Polymer medium-based forming method
By using a polymer-based forming method that leverages temperature-driven morphological transformation and diaphragm assistance, the problems of high equipment cost, insufficient precision, and difficulty in controlling forming defects in existing thin-walled component forming technologies have been solved, achieving low-cost, high-efficiency, and high-precision forming results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIHANG UNIV
- Filing Date
- 2026-03-18
- Publication Date
- 2026-05-15
AI Technical Summary
Existing thin-walled component forming technologies suffer from problems such as high equipment costs, insufficient forming accuracy, and difficulty in controlling forming defects. In particular, in the forming of composite materials and metal components, they face technical bottlenecks such as limited forming pressure and narrow temperature range. Furthermore, the forming processes of rigid molds and flexible media cannot be efficiently converted, resulting in high mold design risks and costs.
A polymer-based molding method is adopted, which utilizes the glassy, highly elastic, and viscous flow states of polymers at different temperatures. Temperature-driven morphological transformation is used to replace traditional rigid mold forming and flexible forming. Combined with a diaphragm to provide stable tangential friction, the material flow path is optimized and the forming quality is improved.
It enables low-cost, high-precision, and high-efficiency thin-walled component forming, is applicable to a variety of materials, broadens the temperature and pressure adaptability range, reduces mold development costs, improves forming pressure and forming quality, significantly suppresses wrinkling and cracking defects, and expands the application temperature range of flexible media.
Smart Images
Figure CN122034355A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of thin-walled component forming technology, specifically to a forming method for sheet metal / composite / polymer materials based on polymers as the force transmission medium. Background Technology
[0002] The forming technologies for various fiber composites, metals, polymers, and the aforementioned structural and functional thin-walled components can be mainly divided into: ① rigid mold forming processes, such as compression molding and drop molding; ② forming processes using flexible media as the force transmission means, such as viscous media forming, thermal insulation film forming, and liquid filling forming; ③ forming methods integrating automated control technology, including multi-point forming, incremental forming, and 3D printing for metal forming; and emerging processes such as automatic placement and in-situ consolidation for composite forming; ④ other typical fiber composite forming processes, such as winding and pultrusion. Essentially, most of these processes were developed for components with specific geometric characteristics or functional requirements, exhibiting strong application specificity and limitations. From the perspective of process universality and scale of use, rigid mold forming and flexible media forming remain the most representative and universal forming methods, widely applicable to the manufacture of various thin-walled components.
[0003] Meanwhile, the aforementioned forming technologies also generally suffer from problems such as high equipment costs, insufficient forming accuracy, and difficulty in defect control. In particular, they face technical bottlenecks such as limited forming pressure in composite material forming and narrow forming temperature ranges in flexible metal component forming. Rigid mold and flexible medium forming are widely used due to their strong applicability; however, the insufficient forming accuracy of rigid molds and the existence of forming gaps further exacerbate component defects, failing to meet finished product quality requirements. While flexible media solves the forming accuracy and defect problems of rigid molds, the poor thermal stability of flexible media itself imposes significant limitations on operating temperatures. Furthermore, the inefficient conversion between flexible medium and rigid mold materials introduces considerable risks and relatively high costs to the initial forming mold design and process selection.
[0004] Therefore, there is a need in this field to optimize existing thin-walled component forming technologies in order to achieve low-cost, high-precision, and high-efficiency forming. Summary of the Invention
[0005] In view of the above problems, the present invention provides a forming method based on polymer media, which overcomes the shortcomings of existing thin-walled component forming processes. This method is based on the fact that polymers possess three physical states at different temperatures: a glassy state, a highly elastic state, and a viscous flow state. It utilizes temperature to drive these state transitions, thereby replacing traditional rigid mold forming, solid particle forming, and flexible forming methods such as fluid medium forming, rubber medium forming, and viscous medium forming.
[0006] According to one embodiment of the present invention, a molding method based on a polymer medium is provided, comprising the following steps: Step S1: Place a certain amount of polymer medium into the medium chamber at room temperature, then place the sheet to be formed between the medium chamber and the mold, and set diaphragms on the upper and lower sides of the sheet respectively. Step S2: Heat the integral forming mold to reach the target temperature and keep it constant. Select the appropriate polymer medium type and determine the target temperature according to the material properties of the sheet to be formed. Prepare the polymer medium in one of the following forms: glassy state, high elastic state, and viscous flow state, based on the target temperature, and use it as a force transmission medium. Step S3: Close the mold and the medium chamber and apply a pressing force to press the upper and lower diaphragms together. The sheet material is covered by the upper and lower diaphragms. The force transmission device below the polymer medium pushes the polymer medium. Then, the polymer medium acts as a force transmission medium to push the sheet material to form until the sheet material is completely attached to the surface of the mold cavity. Then, increase the thrust provided by the force transmission device to hold the pressure and achieve the solidification or curing of the sheet material. Step S4: After the sheet metal is formed and cooled and solidified, remove the part obtained from the sheet metal forming.
[0007] Optionally, in step S1: the polymer medium is selected from any polymer and modified polymer, and the specific polymer medium type is determined according to the sheet material properties and forming process window.
[0008] Optionally, in step S2: the material type of the sheet to be formed is thermosetting fiber reinforced composite material, thermoplastic fiber reinforced composite material, polymer material or film, the process temperature of the sheet to be formed is in the glassy temperature range of the polymer medium, the polymer medium is placed at room temperature to obtain a glassy polymer medium, and the glassy medium is used as the force transmission medium.
[0009] Optionally, in step S2: a glassy polymer medium is used as a force transmission medium. According to the required mold shape, the polymer medium blank is pre-made into a mold by particle injection molding or machining. Then, the mold made of the glassy polymer medium is placed in the medium chamber for subsequent forming.
[0010] Optionally, in step S2: the material type of the sheet to be formed is fiber-reinforced composite material, metal material or polymer material, and the process temperature range of the sheet to be formed is within the high elasticity temperature range of the polymer medium; the polymer medium is prepared to be in a high elasticity state, and the high elasticity polymer medium is used as the force transmission medium.
[0011] Optionally, in step S2: the polymer medium is polyetherimide, the polymer medium is prepared in a highly elastic state, and a target temperature in the temperature range of 220 to 330 degrees Celsius is set.
[0012] Optionally, in step S2: the material type of the sheet to be formed is a metal material, a fiber-reinforced composite material, or a structural functional material; the process temperature range of the sheet to be formed is within the viscous flow temperature range of the polymer medium; the polymer medium is prepared as a viscous flow state; and the viscous flow state polymer medium is used as the force transmission medium.
[0013] Optionally, in step S1: before laying the sheet and diaphragm, a high-temperature sealing structure and corresponding vacuum ducts are provided to ensure the forming under vacuum conditions.
[0014] Optionally, in step S1, the diaphragm material provided on the upper and lower sides of the sheet is a polymer elastic film material.
[0015] A polymer-based molding method according to another embodiment of the present invention includes the following steps: Step S1: Add powdered or granular polymer medium to the injection inlet of the injection system, then heat it to the required molding temperature to obtain a viscous polymer medium. Under the action of the drive motor and plunger pump, the molten viscous polymer medium is injected into the cavity of the lower mold. Step S2: Lay the sheet material to be formed on the top of the lower mold, and set diaphragms on the upper and lower sides of the sheet material respectively; Step S3: Close the upper mold and the lower mold, and use the heating rod located in the lower mold to provide heat to the polymer medium in the cavity of the lower mold, so that the polymer medium is kept in a viscous flow state; Step S4: The drive motor and plunger pump once again provide pressure to the cavity. This pressure is transmitted to the sheet metal through the viscous polymer medium, pushing the sheet metal upward to fit the mold surface inside the cavity of the upper mold. Step S5: After the sheet metal is formed, the formed part is cooled at a controllable rate through a cooling pipe. Then, the drive motor and plunger pump are fed in the opposite direction to unload the pressure, move the upper mold upward, and take out the formed part.
[0016] Compared with the prior art, the polymer-based molding method provided by the present invention has at least the following beneficial effects.
[0017] (1) It is applicable to the forming and manufacturing of various plates, sheets, strips, honeycomb structural materials and laminated plate structures. It has good material adaptability and process expandability, and is suitable for the forming needs of high-performance components in various industrial scenarios.
[0018] (2) Polymers in different phases are used as force transmission mediums. The properties of polymers changing with temperature between different phases (glassy state, high elastic state and viscous flow state) can be utilized to achieve high-quality and high-efficiency forming of thin-walled components in a wide temperature range.
[0019] (3) Integrating various existing forming processes, it provides a flexible forming method that is efficient, low-cost, and highly adaptable based on polymer temperature control and morphology regulation. It is a forming process that can be used for various thin-walled components such as composite materials and metal materials.
[0020] (4) It not only has the reconfigurable capability of "one medium, multiple functions", but also significantly optimizes the shortcomings of the existing forming process in terms of equipment cost, forming accuracy, load control and temperature adaptability, and has broad applicability and engineering promotion prospects.
[0021] (5) Wide applicability and high degree of functional integration. It innovatively utilizes the property that polymers exhibit multiple states at different temperatures, such as glassy state, high elastic state and viscous flow state, so that they can respectively act as rigid molds and flexible molds during the molding process. This technology integrates multiple "moldless" molding modes in a single process, which significantly broadens the functional boundaries of molding methods and has extremely wide material and component adaptability.
[0022] (6) Low material cost and reusable medium. The polymer material (such as polyetherimide PEI) used in this invention as the medium has the advantages of low cost, high temperature resistance, and multiple cycles. The polymer in this invention can achieve polymer medium state switching through temperature control, and there is no need to manufacture multiple rigid molds separately, which greatly reduces the overall cost of mold use and replacement.
[0023] (7) Higher forming pressure and forming quality can be achieved. While maintaining the flexible force transmission characteristics, the process of the present invention can provide a forming pressure and uniformity that are significantly higher than those of traditional processes during the forming of composite materials, thereby improving the fiber layup compactness and interfacial bonding performance, and effectively enhancing the mechanical properties of the components.
[0024] (8) Strong high-temperature adaptability, breaking through the temperature range limitations of traditional flexible media. The polymer used in this invention has a wide temperature adaptability range (approximately 20°C to 400°C), which can cover the high-temperature forming conditions (≥350°C) required by common high-performance thermoplastic composite materials (such as PEEK). This polymer medium is also suitable for thermoforming and superplastic forming of metal materials, effectively breaking through the bottleneck of traditional high-pressure moldless forming technology such as liquid filling forming below 300°C.
[0025] (9) Improve forming limit and component thickness uniformity. The present invention includes setting diaphragms on both sides of the sheet metal, which can provide stable tangential friction during forming, optimize material flow path, significantly suppress defects such as wrinkling and cracking, and help improve the forming limit of the material.
[0026] (10) Replaces rigid mold forming, reducing mold development costs. Compared with traditional rigid mold pressing, this invention has the advantages of flexible molds in both high-elasticity and viscous flow states, which can avoid the generation of suspended areas and introduce the synergistic effect of adhesion and friction, significantly improving the forming quality. In addition, when a rigid punch needs to be formed, the polymer can be directly melted and formed in the die, and then cooled to a glassy state to form a rigid structure, effectively reducing mold development and replacement costs.
[0027] (11) The high temperature resistance is superior to that of rubber molding media. The method provided by the present invention uses polymers such as PEI as media, which can maintain a high elastic state for a long time below 330°C, and has better thermal stability and durability, significantly improving the working life and reliability of flexible media.
[0028] (12) The operating temperature range is significantly better than that of traditional viscous media. The polymer material in this invention can maintain stable viscous flow behavior at high temperatures, which significantly expands the temperature adaptability range of viscous media processes. Attached Figure Description
[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly introduced below. The features and advantages of the present invention can be more clearly understood by referring to the accompanying drawings. The accompanying drawings are schematic and should not be construed as limiting the present invention in any way. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0030] Figure 1a A schematic diagram of an example metal sheet suitable for use in a polymer-based forming method according to an embodiment of the present invention.
[0031] Figure 1b This is a schematic diagram of an example fiber-metal laminate applicable to the polymer-medium-based forming method provided according to an embodiment of the present invention.
[0032] Figure 1c This is a schematic diagram of an example polymer sheet material applicable to the polymer-based molding method provided according to an embodiment of the present invention.
[0033] Figure 1d A schematic diagram of an example fiber composite material applicable to a polymer-based molding method provided according to an embodiment of the present invention.
[0034] Figure 2 This is a schematic diagram illustrating the evolution of polymer medium forming technology at various temperatures in a polymer medium-based forming method provided according to an embodiment of the present invention.
[0035] Figure 3aA schematic diagram of a polymer-based molding method according to an embodiment of the present invention, using a glassy polymer medium.
[0036] Figure 3b This is a schematic diagram of a polymer-based molding method according to an embodiment of the present invention, using a highly elastic polymer medium.
[0037] Figure 3c A schematic diagram of a polymer-based molding method according to an embodiment of the present invention is shown, using a viscous polymer medium.
[0038] Figure 4a This is a schematic diagram of a polymer medium forming process using a glassy state polymer medium in a polymer medium-based forming method provided according to an embodiment of the present invention.
[0039] Figure 4b A schematic diagram of a polymer medium forming process using a highly elastic or viscous polymer medium in an embodiment of the present invention.
[0040] Figure 5a A schematic diagram of an active flexible forming process used in a polymer-based forming method provided according to an embodiment of the present invention.
[0041] Figure 5b A schematic diagram of a passive flexible forming process used in a polymer-based forming method according to an embodiment of the present invention.
[0042] Figure label: 1-Mold, 2-Sheet material, 3-Media chamber, 4-Diaphragm, 5-Sealing ring, 6-Glassy polymer medium, 7-Highly elastic polymer medium, 8-Upper mold, 9-Heating rod, 10-Viscous polymer medium, 11-Lower mold, 12-Vacuum device, 13-Cooling pipe, 14-Pressure sensor, 15-Sheet material and diaphragm, 16-Injection inlet, 17-Plunger pump, 18-Drive motor. Detailed Implementation
[0043] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.
[0044] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.
[0045] The following detailed description of a polymer-based molding method according to embodiments of the present invention is provided with reference to the accompanying drawings. This molding method can mold complex functional materials such as flat panel structures, honeycomb structures, and multilayer boards. The present invention proposes a polymer-based molding process for thin-walled materials, particularly addressing the limitations of existing molding technologies for resin-based composite materials and thin-walled metal components. This polymer-based molding process can integrate and replace various existing processes: in the field of composite material molding processes, it covers hot molding and thermal diaphragm molding; in the field of metal material molding processes, it can include rigid mold forming, multi-point forming, progressive forming, rubber forming, rubber bladder hydroforming, viscous medium forming, and fluid filling forming. Its core lies in utilizing the phase transformation of a single polymer with temperature changes to achieve the integration and replacement of the above processes, and it compensates for shortcomings such as the defects of the rigid mold suspension area, insufficient thermal diaphragm pressure, and limitations of high-temperature and high-pressure fluid media.
[0046] The core technical solution of the polymer-medium-based forming method provided by the embodiments of the present invention is as follows: a specific polymer material replaces the traditional rigid punch, serving as a flexible force-transmitting medium in the sheet metal forming process. During the forming process, different preparation temperatures (e.g., room temperature or heating) are provided to the polymer medium according to different needs, placing it in the desired physical state (glassy state, highly elastic state, or viscous flow state). Subsequently, the polymer medium in the above-mentioned states is used as a force-transmitting medium to transfer forming force to the sheet metal to be formed, thereby achieving component forming. The three states of the polymer medium—glassy state, highly elastic state, and viscous flow state—can correspond to rigid die forming, rubber bladder forming, and viscous medium forming, respectively, thus enabling the use of only one polymer medium material to provide multiple different forming process effects by providing different preparation temperatures. Furthermore, specific diaphragms can be pre-set on both sides of the sheet metal to assist the forming process and improve the sheet metal forming quality.
[0047] The polymer-based molding method provided by the embodiments of the present invention addresses the problems existing in various existing molding processes and proposes a systematic improvement scheme, mainly reflected in the following aspects: Improving molding quality and precision: The diaphragms set on both sides of the sheet metal can provide beneficial frictional force, effectively improving molding quality; when the polymer medium is heated to a highly elastic or viscous flow state, it behaves as a flexible medium, able to adhere to the sheet metal throughout the molding process, avoiding the formation of suspended areas, thereby effectively suppressing wrinkling defects; in the viscous flow state, the polymer can provide a certain degree of viscous adhesion, enhancing the diaphragm's adhesion and further improving the molding quality and dimensional accuracy of the sheet metal. Expanding the temperature and pressure adaptability range and reducing costs: Using typical engineering polymers such as polyetherimide (PEI), polyphenylene sulfide (PPS), and polyether ether ketone (PEEK) as polymer mediums has advantages such as high and low temperature cycling, low cost, and stable performance. Its applicable temperature upper limit can exceed 400°C, and its applicable temperature range far exceeds that of traditional liquid or rubber media (generally below 300°C), significantly expanding the application temperature range of flexible media and solving the limitations of existing processes in high-temperature molding. Furthermore, unlike the limited forming pressure in traditional fiber composite molding processes, the polymer medium used in this invention can effectively transmit a large forming force even in a highly elastic or viscous flow state, thereby achieving reliable forming of complex or high-strength components and improving the applicability of the process and the stability of part quality. This invention also achieves a fusion of multiple process effects: the method not only provides continuous and effective forming force and temperature control during the forming process, but also takes into account wrinkle control, strain uniformity, and precision forming of local features, achieving multiple performance optimizations that are difficult to achieve with traditional single processes. It is particularly suitable for manufacturing fiber composite components with high requirements for controlling forming defects.
[0048] As shown in Figure 1 and Figure 2 As shown, the polymer-based forming method according to an embodiment of the present invention forms a sheet material, comprising the following steps. The sheet material may be a thin-walled component.
[0049] Step S1: Place a certain amount of polymer medium into the medium chamber at room temperature, then place the sheet material to be formed between the medium chamber and the mold, and set diaphragms on the upper and lower sides of the sheet material respectively.
[0050] This embodiment can precisely form sheets of materials such as metals, polymers, resin-based composites, and structural-functional integrated materials related to these materials, such as fiber-reinforced metal laminates, honeycomb sandwich structures, and graphene / carbon fiber hybrid composites. Figures 1a-1d As shown. The polymer-based forming method provided in this embodiment can form sheet materials such as plates, sheets, strips, honeycomb structural materials or laminates.
[0051] In this embodiment, the polymer medium can be selected from one or more engineering polymer materials such as polyetherimide (PEI), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyaryletherketone (PAEK), polypropylene (PP), and polyimide (PI). These engineering polymer materials possess advantages such as high and low temperature cycling capability, low cost, and stable performance. Their applicable temperature limit can exceed 400°C, far exceeding traditional liquid or rubber media (generally below 300°C), significantly expanding the application temperature range of flexible molding media and overcoming the limitations of existing processes in high-temperature molding.
[0052] Optionally, in this step, diaphragms can be provided on the upper and lower sides of the sheet metal. The diaphragm material can be a high-molecular-weight elastic film material such as polyimide. In a thermoforming environment, metal foil such as aluminum foil can be used as the diaphragm material. By providing diaphragms, uniform normal forces can be provided, optimizing the forming effect and preventing resin leakage; they can also provide stable tangential friction during the forming process, constraining the material flow path and significantly suppressing defects such as wrinkling and cracking.
[0053] Optionally, in this step, a high-temperature sealing structure and corresponding vacuum channels can be provided before laying the sheet and diaphragm to ensure the forming under vacuum conditions.
[0054] Step S2: Heat the integral forming mold to reach the target temperature and maintain a constant temperature. Select the appropriate type of polymer and the target temperature according to the material properties of the sheet to be formed. Prepare the polymer medium in one of the following forms: glassy polymer medium, high elastic polymer medium, and viscous flow polymer medium, based on the target temperature, and use it as a force transmission medium.
[0055] Optionally, in this step, depending on the material type of the sheet to be formed, one of the three states of the polymer medium—glassy, elastic, and viscous—can be selected as the force-transfer medium. Specifically, such as... Figure 2 As shown, for thermosetting, thermoplastic fiber-reinforced composite materials, polymer materials, films, etc. as the sheet material to be formed, glassy polymer media can be used; for fiber-reinforced composite materials, metal materials, polymer materials, etc. as the sheet material to be formed, highly elastic polymer media can be used; for metal materials, fiber-reinforced composite materials, structural functional materials, etc. as the sheet material to be formed, viscous flow polymer media can be used.
[0056] Optionally, heating of the polymer medium can be achieved by setting up heating equipment, such as a heating furnace or an environmental chamber. Different preparation temperatures can be set depending on the polymer medium to transform it into the desired state. For example, when using PEI as the polymer medium, in this step, the preparation temperature can be set to room temperature, so that PEI is in a glassy state, used for processing sheet materials of materials such as thermosetting fiber-reinforced composites or thermoplastic fiber-reinforced composites; a preparation temperature of approximately 220 to 330 degrees Celsius can be provided to transform PEI from a glassy state to a highly elastic state, used for processing sheet materials of materials such as fiber-reinforced composites, metals, and polymers; a preparation temperature of approximately 330 degrees Celsius can be provided to transform PEI from a highly elastic state to a viscous flow state, used for processing sheet materials of materials such as metals, fiber-reinforced composites, and structural functional materials. The preparation temperature is the target temperature in step S1.
[0057] Similarly, as with the PEI materials mentioned above, for example, when using polyaryletherketone (PAEK) as the polymer medium, the preparation temperature can be set to room temperature for molding as a glassy polymer medium, 158 degrees Celsius for molding as a highly elastic polymer medium, and 340 degrees Celsius for molding as a viscous flow polymer medium. Likewise, when using polyetheretherketone (PEEK) as the polymer medium, the preparation temperature can be set to room temperature for molding as a glassy polymer medium, 140 degrees Celsius for molding as a highly elastic polymer medium, and so on. The preparation temperature is 340 degrees Celsius, which is used as a viscous polymer medium for molding. For polyphenylene sulfide (PPS) as the polymer medium, the preparation temperature can be set to room temperature, which is used as a glassy polymer medium for molding. The preparation temperature can be set to 100 degrees Celsius, which is used as a highly elastic polymer medium for molding. The preparation temperature can be set to 280 degrees Celsius, which is used as a viscous polymer medium for molding. For polypropylene (PP) as the polymer medium, the preparation temperature can be set to 0 degrees Celsius, which is used as a highly elastic polymer medium for molding. The preparation temperature can be set to 160 degrees Celsius, which is used as a viscous polymer medium for molding.
[0058] Optionally, in this step, when using a glassy polymer medium as the molding medium, the following process may also be included: first, the polymer medium is injection molded or machined to obtain the desired mold surface, and then the glassy polymer medium is placed into the medium chamber. In this state, the glassy polymer medium is similar to hard glass.
[0059] In this embodiment, the polymer medium exhibits a change in mechanical behavior with temperature, simulating the functions of various traditional forming methods under different conditions. This makes it suitable for flexible precision forming of metals, polymers, resin-based composites, and other materials integrating structure and function. The mechanical states of the polymer medium can be categorized into three types as temperature increases: glassy state (low temperature), characterized by high polymer rigidity, high elastic modulus, and minimal deformation (<1%), exhibiting hardness and brittleness; high-elasticity state (rubber state), with reduced elastic modulus and significant reversible deformation (100%~1000%), possessing good flexibility and elasticity, suitable for non-destructive bonding; and viscous flow state (high temperature), where the elastic modulus further decreases to a minimum, resulting in irreversible flow and exhibiting viscous plastic behavior similar to liquids, suitable for achieving complete coverage forming of complex curved surfaces or detailed features.
[0060] Step S3: The mold and the medium chamber close together, and a blank holder force F3 is applied to press the sheet metal and the diaphragm together. The force transmission device below the medium provides an upward force F1, and then the medium transmits force and pushes the sheet metal to form until the sheet metal is completely attached to the surface of the mold cavity. The upward force F1 provided by the force transmission device can then be increased to maintain pressure and achieve solidification or curing of the sheet metal.
[0061] Optionally, before laying the plate material, a sealing ring can be placed in the groove on the upper surface of the media chamber for sealing contact with the plate material, providing a better sealing effect.
[0062] During this process, the medium chamber also acts as a blank holder, converting the received upward force into a blank holder force supplied to the die. This provides sufficient blank holder force, preventing wrinkling of the sheet metal.
[0063] Step S4: After the sheet metal is formed and cooled and solidified, the polymer medium and the medium chamber are moved downwards simultaneously to remove the part formed from the sheet metal.
[0064] The polymer medium, once prepared, can be recycled for subsequent molding processes.
[0065] To better understand the present invention, embodiments of the polymer-based molding method provided according to the present invention are described in detail below.
[0066] Example 1 like Figure 3a As shown, Example 1 illustrates a polymer-based forming method according to an embodiment of the present invention, which uses a glassy polymer medium to form a sheet material. The polymer medium exhibits high rigidity in its glassy (low-temperature) state.
[0067] Step S1: First, a certain amount of polymer medium is formed into the required mold surface to obtain a glassy polymer medium 6, and then the glassy polymer medium 6 is placed into the medium chamber 3. In this Example 1, the glassy polymer medium 6 uses PEEK resin, which is stable at room temperature to low and medium temperatures and has excellent mechanical properties.
[0068] Step S2: Place the sealing ring 5 in the groove on the upper surface of the medium chamber 3, and then lay the plate 2 to be formed on the top of the medium chamber 3. When laying the plate 2, place the diaphragm 4 on the upper and lower sides of the plate 2 respectively.
[0069] In Example 1, the sheet material 2 of the thermosetting fiber composite material is formed in the glassy state of the polymer medium, and the forming temperature of the thermosetting fiber composite material is usually below 200°C.
[0070] Step S3: The force transmission module below the medium chamber provides an upward force F1 to the medium, pushing the glassy polymer medium 6 in the medium chamber 3 upward. At this time, the glassy polymer medium 6, acting as the force transmission medium, converts the upward force F1 provided by the force transmission module into a forming force on the sheet 2, pushing the sheet 2 to conform to the surface of the mold 1. Finally, the sheet 2 and the inner surface of the cavity of the mold 1 are completely bonded. During this process, the medium chamber 3 can also act as a pressure ring, providing a pressure force to the sheet 2.
[0071] Step S4: After completing the above forming operation, the medium and medium chamber 3 are moved downwards simultaneously to obtain a part formed from sheet 2. In this embodiment 1, sheet 2 is a fiber composite material, and the formed part needs to be cooled and solidified to a specified temperature before being removed.
[0072] Example 2 like Figure 3b As shown, Example 2 illustrates a polymer-based molding method according to an embodiment of the present invention, which uses a highly elastic polymer medium to mold a sheet material. When the polymer medium is in a highly elastic (rubber-like) state, it exhibits significant reversible deformation (up to 100%~1000%), possessing good flexibility and elasticity, making it suitable for non-destructive bonding. The specific process is as follows.
[0073] Step S1: Place a certain amount of polymer medium into the medium chamber 3 at room temperature, place a sealing ring 5 in the groove on the upper surface of the medium chamber 3, and then lay the plate material 2 to be formed on the top of the medium chamber 3. When laying the plate material 2, place diaphragms 4 on the upper and lower sides of the plate material 2 respectively.
[0074] Step S2: Heat the polymer medium to a highly elastic state to obtain a highly elastic polymer medium 7. Utilize the elastic properties of the highly elastic polymer medium to promote the forming and curing of the sheet material.
[0075] In Example 2, the sheet 2 of partially thermoset fiber composite material and thermoplastic fiber composite material is used to form the polymer medium in a highly elastic state, and the forming temperature of partially thermoset fiber composite material and thermoplastic fiber composite material is between 200-350°C.
[0076] Step S3: The force transmission module below the medium chamber provides an upward force F1 to the medium, pushing the highly elastic polymer medium 7 in the medium chamber 3 upward. At this time, the highly elastic polymer medium 7, acting as the force transmission medium, converts the upward force F1 provided by the force transmission module into a forming force on the sheet 2, pushing the sheet 2 to conform to the surface of the mold 1. Finally, the sheet 2 and the inner surface of the cavity of the mold 1 are completely bonded. During this process, the medium chamber 3 can also act as a pressure ring, providing a pressure force to the sheet 2.
[0077] Step S4: After completing the above forming operation, the medium and medium chamber 3 are moved downwards simultaneously to obtain a part formed from sheet 2. In this embodiment 2, sheet 2 is a fiber composite material, and the formed part needs to be cooled and solidified to a specified temperature before being removed.
[0078] According to another embodiment of the present invention, a polymer-based forming method is provided, which uses a viscous polymer medium for sheet forming, and includes the following steps.
[0079] Step S1: Add powdered or granular polymer medium to the injection molding system, then heat to the required molding temperature to obtain a viscous polymer medium. Inject the molten viscous polymer medium into the cavity of the lower mold. The flexibility and viscosity of the viscous polymer medium are used to push the sheet metal into shape.
[0080] Step S2: Lay the sheet material to be formed on the top of the lower mold, and set diaphragms on the upper and lower sides of the sheet material respectively.
[0081] Step S3: Close the upper mold and the lower mold. The heating rod located in the lower mold provides heat to the polymer medium in the cavity of the lower mold, so that the polymer medium is kept in a viscous flow state. Step S4: Apply pressure to the cavity, which is transmitted to the sheet metal through the viscous polymer medium, pushing the sheet metal upward to conform to the mold surface inside the cavity of the upper mold; Step S5: After the sheet metal is formed, the part obtained by the sheet metal forming is cooled at a controllable rate, and then the pressure is unloaded and the upper mold is moved upward to remove the formed part.
[0082] The pressure and unloading pressure provided above can be achieved through the operation of the drive motor 18 and the plunger pump 17 of the injection molding system.
[0083] Example 3 like Figure 3cAs shown, Example 3 illustrates a polymer-based forming method according to an embodiment of the present invention, which uses a viscous polymer medium to form a sheet material. When the polymer medium is in a viscous (high-temperature) state, it exhibits irreversible flow and liquid-like viscous plastic behavior, making it suitable for achieving complete coverage forming of complex curved surfaces or detailed features. The specific process is as follows.
[0084] Step S1: Provide a mold including a matching lower mold 11 and an upper mold 8, and supply molten polymer medium to the cavity of the lower mold 11 through an injection molding system.
[0085] In this step, the injection process of the injection system is as follows: a polymer medium is poured into the injection inlet 16, the polymer medium is heated to a viscous flow state in the injection system, and then, under the action of the drive motor 18, the plunger pump 17 moves to the left to push the polymer medium into the cavity of the lower mold 11.
[0086] Step S2: Lay the sheet material 15 to be formed on the top of the lower mold 11. When laying the sheet material 15, set diaphragms on the upper and lower sides of the sheet material 15 respectively.
[0087] Step S3: An upper mold 8 is placed above the sheet material 15, with the cavity of the upper mold 8 facing the sheet material. Specifically, in this embodiment 3, the sheet material 15 is a fiber composite material. After evacuating the sheet material 15 using a vacuum device 12, the upper mold 8 and the lower mold 11 are closed. In other cases, when the sheet material is a metal material, evacuation of the sheet material is not required.
[0088] Step S4: Use the heating rod 9 located at the lower mold 11 to provide heat to the polymer medium in the cavity of the lower mold 11, so that the polymer medium is kept in a viscous flow state, and a viscous flow polymer medium 10 is obtained. Then, pressure is applied to the cavity of the lower mold 11, and the pressure is converted into forming force through the viscous flow polymer medium 10 in the cavity of the lower mold 11, pushing the sheet 15 to fit the surface in the cavity of the upper mold 8.
[0089] In this process, the plunger pump 17 of the injection molding system applies pressure to the cavity of the lower mold 11. The pressure applied by the plunger pump 17 is set to 15 MPa and the molding temperature is above 350°C. Under these conditions, all fiber composite materials and metals can be molded.
[0090] In this embodiment 3, the sheet material to be formed is a fiber composite material, and the pressure needs to be maintained until the formed sheet material is cured. The pressure is detected by the pressure sensor 14 installed in the cavity of the lower mold 11.
[0091] Step S5: After the sheet metal is formed, the part obtained by the sheet metal forming is cooled, then the pressure is unloaded and the upper mold 8 is moved upwards, and then the formed part can be taken out. In this embodiment 3, the sheet metal 2 is a fiber composite material, and the formed part needs to be cooled and solidified to a specified temperature before it can be taken out. During the cooling of the part, the cooling process is controlled by the cooling pipe 13 provided in the upper mold 8 to cool the part to the required state. After the formed part has cooled and solidified, the plunger pump 17 of the injection molding system retracts to the right.
[0092] The polymer-medium-based forming method provided in the aforementioned embodiments is an active forming method, that is, using a polymer medium to replace the traditional punch and form a mating die. In another embodiment, the polymer medium can be placed on the other side of the sheet metal, while a traditional punch is placed in the original position of the polymer medium. As the punch and die close, the sheet metal deforms, and the polymer medium provides reverse pressure, causing the sheet metal to adhere to the surface of the punch and generate beneficial friction, thereby improving the forming effect.
[0093] All of the above-mentioned optional technical solutions can be combined in any way to form optional embodiments of the present invention, and will not be described in detail here.
[0094] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.
[0095] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.
Claims
1. A molding method based on polymer media, characterized in that, Includes the following steps: Step S1: Place a certain amount of polymer medium into the medium chamber at room temperature, then place the sheet to be formed between the medium chamber and the mold, and set diaphragms on the upper and lower sides of the sheet respectively. Step S2: Heat the integral forming mold to reach the target temperature and keep it constant. Select the appropriate polymer medium type and determine the target temperature according to the material properties of the sheet to be formed. Prepare the polymer medium in one of the following forms: glassy state, high elastic state, and viscous flow state, based on the target temperature, and use it as a force transmission medium. Step S3: Close the mold and the medium chamber and apply a pressing force to press the upper and lower diaphragms together. The sheet material is covered by the upper and lower diaphragms. The force transmission device below the polymer medium pushes the polymer medium. Then, the polymer medium acts as a force transmission medium to push the sheet material to form until the sheet material is completely attached to the surface of the mold cavity. Then, increase the thrust provided by the force transmission device to hold the pressure and achieve the solidification or curing of the sheet material. Step S4: After the sheet metal is formed and cooled and solidified, remove the part obtained from the sheet metal forming.
2. The forming method based on polymer media according to claim 1, characterized in that, In step S1: the polymer medium is selected from any polymer and modified polymers. The specific polymer medium type is determined according to the sheet material properties and the forming process window.
3. The molding method based on polymer media according to claim 1, characterized in that, In step S2: the material type of the sheet to be formed is thermosetting fiber reinforced composite material, thermoplastic fiber reinforced composite material, polymer material or film. The process temperature of the sheet to be formed is in the glassy temperature range of the polymer medium. The polymer medium is placed at room temperature to obtain a glassy polymer medium. The glassy medium is used as the force transmission medium.
4. The forming method based on polymer media according to claim 3, characterized in that, In step S2: a glassy polymer medium is used as a force transmission medium. According to the required mold shape, the polymer medium blank is pre-made into a mold by particle injection molding or machining. Then, the mold made of the glassy polymer medium is placed in the medium chamber for subsequent forming.
5. The forming method based on polymer media according to claim 1, characterized in that, In step S2: the material type of the sheet to be formed is fiber-reinforced composite material, metal material or polymer material, and the process temperature range of the sheet to be formed is in the high elasticity temperature range of the polymer medium; the polymer medium is prepared as a high elasticity state and the high elasticity state polymer medium is used as the force transmission medium.
6. The forming method based on a polymer medium according to claim 5, characterized in that, In step S2: Polyetherimide is used as the polymer medium, the polymer medium is prepared in a highly elastic state, and a target temperature range of 220 to 330 degrees Celsius is set.
7. The forming method based on polymer media according to claim 1, characterized in that, In step S2: the material type of the sheet to be formed is a metal material, fiber-reinforced composite material or structural functional material. The process temperature range of the sheet to be formed is within the viscous flow temperature range of the polymer medium. The polymer medium is prepared as a viscous flow state and used as a force transmission medium.
8. The forming method based on polymer media according to claim 1, characterized in that, In step S1: Before laying the sheet metal and diaphragm, a high-temperature sealing structure and corresponding vacuum ducts are provided to ensure the molding process under vacuum.
9. The forming method based on a polymer medium according to claim 1, characterized in that, In step S1: The diaphragm material set on the upper and lower sides of the sheet is a polymer elastic film material.
10. A molding method based on a polymer medium, characterized in that, Includes the following steps: Step S1: Add powdered or granular polymer medium to the injection inlet (16) of the injection system, and then heat it to the required molding temperature to obtain a viscous polymer medium (10). Under the action of the drive motor (18) and the plunger pump (17), the molten viscous polymer medium is injected into the cavity of the lower mold (11). Step S2: Lay the sheet material (15) to be formed on the top of the lower mold (11), and set diaphragms on the upper and lower sides of the sheet material (15); Step S3: Close the upper mold (8) and the lower mold (11), and use the heating rod (9) located in the lower mold (11) to provide heat to the polymer medium in the cavity of the lower mold (11) so that the polymer medium is kept in a viscous flow state; In step S4, the drive motor (18) and plunger pump (17) again provide pressure to the cavity, which is transmitted to the sheet metal (15) through the viscous polymer medium (10), pushing the sheet metal (15) upward to fit the surface of the cavity of the upper mold (8); Step S5: After the sheet metal is formed, the formed part is cooled at a controllable rate through the cooling pipe (13). Then, the drive motor (18) and plunger pump (17) are fed in opposite directions to unload the pressure, move the upper mold (8) upward, and take out the formed part.