Modular transparent acrylic cold isostatic pressing mold

Abstract

The utility model discloses a modular transparent acrylic cold isostatic pressing mould, including a pair of by the acrylic panel splicing of the panel module of the through -hole, by the frame of U -shaped frame module splicing is formed the frame, set up in the high pressure -resistant PE plastic bag of forming cavity, and the internal support frame of accommodating in the bag and by support frame unit splicing is formed, the utility model discloses a modular connection system that panel fixed block, support frame connecting piece and U -shaped frame connecting piece constitute, realizes the quick flexible extension of mould length, width, height, the utility model discloses the full transparent structure makes the loading and exhaust process visible, effectively promotes the quality of blank body, and the internal support structure adopts nylon screw fastening, avoids the pollution of metal scrap to high -purity ceramic powder, and the universal property of mould is greatly improved to modular design, and the manufacturing and use cost are reduced. This mould structure is stable, can bear above 200MPa high pressure, is especially suitable for the cold isostatic pressing forming of high -performance ceramics.

Description

Technical Field

[0001] This utility model relates to the field of ceramic powder molding technology, and in particular to a modular transparent acrylic cold isostatic pressing mold. Background Technology

[0002] There are various methods for forming ceramic products, including slip casting, dry pressing, cold isostatic pressing, hot isostatic pressing, and extrusion. While slip casting can produce complex shapes and large-sized blanks, it generally suffers from the following problems: First, the forming process relies on the liquid absorption of a porous mold, resulting in long demolding and drying cycles and low efficiency. Second, air bubbles are easily introduced again during the preparation-transfer-injection-degassing chain of the slurry, leading to increased porosity and uneven shrinkage in the blank, affecting subsequent sintering defect control. Third, the adsorption / precipitation of the porous mold causes compositional drift and dimensional inconsistencies, posing challenges to quality stability, and there is still room for improvement in mold balance. Furthermore, 3D printing ceramics faces limitations such as slow printing speed, high equipment and material costs, low solid content in the ceramic paste leading to low density of the printed blank, requiring subsequent sintering to improve performance. Unsintered blanks also exhibit low strength, high requirements for powder and binder compatibility, and complex debinding / sintering post-processing.

[0003] To improve the uniformity of ceramic green body density and reduce processing deformation, cold isostatic pressing (COP) technology is widely used for post-densification or direct forming of ceramic green bodies due to its isotropic pressure and more uniform shrinkage. However, traditional COP tooling often uses rigid metal supports and flexible rubber sleeves or fixed cavities, which have practical problems such as poor transparency, lack of intuitiveness in loading and alignment, inconvenience in modularization and dimensional expansion, potential risks of metal shavings contaminating high-purity powder, and high costs and timelines for custom-made molds.

[0004] For direct isostatic pressing of ceramic blanks, patent document CN117445145A proposes an "apparatus and forming method for direct isostatic pressing of ceramic blanks," but in practical use, it still suffers from inconvenience in operation and limited scalability. Therefore, there is an urgent need in the field for a new type of cold isostatic pressing mold that combines visual operation, modular expansion, high cleanliness, and cost-effectiveness to overcome the limitations of existing technologies and meet the process requirements for high-performance ceramic preparation. Summary of the Invention

[0005] In view of the shortcomings of existing cold isostatic pressing molds in terms of transparency, modularity, cleanliness and cost control, the purpose of this utility model is to provide a modular transparent acrylic cold isostatic pressing mold with advantages such as lightweight structure, low cost, strong reusability and easy molding, and is particularly suitable for powder ceramic molding.

[0006] To achieve the above objectives, the technical solution of this utility model is as follows:

[0007] A modular transparent acrylic cold isostatic pressing mold, characterized in that it includes:

[0008] A pair of oppositely arranged panel modules, the panel modules being spliced ​​together from multiple transparent acrylic panels (1), the acrylic panels (1) being uniformly provided with through holes for transmitting fluid pressure;

[0009] A frame is provided around the perimeter of the pair of panel modules to connect and fix the pair of panel modules, thereby forming a three-sided sealed molded cavity; the frame is composed of multiple U-shaped frame modules (4) spliced ​​together.

[0010] A high-pressure resistant PE plastic bag (2) is placed inside the molding cavity to contain ceramic powder;

[0011] An internal support frame, which is detachably assembled from multiple acrylic support frame units (3) and housed inside the high-pressure resistant PE plastic bag (2), is used to support the bag body during filling to prevent wrinkles; and

[0012] Modular connecting component, the component comprising:

[0013] A panel fixing piece (5) for fixing adjacent acrylic panels (1) on opposite sides of the pair of panel modules, and a first metal fastener for locking the panel fixing piece (5); a U-shaped frame connecting piece (7) for fixing adjacent U-shaped frame modules (4) on the outside of the frame frame, and a second metal fastener for locking the U-shaped frame connecting piece (7).

[0014] Support frame connecting piece (6) for fixing adjacent support frame unit (3) in the internal support frame, and nylon screw (8) for locking the support frame connecting piece (6).

[0015] Furthermore, the acrylic panel (1) is a rectangular plate with a through hole diameter of 5mm to 10mm and a thickness of 10mm to 20mm; the four corners of the acrylic panel (1) are provided with threaded holes as the first connection structure for cooperating with the panel fixing piece (5).

[0016] Furthermore, the panel fixing piece (5) is a square aluminum alloy piece with countersunk holes corresponding to the threaded holes at the corners of the acrylic panel (1). It is locked from the outside of the panel by the first metal fastener to fasten two adjacent acrylic panels (1) between the panel fixing piece (5) and the frame.

[0017] Furthermore, the thickness of the high-pressure resistant PE plastic bag (2) is 0.22 mm to 0.30 mm, and it can withstand a cold isostatic pressure of not less than 300 MPa.

[0018] Furthermore, the support frame unit (3) is a long strip of acrylic block with a long strip of through hole extending downwards to form a channel for the powder to flow downwards; the support frame unit (3) has a threaded hole on the side facing the center as a third connection structure for cooperating with the support frame connecting piece (6) and the nylon screw (8).

[0019] Furthermore, the support frame connecting piece (6) is a square acrylic sheet, and the nylon screw (8) passes through the support frame connecting piece (6) and is screwed into the threaded hole on the side of the support frame unit (3), thereby fastening two adjacent support frame units (3) from the inside of the internal support frame.

[0020] Furthermore, the outer side of the U-shaped frame module (4) is provided with a threaded hole as a fourth connection structure; the U-shaped frame connecting piece (7) is a square aluminum alloy piece, which is locked from the outside of the frame frame by the second metal fastener to fix two adjacent U-shaped frame modules (4).

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] 1) The mold is made of high-transparency acrylic material, which makes the entire process of powder loading, venting, sealing and pressing visible. This allows for real-time observation of powder flow and filling status, timely detection and correction of problems such as uneven loading and air trapping, ensuring the uniformity of the blank from the source of the process, and improving molding consistency and product yield.

[0023] 2) Through the standardized design and combination of the panel, support frame, and U-shaped frame, along with dedicated connectors, the mold length, width, and thickness can be quickly adjusted and expanded. The same mold system can adapt to various product specifications, greatly enhancing the equipment's versatility and production scheduling flexibility, making it particularly suitable for the research and development and production of multi-variety, small-batch, and large-size ceramic products.

[0024] 3) Acrylic components and nylon screws are used in the internal support structure that directly contacts the powder to completely avoid metal shavings contamination and ensure the cleanliness of the high-purity ceramic powder during molding. Metal fasteners are used at external load-bearing nodes to effectively guarantee the overall structural strength and reliability of the mold under high-pressure environments.

[0025] 4) The main materials (acrylic, aluminum alloy, nylon) are inexpensive and easy to CNC machine, resulting in short mold manufacturing cycles and low costs. Its high modularity and reusability avoid the frequent customization required for traditional molds, reducing per-production costs and material waste, leading to significant economic benefits.

[0026] 5) Acrylic material has excellent wear resistance, pressure resistance and dimensional stability. The mold can maintain shape accuracy and structural integrity even under long-term high pressure of more than 200MPa. It is not easy to deform or crack, has a long service life, and has a smooth surface and simple structure, making it easy to clean and maintain. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the modular transparent acrylic cold isostatic pressing mold according to an embodiment of this utility model;

[0028] Figure 2 This is a diagram showing the combination of the support frame and the high-pressure resistant PE plastic bag provided in this embodiment of the utility model;

[0029] Figure 3 This is a schematic diagram of the support frame provided in an embodiment of the present utility model;

[0030] Figure 4 This is a front view of the mold assembly provided in this embodiment of the utility model.

[0031] Figure 5 This is a schematic diagram of the bottom of the mold assembly provided in this embodiment of the utility model.

[0032] In the picture: 1. Acrylic panel, 2. High-pressure resistant PE plastic bag, 3. Support frame unit, 4. U-shaped frame module, 5. Panel fixing piece, 6. Support frame connecting piece, 7. U-shaped frame connecting piece, 8. Nylon screw, 9. Metal screw. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but this should not limit the scope of protection of the present invention.

[0034] Please see Figure 1 , Figure 1 This is a schematic diagram of the modular transparent acrylic cold isostatic pressing mold according to an embodiment of the present invention. As shown in the figure, the acrylic square panel has evenly distributed small holes with a diameter of 5mm-10mm for transmitting pressure. The panels are composed of panels of the same size and shape, which speeds up the processing speed and reduces the manufacturing cost. Different widths and heights can be assembled without distinguishing between top, bottom, left and right.

[0035] When using a high-pressure resistant PE plastic bag, cut it to the same width as the acrylic support frame, insert it into the acrylic support frame, seal the bottom with a plastic sealer, and place the acrylic support frame and PE plastic bag in the middle of the mold to contain ceramic powder.

[0036] Acrylic support frame: The support frame adopts a strip-block combination. The vertical and horizontal modules are connected with M8-M10 countersunk screws. Their length, width, height, and screw hole positions are all identical, facilitating processing, saving time and costs. Mass production is possible, facilitating subsequent assembly of larger molds. The support frame has slotted elongated through holes to facilitate the downward flow of ceramic material powder. The support frame is located inside the PE bag to support the bag and prevent wrinkles during filling. Screw holes are located on the inner side of the support frame for connecting modules with increased height, width, and thickness. U-shaped frame: The support frame adopts a strip-block combination. Its length, width, height, and screw hole positions are all identical, facilitating processing, saving time and costs. Mass production is possible, facilitating subsequent assembly of larger molds. The U-shaped frame is made of acrylic material and is used to connect the front and rear acrylic panels, fixing the PE bag's internal structure and providing stable support. The openings of the support frame face outwards for connecting modules with increased height, width, and thickness.

[0037] Panel fixing pieces are made of square aluminum alloy, with uniform size and hole positions, which facilitates processing, saves time and costs, allows for mass production, and facilitates subsequent assembly into larger molds. Panel fixing pieces are used to reinforce and fix adjacent panels behind the panel.

[0038] Nylon screws are made of strong nylon material, are easy to process, and can be mass-produced. Standard nylon screws can also be purchased on the market. The nylon screws used in this patent are of the same specifications. Nylon screws are used to fix the stability of the internal section of the support frame. Nylon screws are only used in this part. Nylon is an organic material and will not cause pollution to the powder added later.

[0039] Metal screws, which are standard screws, are sized to fasten the panel fixing pieces and the U-shaped frame connecting blocks.

[0040] Modular assembly of molds:

[0041] S1: Determine target dimensions and prepare modules

[0042] First, calculate the required length, width, and height of the mold cavity based on the target dimensions of the ceramic blank. Then, count and prepare the corresponding number of acrylic panels (1), U-shaped frame modules (4), support frame modules (3), and various connecting pieces and fasteners. Before assembly, ensure that the surfaces and holes of all modules are clean and free of impurities.

[0043] S2: Assemble the front and rear panels

[0044] Take two acrylic panels (1) and align them. Use panel fixing pieces (5) to tightly adhere to the outside of the seam between the two adjacent panels, aligning the holes on the panel fixing pieces with the holes on the panels. Use metal screws (9) to pass through the panel fixing pieces (5) and screw them into the threaded holes of the acrylic panels (1), and tighten them with a tool to achieve a firm connection between the adjacent panels on the outside. The required number of panels is adjusted according to the size of the blank. In the schematic diagram of this embodiment, nine acrylic panels are installed at the front and nine at the back as a reference. Repeat the above operation to obtain two sets of acrylic panels of the same size, which serve as the base for the front and back panels.

[0045] S3: Construct the U-shaped frame and molding cavity

[0046] Align the required U-shaped frame modules (4), ensuring the screw holes face outwards. Use U-shaped frame connectors (7) to span the seam between adjacent U-shaped frame modules (4) and secure them with metal screws (9) to extend the frame to the required length and height. Then, assemble the front and rear panels with the U-shaped frames (4), connecting and locking them directly to the threaded holes on the edges of the front and rear panels using appropriately sized metal screws (9) through the holes in the U-shaped frames (4), ultimately forming a robust, transparent, sealed molded cavity. All external load-bearing connections here use metal screws to ensure the stability of the overall structure under high pressure.

[0047] Assemble the U-shaped frame – Align the U-shaped frame modules with the screw holes of the U-shaped frame modules facing outwards. Use the U-shaped frame connector to align the screw holes with the holes on the U-shaped frame modules, then use metal screws to fix them in place and tighten them with tools.

[0048] Adjust the height of the U-shaped frame, select the same module for assembly, align the screw holes of the U-shaped frame connecting piece with the holes on the support frame module, then use metal to fix it and tighten it with a tool.

[0049] Combine the assembled acrylic panel with the U-shaped frame, connect the panel and the U-shaped frame with metal screws of appropriate length, and tighten them with tools to form a rectangular cavity.

[0050] Assemble the support frame – the threaded holes of the support frame module face inward, and select the required length and quantity.

[0051] Align the support frame modules, align the screw holes of the support frame connecting pieces with the holes on the support frame modules, and then use nylon screws to fix them in place and tighten them with tools.

[0052] Adjust the height of the support frame, select the same module for assembly, align the screw holes of the support frame connecting piece with the holes on the support frame module, and then use nylon screws to fix it, and tighten it with tools.

[0053] Use a ruler to measure the length and thickness of the assembled support frame.

[0054] Lay the high-pressure resistant PE plastic bag flat on a clean table, cut the bag to a width that matches the size of the support frame, seal the opening with a sealing device, leaving only the filling opening open, and make sure the length of the cut PE bag is 20-30 cm longer than the length of the support frame.

[0055] Place the cut-out high-pressure resistant PE plastic bag over the support frame and slowly move the support frame to the bottom of the high-pressure resistant PE plastic bag.

[0056] Take out the assembled acrylic mold, slowly insert the assembled high-pressure resistant PE plastic bag and support frame into the rectangular opening of the acrylic mold, and slowly send the high-pressure resistant PE plastic bag and support frame into the bottom of the acrylic mold.

[0057] Pour the ceramic raw material into the middle PE bag through the opening at the top of the support frame and PE bag. During this process, slowly pull out the support frame while adding material. Gently shake the mold to observe the flow direction of the ceramic powder during the filling process, so that the powder is evenly filled into the mold until it is full.

[0058] Wipe away any residual powder from the PE bag opening with a clean, lint-free cloth. Heat and seal the bag using a plasticizer. Check the sealed PE bag by pulling on it. If the sealed bag does not tear, it is ready for cold isostatic pressing.

[0059] After the ceramic molding is completed, the high-pressure resistant PE plastic bag is directly removed from the acrylic mold, and the high-pressure resistant PE plastic bag is cut open to remove the pressed sample.

[0060] Remove the finished ceramic product for further processing or repair.

[0061] This utility model achieves flexible adjustment of mold height through modular design, significantly reduces production costs, and improves the adaptability of cold isostatic pressing process. It has obvious advantages in tooling structure and application scenarios: (1) Visualization and process controllability: The visible cavity composed of front and rear acrylic transparent panels and U-shaped frame, combined with the uniformly arranged through holes on the panel for pressure transmission, makes key actions such as loading, leveling, and venting visible, which helps to reduce uneven filling and air trapping hazards; compared with traditional opaque metal cavity or rubber sleeve, it is more intuitive and operable. (2) Modular expansion: The panel fixing piece, support frame fixing piece and U-shaped frame connecting piece correspond to the quick splicing and heightening / widthening / thickening of the panel, internal support and outer frame respectively; the pre-set screw holes on the panel and support frame allow the forming space to be expanded as needed on the same platform. (3) Cleanliness design: For high-purity ceramic powder, acrylic parts and nylon screws are used preferentially for internal load bearing and locking to avoid metal shavings contamination; metal fasteners are only located at external load bearing nodes.

[0062] Applications: This mold is suitable for manufacturing high-performance ceramic powders using the cold isostatic pressing method. It exhibits excellent performance, especially in products requiring high precision and stable shape. It is used for cold isostatic pressing of ceramic powders of different sizes and thicknesses, and is particularly suitable for the production of large-size ceramic plates.

[0063] The cold isostatic pressing mold provided by this utility model solves the problems of high cost, heavy weight, inflexible expansion, complex processing, and poor reusability of traditional metal molds by using acrylic material. Rubber molds suffer from insufficient precision in manufacturing, and long-term use can lead to mold deformation, inflexible expansion, and easy shrinkage. This mold not only possesses high molding accuracy and stability but also effectively improves production efficiency and reduces mold costs. It is suitable for molding high-performance ceramic powders and has significant technical and economic advantages.

Claims

1. A modular transparent acrylic cold isostatic pressing mold, characterized in that, include: A pair of oppositely arranged panel modules, the panel modules being spliced ​​together from multiple transparent acrylic panels (1), the acrylic panels (1) being uniformly provided with through holes for transmitting fluid pressure; A frame is set around the perimeter of a pair of panel modules to connect and fix the pair of panel modules, thereby forming a three-sided sealed molded cavity; the frame is spliced ​​together from multiple U-shaped frame modules (4); A high-pressure resistant PE plastic bag (2) is placed inside the molding cavity to contain ceramic powder; The internal support frame is composed of multiple acrylic support frame units (3) that are detachably spliced ​​together and housed inside the high-pressure resistant PE plastic bag (2) to support the bag body during filling and prevent it from wrinkling. as well as Modular connecting component, the component comprising: A panel fixing piece (5) for fixing adjacent acrylic panels (1) on opposite sides of the pair of panel modules, and a first metal fastener for locking the panel fixing piece (5); a U-shaped frame connecting piece (7) for fixing adjacent U-shaped frame modules (4) on the outside of the frame frame, and a second metal fastener for locking the U-shaped frame connecting piece (7). Support frame connecting piece (6) for fixing adjacent support frame unit (3) in the internal support frame, and nylon screw (8) for locking the support frame connecting piece (6).

2. The modular transparent acrylic cold isostatic pressing mold according to claim 1, characterized in that, The acrylic panel (1) is a rectangular plate with through holes of 5mm to 10mm in diameter and 10mm to 20mm in thickness; the four corners of the acrylic panel (1) are provided with threaded holes as the first connection structure for cooperating with the panel fixing piece (5).

3. The modular transparent acrylic cold isostatic pressing mold according to claim 2, characterized in that, The panel fixing piece (5) is a square aluminum alloy piece with countersunk holes corresponding to the threaded holes at the corners of the acrylic panel (1). It is locked from the outside of the panel by the first metal fastener to fasten two adjacent acrylic panels (1) between the panel fixing piece (5) and the frame.

4. The modular transparent acrylic cold isostatic pressing mold according to claim 1, characterized in that, The thickness of the high-pressure resistant PE plastic bag (2) is 0.22 mm to 0.30 mm, and it can withstand a cold isostatic pressure of not less than 300 MPa.

5. The modular transparent acrylic cold isostatic pressing mold according to claim 1, characterized in that, The support frame unit (3) is a long strip of acrylic block with a long strip of through hole extending downwards to form a channel for the powder to flow downwards; the support frame unit (3) has a threaded hole on the side facing the center as a third connection structure for cooperating with the support frame connecting piece (6) and the nylon screw (8).

6. The modular transparent acrylic cold isostatic pressing mold according to claim 1, characterized in that, The support frame connecting piece (6) is a square acrylic piece. The nylon screw (8) passes through the support frame connecting piece (6) and is screwed into the threaded hole on the side of the support frame unit (3), thereby fastening two adjacent support frame units (3) from the inside of the internal support frame.

7. The modular transparent acrylic cold isostatic pressing mold according to claim 1, characterized in that, The outer side of the U-shaped frame module (4) is provided with a threaded hole as a fourth connection structure; the U-shaped frame connecting piece (7) is a square aluminum alloy piece, which is locked from the outside of the frame frame by the second metal fastener to fix two adjacent U-shaped frame modules (4).

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