An immersion grouting method

Abstract

This invention discloses an immersion grouting method in which grout is injected into a plaster mold through a grouting pipe. The grouting pipe extends to the bottom of the plaster mold and is kept below the grout surface. This method minimizes the risk of gas being drawn into the grout, effectively solving the problem of air bubbles on the surface of the blank. The number of air bubbles on the surface of the resulting blank is significantly reduced, and the product quality is improved.

Description

Technical Field

[0001] This invention relates to the field of grouting technology, and more specifically to an immersion grouting method. Background Technology

[0002] In ceramic production, slip casting is a commonly used method. Based on the physical property of porous plaster molds absorbing moisture, ceramic powder is mixed into a fluid slurry and then poured into a porous mold (mainly a plaster mold). As water is absorbed by the mold (plaster), a uniform slurry layer of a certain thickness is formed. During dehydration and drying, a green body with a certain strength is simultaneously formed. This method is called slip casting. This method is often used to manufacture complex-shaped daily-use ceramics, architectural ceramics, and artistic ceramics. However, the surface of the green body obtained by slip casting using existing techniques has a considerable number of air bubbles. See [link to previous section]. Figure 1 This results in pores on the surface caused by air bubbles, which reduces the fineness of the product and seriously affects its quality.

[0003] Therefore, how to optimize the production process, significantly reduce the low bubble rate on the ceramic surface, and improve the product precision are technical problems that need to be solved by those skilled in the art. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the existing technology, the purpose of the present invention is to provide an immersion grouting method to solve the problem that a certain number of air bubbles exist on the surface of the blank after grouting molding in the existing technology, which seriously affects the appearance of the product.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An immersion grouting method is disclosed, wherein grout is injected into a plaster mold through a grouting pipe; wherein the opening of the grouting pipe extends to the bottom of the plaster mold, the opening of the grouting pipe is opened to perform grouting, and the grouting is carried out until the grouting is completed, and then the grouting pipe is removed from the plaster mold; during the grouting process, the opening of the grouting pipe is submerged below the surface of the grout liquid in the plaster mold until the grouting is completed.

[0007] This invention, after studying existing grouting methods, discovered that the resulting green bodies have a large number of air bubbles on their surface, severely affecting the product's appearance. Furthermore, these methods also create pores inside the green body, which negatively impacts the quality of the fired product. Further investigation revealed that these bubbles are caused by the grouting pipe's opening being located above the plaster mold opening, creating a significant height difference between the pipe opening and the bottom of the mold. This allows air to be easily trapped within the grout during the grouting process, resulting in bubbles. To address this, the distance between the grouting pipe opening and the grout surface inside the mold was shortened. A method was adopted where the grouting pipe maintains a small distance from the grout within the mold. While this reduces surface and internal bubbles to some extent, the effect is limited. A considerable number of air bubbles remain visible on the surface of the green body obtained through this method, the product's appearance is not fundamentally improved, and the quality of the fired product remains unsatisfactory. Even if the grouting pipe maintains a small distance from the grout surface inside the plaster mold, some air bubbles will still be introduced. Furthermore, this invention has found that if the opening of the grouting pipe is kept at the bottom of the plaster mold during the grouting process, the number of air bubbles on the surface of the resulting blank decreases significantly. This grouting method not only fundamentally solves the problem of air bubbles on the surface of the blank, but also the blank obtained by the grouting method described in this invention has a significantly better product quality after firing than the product obtained by the above-mentioned grouting method.

[0008] Preferably, the grouting pipe is filled with grout before grouting. Further research revealed that the air bubbles on the surface of the blank originate not only from air introduced during grouting due to the excessive height between the grouting pipe and the bottom of the plaster mold, but also from air within the grouting pipe itself. Because existing grouting pipes are generally too long, when the grouting pipe is opened for grouting, the grout carries air that cannot be expelled from the pipe into the mold, further increasing the number of air bubbles in the grout. Therefore, this invention fills the grouting pipe with grout before grouting, eliminating any air, thus preventing gas from being introduced into the grout during the grouting process and causing air bubbles to form on the blank surface. Combined with the above grouting method, this significantly reduces the number of air bubbles on the blank surface and improves product quality.

[0009] Preferably, the inlet of the grouting pipe is 0.5 to 15 cm away from the bottom of the plaster mold.

[0010] Preferably, the plaster mold is in a state of uniform rotation when the slurry is injected.

[0011] Preferably, the rotation speed of the plaster mold is 1-200 r / min.

[0012] Preferably, the plaster mold is stationary when the slurry is injected.

[0013] Preferably, the position of the grouting pipe opening remains unchanged during the grouting process.

[0014] Preferably, the grouting pipe is made of a rigid material, and more preferably, it is made of a material that is not easily bent at room temperature.

[0015] Preferably, the grout flow rate is controlled at 1500~3000ml / min during grouting.

[0016] Preferably, during the grout injection process, the position of the grouting pipe opening moves as the grout level rises. In practice, the grouting pipe opening can move, but it remains below the grout level until grouting is completed, at which point the grouting pipe is removed from the plaster mold.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. This invention uses immersion grouting, and the grouting pipe is inserted into the vicinity of the bottom of the plaster mold for grouting. The grouting pipe is then pulled out after grouting is completed. This can minimize the risk of gas being drawn into the grout, effectively solving the problem of air bubbles on the surface of the blank. The number of air bubbles on the surface of the obtained blank is significantly reduced, and the product quality is improved.

[0019] 2. This invention changes the original injection method from the mold opening to an insertion injection method, and the pipe is 0.5~15cm away from the bottom of the mold for grout seepage, thereby solving the problem of pores caused by distance impact; at the same time, the insertion injection method solves the problem that the grout in the grout pipe becomes turbulent during the grouting process due to the excessive length of the grout pipe, which in turn traps air in the grout pipe, thereby avoiding the formation of pores.

[0020] 3. This invention has a clever design that significantly improves product precision without increasing production costs, and greatly reduces the bubble rate.

[0021] 4. The method of the present invention fills the grouting pipe with grout before grouting, eliminating the air content and preventing gas from being introduced into the grout during the grouting process, which would cause air bubbles to form on the surface of the billet. Combined with immersion grouting, the number of air bubbles on the surface of the billet can be further reduced, thereby further improving the product quality. Attached Figure Description

[0022] Figure 1 Background Art: A schematic diagram of the structure of an existing grouting device;

[0023] Figure 2 This is a schematic diagram of the control device of the grouting device used in the present invention in the open state.

[0024] Figure 3 This is a schematic diagram of the grouting device control device in the closed state used in this invention.

[0025] In the diagram: 1. Feed pipe; 2. Feed valve; 3. Sealing plate; 4. Control switch; 5. Lifting bracket; 6. Grouting pipe; 7. Control rod; 8. Grouting moving vehicle; 9. Mold plate; 10. Mold; 11. Connecting block; 12. Flexible pipe; 13. Main pipe; 14. Casters. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] I. Immersion Grouting Method

[0028] The present invention relates to an immersion grouting method in which grout is injected into a plaster mold through a grouting pipe. The inlet of the grouting pipe extends to the bottom of the plaster mold, and the inlet of the grouting pipe is opened for grouting. After grouting is completed, the grouting pipe is removed from the plaster mold. During the grouting process, the inlet of the grouting pipe is submerged below the surface of the grout liquid in the plaster mold until grouting is completed.

[0029] This invention, after studying existing grouting methods, discovered that the resulting green body has a large number of air bubbles on its surface, which severely affects the product's appearance quality. Furthermore, it also creates pores inside the green body. A large number of pores inside the green body will inevitably have a very negative impact on the quality of the product after firing. Further research revealed that these bubbles are caused by the grouting pipe opening being located above the plaster mold opening, creating a significant height difference between the pipe opening and the bottom of the mold. This allows air to be easily trapped into the grout during the grouting process, forming bubbles. Therefore, to shorten the distance between the grouting pipe opening and the grout surface inside the mold, a method is adopted where the grouting pipe maintains a small distance from the grout inside the mold during grouting. While this reduces the number of air bubbles on the green body surface and inside to some extent, the effect is limited. A considerable number of air bubbles are still visible on the surface of the green body obtained in this way, the product's appearance is not fundamentally improved, and the quality of the fired product remains unsatisfactory. Even if the grouting pipe maintains a small distance from the grout surface inside the plaster mold, some air bubbles will still be introduced. Existing ceramic product standards have clear limits on the number of air bubbles on the product surface. Although there are no limits on the porosity of the product, if there are too many air bubbles in the blank, it will inevitably result in more air bubbles appearing on the blank surface, leading to more air bubbles on the product surface and poor product quality.

[0030] Furthermore, this invention reveals that if the inlet of the grouting pipe remains at the bottom of the plaster mold throughout the grouting process, the grout will only come into contact with air for a very short period at the beginning of the grouting process. However, this period is too short, and the grout has not had time to entrain air before it submerges the inlet of the grouting pipe. Thus, the grout will no longer come into contact with air as it enters the plaster mold from the grouting pipe, fundamentally avoiding contact between the grout and air. This also completely prevents the grout from carrying air within it. When applied to actual production, the number of air bubbles on the surface of the resulting blank has decreased significantly. This grouting method not only fundamentally solves the problem of air bubbles on the surface of the blank, but also results in a significantly higher quality product after firing than the product obtained by the grouting method described in this invention. Meanwhile, during the grout injection process, in order to keep the grouting pipe opening below the grout level at all times, in specific implementation, the grouting pipe opening can be moved as the grout level rises, but the grouting pipe opening must always be kept below the grout level until the grouting is completed. Then the grouting pipe is removed from the plaster mold. Grouting in this way can achieve the same technical effect as mentioned above.

[0031] The method described in this invention is carried out using the following apparatus, but the method is not limited to the following apparatus; any apparatus capable of implementing the method described in this invention may be used. The grouting apparatus used in this invention includes a feed pipe 1, on which a feed valve 2 is provided. The feed end of the feed pipe 1 is connected to a storage tank via a pipe; the discharge end of the feed pipe 1 is connected to a grouting pipe 6, which is vertically arranged and driven by a lifting and adjusting mechanism to adjust its depth into the cavity of the mold 10; and the grouting pipe 6 extends vertically with its extension length corresponding to the cavity depth of the mold 10.

[0032] The lifting and adjusting mechanism includes a lifting bracket 5 and a driving device (not shown in the figure) for driving the lifting bracket 5 to move up and down; the feed pipe 1 is fixedly connected to the lifting bracket 5; when the driving device drives the lifting bracket 5 to move up and down, it simultaneously drives the grouting pipe 6 to move up and down vertically through the feed pipe 1. The length of the grouting pipe 6 corresponds to or is greater than the cavity depth of the mold 10, and the vertical movement stroke of the grouting pipe 6 driven by the lifting and adjusting mechanism is greater than the cavity depth of the mold 10.

[0033] The discharge end of the grouting pipe 6 is provided with a plug for opening and closing the discharge port of the grouting pipe 6, and the plug is connected to the control switch 4.

[0034] The control switch 4 is located above the grouting pipe 6. The plug includes a sealing plate 3, which seals and covers the outside of the outlet of the grouting pipe 6. One end of the control switch 4 is connected to a control rod 7, the other end of which is sealed and slidably inserted into the grouting pipe 6 and extends downward to connect to the sealing plate 3. The control switch 4 drives the sealing plate 3 to rise and fall via the control rod 7 to control the opening and closing of the outlet of the grouting pipe 6. In implementation, the control switch 4 can be a pneumatic telescopic cylinder or a manual push-pull mechanism.

[0035] In this way, a mechanical plug and control method are adopted, which is reliable and easy to maintain. The area of ​​the sealing plate 3 is larger than the outlet diameter of the grouting pipe 6. The control switch 4 drives the sealing plate 3 to descend and open the outlet through the control rod 7. During grouting, the grout will not directly impact the bottom of the mold cavity, but will first act on the sealing plate 3 and then spread to the bottom of the mold cavity, which can further reduce the impact air bubbles brought in by the grout.

[0036] In this embodiment, the discharge end of the feed pipe 1 is connected to the grouting pipe 6 through a connecting block 11. The connecting block 11 has a vertically connected horizontal channel section and a downwardly extending vertical channel section. The outer ends of the horizontal channel section and the vertical channel section both pass through the connecting block 11. The discharge end of the feed pipe 1 is connected to the outer end of the horizontal channel section and is connected. The upper end of the grouting pipe 6 is connected to the outer end of the vertical channel section and is connected.

[0037] The control switch 4 is connected to the upper surface of the connecting block 11. The control rod 7 is sealed and inserted into the upper surface of the connecting block 11 and can slide up and down. The control rod 7 extends downward through the vertical channel section and then into the grouting pipe 6. The feed pipe 1 and the grouting pipe 6 are connected by a connecting block 11, and the control switch 4 is connected to the connecting block 11. This structural design facilitates the installation of the control switch. Compared with directly sealing the control rod 7 through the pipe, there is a sufficiently large connection position for the control rod 7 to slide through and arrange dynamic seals to avoid grout leakage.

[0038] In practice, both the feed pipe 1 and the grouting pipe 6 are rigid components, i.e., metal pipes. The feed pipe 1 is horizontally mounted on the lifting support 5, and the connecting block 11 can be made of hard plastic for easy connection.

[0039] Working principle: Before grouting, first open the feed valve 2 and control switch 4 to allow the grout to flow out along the grouting pipe 6 for a period of time, expelling any air bubbles present in the grouting pipe 6. Then close the control switch 4. This avoids the problem of the grout easily carrying air bubbles into the grout due to the distance between the feed valve 2 and the opening of the grouting pipe 6, which could affect the quality of the molded blank. The grout flowing out at this time can be collected in a container and then poured into the storage tank to avoid waste. After closing the control switch 4, the lifting bracket 5 is driven by the drive device to adjust the depth of the grouting pipe 6 into the mold 10. When the grouting pipe 6 is inserted into the mold 10 and is 0.5~15cm from the bottom of the mold 10, the drive device is closed, and then the control switch 4 is opened again for immersion grouting. The lifting adjustment mechanism here allows for flexible control of the depth of the grouting pipe 6 into the mold 10, facilitating the insertion and removal of the grouting pipe 6. Simultaneously, the grouting pipe 6 is inserted into the mold 10, and grouting is performed when it is 0.5~15cm from the bottom of the mold 10. This distance is maintained throughout the grouting process, and the grouting pipe remains stationary. This shortens the distance between the grouting pipe opening and the bottom of the plaster mold in the initial stage of grouting, reducing the contact time between the grout and air. This prevents the grout from encapsulating air before submerging the pipe opening, thus reducing the amount of air bubbles in the grout. This effectively avoids the problems associated with traditional grouting devices (such as...). Figure 1 As shown, the outlet of the grouting pipe is suspended above the mold 10. When the grout flows out of the grouting pipe, it impacts the bottom of the mold 10 or the existing grout in the mold 10, generating impact bubbles, which leads to poor quality of the formed green body. On the other hand, maintaining this distance allows the grout to quickly submerge the opening of the grouting pipe, ensuring that the opening of the grouting pipe is inside the grout for most of the grouting process. This fundamentally prevents air from entering the grout, thereby minimizing the number of bubbles in the grout. Moreover, the green body obtained by this grouting method shows a significant reduction in the number of bubbles on its surface even after firing, resulting in a very smooth product surface and a substantial improvement in surface quality.

[0040] In practice, the plug can be a ball valve or a piston valve, and the control method (control switch) can be achieved through wireless electronic control, which simplifies the control structure but reduces stability and makes maintenance difficult. The control switch described in this invention uses a pneumatic valve or a manual switch, employing a mechanical connection and control method, which is more reliable, lower in cost, and easier to maintain. Of course, the control method is not limited to the above structure; any device capable of opening and closing the grouting pipe opening is acceptable.

[0041] In practice, the drive device can be an electric, hydraulic, or pneumatic drive device, which are existing technologies and will not be described in detail here.

[0042] In practical implementation, when injecting the slurry, the plaster mold can be in a state of uniform rotation or in a static state, preferably in a state of uniform rotation. This allows the slurry to be evenly coated on the inner wall of the plaster mold. Simultaneously, the rotation also causes the slurry particles to be thrown to the outermost layer by centrifugal force and evenly adhere to the plaster mold. Air bubbles, due to their lighter mass, remain in the center of the slurry and adhere to the injection pipe. When the injection pipe is withdrawn from the slurry, this withdrawal action pulls on the air bubbles attached to the injection pipe, causing them to deform and eventually rupture, thereby further reducing the formation of pores within the slurry. The rotation speed of the plaster mold is 1-200 r / min.

[0043] II. Examples and Comparative Examples

[0044] Table 1

[0045] Grouting process Rotation speed of plaster mold (r / min) Grout flow rate during grouting (ml / min) Location of grouting pipe inlet Porosity of green body (%) Bubble formation on the surface of the product after sintering Example 1 5 1800 1cm from the bottom of the plaster mold 3.4 Almost no bubbles Example 2 25 2000 1cm from the bottom of the plaster mold 3.1 Almost no bubbles Example 3 45 2200 2cm from the bottom of the plaster mold 2.8 Almost no bubbles Example 4 15 2400 2cm from the bottom of the plaster mold 1.6 Almost no bubbles Example 5 35 2550 1.5cm from the bottom of the plaster mold 2.5 Almost no bubbles Example 6 40 2700 1.5cm from the bottom of the plaster mold 2.2 Almost no bubbles Example 7 45 1500 2cm from the bottom of the plaster mold 2.4 Almost no bubbles Compare with Example 1 5 1800 Located 2cm above the opening of the plaster mold 22 Visible bubbles Compare with Example 2 5 1800 The grout should be placed 2cm from the bottom of the plaster mold, above the grout surface during the grouting process, and maintained at a distance of 2cm from the grout surface. 18 Visible bubbles Compare with Example 3 15 3000 2cm from the bottom of the plaster mold 15 There are bubbles

[0046] As can be seen from Table 1:

[0047] (1) The position of the grouting pipe opening has an important influence on the porosity of the green body. During the grouting process, when the grouting pipe opening is a certain distance away from the bottom of the gypsum mold, the porosity of the green body is very low, and no visible bubbles appear on the surface of the product after sintering. Compared with Comparative Examples 1 and 2, the porosity has been significantly reduced. Comparative Example 2 also confirmed that the grouting method of Comparative Example 2 can reduce the porosity in the green body on the basis of Comparative Example 1, but the reduction effect is not obvious. This also indicates that during the grouting process, the grouting pipe opening is located above the slurry liquid surface. Even if the grouting is carried out at a close distance to the slurry liquid surface, air is still very easy to be carried into the slurry, resulting in a high porosity of the green body. Moreover, there are still a considerable number of visible bubbles on the surface of the product after sintering.

[0048] (2) As can be seen from the examples and comparative examples, the flow rate of the slurry during grouting also affects the porosity of the green body. When the rotation speed of the plaster mold is low, the bubble rate in the green body begins to increase as the slurry flow rate increases, for example, in Example 4 and Comparative Example 3. Although the porosity of Comparative Example 3 is improved to a certain extent, it is still lower than that of Comparative Example 1 and Comparative Example 2. When the rotation speed of the plaster mold is high, the effect of the slurry flow rate on the bubble rate in the green body is very limited, for example, in Example 3 and Example 7. Therefore, the rotation speed of the plaster mold is controlled in the range of 1~200 r / min, and further optimized to be controlled in the range of 5~50 r / min. The slurry flow rate during grouting is controlled in the range of 1500~3000 ml / min, and the porosity of the green body can be controlled between 1~15%, and further controlled between 1.5~5.0%.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the technical solutions. Those skilled in the art should understand that any modifications or equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. An immersion grouting method, characterized in that, The grout is injected into the plaster mold through a grouting pipe; the opening of the grouting pipe extends to the bottom of the plaster mold, the opening of the grouting pipe is opened to inject grout, and the grouting is carried out until the grouting is completed, and then the grouting pipe is removed from the plaster mold; during the grouting process, the opening of the grouting pipe is submerged below the surface of the grout liquid in the plaster mold until the grouting is completed. The grouting device includes a feed pipe (1) and a feed valve (2) on the feed pipe; the feed end of the feed pipe is connected to the storage tank through a pipe; the discharge end of the feed pipe is connected to the grouting pipe (6), the grouting pipe is vertically set and driven by a lifting adjustment mechanism to adjust its depth into the cavity of the mold (10); and the grouting pipe extends vertically and its extension length corresponds to the cavity depth of the mold. The discharge end of the grouting pipe is provided with a plug for opening and closing the discharge port of the grouting pipe. The plug is connected to a control switch (4). The control switch is located above the grouting pipe. The plug includes a sealing plate (3). The sealing plate seals and covers the outside of the discharge port of the grouting pipe. The control switch is connected to one end of a control rod (7). The other end of the control rod is sealed and can slide up and down into the grouting pipe, and extends downward to connect to the sealing plate. The control switch drives the sealing plate to rise and fall through the control rod to control the opening and closing of the discharge port of the grouting pipe. Before grouting, open the feed valve and control switch to allow the grout to flow out along the grouting pipe for a period of time to expel air bubbles in the grouting pipe, and then close the control switch. After turning off the control switch, drive the lifting bracket (5) through the drive device to adjust the depth of the grouting pipe into the mold. When the grouting pipe is inserted into the mold and 1-2 cm away from the bottom of the mold, turn off the drive device and then turn on the control switch to perform immersion grouting. The rotation speed of the plaster mold should be controlled within the range of 5~50 r / min, and the grout flow rate should be controlled within the range of 1500~3000 ml / min during grouting.

2. The immersion grouting method according to claim 1, characterized in that, Before grouting, the grouting pipe is filled with grout.

3. The immersion grouting method according to claim 1, characterized in that, When the slurry is injected, the plaster mold is in a state of uniform rotation.

4. The immersion grouting method according to claim 1, characterized in that, During the grout injection process, the position of the grouting pipe opening remains unchanged.

5. The immersion grouting method according to claim 1, characterized in that, During the grout injection process, the position of the grouting pipe opening moves as the grout level rises.

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