Extruder apparatus for producing core-in-sheath 3D printing wire

Abstract

The utility model provides a kind of extruder equipment of production cored 3D printing wire rod, comprising: two single screw extruders, respectively for melting first raw material and second raw material;Wire rod extrusion die, with the two single screw extruders intercommunication;Partition temperature control cooling mechanism, set in the downstream of wire rod extrusion die;Control system, electrically connected and control the two single screw extruders and the partition temperature control cooling system;Wire rod extrusion die inside is provided with first melt flow pipeline and second melt flow pipeline, for isolating the first raw material and the second raw material are transported;The wire rod extrusion die has a concentric circle structure extrusion port, the first melt flow pipeline and the second melt flow pipeline meet at the extrusion port;By the setting of two extruders and concentric circle die, the composite wire rod of core-skin structure can be stably extruded.

Description

Technical Field

[0001] This utility model relates to the field of 3D printing filament extrusion equipment, specifically an extruder for producing cored 3D printing filaments. Background Technology

[0002] Fused deposition modeling (FDM) 3D printers bring 3D digital models to life through a process of melting, depositing, and cooling 3D filaments. Currently, the material properties of the 3D filaments used largely determine the performance of the 3D model.

[0003] Existing 3D filaments are usually made of a single material, so the 3D models printed only have a single property. In addition, some materials (such as polymers with a high proportion of carbon fiber) have excellent properties, but they are also brittle, which is not conducive to the winding and shaping of filaments during the production process.

[0004] When producing cored wire, especially when the thermal properties (such as thermal shrinkage rate and crystallization rate) of the core and sheath materials differ significantly, traditional single-temperature cooling methods (such as cold water baths) can lead to severely uneven cooling rates between the inner and outer layers. The rapid cooling and shrinkage of the outer layer (sheath) creates stress conflict with the slow cooling of the inner layer (core), resulting in a large accumulation of internal stress within the finished wire. This can cause dimensional instability, warping, or core-sheath delamination, severely affecting the wire's performance.

[0005] Therefore, the market needs equipment capable of producing composite performance wires to solve the above problems, such as combining flexible and rigid materials, or wrapping highly brittle carbon fiber materials in tough materials to achieve reliable winding and forming of wires. Utility Model Content

[0006] The main objective of this invention is to overcome the shortcomings of existing technologies and provide an extruder for producing cored 3D printed filaments. This equipment aims to solve the following technical problems: high internal stress, warping, and core-skin delamination in filaments caused by differences in the thermal properties of the core and sheath materials under traditional cooling methods.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an extruder for producing cored 3D printed filaments, comprising: two single-screw extruders, respectively used for melting a first raw material and a second raw material; a filament extrusion die connected to the two single-screw extruders; a zoned temperature control and cooling mechanism disposed downstream of the filament extrusion die; and a control system electrically connected to and controlling the two single-screw extruders and the zoned temperature control and cooling system; the filament extrusion die is provided with a first melt flow pipeline and a second melt flow pipeline for isolating and conveying the first raw material melt and the second raw material melt; the filament extrusion die has a concentric extrusion port, where the first melt flow pipeline and the second melt flow pipeline converge; the zoned temperature control and cooling mechanism includes multiple cooling water zones arrayed along the output direction of the extrusion port, with the temperature of each cooling water zone decreasing in a gradient. As a preferred embodiment, the zoned temperature control and cooling mechanism further includes a traction unit that can slide along the output direction of the extrusion port; the traction unit is provided with a clamping plate for clamping the filament.

[0008] As a preferred embodiment, the zoned temperature control cooling mechanism includes a guide groove for the traction unit to slide; the guide groove is provided with a mountain-shaped bend between adjacent cooling water zones, and the traction unit will slide in the vertical direction when passing through the mountain-shaped bend.

[0009] As a preferred embodiment, a conveyor frame is also provided, which is used to support the cooling water zone and the traction unit.

[0010] As a preferred embodiment, a cooling fan is provided between adjacent cooling water zones on the conveyor frame.

[0011] As a preferred embodiment, the inner diameter of the first melt flow pipe and the second melt flow pipe is 16 mm.

[0012] As a preferred embodiment, the diameter of the extrusion port is 2.8 mm.

[0013] Compared with existing technologies, this invention has the following significant advantages: By using two extruders and concentric dies, core-skin composite wires can be stably extruded. More importantly, by setting up multiple cooling water zones with gradually decreasing temperatures, the wire undergoes a controlled cooling process, gradually cooling from high temperature to room temperature. This effectively avoids thermal shock, allowing the core and skin materials to shrink and crystallize relatively synchronously, significantly reducing residual stress within the wire and preventing warping and core-skin delamination. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present utility model; Figure 2 This is a cross-sectional view of a wire extrusion die in one embodiment of the present invention; Figure 3 This is a cross-sectional view of a zoned temperature control cooling mechanism in one embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures: 1. Single screw extruder; 2. Wire extrusion die; 21. First melt flow pipeline; 22. Second melt flow pipeline; 23. Extrusion port; 3. Zoned temperature control and cooling mechanism; 31. Cooling water zone; 32. Traction unit; 33. Clamping plate; 34. Guide groove; 341. Mountain-shaped bend; 35. Conveyor frame; 36. Cooling fan. Detailed Implementation

[0017] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent. To better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product.

[0018] It will be understood by those skilled in the art that certain well-known structures and their descriptions may be omitted in the accompanying drawings. The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0019] Example 1 Please see Figures 1 to 3 This invention provides an extruder for producing cored 3D printing filaments, addressing the problems of excessive internal stress and temperature contamination caused by differences in thermal properties during the cooling process of composite filaments. Figure 1 As shown, this equipment includes two single-screw extruders 1, a wire extrusion die 2, a zoned temperature control and cooling mechanism 3, and a control system.

[0020] Two single-screw extruders 1 are arranged side by side. For example, one single-screw extruder 1 is used to melt a first raw material (such as PLA or PETG with good toughness, used as the skin layer), and the other single-screw extruder 1 is used to melt a second raw material (such as a high-proportion carbon fiber composite material, used as the core material). The control system controls the heating temperature and screw speed of the two single-screw extruders 1 respectively to precisely control the melting state and extrusion rate of the two raw materials.

[0021] The wire extrusion die 2 is simultaneously connected to the discharge port of the single-screw extruder 1. The die interior is equipped with a first melt flow channel 21 and a second melt flow channel 22, which are isolated from each other. In this embodiment, the channels are concentrically arranged; for example, the second channel is located at the center of the first channel. The two melts are transported independently within the channels until they converge at the extrusion port 23 at the end of the die. The extrusion port 23 has a concentric circular structure, ensuring that the second raw material melt is uniformly coated by the first raw material melt before extrusion, forming a cored wire.

[0022] As a specific implementation, the inner diameters of the first melt flow pipe 21 and the second melt flow pipe 22 can be set to 16 mm. The diameter of the extrusion port 23 can be set to 2.8 mm to accommodate the production of wires with nominal diameters.

[0023] A zoned temperature-controlled cooling mechanism 3 is located downstream of the wire extrusion die 2 and is used to cool and shape the freshly extruded high-temperature cored wire. The zoned temperature-controlled cooling mechanism 3 is mounted on a conveyor frame 35. The zoned temperature-controlled cooling mechanism 3 includes multiple cooling water zones 31 arrayed along the wire output direction. A control system is electrically connected to and controls these cooling water zones 31, causing the temperature of each cooling water zone 31 to decrease in a gradient. For example, the first cooling water zone 31 is set to 70 degrees Celsius, the second cooling water zone 31 is set to 50 degrees Celsius, and the third cooling water zone 31 is set to 30 degrees Celsius. This design allows the wire to undergo a gradual cooling process, avoiding stress concentration caused by drastic temperature differences between the inner and outer layers.

[0024] To achieve stable wire feeding, the zoned temperature control cooling mechanism 3 also includes a traction unit 32. The traction unit 32 is equipped with a clamping plate 33 for clamping the head of the wire. The traction unit 32 can slide along the output direction of the extrusion port 23 on the conveyor frame 35. To solve the "temperature contamination" problem mentioned in the background art, this invention designs an ingenious isolation structure. The conveyor frame 35 is provided with a guide groove 34 for the traction unit 32 to slide. Crucially, at the location of the adjacent cooling water zone 31, the guide groove 34 is provided with a mountain-shaped bend 341. When the traction unit 32 pulls the wire from one water zone to another, it must pass through this mountain-shaped bend 341. The mountain-shaped bend 341 forces the traction unit 32 and the wire to slide vertically (i.e., first ascending over the "peak," then sliding down into the next water zone). This brief "water exit" process uses gravity to remove most of the water adhering to the surface of the wire. Meanwhile, in order to completely eliminate moisture carryover, a cooling fan 36 is installed between adjacent cooling water zones 31 on the conveyor frame 35. When the wire is lifted by the mountain-shaped bend 341, the cooling fan 36 immediately blows a strong airflow onto it, completely blowing away or evaporating any remaining water droplets and attached moisture.

[0025] Workflow Summary: The control system starts, setting the temperature and speed of the single-screw extruder 1, as well as the temperature gradient of the cooling water zone 31. After the sheath and core material melt separately, they are combined in the die to form a cored wire, which is then extruded. The wire head is clamped by the clamping plate 33 of the traction unit 32. The traction unit 32 starts, pulling the wire sequentially into: the first cooling water zone 31 for initial high-temperature cooling and shaping; passing through the mountain-shaped bend 341 and the cooling fan 36 area; the wire is lifted, splashed with water, and powerfully dried, effectively preventing high-temperature moisture from entering the next zone; the second cooling water zone 31 for medium-temperature cooling; passing through the mountain-shaped bend 341 and the cooling fan 36 area again for further isolation and drying; and the third cooling water zone 31 for low-temperature cooling. Finally, the traction unit 32 transports the fully cooled and low-stress finished wire to the subsequent winding equipment. The control system of this utility model is an integrated controller (such as a PLC or industrial computer), which is electrically connected to and centrally controls two single-screw extruders 1, a zoned temperature control and cooling mechanism 3, controls the temperature of each water zone, the start and stop of the fan, and the traction speed of the traction unit 32, ensuring the coordination and stability of the entire production process.

[0026] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An extruder for producing core-spun 3D printing filaments, characterized in that, include: Two single-screw extruders are used to melt the first and second raw materials, respectively; The wire extrusion die is connected to the two single-screw extruders; A zoned temperature control and cooling mechanism is located downstream of the wire extrusion die; The control system is electrically connected to and controls the two single-screw extruders and the zoned temperature control and cooling system. The wire extrusion die is provided with a first melt flow pipeline and a second melt flow pipeline inside, which are used to isolate and transport the first raw material and the second raw material; the wire extrusion die has a concentric extrusion port, and the first melt flow pipeline and the second melt flow pipeline converge at the extrusion port; The zoned temperature control cooling mechanism includes multiple cooling water zones arrayed along the output direction of the extrusion port, with the temperature of each cooling water zone decreasing in a gradient.

2. The extruder equipment for producing core-spun 3D printing filaments according to claim 1, characterized in that, The zoned temperature control and cooling mechanism also includes a traction unit, which can slide along the output direction of the extrusion port; The traction section is provided with a clamping plate for holding the wire.

3. The extruder equipment for producing core-spun 3D printing filaments according to claim 2, characterized in that, The partitioned temperature control and cooling mechanism includes a guide groove for the traction unit to slide. The guide groove has a mountain-shaped bend between adjacent cooling water zones, and the traction part slides vertically when it passes through the mountain-shaped bend.

4. The extruder equipment for producing core-spun 3D printing filaments according to claim 3, characterized in that, It is also equipped with a conveyor frame, which is used to carry the cooling water zone and the traction unit.

5. The extruder equipment for producing core-spun 3D printing filaments according to claim 4, characterized in that, Cooling fans are positioned between adjacent cooling water zones on the conveyor frame.

6. The extruder equipment for producing core-spun 3D printing filaments according to claim 1, characterized in that, The inner diameter of the first melt flow pipe and the second melt flow pipe is 16 mm.

7. The extruder equipment for producing core-spun 3D printing filaments according to claim 1, characterized in that, The diameter of the extrusion port is 2.8 mm.

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