A molding device and a molding method for isostatic pressing of large-sized ceramic green bodies

Abstract

The application provides a forming device and a forming method for isostatic pressing of large-size ceramic green bodies, which comprises a mold body, a stirring frame and a film sleeve. The forming device and the forming method for isostatic pressing of large-size ceramic green bodies are suitable for isostatic pressing of large-size ceramic green bodies, and can guarantee the pressing density and the pressing efficiency of the forming of large-size ceramic products.

Description

Technical Field

[0001] This invention belongs to the technical field of isostatic pressing equipment, and particularly relates to a molding device and molding method for isostatic pressing of large-size ceramic blanks. Background Technology

[0002] Existing ceramic forming technologies mainly include dry pressing, slip casting, extrusion molding, and isostatic pressing. However, none of these are suitable for forming large-sized ceramic blanks. For example, slip-cast products have low density; extruded products have small volume; and isostatic pressing requires dry pressing to create a specific shape, which necessitates high-tonnage presses and is prone to defects such as cracking and delamination. Therefore, there is an urgent need for a method that can directly use powder for isostatic pressing to ensure the density and efficiency of forming large-sized ceramic products. Summary of the Invention

[0003] To address the aforementioned problems, the present invention aims to provide a molding apparatus and method for isostatic pressing of large-size ceramic blanks, which can ensure the pressing density and pressing efficiency of large-size ceramic products.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] In a first aspect, the present invention provides a forming apparatus for isostatic pressing of large-size ceramic blanks, comprising:

[0006] The mold body includes a cavity for holding ceramic powder to be formed by isostatic pressing. The entire wall of the mold body is provided with uniformly distributed first perforations for injecting or draining medium oil or medium water that generates pressure during isostatic pressing.

[0007] A mixing rack includes at least two vertical support rods, at least one crossbeam, and a crossbar connecting the bottom of the support rods. The external dimensions of the mixing rack are matched with the cavity of the mold body, and the mixing rack can be inserted into the cavity of the mold body.

[0008] A thin film sleeve, which is open at the top and sealed at the bottom, is used to hold the ceramic powder and can be fitted over the outside of the stirring frame.

[0009] Preferably, the crossbeams and crossbars of the stirring rack are provided with second perforations for the ceramic powder to pass through.

[0010] Preferably, the shape of the cavity of the mold body is selected from a cuboid plate, an arc shape, or a cylinder.

[0011] Preferably, the cavity of the mold body is in the shape of a cuboid plate.

[0012] Preferably, the shape of the crossbeams and crossbars of the stirring rack is selected from straight, arc-shaped, or circular.

[0013] Preferably, the crossbeams and crossbars of the stirring rack are straight.

[0014] Preferably, the material of the mold body is selected from at least one of polymer materials, graphite materials, carbon-carbon composite materials and metal materials, and the material of the film sleeve is plastic or other tough materials.

[0015] Secondly, the present invention also provides a forming method for isostatic pressing of large-size ceramic blanks, comprising the following steps:

[0016] Step (1): Design and manufacture the mold body as described above according to the shrinkage ratio required for the ceramic product;

[0017] Step (2): Make the mixing rack as described above;

[0018] Step (3): Cover the stirring rack described in step (2) with the film sleeve as described above from bottom to top, and the upper edge of the film sleeve is slightly higher than the upper edge of the stirring rack;

[0019] Step (4): Insert the stirring rack with the film sleeve into the mold body described in step (1), inject ceramic powder from the top opening of the film sleeve, and move the stirring rack up and down while adding the material until the material is finished, then pull out the stirring rack.

[0020] Step (5): Vacuum the film sleeve containing the ceramic powder and seal the top of the film sleeve with plastic.

[0021] Step (6): The mold body containing ceramic powder is placed into an isostatic press, and the ceramic powder in the mold body is isostatically pressed by injecting medium oil or medium water.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention provides a molding apparatus and molding method for isostatic pressing of large-size ceramic blanks, which is suitable for isostatic pressing of large-size ceramic blanks and can ensure the pressing density and pressing efficiency of large-size ceramic products. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the mold body of the molding device according to Embodiment 1 of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the stirring rack of the molding device according to Embodiment 1 of the present invention;

[0026] Figure 3This is a schematic diagram of the structure of the film sleeve on the stirring rack according to Embodiment 1 of the present invention;

[0027] Figure 4 This is a schematic diagram of the assembly of the mold body, stirring rack, and film sleeve according to Embodiment 1 of the present invention.

[0028] Figure 5 This is a schematic diagram of the upper opening of the film sleeve after loading, according to Embodiment 1 of the present invention;

[0029] Figure 6 This is a schematic diagram of the mold body of the molding device according to Embodiment 2 of the present invention;

[0030] Figure 7 This is a schematic diagram of the structure of the stirring frame of the molding device according to Embodiment 2 of the present invention;

[0031] Figure 8 This is a schematic diagram of the mold body of the molding device according to Embodiment 3 of the present invention;

[0032] Figure 9 This is a schematic diagram of the structure of the stirring rack of the molding device according to Embodiment 3 of the present invention. Detailed Implementation

[0033] The present invention will be further illustrated by the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention.

[0034] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0035] Example 1

[0036] This embodiment provides a molding apparatus for isostatic pressing of large-size ceramic blanks, including a mold body, a stirring rack, and a film sleeve.

[0037] like Figure 1 As shown, the mold body 1 includes a rectangular plate-shaped cavity 11, which is used to hold ceramic powder for isostatic pressing. The mold body 1 has uniformly distributed first perforations 12 on its entire wall, which are used to inject or drain medium oil or medium water that generates pressure during isostatic pressing.

[0038] like Figure 2 As shown, the stirring rack 2 includes at least two vertical support rods 21, at least one crossbeam 22, and a crossbar 23 connecting the bottom of the support rods 21. In this embodiment, the crossbeam 22 and crossbar 23 of the stirring rack 2 are straight. The external dimensions of the stirring rack 2 match the cavity 11 of the mold body 1, and the stirring rack 2 can be inserted into the cavity 11 of the mold body 1. The crossbeam 22 and crossbar 23 of the stirring rack 2 are provided with second through holes 24 for ceramic powder to pass through.

[0039] like Figure 3 As shown, the film sleeve 3 has an open top and a sealed bottom, is used to hold ceramic powder, and can be fitted over the outside of the stirring rack 2.

[0040] In one embodiment of the present invention, the material of the mold body is selected from at least one of polymer materials, graphite materials, carbon-carbon composite materials and metal materials, and the material of the film sleeve is plastic or other tough materials.

[0041] In one embodiment of the present invention, a forming method for isostatic pressing of large-size ceramic blanks is also provided, comprising the following steps:

[0042] Step (1): Design and manufacture the mold body 1 as described above according to the shrinkage ratio required for the ceramic product;

[0043] Step (2), make the mixing rack 2 as described above;

[0044] Step (3): The film sleeve 3 as described above is placed over the stirring rack 2 obtained in step (2) from bottom to top, and the upper edge of the film sleeve 3 is slightly higher than the upper edge of the stirring rack 2;

[0045] Step (4): Insert the entire stirring rack 2, fitted with the film sleeve 3, into the mold body 1 obtained in step (1), as follows: Figure 4 As shown, ceramic powder is injected from the top of the film sleeve 3. While adding the material, the stirring rack 2 is pulled up and down. Under the action of gravity and the pulling of the stirring rack 2, some of the ceramic powder passes through the second perforation 24 of the stirring rack 2. The ceramic powder is evenly spread inside the cavity 11 of the mold body 1 until the material is completely added, and then the stirring rack 2 is pulled out.

[0046] Step (5): Vacuum the film sleeve 3 containing the ceramic powder and seal the top of the film sleeve 3 with plastic, such as... Figure 5 As shown;

[0047] Step (6): The mold body containing ceramic powder is placed into an isostatic press, and the ceramic powder in the mold body is isostatically pressed by injecting medium oil or medium water.

[0048] In a preferred embodiment, during the molding process in step (5), the mold body 1 is laid flat to avoid the situation where the powder in the upper part of the cavity 11 is less than the powder in the lower part due to gravity.

[0049] Example 2

[0050] Unlike Example 1, the molding apparatus for isostatic pressing of large-size ceramic blanks in Example 2 employs, as shown in Example 2... Figure 6 The arc-shaped mold body shown and as Figure 7 The crossbeams and crossbars shown are arc-shaped mixing racks.

[0051] Example 3

[0052] Unlike Example 1, the molding apparatus for isostatic pressing of large-size ceramic blanks in Example 3 employs, as shown in Example 3... Figure 8 The cylindrical mold body shown and as Figure 9 The beams and crossbars shown are circular mixing racks.

[0053] Table 1 compares the densities of products of different sizes and with different molding processes.

[0054] Table 1 100×100mm <![CDATA[2.6g / cm 3 ]]> <![CDATA[4.2g / cm 3 ]]> 100×200mm <![CDATA[2.1g / cm 3 ]]> <![CDATA[4.2g / cm 3 ]]> 100×300mm <![CDATA[1.8g / cm 3 ]]> <![CDATA[4.2g / cm 3 ]]> 200×200mm <![CDATA[1.6g / cm 3 ]]> <![CDATA[4.2g / cm 3 ]]> 300×300mm <![CDATA[1.3g / cm 3 ]]> <![CDATA[4.2g / cm 3 ]]>

[0055] Finally, it is necessary to state that the above embodiments are only used to further illustrate the technical solution of the present invention in detail, and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A forming apparatus for isostatic pressing of large-size ceramic blanks, characterized in that, include: The mold body includes a cavity for holding ceramic powder to be formed by isostatic pressing. The entire wall of the mold body is provided with uniformly distributed first perforations for injecting or draining medium oil or medium water that generates pressure during isostatic pressing. The stirring rack includes at least two vertical support rods, at least one crossbeam, and a crossbar connecting the bottom of the support rods. The external dimensions of the stirring rack are matched with the cavity of the mold body, and the stirring rack can be inserted into the cavity of the mold body. The crossbeam and crossbar of the stirring rack are provided with second perforations for the ceramic powder to pass through. A thin film sleeve, which is open at the top and sealed at the bottom, is used to hold the ceramic powder and can be fitted over the outside of the stirring frame.

2. The forming apparatus for isostatic pressing of large-size ceramic blanks according to claim 1, characterized in that, The shape of the cavity of the mold body is selected from cuboid plate, arc shape or cylinder.

3. The forming apparatus for isostatic pressing of large-size ceramic blanks according to claim 2, characterized in that, The cavity of the mold body is shaped like a rectangular plate.

4. The forming apparatus for isostatic pressing of large-size ceramic blanks according to claim 2, characterized in that, The shape of the crossbeams and crossbars of the mixing rack is selected from straight lines, arcs, or circles.

5. A forming apparatus for isostatic pressing of large-size ceramic blanks according to claim 4, characterized in that, The crossbeams and crossbars of the mixing rack are straight.

6. A forming apparatus for isostatic pressing of large-size ceramic blanks according to any one of claims 1-5, characterized in that, The material of the mold body is selected from at least one of polymer materials, graphite materials, carbon-carbon composite materials and metal materials, and the material of the film sleeve is plastic or other tough materials.

7. A forming method for isostatic pressing of large-size ceramic blanks, characterized in that, Includes the following steps: Step (1): Design and manufacture the mold body as described in claim 1 according to the shrinkage ratio required for the ceramic product; Step (2): Fabricate the stirring rack as described in claim 1; Step (3): Cover the stirring rack described in step (2) with the film sleeve as described in claim 1 from bottom to top, and the upper edge of the film sleeve is slightly higher than the upper edge of the stirring rack; Step (4): Insert the stirring rack with the film sleeve into the mold body described in step (1), inject ceramic powder from the top opening of the film sleeve, and move the stirring rack up and down while adding the material until the material is finished, then pull out the stirring rack. Step (5): Vacuum the film sleeve containing the ceramic powder and seal the top of the film sleeve with plastic. Step (6): Place the mold body containing ceramic powder into an isostatic press and press the ceramic powder in the mold body by injecting medium oil or medium water.

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