A one-piece all-ceramic vacuum insulated cup and its laser microstructure heat insulation method

Abstract

This invention relates to the field of inorganic non-metallic materials technology, providing an all-ceramic integrated vacuum insulated cup and its laser microstructure heat insulation method, solving the problem that existing inorganic non-metallic materials cannot achieve integrated all-ceramic vacuum sealing and efficient heat insulation due to material, structural, and process limitations. The invention includes a cup body and a lid located on top of the cup body. The cup body includes an annular opening and a partition cup body arranged sequentially from top to bottom. The partition cup body includes an inner layer and an outer layer spaced apart, forming a heat insulation cavity between the inner and outer layers. A process hole is provided at the bottom of the partition cup body, communicating with the heat insulation cavity. A heat-insulating layer with a micron to submicron surface morphology is provided on the outer surface of the partition cup body. By providing a laser microstructure heat-insulating layer with a specific roughness on the outer surface of the partition cup body, the heat loss caused by the high thermal conductivity of the ceramic material itself is reduced.

Description

Technical Field

[0001] This invention relates to the field of inorganic non-metallic materials technology, specifically to an all-ceramic integrated vacuum thermos cup and its laser microstructure heat insulation method. Background Technology

[0002] Currently, most so-called "inorganic non-metallic materials (ceramics)" on the market are layered structures consisting of a ceramic inner liner and a metal or plastic outer shell. These products generally suffer from the following technical problems:

[0003] Material heterogeneity: There is a large difference in the coefficient of thermal expansion between ceramics and metals (or plastics), which can easily lead to delamination and cracking after long-term use.

[0004] Complex structure: The mouth of the cup usually needs to be fitted with metal threads or sealing inserts, which increases the weight and affects the drinking experience.

[0005] Poor sealing reliability: The vacuum channel of the interlayer often needs to rely on glass-metal sealing or resin sealing, which has poor high temperature resistance and limited vacuum life.

[0006] High thermal conductivity: ceramics have a higher thermal conductivity than glass, and it is difficult to achieve the same heat preservation performance as glass bottles by relying solely on a vacuum layer.

[0007] Although existing "all-ceramic integrated thermos cups" attempt to adopt a hollow sandwich structure, due to the high firing temperature of ceramics and the difficulty in sealing the pores in the vacuum process, it is impossible to achieve vacuum sealing or nitrogen filling sealing after sintering. Therefore, their heat insulation performance is still limited and they have failed to achieve a true vacuum heat preservation effect. Summary of the Invention

[0008] Therefore, in view of the above problems, the present invention provides an all-ceramic integrated vacuum insulated cup and its laser microstructure heat insulation method, which solves the problem that existing inorganic non-metallic materials cannot achieve integrated all-ceramic vacuum sealing and efficient heat preservation due to material, structure and process limitations.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0010] A one-piece all-ceramic vacuum insulated cup includes a cup body and a lid on top of the cup body. The cup body includes a ring-shaped opening and a partitioned cup body arranged sequentially from top to bottom. The partitioned cup body includes an inner layer and an outer layer spaced apart, forming a heat-insulating cavity between the inner and outer layers. The heat-insulating cavity has an internal vacuum degree of no more than 10. −2 Pa's vacuum cavity;

[0011] The bottom of the partition cup is provided with a process hole, which is connected to the heat insulation cavity. The diameter D of the process hole is 0.5-2.0 mm. After the vacuum cavity reaches the vacuum level, it is sealed in a vacuum environment by ceramic sealing material.

[0012] The outer surface of the partition cup is provided with a heat-insulating layer, which has a surface morphology of micron to submicron and a surface roughness Ra of 2-5 μm.

[0013] Furthermore, the surface morphology of the heat-insulating layer is a periodic or non-periodic array of protrusions, grooves, or a honeycomb structure.

[0014] Furthermore, the inner surface of the partition cup is coated with a low-emissivity metal coating, the reflectivity of which is not less than 95%.

[0015] Furthermore, the metal plating is made of silver or platinum.

[0016] Furthermore, the ceramic sealing material is a non-sintering ceramic sealing adhesive with a viscosity of 2000-3000 cP.

[0017] Furthermore, the partition cup body is formed by bonding the inner layer and the outer layer with high-temperature ceramic slurry along the opening to form a hollow blank, and then firing it as a whole in one go.

[0018] Furthermore, a sealing ring is provided at the top of the annular portion, and the sealing ring is integrally formed with the annular portion.

[0019] A laser microstructure heat-resistant method for all-inorganic non-metallic materials is disclosed for fabricating the aforementioned all-ceramic integrated vacuum insulated cup. The method plans and executes laser processing based on the aperture D (0.5mm ≤ D ≤ 2.0mm) of the process hole, and includes the following steps:

[0020] S1. Differentiated planning: Provide a cup blank having the heat insulation cavity structure, and determine the required laser processing intensity or microstructure density in the area surrounding the process hole according to the maximum aperture D of the process hole, wherein the processing intensity or microstructure density is configured to be positively correlated with the aperture D;

[0021] S2. Laser scanning processing: Using a pulsed fiber laser, the outer surface of the cup blank is laser scanned according to the plan in step S1. At least in the area around the process hole, differential laser processing corresponding to the plan is performed to form the heat-insulating layer with a surface roughness Ra of 2-5 μm.

[0022] Furthermore, in step S1, the planning that is positively correlated with the aperture D specifically means that when the aperture D increases, a lower laser scanning speed, a higher laser power density, or a denser scanning path is planned in the area surrounding the process hole.

[0023] Furthermore, the method is performed after the cup body blank has been integrally fired and before vacuum sealing.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. The cup body of this invention is made entirely of homogeneous ceramic material. The inner layer, outer layer, rim, and sealing ring are integrally molded or fired as a whole, completely eliminating the difference in thermal expansion coefficients between ceramic and metal / plastic. This fundamentally solves the problems of delamination and cracking caused by thermal stress in traditional composite structures. The all-ceramic integrated design eliminates the need for metal threads or sealing inserts at the cup mouth, reducing the weight of the cup body. By setting small-diameter process holes at the bottom of the partition cup body and sealing it with ceramic sealing material under high vacuum, gas heat conduction and convection are effectively suppressed, achieving insulation performance close to that of a glass vacuum bottle liner. Both the all-ceramic material and the ceramic sealing adhesive have excellent high-temperature resistance and chemical stability, can withstand high-temperature sterilization, and have a long vacuum life, avoiding the problems of easy aging and leakage of resin or glass-metal sealing structures.

[0026] 2. This invention significantly extends the heat conduction path and enhances phonon scattering by setting a laser microstructure heat-insulating layer with a specific roughness on the outer surface of the partition cup, thereby reducing the heat loss caused by the high thermal conductivity of the ceramic material itself. The small-diameter process holes, combined with the heat-insulating layer design on the outer surface, effectively compensate for the local thermal bridges that may be formed due to the sealing of the process holes, making the temperature distribution on the surface of the cup more uniform and further improving the heat preservation consistency.

[0027] 3. This invention utilizes laser processing methods to differentiate the planning based on the specific aperture of the process holes, ensuring a precise match between the performance of the heat-insulating layer and the thermal bridge compensation requirements. The laser processing intensity or microstructure density (such as scanning speed, power density, and path density) is dynamically adjusted according to the aperture D, optimizing processing efficiency while ensuring heat insulation effects and avoiding over-processing or under-processing. Especially in the area surrounding the process holes, differentiated processing can form more significant microstructures in this critical region, specifically suppressing heat flow concentration and improving overall heat insulation uniformity. By planning and controlling laser parameters, a surface roughness of Ra=2-5μm can be stably achieved on cups with different apertures, ensuring the repeatability of the heat-insulating layer performance and product consistency. The method specifies that laser processing is performed after the cup body is sintered and before vacuum sealing to avoid damage to the already formed microstructures caused by high-temperature sintering and to prevent processing contamination from affecting the subsequent vacuum sealing process. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the cross-sectional structure of a cup body according to an embodiment of the present invention.

[0029] Explanation of icon numbers:

[0030] Cup body 10;

[0031] 11 ring opening; 111 sealing ring;

[0032] 12-layer cup body; 121-inner layer; 122-outer layer; 123-heat insulation cavity; 124-process hole; 125-sealing block;

[0033] 20. Cover. Detailed Implementation

[0034] The following will describe in detail the implementation of the present invention with reference to specific embodiments, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0035] Example 1: A one-piece all-ceramic vacuum insulated cup, such as Figure 1 As shown, this embodiment provides an all-ceramic integrated vacuum insulated cup, including a cup body 10 and a lid 20 connected to the top of the cup body 10 by threads or snaps.

[0036] The cup body 10 includes an integrally formed annular opening 11 and a partitioned cup body 12 located below it. The top of the annular opening 11 is provided with an integrally formed sealing ring 111 for sealing with the cap 20. The sealing ring 111 is integrally formed with the annular opening 11, and the thickness of the sealing ring 111 is greater than the thickness of the annular opening 11. The cap 20 is provided with a groove corresponding to the sealing ring 111.

[0037] In other preferred embodiments, the sealing ring 111 may be made of rubber.

[0038] The partition cup 12 comprises an inner layer 121 and an outer layer 122 coaxially spaced apart. Each layer is manufactured using a roll forming process, resulting in extremely high density and dimensional accuracy. The inner layer 121 and the outer layer 122 are connected at their upper ends (i.e., the lower edge of the annular portion 11), thus forming a closed annular heat-insulating cavity 123 between them. This heat-insulating cavity 123 is a high-vacuum environment, with an internal vacuum level not exceeding 1.0 × 10⁻⁶. −2 Pa.

[0039] To achieve this high vacuum, a process hole 124 is provided at the bottom center of the partition cup 12. The process hole 124 penetrates the outer layer 122 and communicates with the heat insulation cavity 123.

[0040] In this embodiment, the aperture D of process hole 124 is designed to be 1.0 mm. To seal this hole, a vacuum glove box (cavity vacuum degree ≤ 5 × 10⁻⁶) is used. −3 In a vacuum environment, a non-heat-curing sealing material with a viscosity of 2500 cP (such as room-temperature curing ceramic slurry or nano-alumina-based sealing adhesive) is injected into process holes 124 and leveled. It is then initially cured to form a sealing block 125. The thermal conductivity of the cured sealing adhesive is approximately 1.2 W·m. -1 ·K -1 .

[0041] To suppress the high thermal conductivity of the ceramic material itself (e.g., zirconia ceramic has a thermal conductivity of approximately 2.5 W·m), -1 ·K -1 The heat is conducted through the solid wall, and the heat is compensated for by the local thermal bridges that may be formed by the process holes 124 and the sealing block 125. A heat-insulating layer is formed on the entire outer surface (including the bottom) of the partition cup 12 by laser micromachining. The heat-insulating layer has a honeycomb array microstructure with a surface roughness Ra of 3.5±0.5μm and a depth of about 10μm.

[0042] To further improve the heat preservation performance, a silver plating layer is pre-deposited on the inner surface of the inner layer 121 of the partition cup body 12 by magnetron sputtering. The plating layer is about 100nm thick and its infrared reflectivity is greater than 95%, which can effectively reduce the radiative heat loss of the inner liner.

[0043] The preparation process of the cup body 10 is as follows:

[0044] (1) Molding: The inner layer 121 and the outer layer 122 are prepared by casting or slip casting processes respectively. High-temperature ceramic slurry is applied to the contact area of ​​the openings of the two as a binder. After stacking, the openings are tightly joined by rolling to form an integral green body with a hollow heat-insulating cavity 123 and a bottom process hole 124.

[0045] (2) Firing: The whole green body is placed in a high-temperature kiln and fired once at 1250℃ for 2 hours to obtain a dense ceramic cup body. The firing process enables the inner and outer layers to achieve complete ceramic metallurgical bonding at the opening.

[0046] (3) Inner wall coating: The inner wall of the cup after firing is activated by plasma cleaning, and then a silver coating is deposited by magnetron sputtering.

[0047] (4) Laser processing of the outer wall (see method in Example 2).

[0048] (5) Vacuum sealing: Place the laser-processed cup body in a vacuum glove box, and evacuate the heat insulation cavity 123 to 5×10 through the process hole 124. −3Pa, and then the process hole 124 is sealed with the above-mentioned non-sintering ceramic sealing adhesive.

[0049] Example 2: This example provides a laser microstructure heat-resistant method for preparing the all-inorganic non-metallic material described in Example 1. This method is implemented after the cup body is fired as a whole and before vacuum sealing.

[0050] S1. Differentiation Planning: Provide a cup body blank that has been fully fired and silver-plated on the inner wall. Obtain the measured diameter D of the bottom process hole 124 of the blank (D=1.0mm in this example).

[0051] The planning is determined through the following path:

[0052] (a) Simulation to obtain baseline data: Using thermal simulation software, a three-dimensional model with the same material and structural dimensions as the cup body in this embodiment was established. The heat insulation cavity 123 was set to a vacuum (thermal conductivity ≈ 0), the thermal conductivity of the ceramic matrix was set to 2.5 W / (m·K), and the thermal conductivity of the filling material (sealing adhesive) of the process hole 124 was set to 1.2 W / (m·K). Simulation was conducted under steady-state conditions of ambient temperature 20℃ and inner tank water temperature 95℃. The calculation showed that when the hole diameter D = 1.0 mm, the temperature of the outer surface point (point A) directly above the center of the process hole sealing block 125 was 34.5℃, while the temperature of the outer surface point (point B) 10 mm away from the center of the hole was 32.0℃.

[0053] Therefore, the initial temperature difference ΔT1 = 34.5 - 32.0 = 2.5℃.

[0054] (b) Set compensation target: In order to obtain a uniform heat preservation effect, set the residual temperature difference target between point A and point B after compensation to ΔT2≤0.5℃.

[0055] Therefore, the temperature difference that needs to be compensated is ΔT3 = 2.5 - 0.5 = 2.0℃.

[0056] (c) Experimental Calibration of Laser Effect: Pre-calibration was performed using a process experiment with the same laser system (parameters: wavelength 1064 nm, pulse width 50 ns, frequency 80 kHz) processed on ceramic specimens. Experiments showed that when the laser scanning speed V = 1200 mm / s and the line spacing S = 0.03 mm (defined as "standard intensity"), the temperature drop in a localized area of ​​the specimen surface under the same test conditions was approximately 1.2 °C. When the scanning speed was reduced to V = 800 mm / s and the line spacing was increased to S = 0.02 mm (defined as "enhanced intensity"), a temperature drop of 2.3 °C was achieved.

[0057] (d) Making a planning decision: Comparing ΔT3=2.0℃ with the calibration results, 1.2℃ is insufficient, while 2.3℃ meets the requirements. Therefore, the planning decision is: for the process hole with D=1.0mm, use the "enhanced intensity" parameter for laser processing in its surrounding area (e.g., within a circle with a radius of 3mm centered on the hole center), i.e., a lower scanning speed and a denser scanning path; while use the "standard intensity" parameter in other areas.

[0058] S2. Laser scanning processing: A pulsed fiber laser system is used, with the following parameters: wavelength 1064nm, pulse width 50ns, repetition frequency 80kHz, and average power 15W.

[0059] The cup blank is fixed on a five-axis linkage worktable. First, the entire outer surface of the cup blank (except for the ring mouth) is scanned with a baseline. The scanning speed is set to 1200 mm / s and the line spacing is 0.03 mm to form a basic microstructure.

[0060] Then, perform differentiated processing: for the area around the process hole (circular area with a radius of 3mm) planned in step S1, reduce the scanning speed to 900mm / s, and at the same time, reduce the line spacing to 0.02mm, and perform a second scan.

[0061] Through the above processing, a uniform laser microstructure with honeycomb characteristics is formed on the entire outer surface. Measured with a white light interferometer, the average surface roughness Ra of the outer surface is 3.2 μm. In the area surrounding the process holes, due to the higher processing intensity, Ra slightly increases to 3.8 μm, and the microstructure is also denser. This forms a heat-insulating layer with a surface roughness Ra in the range of 2-5 μm.

[0062] The beneficial effects of this method are as follows: by differentiating the planning and processing based on aperture D, it ensures that the heat-insulating layer has a stronger thermal resistance enhancement capability in the area most sensitive to thermal bridges (around the process holes). Without excessively increasing the overall processing time and cost, it efficiently compensates for local heat loss, making the outer surface temperature distribution of the cup body more uniform after vacuum sealing. The actual test shows that the heat preservation performance (water temperature after 6 hours of hot water at 95℃) of the cup body processed by this method is about 8% higher than that of the comparison sample that did not undergo differentiated processing and only underwent uniform scanning.

[0063] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A one-piece all-ceramic vacuum insulated cup, comprising a cup body and a lid disposed on the top of the cup body, characterized in that: The cup body includes a ring-shaped opening and a partitioned cup body arranged sequentially from top to bottom. The partitioned cup body includes an inner layer and an outer layer spaced apart, forming a heat-insulating cavity between the inner and outer layers. The heat-insulating cavity has an internal vacuum degree not exceeding 10. −2 Pa's vacuum cavity; The bottom of the partition cup is provided with a process hole, which is connected to the heat insulation cavity. The diameter D of the process hole is 0.5-2.0 mm. After the vacuum cavity reaches the vacuum level, it is sealed in a vacuum environment by ceramic sealing material. The outer surface of the partition cup is provided with a heat-insulating layer, which has a surface morphology of micron to submicron and a surface roughness Ra of 2-5 μm. The machining of the process holes includes the following steps: S1. Differentiated planning: Provide a cup blank having the heat insulation cavity structure, and determine the required laser processing intensity or microstructure density in the area surrounding the process hole according to the maximum aperture D of the process hole, wherein the processing intensity or microstructure density is configured to be positively correlated with the aperture D; S2. Laser scanning processing: Using a pulsed fiber laser, the outer surface of the cup blank is laser scanned according to the plan in step S1. At least in the area around the process hole, differential laser processing corresponding to the plan is performed to form the heat-insulating layer with a surface roughness Ra of 2-5 μm. The process holes are machined after the cup body blank has been integrally fired and before vacuum sealing.

2. The all-ceramic integrated vacuum insulated cup according to claim 1, characterized in that: The surface morphology of the heat-insulating layer is a periodic or non-periodic array of protrusions, grooves, or a honeycomb structure.

3. A one-piece all-ceramic vacuum insulated cup according to claim 1 or 2, characterized in that: The inner surface of the partition cup is covered with a low-emissivity metal coating, and the reflectivity of the metal coating is not less than 95%.

4. The all-ceramic integrated vacuum insulated cup according to claim 3, characterized in that: The metal plating is made of silver or platinum.

5. The all-ceramic integrated vacuum insulated cup according to claim 1, characterized in that: The ceramic sealing material is a non-sintering ceramic sealing adhesive with a viscosity of 2000-3000 cP.

6. The all-ceramic integrated vacuum insulated cup according to claim 1, characterized in that: The partition cup body is formed by bonding the inner layer and the outer layer with high-temperature ceramic slurry along the opening to form a hollow blank, and then firing it as a whole in one go.

7. The all-ceramic integrated vacuum insulated cup according to claim 1, characterized in that: A sealing ring is provided at the top of the annular opening, and the sealing ring is integrally formed with the annular opening.

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