Extrusion die based on additive manufacturing and manufacturing method thereof

Abstract

The invention provides an extrusion die based on additive manufacturing, which enables wall thicknesses corresponding to runners to be consistent and ensures that materials flowing along the runners have consistency in heating and heat dissipation processes. The mounting structure comprises a first mounting matching end; a second mounting mating end; the runner carrier is of an axial extension structure with a geometrical shape and comprises a central inner cavity, a peripheral surface and a uniform-temperature filling cavity, and a continuous concave runner groove is formed in the peripheral surface in the direction of the material runner; one axial end of the flow channel carrier is a first mounting matching end, the other axial end of the flow channel carrier is a second mounting matching end, a central inner cavity of the flow channel carrier is used for placing a temperature adjusting device, and a uniform-temperature filling cavity of the flow channel carrier is used for filling a uniform-temperature medium; the temperature equalizing medium conducts heat energy to materials flowing along the inwards-concave runner grooves through heat conduction, and the wall thicknesses of the portions, corresponding to the inwards-concave runner grooves, of the base body are equal.

Description

Technical Field

[0001] This invention relates to the technical field of extrusion dies, specifically to an extrusion die based on additive manufacturing, and also provides a method for manufacturing the extrusion die. Background Technology

[0002] Extrusion dies are widely used in the production of various polymer products. Because the extrusion process requires the material to maintain a certain degree of fluidity, the overall process environment needs to be kept at a specific temperature. Metal dies, due to their good thermal conductivity, transfer heat quickly. When used with materials that have strict temperature requirements, factors such as the die temperature dropping too quickly or uneven die temperature can lead to product molding defects.

[0003] The mold as a whole needs to maintain a uniform temperature to avoid localized overheating or undercooling. Uneven temperature will cause inconsistent material flow during extrusion, affecting the dimensional accuracy and surface quality of the finished product. At the same time, the mold should have good thermal insulation properties to effectively reduce heat loss and maintain the required process temperature. This helps reduce energy consumption, improve production efficiency, and ensure consistent product quality.

[0004] Existing extrusion dies, obtained through machining, often suffer from uneven wall thickness due to the complex flow channel structure. Thicker walls result in slower heat transfer, while thinner walls dissipate heat more easily, leading to uneven temperature distribution within the die. Furthermore, existing extrusion dies typically rely on external heating or cooling pipes for temperature regulation. These pipes are located at a distance from the flow channel, making precise temperature control of critical die components impossible, and resulting in low heat transfer efficiency and slow temperature response. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an additive manufacturing-based extrusion die that ensures consistent wall thickness along the flow channels and guarantees uniform material flow during heating and cooling, thereby ensuring the material reaches a reliable process temperature and improving heat transfer efficiency.

[0006] An additive manufacturing-based extrusion die, characterized in that it comprises:

[0007] First installation mating end;

[0008] Second installation mating end;

[0009] And a flow channel carrier, which is an axially extended structure with a geometric shape, including a central inner cavity, an outer peripheral surface, and a uniform temperature filling cavity, wherein a continuous concave flow channel groove is provided on the outer peripheral surface along the material flow channel direction;

[0010] One axial end of the flow channel carrier is a first mounting end and the other axial end is a second mounting end. The central inner cavity of the flow channel carrier is used to place a temperature regulating device. The uniform temperature filling cavity of the flow channel carrier is used to fill a uniform temperature medium. The uniform temperature medium conducts heat energy to the material flowing along the concave flow channel groove through heat conduction. The wall thickness of the substrate on the outer peripheral surface corresponding to the concave flow channel groove is equal.

[0011] The uniform temperature filling cavity ensures the uniformity of the wall thickness of the flow channel corresponding to the concave flow channel groove, and at the same time provides a space carrier for the uniform temperature material. The uniformity of the matrix wall thickness ensures the uniformity of heat conduction, and the uniform temperature material of the phase change material further eliminates the possible heat difference. The combination of the two produces a synergistic effect, which can more effectively achieve the temperature uniformity of the flow channel of the extrusion die. This synergistic design is not reflected in the existing extrusion die design.

[0012] Its further features are:

[0013] The flow channel carrier is specifically a truncated cone-shaped structure. The first mounting end is a mounting flange, the second mounting end is the relative tip position of the truncated cone-shaped structure, the outer peripheral surface is a truncated cone-shaped area, and the concave flow channel groove is spirally arranged along the direction from the major diameter to the minor diameter of the outer peripheral surface.

[0014] The uniform temperature filling cavity has a conformal concave structure at the position corresponding to the concave flow channel groove, and the base wall thickness between the uniform temperature filling cavity and the concave flow channel groove is equal.

[0015] The mounting flange is a frustum structure that protrudes from the large-diameter end of the flow channel carrier. The radially protruding mounting flange has a number of mounting positioning holes evenly distributed. The mounting flange is fixed to the outside through the mounting positioning holes. The mounting positioning holes do not communicate with the temperature equalization filling cavity.

[0016] The uniform temperature filling cavity extends to the flange stop face of the mounting flange, and at least one powder cleaning hole is arranged on the flange stop face, the powder cleaning hole being connected to the uniform temperature filling cavity.

[0017] The isothermal filling medium in the isothermal filling cavity is paraffin wax. Paraffin wax has unique phase change characteristics and can absorb and release a large amount of heat when the temperature changes, so as to achieve rapid dynamic adjustment of the flow channel temperature. This method of using phase change materials to isothermize the mold flow channel is a brand-new idea and method compared with the traditional method.

[0018] The diameter of the powder cleaning hole is not less than 3mm, which facilitates the cleaning of powder inside the cavity after molding. After the uniform temperature paraffin is injected through the powder cleaning hole, the powder cleaning hole is sealed by welding.

[0019] The mounting flange also integrates positioning pin holes, which facilitate quick and accurate positioning of the extrusion mold during installation, ensuring assembly accuracy.

[0020] The central cavity is located at the radial center and extends through the center axially.

[0021] A method for manufacturing an extrusion die based on additive manufacturing is characterized in that the extrusion die is integrally formed using additive manufacturing technology. By layer-by-layer additive manufacturing, an internal cavity that conforms to the shape of the concave flow channel is constructed inside the concave flow channel, so that the wall thickness of the matrix is ​​consistent. At the same time, the integral forming of the uniform temperature filling cavity ensures the sealing performance after the uniform temperature material is filled.

[0022] The beneficial effects of adopting the technology of this invention are as follows:

[0023] 1. Process Innovation: The additive manufacturing process is used to form an integrated extrusion die. Through the additive manufacturing process of layer-by-layer deposition, an internal cavity that conforms to the concave flow channel is built inside the concave flow channel, so that the wall thickness of the matrix is ​​consistent. At the same time, the integrated molding of the homogeneous filling cavity ensures the sealing of the homogeneous material after filling.

[0024] 2. Innovative Temperature Equalization Method: Currently, temperature equalization methods for extrusion dies mainly focus on external heating and cooling devices or internal heating and cooling pipes. These methods suffer from slow temperature response and difficulty in controlling localized temperatures. This invention innovatively uses paraffin wax as the temperature equalization material to fill the internal cavity of the die runner. Paraffin wax has unique phase change properties, enabling it to absorb and release a large amount of heat when the temperature changes, achieving rapid dynamic adjustment of the runner temperature. This method of using phase change materials for die runner temperature equalization represents a completely new approach and method compared to traditional methods.

[0025] 3. Integrated structural and functional design: The uniform temperature filling cavity structure not only solves the problem of consistent flow channel wall thickness, but also provides a spatial carrier for the uniform temperature material. The consistent wall thickness ensures the uniformity of heat conduction, and the uniform temperature material of the phase change material further eliminates the possible heat difference. The combination of the two produces a synergistic effect, which can more effectively achieve the temperature uniformity of the extrusion die flow channel. This synergistic design is not reflected in the existing extrusion die design. Attached Figure Description

[0026] Figure 1 A three-dimensional representation of a specific embodiment of the extrusion die of the present invention. Figure 1 ;

[0027] Figure 2 A three-dimensional representation of a specific embodiment of the extrusion die of the present invention. Figure 2 ;

[0028] Figure 3This is a front view of a specific embodiment of the extrusion die of the present invention;

[0029] Figure 4 for Figure 3 A schematic diagram of the AA cross-section structure;

[0030] The names corresponding to the serial numbers in the diagram are as follows:

[0031] First mounting end 10, second mounting end 20, flow channel carrier 30, central inner cavity 31, outer peripheral surface 32, uniform temperature filling cavity 33, and concave flow channel groove 34;

[0032] Installation positioning hole 1, powder cleaning hole 2, positioning pin hole 3. Detailed Implementation

[0033] An additive manufacturing-based extrusion die, see Figures 1-4 It includes a first mounting end 10, a second mounting end 20, and a flow channel carrier 30;

[0034] The flow carrier 30 is an axially extended structure with a geometric shape, including a central inner cavity 31, an outer peripheral surface 32, and a uniform temperature filling cavity 33. A continuous concave flow channel groove 34 is provided on the outer peripheral surface 32 along the material flow channel direction.

[0035] One axial end of the flow channel carrier 30 is the first mounting end 10, and the other axial end is the second mounting end 20. The central inner cavity 31 of the flow channel carrier 30 is used to place the temperature regulating device. The temperature equalization filling cavity 33 of the flow channel carrier 30 is used to fill the temperature equalization medium. The temperature equalization medium conducts heat energy to the material flowing along the concave flow channel groove 34 through heat conduction. The wall thickness of the substrate of the outer peripheral surface 32 corresponding to the concave flow channel groove 34 is equal. Considering the subsequent process and mold performance, the wall thickness needs to be more than 2mm.

[0036] The uniform temperature filling cavity 33 ensures the uniformity of the wall thickness of the flow channel corresponding to the concave flow channel groove 34, and at the same time provides a space carrier for the uniform temperature material. The uniformity of the matrix wall thickness ensures the uniformity of heat conduction. The uniform temperature material of the phase change material further eliminates the possible heat difference. The combination of the two produces a synergistic effect, which can more effectively achieve the temperature uniformity of the flow channel of the extrusion die. This synergistic design is not reflected in the existing extrusion die design.

[0037] For specific implementation examples, see Figures 1-4 The flow channel carrier 30 is specifically a truncated cone-shaped structure. The first mounting end 10 is a mounting flange, the second mounting end 20 is the relative tip position of the truncated cone-shaped structure, the outer peripheral surface 32 is a truncated cone-shaped area, and the concave flow channel groove 34 is spirally arranged along the direction from the major diameter to the minor diameter of the outer peripheral surface 32.

[0038] The uniform temperature filling cavity 33 has a concave structure with conformal design at the position corresponding to the concave flow channel groove 34, and the base wall thickness between the uniform temperature filling cavity 33 and the concave flow channel groove 34 is equal.

[0039] The mounting flange is a frustum structure with a large diameter end protruding on the side of the flow channel carrier 30. The radially protruding mounting flange has four mounting positioning holes 1 evenly distributed. The mounting flange is fixed to the external setting through the mounting positioning holes 1. The mounting positioning holes 1 are not connected to the uniform temperature filling cavity 33.

[0040] The uniform temperature filling cavity 33 extends to the flange stop face 35 of the mounting flange. Two powder cleaning holes 2 are arranged on the flange stop face 35, and the powder cleaning holes 2 are connected to the uniform temperature filling cavity 33.

[0041] The isothermal filling medium in the isothermal filling cavity 33 is paraffin wax. Paraffin wax has unique phase change characteristics and can absorb and release a large amount of heat when the temperature changes, so as to achieve rapid dynamic adjustment of the flow channel temperature. This method of using phase change materials to isothermize the mold flow channel is a brand-new idea and method compared with the traditional method.

[0042] The diameter of the powder cleaning hole 2 is not less than 3mm, which facilitates the cleaning of powder inside the cavity after molding. After the uniform temperature paraffin is injected through the powder cleaning hole 2, the powder cleaning hole is sealed by welding.

[0043] The mounting flange also integrates positioning pin holes 3. When installing the extrusion die, the positioning pin holes 3 facilitate quick and accurate positioning of the extrusion die, ensuring assembly accuracy.

[0044] The central cavity 31 is located at the radial center and is axially penetrating.

[0045] A method for manufacturing an extrusion die based on additive manufacturing: the extrusion die is integrally formed using additive manufacturing process. By layer-by-layer additive manufacturing, an internal cavity that conforms to the concave flow channel is constructed inside the concave flow channel, so that the wall thickness of the matrix is ​​consistent. At the same time, the integral forming of the uniform temperature filling cavity ensures the sealing performance after the uniform temperature material is filled.

[0046] It includes the following steps:

[0047] S1. Design simulation: The outer flow channel of the extrusion die is a conformal spiral flow channel. The simulation calculation results show that it is the optimal flow path. A uniform temperature filling cavity that conforms to the flow channel is set inside the flow channel of the extrusion die.

[0048] S2, 3D printing: Using laser selective melting technology, metal powder is rapidly melted and solidified by a high-energy-density laser to obtain the extrusion die printing blank designed in step S1.

[0049] S3. Heat treatment: Stress-relieving annealing treatment of the extrusion die printing blank at 750℃-850℃ for 2h-4h.

[0050] S4. Non-destructive testing of parts: X-ray or industrial CT is used to inspect the internal quality of the extrusion die blank. The X-ray inspection standard shall be implemented in accordance with GJB 1187A-2019, and the industrial CT inspection standard shall be implemented in accordance with GJB 5312-2004. 100% fluorescence penetrant testing shall be carried out. The fluorescence penetrant testing shall be implemented in accordance with GJB 2367A-2005. No visible cracks, folds, inclusions, looseness, pores, cold shuts and oxide scars are allowed on the surface of the parts.

[0051] S5. Remove supports and polish to obtain the finished extrusion mold; according to the product structure characteristics, select appropriate fitter tools (rubber hammer, iron hammer, pneumatic impact drill, sander, straight grinder, angle grinder and other pneumatic and electric tools with large removal volume, in conjunction with saw blade, hand pliers, sandpaper and other fitter tools) to remove the solid supports and block supports of the product until all parts supports are removed. Use white corundum grinding head, paper belt wheel and abrasive cloth wheel to polish the root of the remaining block support and the remaining part of the solid support on the support surface until it is smooth and consistent with the non-support surface. Complete the extrusion mold interface and ensure dimensional accuracy through lathe, grinding machine, milling machine and other processes.

[0052] Its beneficial effects are as follows:

[0053] 1. Process Innovation: The additive manufacturing process is used to form an integrated extrusion die. Through the additive manufacturing process of layer-by-layer deposition, an internal cavity that conforms to the concave flow channel is built inside the concave flow channel, so that the wall thickness of the matrix is ​​consistent. At the same time, the integrated molding of the homogeneous filling cavity ensures the sealing of the homogeneous material after filling.

[0054] 2. Innovative Temperature Equalization Method: Currently, temperature equalization methods for extrusion dies mainly focus on external heating and cooling devices or internal heating and cooling pipes. These methods suffer from slow temperature response and difficulty in controlling localized temperatures. This invention innovatively uses paraffin wax as the temperature equalization material to fill the internal cavity of the die runner. Paraffin wax has unique phase change properties, enabling it to absorb and release a large amount of heat when the temperature changes, achieving rapid dynamic adjustment of the runner temperature. This method of using phase change materials for die runner temperature equalization represents a completely new approach and method compared to traditional methods.

[0055] 3. Integrated structural and functional design: The uniform temperature filling cavity structure not only solves the problem of consistent flow channel wall thickness, but also provides a spatial carrier for the uniform temperature material. The consistent wall thickness ensures the uniformity of heat conduction, and the uniform temperature material of the phase change material further eliminates the possible heat difference. The combination of the two produces a synergistic effect, which can more effectively achieve the temperature uniformity of the extrusion die flow channel. This synergistic design is not reflected in the existing extrusion die design.

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An extrusion die based on additive manufacturing, characterized in that, It includes: First installation mating end; Second installation mating end; And a flow channel carrier, which is an axially extended structure with a geometric shape, including a central inner cavity, an outer peripheral surface, and a uniform temperature filling cavity, wherein a continuous concave flow channel groove is provided on the outer peripheral surface along the material flow channel direction; One axial end of the flow channel carrier is a first mounting end, and the other axial end is a second mounting end. The central cavity of the flow channel carrier is used to house a temperature regulating device. The uniform temperature filling cavity of the flow channel carrier is used to fill a uniform temperature medium. The uniform temperature medium conducts heat energy to the material flowing along the concave flow channel groove through thermal conduction. The wall thickness of the substrate on the outer peripheral surface corresponding to the concave flow channel groove is equal.

2. The extrusion die based on additive manufacturing according to claim 1, characterized in that: The flow channel carrier is specifically a truncated cone-shaped structure. The first mounting end is a mounting flange, the second mounting end is the relative tip position of the truncated cone-shaped structure, the outer peripheral surface is a truncated cone-shaped area, and the concave flow channel groove is spirally arranged along the direction from the major diameter to the minor diameter of the outer peripheral surface.

3. The extrusion die based on additive manufacturing according to claim 2, characterized in that: The uniform temperature filling cavity has a conformal concave structure corresponding to the position of the concave flow channel groove, and the base wall thickness between the uniform temperature filling cavity and the concave flow channel groove is equal.

4. The extrusion die based on additive manufacturing according to claim 2, characterized in that: The mounting flange is a frustum-shaped structure that protrudes from the large-diameter end of the flow channel carrier. The radially protruding mounting flange has a plurality of mounting positioning holes evenly distributed on it. The mounting flange is fixed to the outside through the mounting positioning holes, and the mounting positioning holes are not connected to the temperature equalization filling cavity.

5. An extrusion die based on additive manufacturing according to claim 2, characterized in that: The uniform temperature filling cavity extends to the flange end face of the mounting flange, and at least one powder cleaning hole is arranged on the flange end face, the powder cleaning hole being connected to the uniform temperature filling cavity.

6. An extrusion die based on additive manufacturing according to claim 2, characterized in that: The isothermal filling medium in the isothermal filling cavity is paraffin wax. Paraffin wax has unique phase change characteristics and can absorb and release a large amount of heat when the temperature changes, thereby achieving rapid dynamic adjustment of the flow channel temperature.

7. An extrusion die based on additive manufacturing according to claim 5, characterized in that: The diameter of the powder cleaning hole is not less than 3mm.

8. An extrusion die based on additive manufacturing according to claim 2, characterized in that: The mounting flange also integrates positioning pin holes, which facilitate quick and accurate positioning of the extrusion die during installation, ensuring assembly precision.

9. An extrusion die based on additive manufacturing according to claim 2, characterized in that: The central cavity is located at the radial center and extends through the center axially.

10. A method for manufacturing an extrusion die based on additive manufacturing, used to manufacture the extrusion die as described in any one of claims 1-9, characterized in that, It adopts an additive manufacturing process to form an integrated extrusion mold. Through additive manufacturing and layer-by-layer stacking, an internal cavity that conforms to the shape of the concave flow channel is built inside the concave flow channel, so that the wall thickness of the matrix is ​​consistent. At the same time, the integrated molding of the uniform temperature filling cavity ensures the sealing of the uniform temperature material after filling.

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