Electric heating film ceramic kettle and preparation method thereof

Abstract

The present invention discloses an electric heating film ceramic kettle and its preparation method. The electric heating film ceramic kettle comprises a ceramic kettle body, glaze and electric heating film; the preparation method of the kettle body comprises: preparing the clay material and glaze slurry of the ceramic kettle body, mechanically rolling and forming the upper and bottom parts of the kettle body respectively according to their shapes, glazing, firing and preparing the electric heating film. The outer bottom of the electric heating film-heated ceramic kettle provided by the present invention can withstand a heating power of 7.5W per square centimeter and a thermal shock of 400°C within 30 seconds. Its thermal stability is at least 500°C, its vitrification degree is at least 97%, and its water absorption rate is less than 0.3%. It overcomes the disadvantages of the prior art ceramic kettle that water seeps into the electric heating film, causing electric arc damage to the electric heating film and leakage injury. After 60 days of 24-hour uninterrupted aging testing, it was shown that the kettle body made by the present invention was intact, and the power attenuation of 1000W was less than 30W.

Description

Technical Field

[0001] The present invention relates to a kettle, in particular to an electric heating film ceramic kettle and a preparation method thereof. Background Art

[0002] Prior art discloses an electric heating film that is directly sprayed, brushed, or printed onto the outside of the bottom surface of a ceramic pot. After drying and sintering, it is permanently integrated with the pot. By adjusting the film's formulation, process, film thickness, and film geometry, the heating power of the film can be accurately controlled. A switch can be used to change the series or parallel connection of the film, thereby adjusting the film's power and power density. The film is integrated with the pot, creating a maximum heat transfer surface with minimal thermal resistance. The film itself weighs only about 10 grams, and its heat capacity and energy consumption are negligible. Heat generated by the film is directly absorbed by the pot through thermal conduction, maintaining a constant balanced heating state. This creates a remarkable unidirectional heat transfer effect, resulting in a thermal efficiency of over 70% for ceramic pots heated with electric heating wires, saving over 40% energy. The electric heating film replaces the heating method of electric heating wire, electric stove and electric heating tube, which greatly simplifies the structure of the pot body and significantly reduces the product cost. After the power is turned on, the electric porcelain pot heats the water to 100℃ and boils, but the temperature of the electric heating film is only about 180℃. The temperature difference between the inside and outside of the bottom of the ceramic pot is less than 100℃. This shows that the risk of uneven heating caused by the electric heating wire heating method and the risk of ceramic stress cracking caused by large temperature difference are avoided, which greatly reduces the requirements for the thermal shock resistance of ceramics, making it possible to use ordinary ceramics as the electric heating pot body. Summary of the Invention

[0003] After extensive research, observation, and analysis, the inventors discovered that electric heating film all-ceramic kettles still have the following drawbacks: When the heating power per square centimeter of the bottom of the ceramic kettle reaches 7.5W, it will reach a thermal shock of 400°C within 30 seconds. Therefore, its thermal stability cannot be lower than 500°C. If the vitrification degree is less than 97% and the water absorption rate exceeds 0.3%, water seeping into the electric heating film can cause arcing, resulting in damage to the electric heating film and possible electric leakage and injury. Therefore, the ceramic kettle body must have a thermal stability of above 500°C, a vitrification degree of above 97%, and a water absorption rate of less than 0.3%.

[0004] To this end, the first purpose of the present invention is to provide an electromagnetic membrane kettle that meets people's health and safety standards for drinking water without heavy metal and chemical pollution and also meets aging requirements.

[0005] The second object of the present invention is to provide an electric heating film kettle that can withstand a heating power of 7.5W per square centimeter, a thermal shock of 400°C within 30 seconds, a thermal stability of at least 500°C, a vitrification degree of at least 97%, and a water absorption rate of less than 0.3%.

[0006] The technical solutions for achieving the purpose of the present invention are as follows:

[0007] The present invention provides an electric heating film ceramic kettle, which comprises a ceramic kettle body, a glaze and an electric heating film. The improvement thereof is that, by mass percentage:

[0008] 1) The raw materials for preparing the kettle body include: 50-60% kaolin and 40-50% spodumene;

[0009] Wherein, the kaolin comprises:

[0010] Aluminum oxide 32-38%, silicon dioxide 50-60%; potassium, sodium, calcium, iron and unavoidable impurities less than 10%;

[0011] The spodumene comprises: 5.0-8.5% lithium oxide, 20-25% aluminum oxide, 65-70% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%;

[0012] 2) The raw materials for preparing the glaze include 55-65% spodumene, 5-17% clay, 4-12% barium carbonate, 10-20% silicon dioxide and 8-19% aluminum oxide powder;

[0013] Wherein, the spodumene comprises:

[0014] Lithium oxide 5.0-8.0%, aluminum oxide 20-25%, silicon dioxide 65-70%; potassium, sodium, calcium, iron and unavoidable impurities less than 3.5%;

[0015] The clay comprises: 30-40% aluminum oxide, 50-60% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%;

[0016] 3) The components for preparing the electric heating film include:

[0017] Resin 10-35%, titanium carbide 1-8%, silicon carbide 2-10%, glass powder 2-15%, graphene 2-16%, bismuth oxide 0.1-4%, antimony powder 1-6%, nickel powder 1-5%, graphite 4-50% and additives 0.1-4%.

[0018] in,

[0019] 1) The raw materials for preparing the kettle body include: 55-60% kaolin and 40-55% spodumene;

[0020] Wherein, the kaolin comprises:

[0021] Aluminum oxide 32-36%, silicon dioxide 54-58%; potassium, sodium, calcium, iron and unavoidable impurities less than 10%;

[0022] The spodumene comprises: 6.0-7.5% lithium oxide, 20-23% aluminum oxide, 68-70% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%;

[0023] 2) The raw materials for preparing the glaze include 55-60% spodumene, 6-10% clay, 8-10% barium carbonate, 12-20% silicon dioxide and 9-10% aluminum oxide;

[0024] Wherein, the spodumene comprises:

[0025] Lithium oxide 6.0-7.0%, aluminum oxide 20-23%, silicon dioxide 67-70%; potassium, sodium, calcium, iron and unavoidable impurities less than 3.5%;

[0026] The clay comprises: 33-35% aluminum oxide, 55-58% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%;

[0027] 3) The components for preparing the electric heating film include:

[0028] Resin 15-30%, titanium carbide 2-6%, silicon carbide 3-7%, glass powder 6-15%, graphene 8-16%, bismuth oxide 0.1-3%, antimony powder 4-6%, nickel powder 3-5%, graphite 9-50% and additives 0.1-3%.

[0029] The raw materials of the ceramic kettle body include:

[0030] 1) The raw materials for preparing the kettle body include: 60% kaolin and 40% spodumene;

[0031] Wherein, the kaolin comprises:

[0032] Aluminum oxide 35%, silicon dioxide 55%; potassium, sodium, calcium, iron and unavoidable impurities less than 10%;

[0033] The spodumene comprises: 6.5% lithium oxide, 22% aluminum oxide, 68% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%;

[0034] 2) The raw materials for preparing the glaze include 60% spodumene, 7% clay, 8% barium carbonate, 15% silicon dioxide and 10% aluminum oxide;

[0035] Wherein, the spodumene comprises:

[0036] Lithium oxide 6.5%, aluminum oxide 22%, silicon dioxide 68%; potassium, sodium, calcium, iron and unavoidable impurities less than 3.5%;

[0037] The clay comprises: 35% aluminum oxide, 55% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%;

[0038] 3) The components for preparing the electric heating film include:

[0039] Resin 10-28%, titanium carbide 1-5%, silicon carbide 2-5%, glass powder 2-8%, graphene 2-10%, bismuth oxide 0.1-2%, antimony powder 1-5%, nickel powder 1-2%, graphite 5-50% and additives 0.1-1%.

[0040] The method includes a method for preparing the kettle body and a method for preparing the electric heating film, and is characterized in that the method for preparing the kettle body includes:

[0041] 1) Using the ceramic kettle body raw material and glaze raw material, respectively prepare ceramic kettle body clay and glaze:

[0042] 2) rolling the upper and lower parts of the ceramic kettle into the shape of the upper and lower parts;

[0043] 3) glazing;

[0044] 4) firing; and

[0045] 5) Prepare the electric heating film.

[0046] 5. The method for preparing the electric heating film ceramic kettle according to claim 4, characterized in that:

[0047] The pot body ingredients are ground with a ball mill, passed through a 200-mesh sieve, wherein the sieve residue per kilogram does not exceed 10g, and after preparing mud with water, filter-pressed to form a mud cake, and kneaded in a vacuum kneading machine for three to five times to obtain the pot body mud material;

[0048] The preparation method of the glaze slurry is as follows:

[0049] Prepare a glaze slurry by mixing the glaze with water; the ratio of the glaze to water is 58:42 by weight;

[0050] The glaze slurry is obtained by grinding the glaze material in a ball mill and then passing it through a 300-mesh vibrating sieve.

[0051] Wherein, the firing temperature curve of step 4) is as follows:

[0052]

[0053] Wherein, in said step 5), the preparation method of the electric heating film is as follows:

[0054] The electric heating film raw material at 700-800° C. is printed on the outer bottom of the fired ceramic kettle by screen printing, and then baked in a kiln at 700-800° C. to obtain an electric heating film ceramic kettle.

[0055] The silver paste is printed on the edge of the electric heating film at the bottom of the kettle using a silk screen to prepare independent conductive silver strips with a thickness of 0.09 to 0.11 mm.

[0056] The preparation method of the silver paste includes mixing silver powder, varnish and bismuth oxide in a ratio of 10:3:1 and then baking at 800° C. for one hour.

[0057] Compared with the closest existing technology, the technical solution provided by the present invention has the following excellent effects:

[0058] The outer bottom of the electric heating film-heated ceramic kettle provided by the present invention can withstand a heating power of 7.5W per square centimeter and a thermal shock of 400°C within 30 seconds. Its thermal stability is at least 500°C, its vitrification degree is at least 97%, and its water absorption rate is less than 0.3%, thereby overcoming the disadvantages of the existing ceramic kettle that water seeps into the electric heating film, causing arc damage to the electric heating film and leakage of electricity to injure people.

[0059] In the technical solution provided by the present invention, the amount of low-expansion material spodumene (LiO2 content 5-7%) and the corresponding firing system are added to the ceramic raw materials of the pot body to obtain a vitrification degree of at least 97%, which greatly reduces the gaps between the ceramic particles, increases the density of the heat-resistant porcelain body, and increases the strength, resulting in a water absorption rate of less than 0.3%.

[0060] After 60 days of 24-hour uninterrupted aging testing, it was shown that the kettle body made by the present invention was intact and the power attenuation of 1000W was less than 30W.

[0061] In addition, the detection of heavy metal ions in the boiled water produced by the electromagnetic membrane kettle provided by the present invention fully complies with the drinking water standard.

[0062] In the technical solution of the present invention, since the water content of the clay strips made from the clay material of the pot body does not exceed 20%, the pressed pot bottom should be smooth and flat, and the density of the pot bottom after being porcelainized is high, and the water absorption rate does not exceed 0.3%.

[0063] The invention provides a pot pot with 10% silicon dioxide, thereby improving the strength of the glaze surface of the pot body.

[0064] The present invention adopts 8% clay to ensure the bonding between the glaze and the body, uses 10% silicon dioxide to increase the strength of the glaze, uses 7% barium carbonate to assist in the mutual melting of various components in the glaze to form crystals, and adds 10% high-purity aluminum oxide to prevent excessive glass phase components in the glaze.

[0065] The temperature curve in the technical solution provided by the present invention can enable a lithium molecule to form fine and numerous crystals with several silicon molecules, forming microcrystalline porcelain, which can ensure the thermal stability of the pot body at 500°C and obtain a vitrification degree of 99.7%. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is a structural diagram of Example 1 of an electric heating film all-ceramic kettle of the present invention;

[0067] Figure 2 This is a structural schematic diagram of Example 2 of an electric heating film all-ceramic kettle of the present invention;

[0068] Figure 3 For the present invention Figure 2 Schematic diagram of the structure of the control panel;

[0069] Among them: 1- kettle body, 2- kettle bottom, 3- kettle lid, 4- electric heating film, 5- thermal insulation cotton, 6- kettle handle, 7- power coupler, 8- power supply base, 9- thermocouple, 10- temperature control circuit module, 11- ultrasonic water level sensor, 12- ceramic tube, 13- control panel, 71- coupler housing, 72- metal terminal, 81- base housing, 82- external power cord, 83- coupling interface, 84- control circuit module, 85- water inlet pipe, 86- water supply pump, 87- water adding tap, 101- water inlet, 102- water outlet, 103- kettle handle fixing structure, 301- handle, 302- air vent, 303- positioning step, 131- temperature setting button, 132- fully automatic boiling water button, 133- double-click switch button, 134- temperature display screen, 1311- set 80℃ button, 1312- set 100℃ button. DETAILED DESCRIPTION

[0070] In order to better understand the present invention, the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0071] Example 1

[0072] like Figure 1As shown, an electric heating film all-ceramic kettle comprises: a kettle body, an electric heating film 4, thermal insulation cotton 5, a kettle handle 6 and a power coupler 7; the kettle body comprises a kettle body 1, a kettle bottom 2 and a kettle lid 3, and the surface of the kettle body except the lower surface of the kettle bottom 2 is glazed; the kettle body 1 comprises a water inlet 101 at the top, a kettle bottom assembly port at the bottom, a water outlet 102 at the side and a kettle handle fixing structure 103; the kettle bottom 2 is a flat sheet structure, and the outer edge shape is consistent with the kettle bottom assembly port. The kettle bottom 2 is sealed and connected to the kettle bottom assembly port by mud bonding and fired and fixed to form an integral closed structure with the kettle body 1; the kettle lid 3 comprises air vents 302 and a The handheld handle 301 has a positioning step 303 on its outer edge that cooperates with the water inlet 101; the electric heating film 4 is fixed to the lower surface of the bottom 2 of the pot, and the electric heating film 4 has two electrodes connected to the power cord; the power coupler 7 is fixed under the bottom of the pot and is electrically connected to the electrodes of the electric heating film 4 to connect the power supply; the thermal insulation cotton 5 is fixed to the bottom 2 of the pot and is located between the electric heating film 4 and the power coupler 7, its shape is adapted to the electric heating film 4, and its outer dimensions are larger than the electric heating film 4; the pot handle 6 includes an arc-shaped hollow structure, the upper end of which is connected to the pot body 1 through the pot handle fixing structure 103, and the lower end is connected and fixed to the power coupler 7.

[0073] Preferably, the pot body 1 and pot base 2 are both mechanically rolled. Specifically, the upper portion of the pot body and the pot base 2 are separately rolled and then joined together with mud while still wet to form a complete, sealed ceramic pot. During the production process, the moisture content of the mud strips should be strictly controlled to not exceed 20%. The pressed pot base 2 should be smooth and flat. After being formed into porcelain, the base 2 has a high density and a water absorption rate of no more than 0.3%, effectively preventing water seepage, uneven heating, and subsequent pot explosion.

[0074] Preferably, the electric heating film 4 is screen-printed onto the lower surface of the kettle bottom 2, and then baked in a kiln at 700°C-800°C to set the shape. The heating power is controlled by the area and thickness of the electric heating film 4, as well as the temperature and time during baking. The components of the electric heating material include: 10-28% resin, 1-5% titanium carbide, 2-5% silicon carbide, 2-8% glass powder, 2-10% graphene, 0.1-2% bismuth oxide, 1-5% antimony powder, 1-2% nickel powder, 5-50% graphite, and 0.1-1% additives, etc., which are mixed into a slurry. The addition of highly conductive graphene accelerates the transfer of electricity and heat, which is an important factor in ensuring uniform heating and preventing explosions in the electric ceramic kettle.

[0075] Preferably, the insulation 5 comprises ceramic fiber wool. With a temperature resistance of 1100°C, the insulation 5 is composed of nanoporous insulation material with a thermal conductivity of 0.019 (u / mk). It primarily insulates and preserves heat, protecting the electronic components and the bottom housing while preventing heat from escaping the heating film 4, allowing for faster water heating.

[0076] Preferably, the handle 6 is injection-molded from thermosetting plastic, offering the advantages of high temperature resistance and durability. The handle fixing structure 103 includes a groove structure for snapping in place, which is connected to the handle 5 via a snap-fit ​​structure and secured with heat-resistant structural adhesive. The lower end of the handle 6 is secured to the outer side of the power coupler 7 via screws.

[0077] Preferably, the power coupler 7 comprises a coupler housing 71 connected to the kettle bottom 2 or kettle body and a plurality of metal terminals 72 for transmitting power or control signals. The metal segments 72 are respectively connected to the two electrodes of the electric heating film 4 through wires.

[0078] Preferably, the electric heating film all-ceramic kettle also includes a power supply base 8 for connecting to a power source, the power supply base includes a shell 81, an external power cord 82 and a coupling interface 83, and the coupling interface 83 is connected to the power coupler 7.

[0079] The present invention adopts a connection method of separating the bottom and the body of the pot and then gluing and sintering them, so that the bottom of the pot can be rolled into a blank by mechanical rolling. The pressed bottom of the pot should be smooth and flat. After being porcelainized, the density of the bottom of the pot is high and the water absorption rate will not exceed 0.3%, which can effectively avoid the problem of water seepage and pot explosion.

[0080] Example 2

[0081] like Figure 2 As shown, an electric heating film all-ceramic kettle comprises: a kettle body, an electric heating film 4, thermal insulation cotton 5, a kettle handle 6 and a power coupler 7; the kettle body comprises a kettle body 1, a kettle bottom 2 and a kettle lid 3, and the surface of the kettle body except the lower surface of the kettle bottom 2 is glazed; the kettle body 1 comprises a water inlet 101 at the top, a kettle bottom assembly port at the bottom, a water outlet 102 at the side and a kettle handle fixing structure 103; the kettle bottom 2 is a flat sheet structure, and the outer edge shape is consistent with the kettle bottom assembly port. The kettle bottom 2 is sealed and connected to the kettle bottom assembly port by mud bonding and fired and fixed to form an integral closed structure with the kettle body 1; the kettle lid 3 comprises air vents 302 and a The handheld handle 301 has a positioning step 303 on its outer edge that cooperates with the water inlet 101; the electric heating film 4 is fixed to the lower surface of the bottom 2 of the pot, and the electric heating film 4 has two electrodes connected to the power cord; the power coupler 7 is fixed under the bottom of the pot and is electrically connected to the electrodes of the electric heating film 4 to connect the power supply; the thermal insulation cotton 5 is fixed to the bottom 2 of the pot and is located between the electric heating film 4 and the power coupler 7, its shape is adapted to the electric heating film 4, and its outer dimensions are larger than the electric heating film 4; the pot handle 6 includes an arc-shaped hollow structure, the upper end of which is connected to the pot body 1 through the pot handle fixing structure 103, and the lower end is connected and fixed to the power coupler 7.

[0082] Preferably, the insulation 5 comprises ceramic fiber wool. With a temperature resistance of 1100°C, the insulation 5 is composed of nanoporous insulation material with a thermal conductivity of 0.019 (u / mk). It primarily insulates and preserves heat, protecting the electronic components and the bottom housing while preventing heat from escaping the heating film 4, allowing for faster water heating.

[0083] Preferably, the power coupler 7 includes a coupler housing 71 connected to the kettle bottom 2 or the kettle body and a plurality of metal terminals 72 fixed on the coupler housing 71 for transmitting power or control signals.

[0084] Preferably, the electric heating film all-ceramic kettle also includes: a thermocouple 9 fixed on the surface of the electric heating film 4 and a temperature control circuit module 10 fixed in the power coupler 7 and connected in series with the power line; the temperature control circuit module 10 is electrically connected to the thermocouple 9 to receive the temperature signal.

[0085] Preferably, the electric heating film all-ceramic kettle further includes: an ultrasonic water level sensor 11 installed in the kettle handle 6 and connected to the power coupler 7.

[0086] Preferably, the kettle body 1 includes a ceramic tube 12 embedded in its side wall for mounting a thermistor.

[0087] Preferably, there is thermal grease between the inner wall of the ceramic tube and the thermistor (not shown in the figure) for detecting water temperature to fill the gap and improve the thermal conductivity.

[0088] Preferably, a high-temperature thermally conductive adhesive is provided between the mouth of the ceramic tube and the thermistor for fixing and sealing.

[0089] Preferably, the electric heating film all-ceramic kettle further includes a power supply base 8 connected thereto via the power coupler 7 .

[0090] Preferably, the power supply base 8 includes a base shell 81, a control panel 13 located on the upper surface of the base shell 81, a coupling interface 83 located on the upper surface of the base shell and cooperating with the power coupler, a control circuit module 84 electrically connected to the control panel and the coupling interface 83, and an external power cord 82 connected to the control circuit module 84 to connect to the power supply.

[0091] Furthermore, the power supply base 8 also includes a water inlet pipe 85 that passes through and is fixed to the base shell, a water supply pump 86 located inside the base shell 81 and connected to the water inlet pipe 85, and a water filling tap 87 fixed on the upper surface of the base shell 81 and connected to the water supply pump 86; the water supply pump 86 is connected to the control circuit module 84 to obtain power supply and control signals.

[0092] like Figure 3As shown, the control panel 13 includes a temperature setting button 131, a fully automatic water boiling button 132, a double-click switch button 133, and a temperature display screen 134. The temperature setting button 131 includes a setting 80°C button 1311 and a temperature setting 100°C button 1312. The temperature display screen 134 is used to display the water temperature.

[0093] 1. Preparation of clay and glaze for the pot body

[0094] ⑴ Material selection and production of the body clay: Select several types of kaolin with good plasticity and containing more than 35% of aluminum oxide as the adhesive material, accounting for 55%. Spodumene, a low-expansion material containing 6-7.5% lithium dioxide, is used at 45%, ensuring that the lithium dioxide content in the body clay is not less than 2.6%.

[0095] The content of aluminum oxide should not be less than 36%, the content of silicon dioxide should not be less than 60%, the content of potassium, sodium and iron should not exceed 1.4%, and the content of iron should be less than 0.2 mg per kilogram. It should be ground into a 200-mesh sieve with a ball mill, and the residue per kilogram should not exceed 10 g. Then it should be iron-removed. The mud should be filtered into a mud cake and then smelted in a vacuum mud machine for more than three times to make mud strips for later use.

[0096] (2) The glaze is made of spodumene with a lithium dioxide content of 6.5%, accounting for 60%, ensuring that the lithium dioxide content in the glaze is not less than 3.8%. 8% high-quality clay is used to ensure the bonding between the glaze and the body, 10% high-purity silica is added to increase the strength of the glaze surface, and 7% barium carbonate is used to assist the various components in the glaze to melt and form crystals. In order to prevent excessive glass phase components in the glaze surface, 10% high-purity aluminum oxide powder is added. The glaze is added to the ball mill and finely ground. The glaze slurry is required to pass a 300-mesh vibrating screen. The ratio of glaze to water is 58:42.

[0097] 2. Pot body molding:

[0098] The body of a teapot typically has a small mouth, a large belly, and a spout and handle that cannot be mechanically rolled. The usual method is to use a plaster model slipcasting method, where mud settles and accumulates, and the water is absorbed by the plaster to form the pot. However, this method creates a loose body, making uniform shrinkage during drying and firing difficult. This not only hinders the installation of the bottom shell, but also creates micropores in the porcelainized bottom that can leak water, causing leakage and shortening the life of the heating film. Therefore, the body must be mechanically rolled. Specifically, the upper body (body and lid) and the bottom (bottom) are rolled separately, and then joined with mud while still wet to form the complete body. During the production process, the moisture content of the mud strips must be strictly controlled to no more than 20%. The pressed bottom should be smooth and flat, and the porcelainized bottom has a high density, with a water absorption rate of no more than 0.3%.

[0099] 3. Setting the temperature rise curve for firing the pot body:

[0100] To produce a ceramic pot with a thermal stability of 500°C and a vitrification degree of 99.7%, in addition to preparing the clay and glaze, the temperature curve during firing is crucial. The principle is that at the critical temperature for porcelain formation, the finer and more numerous the crystals formed by a lithium molecule and several silicon molecules become, the more microcrystalline porcelain is formed, and the thermal stability and vitrification degree will meet the requirements. We use a 20-cubic-meter drawer kiln with computer-controlled temperature and time. The established temperature curve is as follows:

[0101] normal temperature 3 hours 300℃ 2 hours 800℃ 3 hours 1000℃ 3 hours 1100℃ 3 hours 1180℃ 3 hours 1250℃ 3 Hour 1300℃ 6 hours 800℃ kiln door opening Several hours Normal temperature.

[0102] 4. Preparation method of electric heating film on the bottom of ceramic kettle:

[0103] (1) Use a diamond sand grinding disc to smooth the bottom of the ceramic pot. The thickness of the bottom of the pot should be controlled between 5-6mm. The bottom of the pot should be flat and smooth without any bumps. Make the shape shown in the figure and use a screen to print silver paste on the bottom of the pot to form a conductive silver strip with a thickness of about 0.1mm. The preparation method of silver paste is to mix 100g of ultrafine silver powder with 30g of ink oil. Since the melting point of silver is 930℃, 10g of bismuth oxide is added and baked at 800℃ for one hour.

[0104] (2) The common method of electric heating film is thermal spraying:

[0105] An insulating material is heated to 700-800°C, then a slurry of electric heating material is sprayed onto the object. However, conventional ceramic products cannot withstand such rapid heating and cooling, resulting in a high breakage rate. Furthermore, hydrochloric acid and chloride in the electric heating material can vaporize and evaporate, polluting the processing environment and harming the health of operators. Therefore, we use environmentally friendly electric heating material to form a slurry, screen-print it onto the outside bottom of the ceramic pot, and then bake it in a kiln at 700-800°C. The printed effect is shown below. The heating power is controlled by the size and thickness of the electric heating film, as well as the baking temperature and duration. The electric heating material is composed of: 10-28% resin and 1-5% titanium carbide. Silicon carbide 2-5%, glass powder 2-8%, graphene 2-10%, bismuth oxide 0.1-2%, antimony powder 1-5%, nickel powder 1-2%, graphite 5-50%, additives 0.1-1% are prepared into a slurry. The addition of highly conductive material graphene accelerates the transfer of electricity and heat, which is an important factor in ensuring uniform heating of the electric ceramic kettle and preventing the kettle from exploding.

[0106] 5. Assembly method of electric ceramic kettle

[0107] (1) Conductive wire welding method

[0108] The conductive wire is welded to both ends of the silver bar using solder wire using an electric soldering iron. The welding should be firm enough to withstand a pulling force of 5 kg without falling off.

[0109] (2) The role of thermal insulation cotton

[0110] The insulation cotton is heat-resistant to 1100°C and is made of nano-porous insulation material with a thermal conductivity of 0.019 (u / mk). It is mainly used for insulation and heat preservation. It protects electronic components and the bottom shell, and prevents the heat of the electric heating film from escaping, making the water boil faster.

[0111] (3) Assembly of temperature measuring thermistor

[0112] Typically, stainless steel and glass electric kettles have a metal thermistor mounted on a stainless steel heating plate at the bottom of the kettle. However, our ceramic kettle features a 7mm long, 1mm thick, 6mm deep ceramic cylinder mounted on the inner wall. This cylinder is fired simultaneously with the kettle body and serves to facilitate the thermistor's installation. Thermal grease is applied to the cylinder's hole and then secured with high-temperature thermal adhesive. This installation method allows for precise control of the boiling water temperature, achieving a boil at 98°C and a stop at 100°C, while also eliminating any metal or plastic components from the ceramic kettle.

[0113] 6. Overheat protection setting

[0114] Overheat protection is achieved by using a thermocouple to detect the temperature of the heating film. The control panel sets the temperature to protect the ceramic kettle and the heating film from overheating. When the control panel sets the protection temperature to 380°C, the heating film will not rise above 380°C, effectively protecting the ceramic kettle and the heating film. The thermocouple is installed under the insulation cotton and fixed to the heating film with a heat-resistant ceramic buckle to achieve effective temperature control.

[0115] 7. Anti-dry burning setting

[0116] Boiling dry without water can damage the kettle. Electric kettles typically implement dry-boiling prevention using spring-loaded switches, pressure switches, electronic scales, and stainless steel signal cables installed inside the kettle. However, implementing this method in a fully ceramic kettle presents technical limitations and challenges. This fully ceramic kettle utilizes a novel, non-contact ultrasonic water level sensor. This sensor, mounted on the outside of the kettle, detects the presence of water through ultrasonic feedback to the control cable base. If no water is detected, the kettle stops heating. Only when water is present does the kettle heat up, achieving the same dry-boiling prevention effect as a fully ceramic kettle.

[0117] 8. Automatic control of water level

[0118] Automatic water level control is achieved by feeding signals from an ultrasonic water level detector to the control base. Double-clicking the on / off switch on the control panel and then pressing the fully automatic water boiling button activates the ultrasonic water level detector. Regardless of the amount of water in the all-ceramic kettle, it automatically fills the kettle with water until it reaches the water level detector, effectively achieving intelligent water addition. The ultrasonic water level detector is installed inside the handle, aligning with the water level inside the kettle.

[0119] The preferred formula of the kettle body, glaze and electric heating film of the electric heating film all-ceramic kettle in terms of mass percentage is as follows:

[0120] Preparation of raw materials

[0121] 1. The raw materials for preparing the kettle body include: 55% kaolin and 45% spodumene;

[0122] The kaolin comprises 35% of aluminum oxide, 55% of silicon dioxide, and less than 10% of potassium, sodium, calcium, iron and inevitable impurities.

[0123] The spodumene comprises 6.5% lithium oxide, 22% aluminum oxide, 68% silicon dioxide, and a small amount of potassium, sodium, calcium, iron and unavoidable impurities exceeding 3.5%.

[0124] 2. The raw materials for preparing the glaze include 60% spodumene, 7% clay, 8% barium carbonate, 15% silicon dioxide and 10% aluminum oxide;

[0125] The spodumene comprises 6.5% lithium oxide, 22% aluminum oxide, 68% silicon dioxide, and a small amount of potassium, sodium, calcium, iron and inevitable impurities exceeding 3.5%.

[0126] The clay comprises 35% of aluminum oxide, 55% of silicon dioxide, and less than 10% of potassium, sodium, calcium, iron and inevitable impurities.

[0127] 3. The electric heating film is made of the following components:

[0128] Resin 20%, titanium carbide 4%, silicon carbide 5%, glass powder 8%, graphene 10%, bismuth oxide 2%, antimony 5%, nickel 2%, graphite 43% and additive 1%.

[0129] The preparation method of the electric heating film all-ceramic kettle includes:

[0130] 1. Prepare the clay slurry for the ceramic kettle body:

[0131] The clay material for the pot body is ball-milled through a 200-mesh sieve, and the residue per kilogram is no more than 10 g. The clay is then filtered with water to form a slurry with a water content of 18%, and the clay cake is slurried three to five times in a vacuum slurry machine to obtain the clay material for the pot body.

[0132] 2. Use a machine to roll the upper and bottom parts of the pot into shape:

[0133] The pot body slurry is rolled and formed into two shapes, the upper part and the bottom part of the pot body respectively. When the rolled upper part and the bottom part of the pot body are still wet, the upper part and the bottom part of the pot body are joined into one pot body using the prepared pot body mud.

[0134] 3. Glaze making:

[0135] The glaze was prepared in a mass ratio of glaze to water of 58:42, and then ball-milled to a size of 300 mesh to obtain the glaze slurry.

[0136] 4. Glazing

[0137] 5. Firing according to the following system:

[0138]

[0139] 6. Prepare the electric heating film. The preparation method of the electric heating film is as follows:

[0140] The electric heating film raw material heated to 700-800°C is printed on the outer bottom of the fired ceramic kettle by screen printing, and then baked in a kiln at 700°C to obtain an electric heating film all-ceramic kettle.

[0141] Example 3

[0142] An all-ceramic kettle with an electric heating film is the same as Example 2, except that the kettle body raw materials, glaze and electric heating film components listed in Tables 1-3 below are used, and the electric heating film is prepared by screen printing, the electric heating film raw materials heated to 75°C are printed on the outer bottom of the fired ceramic kettle, and then the kettle is baked in a kiln at 750°C to obtain the all-ceramic kettle with an electric heating film.

[0143] Table 1: Formula of clay material for the body of the electric heating film all-ceramic kettle provided by the present invention (by mass percentage)

[0144]

[0145]

[0146] Table 2: Glaze formula applied to the body of the electric heating film all-ceramic kettle of the present invention (by mass percentage)

[0147]

[0148] Table 3: Formula of the electric heating film of the electric heating film all-ceramic kettle body of the present invention

[0149]

[0150] Example 4

[0151] An electric heating film all-ceramic kettle is different from Example 3 in that the electric heating film raw material heated to 80°C is printed on the outer bottom of the fired ceramic kettle, and then baked in a kiln at 800°C to obtain the electric heating film all-ceramic kettle. Other differences are the same as Example 3.

[0152] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. An electric heating film ceramic kettle, comprising a ceramic kettle body, glaze and an electric heating film, characterized in that: By mass percentage: 1) The raw materials for preparing the kettle body include: 50-60% kaolin and 40-50% spodumene; The kaolin comprises: 32-38% aluminum oxide, 50-60% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%; The spodumene comprises: 5.0-8.5% lithium oxide, 20-25% aluminum oxide, 65-70% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%; 2) The raw materials for preparing the glaze include 55-65% spodumene, 5-17% clay, 4-12% barium carbonate, 10-20% silicon dioxide, and 8-19% aluminum oxide powder; The spodumene comprises: 5.0-8.0% lithium oxide, 20-25% aluminum oxide, 65-70% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%; The clay comprises: 30-40% aluminum oxide, 50-60% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%; 3) The components for preparing the electric heating film include: 10-35% resin, 1-8% titanium carbide, 2-10% silicon carbide, 2-15% glass powder, 2-16% graphene, 0.1-4% bismuth oxide, 1-6% antimony powder, 1-5% nickel powder, 4-50% graphite and 0.1-4% additives.

2. An electric heating film ceramic kettle as claimed in claim 1, characterized in that: 1) The raw materials for preparing the kettle body include: 55-60% kaolin and 40-45% spodumene; The kaolin comprises: 32-36% aluminum oxide, 54-58% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%; The spodumene comprises: 6.0-7.5% lithium oxide, 20-23% aluminum oxide, 68-70% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%; 2) The raw materials for preparing the glaze include 55-60% spodumene, 6-10% clay, 8-10% barium carbonate, 12-20% silicon dioxide, and 9-10% aluminum oxide; The spodumene comprises: 6.0-7.0% lithium oxide, 20-23% aluminum oxide, 67-70% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%; The clay comprises: 33-35% aluminum oxide, 55-58% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%; 3) The components for preparing the electric heating film include: 15-30% resin, 2-6% titanium carbide, 3-7% silicon carbide, 6-15% glass powder, 8-16% graphene, 0.1-3% bismuth oxide, 4-6% antimony powder, 3-5% nickel powder, 9-50% graphite and 0.1-3% additives.

3. An electric heating film ceramic kettle as claimed in claim 1, characterized in that: The raw materials of the ceramic kettle body include: 1) The raw materials for preparing the kettle body include: 60% kaolin and 40% spodumene; The kaolin comprises: 35% aluminum oxide, 55% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%; The spodumene comprises: 6.5% lithium oxide, 22% aluminum oxide, 68% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%; 2) The raw materials for preparing the glaze include 60% spodumene, 8% clay, 7% barium carbonate, 15% silicon dioxide and 10% aluminum oxide; The spodumene comprises: 6.5% lithium oxide, 22% aluminum oxide, 68% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 3.5%; The clay comprises: 35% aluminum oxide, 55% silicon dioxide; potassium, sodium, calcium, iron and unavoidable impurities are less than 10%; 3) The components for preparing the electric heating film include: Resin 10-28%, titanium carbide 1-5%, silicon carbide 2-5%, glass powder 2-8%, graphene 2-10%, bismuth oxide 0.1-2%, antimony powder 1-5%, nickel powder 1-2%, graphite 5-50% and additives 0.1-1%.

4. The method for preparing an electric heating film ceramic kettle according to any one of claims 1 to 3, comprising a method for preparing the kettle body and a method for preparing the electric heating film, characterized in that: The preparation method of the kettle body comprises: 1) Prepare the ceramic kettle body clay and glaze respectively using the ceramic kettle body raw material and glaze raw material: 2) rolling the upper and bottom portions of the ceramic kettle into respective shapes; 3) glazing; 4) firing; and 5) Prepare electric heating film.

5. The method for preparing the electric heating film ceramic kettle according to claim 4, characterized in that: The pot body ingredients are ground with a ball mill, passed through a 200-mesh sieve, wherein the sieve residue per kilogram does not exceed 10g, and the mud is prepared with water and filtered to form a mud cake, and then slurried in a vacuum slurry machine for three to five times to obtain the pot body mud material; The preparation method of the glaze slurry is as follows: The glaze is prepared into a glaze slurry with water; the ratio of the glaze to water is 58:42 by weight; After the glaze is finely ground in a ball mill, it is passed through a 300-mesh vibration sieve to obtain the glaze slurry.

6. The method for preparing the electric heating film ceramic kettle according to claim 4, characterized in that: The firing system of step 4) is as follows:

7. The method for preparing an electric heating film ceramic kettle according to claim 4, characterized in that: The method for preparing the electric heating film in step 5) includes: The electric heating film raw material at 700-800° C. is printed on the outer bottom of the fired ceramic kettle by screen printing, and then baked in a kiln at 700-800° C. to obtain an electric heating film ceramic kettle.

8. The method for preparing an electric heating film ceramic kettle according to claim 4, characterized in that: Silver paste is printed on the outer edge of the electric heating film at the bottom of the prepared kettle using a silk screen to prepare independent conductive silver strips with a thickness of 0.09 to 0.11 mm. The preparation method of the silver paste includes mixing silver powder, varnish and bismuth oxide in a ratio of 10:3:1 and then baking at 800°C for one hour.

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