Self-locking split type hot press forming mold for ultra-high molecular weight polymer

Abstract

The utility model relates to a self-locking split type hot press forming mold for an ultra-high molecular weight polymer, and relates to the technical field of molds, the self-locking split type hot press forming mold for the ultra-high molecular weight polymer comprises a lower mold and an upper mold, the lower mold comprises a lower cavity and a lower insert plate, the lower cavity is hollow, and the lower insert plate is arranged in the lower cavity; the upper die is arranged at the upper end of the lower die, the upper die comprises an upper cavity and an upper pressing plate, the upper cavity is hollow and is fixedly matched with the lower cavity in a stepped mode, the upper pressing plate is arranged in the upper cavity, powder is arranged in the upper cavity and the lower cavity in a surrounding mode, and the powder is located between the upper pressing plate and the lower insert plate. The hot-press forming mold is used for solving the problem that when the hot-press pressure of an existing hot-press forming mold for the ultra-high molecular weight polymer is too large, powder is likely to be extruded out, and consequently plates deform.

Description

Technical Field

[0001] This application relates to the field of mold technology, and in particular to a self-locking split-type thermoforming mold for ultra-high molecular weight polymers. Background Technology

[0002] Hot pressing technology is widely used in powder metallurgy, ceramic processing, and other fields. It achieves material densification and shape fixation by applying high temperature and pressure to powder materials, and is an indispensable part of modern industrial production. Ultra-high molecular weight polymers (UHMWPEs) have high viscosity-average molecular weights and poor melt flowability. For example, UHMWPE is a highly crystalline thermoplastic engineering plastic with a viscosity-average molecular weight greater than 1 million. It possesses excellent wear resistance, impact resistance, corrosion resistance, and good biocompatibility, but its extremely poor melt flowability makes it difficult to process using conventional methods. Currently, the mainstream processing method is still pressing and sintering using molds.

[0003] Ultra-high molecular weight polymer sheets are typically large and thick. While using a split mold makes demolding convenient, excessive pressure during hot pressing can cause the powder to be extruded along the joint gaps after molding, lifting the mold and resulting in unstable dimensions or even deformation defects in the final product. This seriously affects the quality and pass rate of the finished product. Utility Model Content

[0004] This application provides a self-locking split-type thermoforming mold for ultra-high molecular weight polymers, which solves the problem that the powder is easily squeezed out and the sheet material is deformed when the current thermoforming mold for ultra-high molecular weight polymers is subjected to excessive pressure during hot pressing.

[0005] A self-locking, split-type thermoforming mold for ultra-high molecular weight polymers includes:

[0006] The lower mold includes a lower cavity and a lower insert plate. The lower cavity is hollow inside, and the lower insert plate is disposed inside the lower cavity.

[0007] An upper mold is located at the upper end of the lower mold. The upper mold includes an upper cavity and an upper pressure plate. The upper cavity is hollow and is fixed to the lower cavity in a stepped manner. The upper pressure plate is located inside the upper cavity. Both the upper cavity and the lower cavity are surrounded by powder material, and the powder material is located between the upper pressure plate and the lower plate.

[0008] By adopting the above technical solution, the press presses down on the upper cavity, so that the upper and lower cavities are tightly fixed in a stepped manner, effectively preventing the powder from overflowing from the gap between the upper and lower cavities. As a result, during hot pressing and sintering, the powder is difficult to lift the upper cavity, so that the formed plate will not deform, ensuring the dimensional accuracy and surface quality of the plate, and improving the molding quality of the product.

[0009] In one embodiment, the upper cavity is square and has an annular block protruding from its lower end. The lower cavity is square and corresponds to the upper cavity. The lower cavity includes a first border and a second border. The second border is located above the first border and is smaller than the first border. The second border is in close contact with the upper cavity, and the first border is in close contact with the annular block.

[0010] By adopting the above technical solution, the upper cavity is tightly abutted against the second frame, and the first frame is tightly abutted against the annular block, so that the stepped structure of the upper and lower cavities is combined to form a complete cavity. This structure forms a good sealing effect during hot pressing, effectively preventing powder from overflowing from the gap between the upper and lower cavities, ensuring the integrity of the sheet forming, reducing waste generation, and improving production efficiency.

[0011] In one embodiment, the lower panel is square and includes a first panel and a second panel. The first panel is larger than the second panel and is located at the upper end of the second panel. The lower cavity also includes a third frame, which is disposed within the second frame. The height of the third frame is less than the height of the first frame. The second panel is disposed within the third frame, and the first panel is disposed within the second frame.

[0012] By adopting the above technical solution, the powder is jointly abutted by the first panel, the second frame, the upper cavity, and the upper pressure plate. This structure provides a uniform and stable pressure environment for the powder, which helps the powder to better fuse and form during the hot pressing process, thereby improving the density and strength of the board.

[0013] In one embodiment, the height of the third frame is greater than the height of the second panel.

[0014] By adopting the above technical solution, even if the powder flows out along the gap between the lower cavity and the lower panel, the panel will not be lifted. This ensures the positional stability of the lower panel during the hot pressing process, avoids affecting the molding quality of the sheet material due to panel displacement, and ensures the consistency and stability of the product.

[0015] In one embodiment, the corners of the second and third borders are rounded, and the corners of the first and second panels are also rounded.

[0016] By adopting the above technical solution, stress concentration is effectively avoided. During the hot pressing process, the various components of the mold are subjected to significant pressure and temperature changes. The rounded corner design can reduce local stress, prevent the mold from cracking or being damaged due to stress concentration, and extend the service life of the mold. At the same time, it eliminates sharp edges and corners, reducing the risk of operators being scratched during operation, improving operational safety, and meeting the requirements of safe production.

[0017] In one embodiment, the upper cavity further includes a plurality of elastic elements disposed at the upper end of the upper cavity.

[0018] By adopting the above technical solution, the elastic element at the upper end of the upper cavity transmits pressure to the upper cavity when pressed, ensuring a tight connection between the upper and lower cavities and guaranteeing the molding effect of the powder during hot pressing. After hot pressing, the elastic element returns to its original shape, and the upper cavity can be easily lifted, achieving rapid demolding, improving production efficiency, and reducing damage to the sheet material during demolding.

[0019] In one embodiment, each of the elastic elements includes a guide post and a spring. The guide post is T-shaped. One end of the spring is fixed to the upper cavity, and the other end abuts against the guide post. The upper cavity is also provided with a limiting hole. The guide post and the limiting hole correspond one-to-one. One end of the guide post is located in the limiting hole.

[0020] By adopting the above technical solution, the elastic element consists of a guide post and a spring. The press presses down on the guide post, causing the spring to be stressed, which in turn presses down on the upper cavity, achieving a tight fixation between the upper and lower cavities. After hot pressing, the press slowly rises, the spring recovers, and the upper cavity is lifted to complete demolding. This structural design precisely controls the hot pressing and demolding processes, ensuring operational accuracy and stability, and improving production controllability. Through the buffering effect of the spring, the direct impact of the hot press on the mold is reduced, decreasing wear on mold components, extending mold life, and lowering production costs.

[0021] In one embodiment, the sum of the heights of the upper pressure plate and the powder is greater than the height of the upper cavity, and the height of the guide post protruding from the upper cavity is greater than the height of the upper pressure plate protruding from the upper cavity.

[0022] By adopting the above technical solution, the upper pressure plate can adapt to the pressing height when the press presses products of different thicknesses. This design realizes the function of hot pressing products of different thicknesses with one set of molds, improves the versatility of molds, reduces the types and number of molds, and reduces production costs. The press first presses the guide pillar to ensure tight fixation between the upper and lower cavities, and then presses the upper pressure plate, making it more difficult for powder to be squeezed out from the gaps between the cavities during hot pressing.

[0023] In one embodiment, the upper surface of the upper pressure plate is provided with multiple interfaces, and the upper cavity is provided with handles located on opposite sides of the upper cavity.

[0024] By adopting the above technical solutions, the interface on the upper surface of the upper pressure plate facilitates the installation of a detachable handle, making it convenient to move the upper pressure plate; the handles on the opposite sides of the upper cavity facilitate the movement of the upper cavity. These designs improve the ease of handling the mold during the production process, reduce labor costs and labor intensity, and increase production efficiency.

[0025] In one embodiment, the lower cavity is further provided with a receiving hole, and the receiving hole is provided with a temperature sensor.

[0026] By adopting the above technical solution, the temperature sensor can monitor the temperature change of the product in real time during the hot pressing process, which helps to adjust the hot pressing process parameters in a timely manner and ensure the stability of product quality. At the same time, it provides important reference data. By analyzing the temperature data, the quality status of the product can be evaluated, potential problems can be identified, and a basis for product quality improvement and optimization can be provided, thereby improving product quality and market competitiveness.

[0027] In summary, this application includes at least one beneficial effect:

[0028] 1. The press presses down on the upper cavity, making the upper and lower cavities tightly fixed in a stepped manner. This effectively prevents the powder from overflowing from the gap between the upper and lower cavities. As a result, during hot pressing and sintering, the powder is difficult to lift the upper cavity, so that the formed board will not deform. This ensures the dimensional accuracy and surface quality of the board and improves the molding quality of the product.

[0029] 2. Even if powder flows out along the gap between the lower cavity and the lower panel, the panel will not be lifted. This ensures the positional stability of the lower panel during the hot pressing process, avoids affecting the molding quality of the board due to panel displacement, and ensures the consistency and stability of the product.

[0030] 3. The elastic element consists of guide pillars and springs. The press presses down on the guide pillars, causing the springs to be stressed, which in turn presses down on the upper cavity, achieving a tight fixation between the upper and lower cavities. After hot pressing, the press slowly rises, the springs return to their original position, and the upper cavity is lifted to complete demolding. This structural design precisely controls the hot pressing and demolding processes, ensuring operational accuracy and stability, and improving production controllability. The spring's buffering effect reduces the direct impact of the hot press on the mold, lowers wear on mold components, extends mold life, and reduces production costs. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the overall structure of a self-locking split-type hot press molding die for ultra-high molecular weight polymers provided in the embodiments of this application;

[0032] Figure 2 This is a schematic diagram of the structure of a lower cavity provided in an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the structure of a lower panel provided in an embodiment of this application;

[0034] Figure 4 This is a schematic diagram of the upper cavity structure provided in an embodiment of this application;

[0035] Figure 5 This is a schematic diagram of the structure of an upper pressure plate provided in an embodiment of this application;

[0036] Figure 6 This is a cross-sectional structural schematic diagram of a self-locking split-type hot pressing mold for ultra-high molecular weight polymers provided in an embodiment of this application.

[0037] Explanation of reference numerals in the attached drawings: 1. Self-locking split-type thermoforming mold for ultra-high molecular weight polymers; 11. Lower mold; 111. Lower cavity; 1111. First frame; 1112. Second frame; 1113. Third frame; 1114. Receiving hole; 112. Lower insert; 1121. First insert; 1122. Second insert; 12. Upper mold; 121. Upper cavity; 1211. Limiting hole; 1212. Ring block; 1213. Handle; 122. Upper pressure plate; 1221. Interface; 123. Elastic element; 1231. Guide post; 1232. Spring. Detailed Implementation

[0038] The following is in conjunction with the appendix Figure 1-6 The self-locking split-type thermoforming mold for ultra-high molecular weight polymers provided in this application will be described in further detail.

[0039] Example 1

[0040] Please see Figure 1-6 The self-locking split-type thermoforming mold 1 for ultra-high molecular weight polymers provided in this application includes a lower mold 11 and an upper mold 12.

[0041] like Figures 1 to 3 As shown, the lower mold 11 is composed of a lower cavity 111 and a lower insert 112. The lower cavity 111 is hollow, and the lower insert 112 is disposed within the lower cavity 111. Specifically, the lower cavity 111 mainly includes a first frame 1111, a second frame 1112, and a third frame 1113. The second frame 1112 is located above the first frame 1111 and is smaller than the first frame 1111. The third frame 1113 is located inside the second frame 1112, and the lower end of the third frame 1113 is flush with the lower end of the first frame 1111. The height of the third frame 1113 is less than the height of the first frame 1111, thus forming a stepped distribution. The lower cavity 111 is made entirely of high-temperature resistant materials, such as ceramic materials, metal alloy materials, graphite and carbon materials, etc., to resist corrosion damage caused by extreme working conditions.

[0042] The lower panel 112 is further divided into a first panel 1121 and a second panel 1122. Specifically, the area of ​​the first panel 1121 is larger than that of the second panel 1122. The first panel 1121 and the second panel 1122 are integrally formed, with the first panel 1121 positioned above the second panel 1122. The first panel 1121 mates with the second frame 1112, and the second panel 1122 mates with the third frame 1113. The height of the first panel 1121 can be less than the height of the second frame 1112, allowing some powder to be placed inside the second frame 1112. The lower panel 112 is also made of a high-temperature resistant material. Both the lower cavity 111 and the lower panel 112 can be square. The corners of the second frame 1112 and the third frame 1113 are rounded, and the edges of the first panel 1121 and the second panel 1122 are also rounded. This design can, to some extent, avoid stress concentration and safety hazards caused by sharp corners.

[0043] like Figures 4 to 6 As shown, the upper mold 12 is located above the lower mold 11 and includes an upper cavity 121 and an upper pressure plate 122. The upper cavity 121 is hollow and is fixed to the lower cavity 111 in a stepped manner. The upper pressure plate 122 is located inside the upper cavity 121. Both the upper cavity 121 and the lower cavity 111 are surrounded by powder, and the powder is located between the upper pressure plate 122 and the lower insert plate 112. Specifically, an annular block 1212 protrudes from the lower end of the upper cavity 121. The annular block 1212 is partially fixed to the upper cavity 121, forming a stepped structure. The upper end of the second frame 1112 is in close contact with the lower end of the upper cavity 121, and the lower end of the annular block 1212 is in close contact with the upper end of the first frame 1111. The upper pressure plate 122 has a smooth surface, and multiple interfaces 1221 can be evenly arranged on its upper surface. A handle can be provided in the interface 1221 to facilitate the handling of the upper pressure plate 122. It is placed in the upper cavity 121, and then the handle is removed. The upper pressure plate 122 has a large weight, which facilitates the compaction of powder. In this embodiment, the corners of the upper pressure plate 122 can also be rounded, and the corners of the inner wall of the upper cavity 121 are also rounded. The powder is abutted by the second frame 1112 and the inner wall of the upper cavity 121. The upper pressure plate 122 and the first insert 1121 are respectively located at the upper and lower ends of the powder. By applying force to the upper pressure plate 122 and the upper cavity 121 and then hot pressing, the powder can form a plate and is difficult to squeeze out from the gap between the upper and lower cavities, thereby lifting the upper cavity 121 and deforming the plate. In addition, the height of the third frame 1113 can be greater than the height of the second panel 1122, so that when the powder flows out of the second panel 1122 from the gap between the second frame 1112 and the first panel 1121, it will not push up the second panel 1122 and deform the board.

[0044] A gap may also exist between the upper cavity 121 and the upper pressure plate 122 to facilitate venting during hot pressing and prevent air bubbles from forming inside the plate. The outer wall of the upper cavity 121 is also provided with handles 1213, which are positioned opposite each other. The height of the handles 1213 within the upper cavity 121 is greater than the minimum height of the forklift forks for easy handling. The lower cavity 111 is also provided with a receiving hole 1114, which contains a temperature sensor. The temperature sensor detects the product temperature, providing a reference for subsequent product quality inspection.

[0045] The upper cavity 121 may also include multiple elastic elements 123, which are located at the upper end of the upper cavity 121. Specifically, each elastic element 123 may include a guide post 1231 and a spring 1232. The guide post 1231 is T-shaped. One end of the spring 1232 is fixed to the upper surface of the upper cavity 121, and the other end is sleeved on the guide post 1231 and abuts against the guide post 1231. The upper cavity 121 is also provided with a limiting hole 1211. The guide post 1231 corresponds one-to-one with the limiting hole 1211, and one end of the guide post 1231 is located in the limiting hole 1211. The height of the upper pressure plate 122 may be greater than the difference between the height of the upper cavity 121 and the height of the powder, so that part of the upper pressure plate 122 is exposed in the upper cavity 121, and the height of the elastic element 123 is greater than the height of the part of the upper pressure plate 122 exposed in the upper cavity 121. In this embodiment, four limiting holes 1211 and four elastic elements 123 are provided, located at the four corners of the upper cavity 121, so that the upper cavity 121 can be subjected to uniform force. When the press presses down on the mold, it first presses the guide post 1231, and then the guide post 1231 applies force to the spring 1232, causing the spring 1232 to contract and press tightly against the upper cavity 121, so that the upper cavity 121 and the lower cavity 111 are tightly fixed. Then the press presses down on the upper pressure plate 122 to shape the powder, making it more difficult for the powder to be squeezed out between the upper and lower cavities. Then hot pressing is performed to form a sheet. After hot pressing, the press slowly releases force so that the spring 1232 slowly recovers. Finally, the upper cavity 121 and the upper pressure plate 122 can be easily lifted to complete demolding, reducing the extrusion process of the product in the mold and avoiding damage to the product surface.

[0046] The implementation principle of this embodiment is as follows: by using a stepped structure to tightly abut the upper and lower cavities 111, and by ensuring that the height of the second insert 1122 is less than the height of the first frame 1111, it is difficult for the powder to be squeezed out along the gap between the upper and lower cavities 111 during hot pressing, thus lifting the upper cavity 121. At the same time, it also prevents the powder from being squeezed out along the gap between the third frame 1113 and the second insert 1122, thereby lifting the second insert 1122 and thus avoiding deformation of the board.

[0047] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A self-locking, split-type thermoforming mold for ultra-high molecular weight polymers, characterized in that, include: The lower mold (11) includes a lower cavity (111) and a lower insert (112). The lower cavity (111) is hollow inside, and the lower insert (112) is disposed inside the lower cavity (111). An upper mold (12) is located at the upper end of the lower mold (11). The upper mold (12) includes an upper cavity (121) and an upper pressure plate (122). The upper cavity (121) is hollow inside and is fixed in a stepped fit with the lower cavity (111). The upper pressure plate (122) is located inside the upper cavity (121). Both the upper cavity (121) and the lower cavity (111) are surrounded by powder, and the powder is located between the upper pressure plate (122) and the lower plate (112).

2. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 1, characterized in that, The upper cavity (121) is square and has an annular block (1212) protruding from its lower end. The lower cavity (111) is square and corresponds to the upper cavity (121). The lower cavity (111) includes a first border (1111) and a second border (1112). The second border (1112) is located at the upper end of the first border (1111). The second border (1112) is smaller than the first border (1111). The second border (1112) is in close contact with the upper cavity (121), and the first border (1111) is in close contact with the annular block (1212).

3. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 2, characterized in that, The lower panel (112) is square and includes a first panel (1121) and a second panel (1122). The first panel (1121) is larger than the second panel (1122) and is located at the upper end of the second panel (1122). The lower cavity (111) also includes a third frame (1113) which is located inside the second frame (1112). The height of the third frame (1113) is less than the height of the first frame (1111). The second panel (1122) is located inside the third frame (1113), and the first panel (1121) is located inside the second frame (1112).

4. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 3, characterized in that, The height of the third frame (1113) is greater than the height of the second panel (1122).

5. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 3, characterized in that, The corners of the second frame (1112) and the third frame (1113) are rounded, and the corners of the first panel (1121) and the second panel (1122) are also rounded.

6. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 1, characterized in that, The upper cavity (121) also includes a plurality of elastic elements (123), which are located at the upper end of the upper cavity (121).

7. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 6, characterized in that, Each of the elastic elements (123) includes a guide post (1231) and a spring (1232). The guide post (1231) is T-shaped. One end of the spring (1232) is fixed to the upper cavity (121), and the other end abuts against the guide post (1231). The upper cavity (121) is also provided with a limiting hole (1211). The guide post (1231) corresponds one-to-one with the limiting hole (1211). One end of the guide post (1231) is located in the limiting hole (1211).

8. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 7, characterized in that, The sum of the heights of the upper pressure plate (122) and the powder is greater than the height of the upper cavity (121), and the height of the guide post (1231) protruding from the upper cavity (121) is greater than the height of the upper pressure plate (122) protruding from the upper cavity (121).

9. The self-locking split-type thermoforming mold for ultra-high molecular weight polymers according to claim 1, characterized in that, The upper surface of the upper pressure plate (122) is provided with multiple interfaces (1221), and the upper cavity (121) is provided with handles (1213), which are located on opposite sides of the upper cavity (121).

10. A self-locking, split-type thermoforming mold for ultra-high molecular weight polymers according to claim 1, characterized in that, The lower cavity (111) is also provided with a receiving hole (1114), and the receiving hole (1114) is provided with a temperature sensor.

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