A sealing process and sealing structure for the mouth of a ceramic container and a lid

Abstract

This invention discloses a sealing process and structure for the mouth and lid of a ceramic container, belonging to the field of ceramic manufacturing technology. This method systematically solves the problems of deformation and poor fit accuracy of the ceramic container mouth and lid by precisely controlling the moisture content of the clay (19%-22%), optimizing rolling forming parameters, using specific fixtures during the drying stage, designing a mouth-lid fitting structure with mutually restrictive dimensions, employing a combined coating of isolating sand for firing, and supplementing with a quantitative porcelain-finishing grinding process. This method ensures stable drying shrinkage of the green body, maintains stable concentricity during shrinkage, and controls firing deformation. The final product has high coaxiality of the mouth and lid and good airtightness, increasing the overall yield rate of ceramic containers to over 95%. This invention also provides ceramic containers manufactured using this method.

Description

Technical Field

[0001] This invention relates to the field of sealing technology for ceramic jars, and in particular to a sealing process and sealing structure for the mouth and lid of a ceramic container. Background Technology

[0002] The mouth and lid of a ceramic jar need to meet airtight requirements. Currently, the airtightness between the mouth and lid generally requires an additional sealing structure, such as using third-party materials like non-woven fabric, PE stoppers, cork stoppers, silicone stoppers, aluminum foil, or metal caps to seal with the ceramic. Over time, these materials will powder, fade, and the adhesive will fail, causing them to fall off and lose their sealing effect. Moreover, the cost is high, especially when using metal materials. If it is not necessary to use third-party materials to achieve a seal between the mouth and lid, then the gap between the mouth and lid needs to be controlled during the manufacturing process of the ceramic jar to achieve a seal. However, current manufacturing processes cannot achieve an effective seal. Even if the part of the lid embedded in the mouth fits against the inner wall of the mouth, the airtightness is still insufficient, and it is extremely difficult to remove the lid.

[0003] To address these issues, we propose a sealing process and structure for the mouth and lid of ceramic containers. Summary of the Invention

[0004] The purpose of this invention is to provide a sealing process and structure for the mouth and lid of a ceramic container, to solve the problem that the existing sealing between the mouth and lid generally requires an additional sealing structure, such as using non-woven fabric, PE stoppers, cork stoppers, silicone stoppers, tin foil, metal caps, etc. to bond with the ceramic for sealing. Over time, these materials will powder, fade, and the adhesive will fail, causing them to fall off and lose their sealing effect. Moreover, the cost is high, especially when using metal materials. If the sealing between the mouth and lid is achieved without the need for third-party materials, then the gap between the mouth and lid needs to be controlled during the manufacturing of the ceramic container to achieve a seal. However, the current manufacturing process cannot achieve an effective seal. Even if the part of the lid embedded in the mouth fits against the inner wall of the mouth, the sealing performance is still insufficient, and it is extremely difficult to remove the lid.

[0005] To achieve the above objectives, the present invention provides the following technical solution: The first objective of this invention is to provide a sealing process for the mouth and lid of a ceramic container, comprising the following steps: S1. Selection of clay for ceramic container body and lid: Local clay from Jingdezhen is used, and after being refined by the clay factory, the moisture content of the clay is controlled between 19% and 22%. S2. Roll forming of can body and can lid: The can body and can lid are placed in the plaster mold of the corresponding roll forming machine for roll forming; wherein, the roller head of the roll forming machine and the mold base sleeve rotate in the same direction; S3. Drying and blank removal: After the clay is rolled into shape by the rolling mill, a hemispherical stainless steel fixture is placed at the opening of the blank body and the lid of the rolled container, and the diameter of the hemisphere must be more than 1 cm larger than the inner diameter of the opening of the blank. During the blanking stage, remove the jig, gently take out the blank, place it on a flat wooden board, and let it air dry naturally. S4. Finishing and Shaping: Place the naturally dried billet on a finishing lathe and finish the outer contour according to the theoretical shape curve of the billet. When finishing the dimensions of the can mouth, it is necessary to ensure that the coaxiality of the can lid and the can mouth, the concentricity of the billet, and the clearance tolerance between the two meet the design requirements. The specific steps are as follows: S41. First, trim the forming insert part at the opening of the blank of the can lid, and then trim the front insert part at the opening of the forming insert part. S41. Trim a recessed isolation sand coating section at the rim of the tank opening; Among them, the axial dimension of the front embedding part is 3~5mm, the outer diameter of the molded embedding part is 1~2mm larger than the inner diameter of the can opening, the inner diameter of the front embedding part is 0.2~1mm larger than the inner diameter of the molded embedding part, the inner diameter of the can opening is 0.6~0.8mm smaller than the outer diameter of the front embedding part, the inner diameter of the can body is 1~1.5mm larger than the inner diameter of the can opening, the height of the molded embedding part is maintained at 1~5cm, the depth of the sunken isolation sand coating part is 3-5mm, and its inner diameter is 0.2mm larger than the inner diameter of the can opening. S5. Rapid firing of the body: Place the trimmed body and lid blanks in the kiln and fire them rapidly at a temperature of 700-800℃. S6. Glazing: Glaze the outer surface of the lid and body of the can, and then apply isolation sand to the sunken isolation sand coating part (5); S7. Firing in the kiln (lid firing): The lid of the jar, which has been treated as described above, is placed on the body of the jar. The combined ceramic container is placed on the shelf and then put into the kiln. It is fired and cooled according to the predetermined firing curve. S8. Precision Grinding: After firing, the ceramic container is disassembled and ground to correct firing deformation and ensure the fitting accuracy of the lid. Specifically, this includes: using the inner circular surface of the front insert as a positioning reference, grinding the outer circular surface of the insert; using the ground outer circular surface of the insert as a reference, grinding the inner circular surface of the can opening to ultimately form a fitting gap of about 0.07mm.

[0006] Furthermore, in step S2, the roller head speed is 300-400 rpm, the mold base sleeve speed is 450-600 rpm, and the rolling time is not less than 15 seconds.

[0007] Furthermore, in step S7, the firing process includes three stages: Ignition: Preheat for 3 hours, with the kiln temperature rising at a rate of 4-6℃ / min, and close the kiln door when the temperature reaches 500℃; Oxidation: The kiln temperature rises at a rate of 3-5℃ / min, and the kiln is fired at 1020℃ for 2 hours; Reduction stage: Firing for three hours, as detailed below: First hour: Kiln temperature 1020-1120℃, heating rate 2-3℃ / min; Second hour: Kiln temperature 1120-1220℃, heating rate 1-1.5℃ / min; First hour: kiln temperature 1220-1310℃, heating rate 0.5-1℃ / min.

[0008] Furthermore, in step S8, the grinding equipment is a three-jaw internal grinding mill, using a 200-300 grit diamond grinding wheel. The positioning fixture during grinding is made of aluminum alloy and is stepped, with the last step having a thickness of 5mm, serving as a limit. The outer circle of the can lid is ground, with the can lid vertically embedded in the grinding positioning fixture. The outer diameter is 1-2cm, with deformation of 0.25-0.5mm, and 0.7-1mm is ground away. The internal grinding mill at the can opening uses a three-jaw concentric coaxial clamping mechanism, and the inner diameter of the can opening is less than... The vertical outer diameter of the can lid is 1-2mm. Subtracting 0.6-0.8mm for the gap and leaving a 0.07mm gap, the deformation is 0.25-0.5mm. The actual grinding amount is: 2mm (vertical outer diameter of the can lid) - 0.5mm (maximum deformation) - 0.8mm (maximum gap) - 0.07mm (ceramic gap) = 0.5-0.7mm (grinding amount). The processing speed is fast, about 30 seconds per piece, which can ensure concentricity, coaxiality and surface finish.

[0009] Finally, the bottom of the can and the bottom of the lid are polished smooth with a grinding machine to eliminate roughness. After polishing, the surface is cleaned with water to remove any remaining impurities, and then dried to complete the process.

[0010] Furthermore, in step S4, after the billet is placed on the trimming lathe, it is necessary to ensure that the coaxiality error between the billet and the lathe spindle is ≤0.01mm, and a CNC trimming device with an accuracy controlled within ±0.01mm is used.

[0011] Furthermore, in step S5, the isolation sand is a mixture of borax and water, with the ratio of borax to water being 3:7 to 5:5.

[0012] Furthermore, in step S7, the firing curve includes a total duration of at least 16 hours, of which the high-temperature firing section is no less than 8 hours and the natural cooling section is no less than 8 hours.

[0013] Furthermore, the weight of the hemispherical stainless steel fixture is 50-70g.

[0014] The second objective of this invention is to provide a sealing structure for the mouth and lid of a ceramic container, which is manufactured using the above-mentioned sealing process and includes a lid structure and a mouth structure, wherein both the lid structure and the mouth structure have a pre-forming state and a post-forming state. Both before and after molding, the can lid structure includes a molding insert portion trimmed at the opening of the can lid blank and a pre-embedded portion trimmed at the opening of the molding insert portion. Before molding, the outer diameter of the molding insert is larger than the outer diameter of the front insert, and the inner diameter of the molding insert (4) is smaller than the inner diameter of the front insert. After molding, the outer diameter of the molded insert is the same as the outer diameter of the front insert, and the inner diameter of the molded insert is smaller than the inner diameter of the front insert. Before the can opening structure is formed, it includes a can opening and a recessed isolation sand coating part trimmed at the edge of the can opening. The inner diameter of the recessed isolation sand coating part is larger than the inner diameter of the can opening. After the can opening structure is formed, the inner diameter of the can opening is expanded by grinding, and the recessed isolation sand coating part disappears.

[0015] Furthermore, the inner wall of the can opening begins to narrow in diameter towards the inside of the can body from 1-1.5cm away from the rim. After precision grinding, the coaxiality error between the outer surface of the can lid and the inner surface of the can opening is less than 0.01mm, and the smoothness is greater than 0.4.

[0016] Compared with the prior art, the beneficial effects of the present invention are: the present invention achieves high sealing performance between the can mouth and the can lid through the manufacturing process without the need for third-party materials. Compared with the prior art and existing structures, the sealing cost between the can lid and the can mouth of the formed ceramic can is greatly reduced, and the insertion and removal of the can lid and the can mouth is convenient and smooth, as detailed below: This invention precisely controls the moisture content of the clay (19%-22%) and the drying process, using stainless steel fixtures to stabilize the shrinkage rate of the green body at 3.5%-4.5%, effectively reducing drying deformation and laying the foundation for subsequent processing. Then, through a multi-dimensional constraint structure of the mouth and lid (such as specific gaps, interference fits, and dimensional differences), and by adding isolation sand at the joint, the lid and body can mutually restrain each other's deformation during the joint firing process, significantly reducing the relative deformation of the mouth and lid after firing. The composite process of joint firing combined with subsequent porcelain polishing first uses the mutual restraint effect during firing to stabilize the macroscopic shape, and then corrects the microscopic deformation through high-precision grinding. Ultimately, the coaxiality (roundness) error between the outer circle of the lid and the inner circle of the mouth of the finished product can be controlled within 0.07mm, and the smoothness reaches above 0.4. The concentricity remains stable during shrinkage, thus achieving excellent airtightness. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the can opening and can lid separation structure before molding in this invention; Figure 2 This is a schematic diagram of the combined assembly structure of the can opening and the can lid before molding in this invention; Figure 3 This is a schematic diagram of the assembled structure of the can mouth and can lid after molding in this invention; Figure 4 This is a diagram showing the state of a hemispherical stainless steel fixture placed on a blank in this invention. Detailed Implementation

[0018] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0021] like Figure 1-3 As shown, a sealing process for the mouth and lid of a ceramic container includes the following steps: S1. Selection of clay for ceramic container body and lid: Local clay from Jingdezhen is used, and after being refined by the clay factory, the moisture content of the clay is controlled between 19% and 22%. Using a ceramic clay moisture content tester, clay with moisture content above or below this range is prone to causing defects in the green body during rolling. Specifically, this manifests as follows: ① Clay with moisture content below this range has excessive hardness, making it difficult to spread evenly during rolling, resulting in uneven green body thickness and increased deformation during firing. ② Clay with moisture content above this range tends to stick to the rolling head during rolling, causing clay loss in the green body and uneven green body thickness, leading to firing deformation. In addition, excessively high moisture content will prolong the time it takes for the green body to separate from the plaster mold and may also damage the plaster mold. At the same temperature, clay with a moisture content of 19%-22% will have a shorter demolding time due to natural shrinkage in plaster molds with the same degree of dryness compared to clay with a moisture content of other types (according to actual measurements, at room temperature of 20-30℃, the demolding time for clay with a moisture content of 19%-22% is about 15-20 minutes, while clay with a higher moisture content requires 20-45 minutes, resulting in slower production efficiency). S2. Roll forming of can body and can lid: Place the can body and can lid into the plaster mold of the corresponding roller press for rolling forming; control the room temperature between 0-40℃ (if the room temperature is below 0℃, the moisture in the clay will easily freeze into ice crystals, and the formed blank will be loose; if the room temperature is above 40℃, the moisture in the formed blank will evaporate too quickly, causing the blank to crack). After installing the roller head of the corresponding shape on the roller press, cut the clay with a moisture content of 19%-22% into equal portions according to the clay content required for the corresponding shape, put it into the plaster mold for production, and under the action of the roller press, make the clay evenly spread and adhere to the inner wall of the plaster mold. The power of the roller press drive motor should not be less than 5KW. If it is lower than this power, the pressure applied during the rolling process will be insufficient, which will easily cause the green body to have insufficient density and elongation, and it will be easy to deform during the high-temperature firing stage. In addition, the rolling time should not be less than 15-20S. If it is less than 15S, the clay cannot be spread evenly, resulting in uneven thickness of the green body, which will be easy to deform during the high-temperature firing stage. The rotation speed of the roller head and the rotation speed of the base sleeve of the plaster mold are adjusted by the built-in frequency converter of the equipment. The rotation speed of the roller head is controlled at 300-400 rpm, and the rotation speed of the base sleeve of the plaster mold is not less than 450-600 rpm. The rotation direction of the roller head and the base sleeve is the same. If the speed is lower or higher than the corresponding speed, it will cause uneven expansion of the clay, resulting in uneven thickness of the green body, which is prone to deformation during high-temperature firing later. S3. Drying and Unloading: After the clay is rolled into shape by a rolling mill, a hemispherical stainless steel fixture needs to be placed at the opening of the rolled blank, such as... Figure 4As shown, this fixture is made of stainless steel and weighs between 50-70g. The diameter of the hemisphere must be more than 1cm larger than the inner diameter of the blank opening. Since stainless steel does not absorb water, it will not stick to the contact surface with the stainless steel fixture during the process of the moisture in the blank being absorbed by the plaster mold and naturally drying and shrinking. This effectively ensures that the blank opening does not deform during the shrinkage process, making the blank opening size as close as possible to the design size.

[0022] When the billet dries and shrinks, its size will gradually shrink and become smaller. When a jig weighing 50-70g is placed at the opening of the billet, it can effectively restrict the deformation of the billet during shrinkage. If it is too light, it will not be able to restrict or will restrict the deformation to a limited extent. If it is too heavy, it will cause cracks at the opening of the billet. During the blank removal stage (demolding stage), the jig is removed, the blank is gently taken out and placed on a flat wooden board to air dry naturally. During this process, clay with a moisture content of 19%-22% exhibits a shrinkage rate of 3.5%-4.5% from rolling to natural drying. Higher or lower moisture content will result in larger or smaller shrinkage dimensions. Although the opening size of the blank can be customized, excessively high shrinkage will affect the overall deformation of the blank, and this deformation can easily lead to stretching and deformation of the opening during high-temperature firing. While excessively low moisture content can reduce deformation during shrinkage, it is not conducive to rolling. In production practice, using digital calipers to measure dimensions at each stage, it was found that clay with a moisture content of 19%-22% performs best in both rolling and natural drying shrinkage, and the overall shrinkage of the blank is most controllable, with a stable shrinkage rate of 3.5%-4.5%. S4. Blank Trimming and Shaping: Place the naturally dried blanks (referring to the can lid blanks and can body blanks) on a trimming cart, keeping the blanks centered and concentrically rotated with the base. Using a CNC trimming cart (with controllable precision within 0.01mm), trim the blank shape smoothly according to the blank's curve. When trimming the opening dimensions, the can lid and can opening must be coaxial, and the concentricity of the blanks and the clearance between the can body and can lid must be properly matched (see the cross-sectional view of the can lid and can body openings), forming a double-constrained structure. The specific steps are as follows: S41. First, shape the embedded part 4 at the opening of the blank of the can lid, and then shape the front embedded part 3 at the opening of the shaped embedded part 4. S41. Trim a sunken isolation sand coating section 5 at the rim of the tank opening; in, The axial dimension of the front embedded part 3 is 3~5mm. If it is less than 3mm, it will not have a restraining effect. If it is greater than 5mm, the micro-deformation during the high-temperature firing process will cause the can lid to jam with the can mouth. If the outer diameter of the molding insert 4 is 1-2 mm larger than the inner diameter of the can opening, and less than 1 mm, the can lid will be pushed out or jammed during the high-temperature firing of the blank, making it impossible to remove the whole piece (due to the brittle and hard nature of ceramics), and greater than 2 mm, it will not play a role in mutually restraining and limiting the position, and the degree of deformation will increase. The inner diameter of the front insert 3 is 0.2~1mm larger than the inner diameter of the molded insert 4. The diameter of the front insert 3 is the positioning reference for the outer diameter of the molded insert 4 to be polished later. The inner diameter of the can opening is 0.6~0.8mm smaller than the outer diameter of the front embedded part 3. If the gap is too small, the deformation during the high-temperature firing stage is easy to get stuck. If the gap is too large, it will not have the function of limiting and restraining. Applying isolation sand to the 0.6-0.8mm gap will prevent the blanks from sticking together during the firing process. The inner diameter of the jar body is 1~1.5mm larger than the inner diameter of the jar mouth. This is the thickness of the glaze left inside the jar body. The contact surface of the jar lid that is vertically inserted into the jar mouth is unglazed and needs to be polished on the finished porcelain later. It does not need to be glazed. The height of the molding insert 4 is kept between 1 and 5 cm. If the contact surface is less than 1 cm, the lid is easy to fall off, and there is not enough airtight travel after the porcelain is polished, so the airtight effect cannot be achieved. If it is more than 5 cm, the probability of deformation during the firing stage of the body increases, which increases the difficulty of the later porcelain polishing. The depth of the sunken isolation sand coating part 5 is 3-5mm, and its inner diameter is 0.2mm larger than the inner diameter of the tank opening. This part is used for subsequent coating of isolation sand. S5. Rapid firing of the body: The trimmed body and lid blanks are placed in the kiln and rapidly fired at a temperature of 700-800℃. S6. Glazing: Glaze the outer surface of the lid and body of the can, and then apply isolation sand to the sunken isolation sand coating part 5. The isolation sand will not produce a chemical effect during firing. Its function is to prevent the can lid and the can mouth from sticking together during firing and to prevent the can lid from breaking due to force when separating from the can body, which would affect the yield. During the porcelain grinding, the isolation sand at the can mouth will be completely ground off without leaving any trace. S7. Firing in the kiln: The lid of the jar, which has been treated as described above, is attached to the body of the jar. The assembled ceramic container is placed on the shelf and then placed in the kiln. Firing and cooling are carried out according to the predetermined firing curve. Firing curve: The entire firing process takes at least 16 hours, including 8 hours or more of firing and 8 hours or more of cooling. The firing process includes three stages: Ignite and preheat for 3 hours, with the kiln temperature rising at a rate of approximately 4-6°C per minute. When the kiln reaches 500°C, close the kiln door (this step is to drain steam). During the oxidation stage, the kiln temperature rises by about 3-5℃ / min over 2 hours, until it reaches 1020℃ (i.e., the 102℃ oxidation cone burns off impurities such as iron in the green body). Restoration phase, 3 hours After batch (5000pcs) testing, this heating rate ensures uniform shrinkage of the green body during firing, making it less prone to deformation. In addition, the limiting structure of the green body itself ensures the coaxiality and concentricity of the lid and body, and the deformation can be controlled within 0.25-0.5mm, with an overall yield rate of over 95%. 4. Cooling: After turning off the fire, allow it to cool naturally for 8 hours or more. The kiln can be opened when the temperature inside the kiln is below 100℃. If the temperature is too high when opening the kiln, the glaze may crack, which will affect the yield. S8. Precision grinding: The ceramic container after firing is disassembled and ground to correct firing deformation and ensure the fitting accuracy of the lid; specifically, it includes: using the inner circular surface of the front embedded part 3 as the positioning reference, grinding the outer circular surface of the shaped embedded part 4; using the ground outer circular surface of the shaped embedded part 4 as the reference, grinding the inner circular surface of the can opening to finally form a fitting gap of about 0.07mm.

[0023] In step S8, the grinding equipment is a three-jaw internal grinding mill, using a 200-300 grit diamond grinding wheel. The positioning fixture during grinding is made of aluminum alloy and is stepped, with the last step having a thickness of 5mm, which serves as a limit. The outer circle of the grinding tank cover is vertically embedded in the grinding positioning fixture, with an outer diameter of 1-2cm, a deformation of 0.25-0.5mm, and a grinding loss of 0.7-1mm. The inner diameter grinding mill for the can opening uses a three-jaw concentric and coaxial clamping mechanism. The inner diameter of the can opening is 1-2mm smaller than the outer diameter of the vertical surface of the can lid. Subtracting 0.6-0.8mm for the gap and leaving a 0.07mm gap, the deformation is 0.25-0.5mm. The actual grinding amount is: 2mm (outer diameter of the vertical surface of the can lid) - 0.5mm (maximum deformation) - 0.8mm (maximum gap) - 0.07mm (ceramic gap) = 0.5-0.7mm (grinding amount). The processing speed is fast, about 30 seconds per piece, which can ensure concentricity, coaxiality and surface finish.

[0024] Finally, the bottom of the can and the bottom of the lid are polished smooth with a grinding machine to eliminate roughness. After polishing, the surface is cleaned with water to remove any remaining impurities, and then dried to complete the process.

[0025] Furthermore, in step S5, the isolation sand is a mixture of borax and water, with the ratio of borax to water being 3:7 to 5:5.

[0026] Furthermore, the weight of the hemispherical stainless steel fixture is 50-70g. Example 2

[0027] Please see Figure 1-3 A sealing structure for the mouth and lid of a ceramic container, manufactured using the above-mentioned sealing process, includes a lid structure and a mouth structure, wherein both the lid structure and the mouth structure have a pre-forming state and a post-forming state. Both before and after molding, the can lid structure includes a molding insert 4 trimmed at the opening of the can lid 2 blank and a pre-embedded insert 3 trimmed at the opening of the molding insert 4. Before molding, the outer diameter of the molding insert 4 is larger than the outer diameter of the front insert 3, and the inner diameter of the molding insert 4 is smaller than the inner diameter of the front insert 3. After molding, the outer diameter of the molded insert 4 is the same as the outer diameter of the front insert 3, and the inner diameter of the molded insert 4 is smaller than the inner diameter of the front insert 3. Before the can mouth structure is formed, it includes can mouth 1 and a recessed isolation sand coating part 5 trimmed at the edge of can mouth 1. The inner diameter of the recessed isolation sand coating part 5 is larger than the inner diameter of can mouth 1. After the can mouth structure is formed, the inner diameter of can mouth 1 is expanded by grinding, and the recessed isolation sand coating part 5 disappears.

[0028] Furthermore, the inner wall of the can opening 1 begins to narrow in diameter towards the inside of the can body from 1-1.5cm away from the rim. After precision grinding, the coaxiality error between the outer surface of the can lid 2 and the inner surface of the can opening 1 is less than 0.01mm, and the smoothness is greater than 0.4.

[0029] Under the action of step S4, a stepped assembly is formed between the lid 2 and the mouth 1, which has a high sealing performance. When the lid 2 of the formed ceramic jar is inserted into the mouth 1, there is a uniform and smooth damping feeling. Similarly, when the lid 2 is removed, there is also a uniform and smooth damping feeling.

[0030] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0031] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A sealing process for the mouth and lid of a ceramic container, characterized in that: Includes the following steps: S1. Selection of clay for ceramic container body and lid: Use local Jingdezhen clay, with the moisture content of the clay controlled between 19% and 22%; S2. Roll forming of can body and can lid: The can body and can lid are placed in the plaster mold of the corresponding roll forming machine for roll forming; wherein, the roller head of the roll forming machine and the mold base sleeve rotate in the same direction; S3. Drying and blank removal: After the clay is rolled into shape by the rolling mill, a hemispherical stainless steel fixture is placed at the opening of the blank body and the lid of the rolled container, and the diameter of the hemisphere must be more than 1 cm larger than the inner diameter of the opening of the blank. During the blanking stage, remove the jig, gently take out the blank, place it on a flat wooden board, and let it air dry naturally. S4. Finishing and Shaping: Place the naturally dried billet on a finishing lathe and finish the outer contour according to the theoretical shape curve of the billet. When finishing the dimensions of the can mouth, it is necessary to ensure that the coaxiality of the can lid and the can mouth, the concentricity of the billet, and the clearance tolerance between the two meet the design requirements. The specific steps are as follows: S41. First, shape the embedded part (4) at the opening of the blank of the can lid, and then shape the front embedded part (3) at the opening of the shaped embedded part (4). S41. Trim a sunken isolation sand coating part (5) at the mouth of the tank. Among them, the axial dimension of the front embedding part (3) is 3~5mm, the outer diameter of the molded embedding part (4) is 1~2mm larger than the inner diameter of the can opening, the inner diameter of the front embedding part (3) is 0.2~1mm larger than the inner diameter of the molded embedding part (4), the inner diameter of the can opening is 0.6~0.8mm smaller than the outer diameter of the front embedding part (3), the inner diameter of the can body is 1~1.5mm larger than the inner diameter of the can opening, the height of the molded embedding part (4) is maintained at 1~5cm, the depth of the sunken isolation sand coating part (5) is 3-5mm, and its inner diameter is 0.2mm larger than the inner diameter of the can opening; S5. Rapid firing of the body: The trimmed body and lid blanks are placed in the kiln and rapidly fired at a temperature of 700-800℃. S6. Glazing: Glaze the outer surface of the lid and body of the can, and then apply isolation sand to the sunken isolation sand coating part (5); S7. Firing in the kiln: The lid of the jar, which has been treated as described above, is placed on the body of the jar. The combined ceramic container is placed on the shelf and then put into the kiln. It is fired and cooled according to the predetermined firing curve. S8. Fine grinding of ceramic: After firing, the ceramic container is disassembled and ground to correct the firing deformation and ensure the fitting accuracy of the lid; specifically, it includes: using the inner circle of the front embedded part (3) as the positioning reference, grinding the outer circle of the shaped embedded part (4); using the ground outer circle of the shaped embedded part (4) as the reference, grinding the inner circle of the can mouth to finally form a fitting gap of about 0.07mm.

2. The sealing process for the ceramic container mouth and lid according to claim 1, characterized in that: In step S2, the roller head rotates at 300-400 rpm, the mold base sleeve rotates at 450-600 rpm, and the rolling time is not less than 15 seconds.

3. The sealing process for the mouth and lid of a ceramic container according to claim 1, characterized in that: In step S7, the firing process includes three stages: Ignition: Preheat for 3 hours, with the kiln temperature rising at a rate of 4-6℃ / min, and close the kiln door when the temperature reaches 500℃; Oxidation: The kiln temperature rises at a rate of 3-5℃ / min, and the kiln is fired at 1020℃ for 2 hours; Reduction stage: Firing for three hours, as detailed below: First hour: Kiln temperature 1020-1120℃, heating rate 2-3℃ / min; Second hour: Kiln temperature 1120-1220℃, heating rate 1-1.5℃ / min; First hour: kiln temperature 1220-1310℃, heating rate 0.5-1℃ / min.

4. The sealing process for the mouth and lid of a ceramic container according to claim 1, characterized in that: In step S8, the grinding equipment is a three-jaw internal grinding mill, using a 200-300 grit diamond grinding wheel. The positioning fixture during grinding is made of aluminum alloy and is stepped, with the last step having a thickness of 5 mm. Then, the bottom of the can and the bottom of the lid are polished smooth with a grinding machine to eliminate roughness. After polishing, the surface is cleaned with water to remove any impurities, and then dried to complete the process.

5. The sealing process for the mouth and lid of a ceramic container according to claim 1, characterized in that: In step S4, after the billet is placed on the trimming lathe, it is necessary to ensure that the coaxiality error between the billet and the lathe spindle is ≤0.01mm, and a CNC trimming device with an accuracy controlled within ±0.01mm is used.

6. The sealing process for the mouth and lid of a ceramic container according to claim 1, characterized in that: In step S5, the isolation sand is a mixture of borax and water, with the ratio of borax to water being 3:7 to 5:

5.

7. The sealing process and sealing structure for the ceramic container mouth and lid according to claim 1, characterized in that: In step S7, the firing curve includes a total duration of at least 16 hours, of which the high-temperature firing section is no less than 8 hours and the natural cooling section is no less than 8 hours.

8. The sealing process for the mouth and lid of a ceramic container according to claim 1, characterized in that: The weight of the hemispherical stainless steel fixture is 50-70g.

9. A sealing structure for the mouth and lid of a ceramic container, manufactured using the sealing process described in any one of claims 1-8, characterized in that, It includes a can lid structure and a can mouth structure, both of which have a pre-forming state and a post-forming state; Both before and after molding, the can lid structure includes a molding insert (4) trimmed at the opening of the blank of the can lid (2) and a pre-insertion insert (3) trimmed at the opening of the molding insert (4), wherein, Before molding, the outer diameter of the molding insert (4) is larger than the outer diameter of the front insert (3), and the inner diameter of the molding insert (4) is smaller than the inner diameter of the front insert (3); After molding, the outer diameter of the molding insert (4) is the same as the outer diameter of the front insert (3), and the inner diameter of the molding insert (4) is smaller than the inner diameter of the front insert (3). Before the can mouth structure is formed, it includes a can mouth (1) and a recessed isolation sand coating part (5) trimmed at the edge of the can mouth (1). The inner diameter of the recessed isolation sand coating part (5) is larger than the inner diameter of the can mouth (1). After the can mouth structure is formed, the inner diameter of the can mouth (1) is expanded after grinding, and the recessed isolation sand coating part (5) disappears.

10. The sealing structure for the mouth and lid of a ceramic container according to claim 9, characterized in that: The inner wall of the can opening (1) begins to shrink in diameter towards the inside of the can body from 1-1.5cm away from the rim. After the outer circular surface of the can lid (2) and the inner circular surface of the can opening (1) are finely ground, their coaxiality error is less than 0.01mm and their smoothness is greater than 0.4.

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