

[0045] The strong adaptability is due to the fact that the prepreg filament can be flexibly selected according to the shape and specifications of the printed part, and the path laying is not limited by the material of the printed part, whether it is metal or plastic, and is suitable for printed parts of various complex shapes and sizes.

[0046] The mechanical properties in multiple directions are enhanced simultaneously because the present invention inserts prepreg filaments in specific directions to achieve simultaneous enhancement in different directions, thus overcoming the limitation of traditional reinforcement methods in the anisotropy problem.

[0047] In some embodiments, in step 1, the directions and areas that need to be strengthened are determined according to the stress characteristics of the 3D printed part.

[0048] This embodiment can determine the direction and area that need to be strengthened according to the stress characteristics of the 3D printed part during actual application, thereby improving practicality.

[0049] In some embodiments, in step three, the continuous fiber prepreg 1 is fixed to the hole or channel by glue.

[0050] There are two ways to do this. The first way is to apply glue to the continuous fiber prepreg 1 before inserting the continuous fiber prepreg 1 .

[0051] The second method is to inject glue into the holes or channels before inserting the continuous fiber prepreg yarn 1.

[0052] In some embodiments, the continuous fiber prepreg 1 has a certain stiffness.

[0053] This embodiment has the advantage of high operational flexibility, because the rigidity of the prepreg yarn itself can provide a feeding force during the laying process, and the path is controllable, thereby improving operational flexibility.

[0054] It is understandable that the rigidity of the continuous fiber prepreg 1 depends on the process conditions, and is based on whether it can pass through the hole smoothly. If the hole is wider and shorter, the rigidity required for the prepreg is smaller; if the hole is narrower and longer, the rigidity required for the prepreg is greater.

[0055] In some embodiments, when the 3D printed part is a thermoplastic plastic, in step three, the two ends of the continuous fiber prepreg filament 1 are electrically heated, and the thermoplastic plastic is melted by the heat and fills the gap in the pore or channel, and then solidified by a cooling process, so that the continuous fiber prepreg filament 1 and the 3D printed part form a firm bond.

[0056] In some embodiments, after the continuous fiber prepreg 1 is inserted, the glue is cured so that the glue is cured and firmly bonds the continuous fiber prepreg 1 and the inner wall of the hole or channel.

[0057] In some embodiments, before step three, continuous fiber prepreg 1 needs to be prepared, and the step of preparing continuous fiber prepreg 1 includes: selecting continuous fiber prepreg 1 of shape and specification matching the specification and curvature of the pore or channel.

[0058] In some embodiments, the continuous fiber prepreg 1 is a fiber prepreg such as a carbon fiber prepreg, a glass fiber prepreg, a Kevlar fiber prepreg or a basalt fiber prepreg.

[0059] In some embodiments, the cross-sectional shape of the continuous fiber prepreg 1 includes a circle, a rectangle, and the like.

[0060] The embodiment of the present invention can adjust the laying direction and density of the prepreg according to the specific shape and stress conditions of the printed part to meet different reinforcement requirements. For example, in areas with complex shapes or large curvatures, finer fiber specifications can be selected to facilitate the laying of the prepreg, such as Figure 2 The curvature of the tee is used to insert the prepreg; in areas that are subject to higher pressure or require higher stiffness, the laying density of the prepreg can be increased, such as Figure 3 Different numbers of prepreg wires are inserted into the compression rods and tension rods of the mid-truss structure.

[0061] The present invention also provides the following specific embodiments:

[0062] Implementation Case 1

[0063] like Figure 1 As shown: In this case, a force flow channel is reserved or excavated in the 3D printed part according to the force flow line of the 3D printed part. By pouring epoxy resin into the force flow channel and inserting prepreg, the prepreg is finally fixed by curing the epoxy resin to strengthen the structure of the 3D printed part. This method not only improves the mechanical properties of the 3D printed part, but also maintains its advantages of lightweight and complex geometry.

[0064] The specific process steps are as follows:

[0065] Step 1: Reserve or drill holes or channels according to the force flow lines of the 3D printed part to form a force flow channel.

[0066] Step 2: Epoxy resin infusion: Inject or pour epoxy resin into the force flow pipe. This step needs to be carried out under controlled temperature and pressure to ensure that the epoxy resin can evenly fill the force flow pipe and avoid the generation of bubbles.

[0067] Step 3: Prepreg insertion: When the epoxy resin is semi-cured, insert the prepreg into the force flow pipe along the designed path.

[0068] Step 4: Resin curing: During the curing process, the temperature and time need to be controlled to ensure that the epoxy resin is completely cured and tightly bonded to the fiber to obtain the final part.

[0069] Implementation Case 2:

[0070] This case is aimed at fiber reinforcement of complex irregular rod-shaped structures. In this case, holes or channels are reserved or drilled in each rod of the irregular rod-shaped structure to form a three-way pipe or a multi-way pipe. The rigidity and bendability of the continuous fiber prepreg 1 are utilized, and the prepreg is inserted into holes or channels with different curvatures and thicknesses by manual feeding. The path is controllable, which can improve the load-bearing capacity and durability of the pipeline. The specific process steps are as follows:

[0071] Step 1: Reserve or drill a hole or channel in each rod of the rod-like structure to form a three-way pipe or a multi-way pipe.

[0072] Step 2: Prepreg selection: According to the diameter and curvature of the channel in the three-way pipe or multi-way pipe, select the appropriate prepreg specifications, including the type of fiber (such as carbon fiber, glass fiber, etc.) and the thickness of the prepreg (such as 1K, 3K, 6K, etc.).

[0073] Step 3: Channel preparation: Check the channel structure to ensure that the inner wall of the channel is smooth and has no obvious defects to facilitate the injection of glue and the insertion of prepreg.

[0074] Step 4: Inject epoxy resin into the channel.

[0075] Step 5: Prepreg insertion: Using the rigidity of the prepreg, insert it manually or using a tool along the center line of the channel, and adjust the insertion force and direction in time according to the curvature of the channel, such as Figure 2 b.

[0076] Step 6: Curing treatment: Curing treatment is performed on the channel into which the prepreg is inserted, so that the resin is fully cured and the prepreg is firmly bonded to the inner wall of the channel.

[0077] Step 7: Post-processing: After curing, the prepregs extending from both ends of the channel are cut to ensure the sealing and overall beauty of the channel.

[0078] Special instructions:

[0079] Adaptability to channel curvature: The present invention particularly emphasizes the adaptability of the prepreg in pipes with different curvatures, and achieves smooth insertion in complex channel structures through the stiffness and bending properties of the prepreg.

[0080] Diversity of prepreg wire specifications: The present invention allows the selection of prepreg wires of different specifications according to the thickness of the channel, providing a flexible solution to accommodate channels of different sizes.

[0081] Advantages of manual feeding: Manual feeding allows the operator to adjust the insertion force and speed in a timely manner according to actual conditions, improving the flexibility and accuracy of operation.

[0082] Implementation Case 3:

[0083] This case is aimed at fiber reinforcement of truss structures, and it can also be applied to parts with complex structures and diverse materials. This method can perform customized reinforcement according to the stress conditions of different rods in the truss. By analyzing the stress characteristics of each rod, appropriate fiber bundles (composed of multiple prepreg wires) are selected for insertion, thereby improving the bearing capacity and stability of the entire structure. In this case, the fiber bundles are inserted in different directions through the opening technology at the connection of the rods to achieve the optimal reinforcement effect of the structure. The curing scheme of this case uses thermoplastic plastic as the curing medium, and uses electrical heating at both ends of the prepreg wire to reheat and cure the thermoplastic plastic on the inner wall of the channel, thereby achieving a firm bond between the fiber bundle and the truss structure. The specific process steps are as follows:

[0084] Step 1: Structural analysis: First, conduct a mechanical analysis of the truss structure to determine the stress conditions of each member, including compression, tension, and bending moment, such as Figure 3 shown.

[0085] Step 2: Design reinforcement scheme: Based on the structural analysis results, design the reinforcement scheme for each rod and select the appropriate fiber type, specification and quantity.

[0086] Step 3: Open holes in rods: Open holes at the rod connections that need to be strengthened. The location and size of the holes are determined according to the fiber specifications and insertion direction, such as Figure 4 shown.

[0087] Step 4: Prepreg wire cutting: According to the length of the rod, the prepreg wire is cut into segments of corresponding lengths to facilitate insertion while preventing interference.

[0088] Step 5: Fiber insertion: Insert the prepreg fiber into the channel, adjust the fiber laying angle according to the force direction of the rod, and ensure that the fiber is in the same direction as the axis of the rod.

[0089] Step 6: Curing of thermoplastics: The two ends of the prepreg are heated by electricity. The thermoplastics melt and fill the gaps between the fiber bundles. They are then cured through a cooling process to form a strong bond.

[0090] Step 7: Post-processing: Sand and paint the surface of the truss structure to improve its durability and protective performance.

[0091] Special instructions:

[0092] Customized stress reinforcement: The advantage of the present invention is that it can perform customized fiber reinforcement according to the specific stress conditions of each rod, such as using thicker fiber bundles for compressive rods to reduce the risk of buckling.

[0093] Hole-opening technology at the connection: By opening holes at the connection of the rods and inserting fiber bundles in different directions, the key nodes of the truss structure are strengthened and the overall stability of the structure is improved.

[0094] Thermoplastic curing: Utilizing the repeatable melting properties of thermoplastics provides an efficient and controlled curing method for fiber reinforcement of truss structures.

[0095] Fiber bundle laying angle: The laying angle of the fiber bundle is crucial to the reinforcement effect. In this example, the fiber bundle is required to be consistent with the axis of the rod to achieve the best mechanical properties.

[0096] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A 3D printed part structure reinforcement process based on continuous fiber prepreg, characterized in that: include: Step 1: Determine the direction and area that needs to be enhanced in the 3D print; Step 2: drilling or reserving holes or channels in the area to be reinforced along the direction to be reinforced so as to insert the continuous fiber prepreg; Step 3: Insert the continuous fiber prepreg into the hole or channel and fix it.

2. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 1, characterized in that: In step one, determine the direction and area that needs to be strengthened based on the stress characteristics of the 3D printed part.

3. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 1, characterized in that: In step three, the continuous fiber prepreg is fixed to the hole or channel by glue.

4. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 3, characterized in that: There are two ways of fixing with glue. First, before inserting the continuous fiber prepreg, glue is applied to the continuous fiber prepreg. Second, before inserting the continuous fiber prepreg, glue is poured into the holes or channels.

5. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 1, characterized in that: When the 3D printed part is a thermoplastic plastic, in step three, the two ends of the continuous fiber prepreg are electrically heated, and the thermoplastic plastic is melted by the heat and fills the gaps in the pores or channels, and then solidified by a cooling process, so that the continuous fiber prepreg and the 3D printed part form a firm bond.

6. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 1, characterized in that: The continuous fiber prepreg has a certain rigidity.

7. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 4 or 5, characterized in that: After the continuous fiber prepreg is inserted, the glue is cured so that the glue is cured and firmly adheres to the continuous fiber prepreg and the inner wall of the hole or channel.

8. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 1, characterized in that: Before step three, the continuous fiber prepreg needs to be prepared. The step of preparing the continuous fiber prepreg includes: selecting a continuous fiber prepreg of a shape and specification that matches the specification and curvature of the pore or channel.

9. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 1, characterized in that: The continuous fiber prepreg yarn is a carbon fiber prepreg yarn, a glass fiber prepreg yarn, a Kevlar fiber prepreg yarn or a basalt fiber prepreg yarn.

10. The 3D printed part structure reinforcement process based on continuous fiber prepreg according to claim 1, characterized in that: The cross-sectional shapes of the continuous fiber prepreg include circular and rectangular.

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