CN114195493A

CN114195493A - Preparation method of porous ceramic atomizing core, ceramic atomizing core and application thereof

Info

Publication number: CN114195493A
Application number: CN202111500508.4A
Authority: CN
Inventors: 陈湖; 陆文龙
Original assignee: Shenzhen Geekvape Technology Co Ltd
Current assignee: Shenzhen Geekvape Technology Co Ltd
Priority date: 2021-12-09
Filing date: 2021-12-09
Publication date: 2022-03-18

Abstract

The application discloses a preparation method of a porous ceramic atomizing core, the ceramic atomizing core and application thereof. The method comprises the steps of weighing a mixture and a molten material; uniformly mixing the mixture, and preheating; melting the molten material, adding the preheated mixture, and uniformly mixing to prepare slurry; putting the resistance circuit containing the electrode or the lead into a mould, and injecting slurry to prepare a green body; sintering the green body, and cleaning to obtain a porous ceramic atomizing core; wherein the mixture comprises 40-65% of fused quartz, 10-25% of low-temperature glass powder and 15-35% of pore-forming agent by total mass; the melting material comprises paraffin and/or beeswax, and the dosage of the melting material is 19-35% of the mass of the mixture. According to the method, the formula of the porous ceramic slurry is optimized, so that the prepared ceramic atomizing core has uniform pore size distribution and good open porosity, and has good permeability, tobacco tar can quickly permeate and is transmitted to the edge of a resistance circuit, so that the tobacco tar can be quickly supplemented, overhigh temperature is prevented, and harmful components are reduced.

Description

Preparation method of porous ceramic atomizing core, ceramic atomizing core and application thereof

Technical Field

The application relates to the technical field of electronic atomization, in particular to a preparation method of a porous ceramic atomizing core, the ceramic atomizing core and application thereof.

Background

An electronic atomization device, namely an electronic cigarette, is an electronic product simulating a cigarette, and the electronic atomization device is powered by a battery to drive an atomizer to heat tobacco tar so as to change cigarette components such as nicotine into steam for use. Therefore, the electronic atomization device can have the appearance, smoke and taste of a cigarette.

The atomizing core is a core component for generating smoke in the electronic atomizing device, the smoke is converted into the smoke in an electric heating mode after the smoke is injected, and the quality of the generated smoke is directly determined by the performance of the atomizing core. The atomizing core can be divided into an etching net-covered cotton atomizing core and a porous ceramic atomizing core according to the material. The porous ceramic atomizing core has the advantages of large atomizing steam amount, good continuity, good heating effect, energy conservation, long service life and the like, and is widely researched and applied.

However, in the existing research and report on ceramic atomizing cores, general attention and research are paid to how to bring better mouthfeel to consumers, and even many enterprises seek to obtain better mouthfeel at a glance, so that harmful ingredients generated in the atomizing process are directly ignored. The main components of the tobacco tar are propylene glycol, glycerol and a small amount of essence and nicotine, and the substances can generate components harmful to human bodies, such as formaldehyde, acetaldehyde, acrolein and the like after exceeding a certain temperature.

Therefore, how to reduce the harmful ingredients generated by the atomization of the tobacco tar is a problem to be solved in the field.

Disclosure of Invention

The object of the present application is to provide an improved method for the production of porous ceramic atomizing cores, as well as ceramic atomizing cores produced thereby and the use thereof.

The following technical scheme is adopted in the application:

one aspect of the application discloses a preparation method of a porous ceramic atomizing core, which comprises the steps of weighing a mixture and a molten material according to a mass ratio; uniformly mixing all components in the mixture, and preheating; heating and melting the molten material, adding the preheated mixture, and uniformly stirring to obtain slurry; placing a resistance circuit containing an electrode or a lead into a mould, injecting the prepared slurry, and integrally forming by using the mould to prepare a green body; sintering the green body, and cleaning the green body after sintering to obtain the porous ceramic atomizing core; wherein the mixture comprises 40-65% of fused quartz, 10-25% of low-temperature glass powder and 15-35% of pore-forming agent by mass percent; the melting material comprises paraffin and/or beeswax, and the dosage of the melting material is 19-35% of the mass of the mixture.

It should be noted that, the research of this application finds that the main reason that the tobacco tar generates the harmful components due to the atomization of the tobacco tar is that the porous ceramic atomization core has high temperature in some parts, and the high temperature causes the tobacco tar to generate the harmful components. Therefore, according to the preparation method, the formula is optimized, so that the porous ceramic atomizing core obtained by sintering has uniform pore size distribution and good open porosity, the porous ceramic atomizing core has good permeability, tobacco tar can quickly permeate the porous ceramic and is transmitted to the edge of a resistance circuit, the tobacco tar can be quickly supplemented, the temperature is prevented from being overhigh, and the generation and release of harmful components are reduced. In one implementation mode of the application, the flue gas is collected according to the AFNOR standard to determine the content of aldehyde compounds and heavy metals in the flue gas, wherein the aldehyde compounds comprise formaldehyde, acetaldehyde and acrolein, and the heavy metals comprise lead, chromium, nickel, cadmium, arsenic and antimony, the result is judged according to the TPD (tire pressure monitor) regulation, and the result shows that the harmful components in the flue gas generated by the porous ceramic atomizing core are below the limit value or are not detected. Therefore, the porous ceramic atomizing core obtained by the preparation method can reduce harmful components generated by tobacco tar atomization.

It should be further noted that in the preparation method of the present application, the fused quartz and the low-temperature glass powder are main structures of the porous ceramic atomizing core, during the high-temperature sintering process, the molten material and the pore-forming agent are discharged in sequence, and the low-temperature glass powder is completely or partially melted to bond the fused quartz. Therefore, the porous ceramic atomizing core can meet the required mechanical strength by optimizing the use amount of each component; moreover, a porous structure with uniform micropore distribution, concentrated pore size, mainly distributed at 10-20 microns and open porosity of 50-60% can be formed; make the porous ceramic atomizing core of this application have good permeability, tobacco tar can permeate porous ceramic fast, transmits resistance line border, can supply fast, prevents advantages such as high temperature.

It is understood that too high amounts of fused silica and low temperature glass frits reduce porosity; too low an amount will reduce the mechanical strength of the porous ceramic atomizing core. The pore former is contrary to the pore former, and the mechanical strength is reduced although higher porosity can be obtained when the amount of the pore former is too high; if the amount is too low, the porosity is lowered. The molten material is used as an auxiliary agent for green body forming, and the shrinkage after sintering is large when the using amount is too high, so that the product size is unstable, and the mechanical strength after sintering is reduced; the dosage is too low to be beneficial to molding, and the production difficulty is increased.

In one implementation of the present application, the molten material is composed of paraffin wax in an amount of 18-30% by mass of the mixture and beeswax in an amount of 1-5% by mass of the mixture.

In one implementation of the present application, the particle size D50 of the fused silica is 10-100 microns, the particle size D50 of the low-temperature glass powder is 3-20 microns, and the particle size D50 of the pore-forming agent is 15-70 microns.

It should be noted that in the preparation method of the porous ceramic atomizing core, as the particle sizes of the fused quartz and the low-temperature glass powder are increased, the pore diameter of the formed ceramic atomizing core is increased, and the porosity tends to be reduced; as the particle size of the pore-forming agent is increased, the aperture of the formed ceramic atomizing core is increased, and the porosity of the open pores is increased. Oil leakage is easy to occur due to too large aperture and too high porosity, but unsmooth oil conduction is caused due to too small aperture and too low porosity of the opening, so that too high temperature is caused, and harmful substances are released. Therefore, the particle size D50 of fused silica is 10-100 microns, the particle size D50 of low-temperature glass powder is 3-20 microns, and the particle size D50 of pore-forming agent is 15-70 microns.

In one implementation of the present application, the pore former is at least one of polymethylmethacrylate (abbreviated PMMA), polystyrene (abbreviated PS), flour, starch, and wood chips.

It should be noted that in the preparation method of the present application, the pore-forming agent is used to form pores, thereby increasing the porosity; accordingly, pore formers used in general porous ceramics may be used in the present application. PMMA, PS, flour, starch, and wood chips are only proven pore formers specifically employed in one implementation of the present application, not to preclude the use of other pore formers as well.

In one implementation manner of the present application, the method further includes adding oleic acid, which accounts for one-thousandth to three-thousandth of the mass of the mixture, to the preheated mixture in the molten material during stirring.

In the preparation method, the oleic acid mainly plays a role of a dispersing agent, so that the uniformity of the slurry can be improved, and the stirring time can be shortened; can be added according to the requirement. It is to be understood that oleic acid is only a dispersant specifically employed in one implementation of the present application, and does not preclude the use of other dispersants of similar effect, and is not specifically limited herein.

In one implementation of the present application, the preheat temperature of the mix is 70-90 ℃.

It should be noted that, in the preparation method of the present application, on one hand, preheating the mixture is convenient for placing the mixture into the molten material at an approximate temperature in the following process, so as to avoid the influence on uniformity of the slurry caused by changes in the physical state of the molten material due to too low temperature of the mixture; on the other hand, the water can be further dried to remove the possible residual water, so that the influence of the water on the subsequent pore-forming is avoided.

In one implementation of the present application, the slurry is stored at a constant temperature of 65-80 ℃ prior to injection into the mold, and stirring is continued during storage.

It will be appreciated that the preservation of the slurry at constant temperature is primarily intended to allow the molten mass to penetrate sufficiently into the mix, while preventing solidification. Stirring is continued during the heat preservation process, and the aim is to maintain the uniformity of the slurry and the consistency of the product.

In one implementation of the present application, the resistive circuit is designed using an arc transition.

It should be noted that in the preparation method of the present application, the resistance line may be designed according to the requirement, that is, the shape of the resistance line may be variable; however, preferably, when the circuit is designed, the resistance line is designed in an arc transition manner for a place where energy is easily concentrated, so that local overhigh temperature caused by heat concentration can be avoided, and generation and release of harmful substances are further reduced.

In one implementation of the present application, sintering includes placing the green body into a sagger, covering with a burnout powder, and then sintering in a debindering sintering furnace.

It is understood that the above sintering method is only a specific sintering method used in one implementation of the present application, and does not exclude that other sintering methods may also be used.

Preferably, the sintering condition of the method is that the temperature is raised to 180-250 ℃ at the speed of 1-3 ℃/min, the temperature is kept for 30-120min, and wax is discharged; then raising the temperature to 400-450 ℃ at the speed of 2-5 ℃/min, preserving the temperature for 30-120min, and discharging the pore-forming agent; heating to 600-680 ℃ at the speed of 3-8 ℃/min, and preserving the heat for 5-30min to ensure that the low-temperature glass powder is partially or completely melted into a liquid phase to bond the fused quartz particles; and then, cooling to below 50 ℃ along with the furnace, and finishing sintering.

It should be noted that in the preparation method, the optimization of the formula lays a material foundation for preparing the porous ceramic atomizing core with good permeability and capable of quickly transferring and supplementing the tobacco tar; another key to the present application is that the above effects are further ensured and enhanced by an optimized sintering scheme. That is to say, adopt the sintering condition of this application, can prepare the permeability and be more excellent, can prevent more effectively that local high temperature from atomizing the core.

In an implementation of this application, wash including, clear away the powder of burning of burying to adopt ultrasonic cleaning clean, then dry, obtain the porous ceramic atomizing core of this application promptly.

In an implementation manner of the application, the preparation method further comprises the step of removing metal oxide skin formed on the surface of the electrode or the lead by laser etching after sintering, so that contact resistance is reduced.

The other side of the application discloses a ceramic atomizing core prepared by the preparation method.

It can be understood that the ceramic atomizing core of this application, owing to adopt the preparation method of this application to obtain, consequently, it is good to have the permeability, and tobacco tar can permeate porous ceramic fast, transmits resistance circuit border, can supply fast, prevents the high temperature to have the effect that reduces the harmful component and generate and release in the tobacco tar atomization process.

The application further discloses an atomizer or electronic atomization device adopting the ceramic atomization core.

The electronic atomization device is particularly referred to as an electronic cigarette, and generally comprises two parts, namely an atomizer and a battery rod; the atomizer of the present application refers to a portion for atomizing a liquid, and a battery rod, i.e., a battery case, is used to supply power to the atomizer, and is also referred to as a power supply device. The atomizer and the battery case of the present application may be detachable or not detachable, and are not specifically limited herein. The atomizing core or the ceramic atomizing core is a core component of the atomizer and is also a component mainly used for atomizing liquid, and the atomizer comprises a liquid storage cavity, an air passage, a cigarette holder and other components besides the ceramic atomizing core, and is not particularly limited herein. The electronic atomization device comprises an electronic atomization device which refers to an electronic cigarette in particular, and a device which atomizes other liquid or medicines except tobacco tar. It is understood that the ceramic atomizing core of the present application is not limited to the electronic atomizing device, but is also applicable to other similar devices requiring atomization of liquid or medicine, and is not limited thereto.

Still need explain, the electronic atomization equipment of this application, owing to adopt the ceramic atomization core of this application, it is good to have the permeability, and liquid can permeate porous ceramic fast, transmits resistance circuit border, can supply fast, prevents the high temperature, has the controllable advantage of temperature.

The beneficial effect of this application lies in:

the preparation method of the porous ceramic atomizing core enables the ceramic atomizing core obtained by sintering to have uniform pore size distribution and good open porosity through optimization of the formula of the porous ceramic slurry, so that the porous ceramic atomizing core has good permeability, tobacco tar can quickly permeate the porous ceramic, is transmitted to the edge of a resistance circuit, can be quickly supplemented, prevents overhigh temperature, and further reduces generation and release of harmful components. The preparation method lays a foundation for preparing the safer electronic atomization device.

Drawings

FIG. 1 is a schematic structural view of a porous ceramic atomizing core in an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a resistor circuit in an embodiment of the present application;

FIG. 3 is a scanning electron micrograph of the surface of a porous ceramic atomizing core according to an embodiment of the present application;

FIG. 4 is a plot of pore size distribution test data for a porous ceramic atomizing core in an embodiment of the present application;

FIG. 5 is a plot of pore size distribution test data for another porous ceramic atomizing core of the present examples.

Detailed Description

The present application will be described in further detail with reference to specific examples. The following examples are intended to be illustrative of the present application only and should not be construed as limiting the present application.

Example one

The porous ceramic atomizing core of the present example is composed of porous ceramic and resistance circuit as shown in fig. 1, and the porous ceramic atomizing core with good permeability is prepared by optimizing the formula and sintering conditions of the porous ceramic. By utilizing excellent permeability, the tobacco tar can quickly permeate the porous ceramic and is transferred to the edge of the resistance circuit; moreover, the tobacco tar can be quickly supplemented, so that overhigh temperature is prevented; the effect of reducing the generation of harmful ingredients in the tobacco tar atomization process is achieved. The specific preparation method of the porous ceramic atomizing core comprises the following steps:

(1) preparing materials: weighing the raw materials according to the mass ratio.

(2) Mixing materials: and (3) putting the weighed fused quartz, the pore-forming agent and the low-temperature glass powder into a mixer for mechanical mixing for not less than 30min to obtain a mixture.

(3) Pulping: putting the mixture into an oven in advance, baking and preserving heat, setting the temperature at 70-90 ℃, drying water and preheating in advance; weighing paraffin and beeswax according to the mass ratio, putting the paraffin and the beeswax into a wax mixer, heating the paraffin and the beeswax until the paraffin and the beeswax are completely molten, gradually adding the mixture preheated in advance into the wax mixer, and continuously stirring the mixture for more than 1 hour to obtain uniform slurry. Oleic acid, which can be selected according to one to three thousandths of the mass of the mixture in the stirring process, plays the role of a dispersing agent, increases the uniformity and shortens the stirring time.

(4) Preparing a blank: and injecting the uniformly stirred slurry into a hot-press casting machine, continuously preserving heat and continuously stirring, setting the heat preservation temperature at 65-80 ℃, putting the pre-processed resistance circuit containing the electrode or the lead into a mold, and pressing the slurry into the mold by using the hot-press casting machine for integral molding to obtain a green body.

(5) And (3) sintering: putting the prepared green body into a sagger, covering the green body with the embedded burning powder, putting the green body into a binder removal sintering furnace, heating to 180 ℃ and 250 ℃ at a speed of 1-3 ℃/min, preserving heat for 30-120min, and removing wax; then raising the temperature to 400-450 ℃ at the speed of 2-5 ℃/min, preserving the temperature for 30-120min, and discharging the pore-forming agent; heating to 600-680 deg.C at 3-8 deg.C/min, maintaining for 5-30min, melting part or all of the low-temperature glass powder into liquid phase, bonding the fused quartz powder, and cooling to below 50 deg.C.

(6) Cleaning and drying: after being taken out of the furnace, the embedded burning powder is removed, cleaned by ultrasonic waves and dried to obtain the porous ceramic atomizing core of the embodiment.

(7) Optionally, electrode radium carving is carried out, specifically, metal oxide skin formed on the surface of the electrode or the lead after high-temperature sintering is removed by adopting laser radium carving, and contact resistance of the electrode is reduced.

In the concrete example, 58% of the total weight of the mixture is weighed to obtain fused quartz, 18% of the total weight of the mixture is weighed to obtain low-temperature glass powder with the particle size D50 being 8 microns, 24% of the total weight of the mixture is weighed to obtain a pore-forming agent, the mixture is placed into a V-shaped mixer to be mixed for 3 hours to prepare a mixture, and the mixture is placed into an oven to be dried at 80 ℃ and preheated in advance. Wherein the fused quartz consists of fused quartz with the particle size D50 of 28 micrometers and fused quartz with the particle size D50 of 75 micrometers which are equal in weight; the pore-forming agent consists of PS powder with the particle size D50 of 20 micrometers and wheat starch with the particle size D50 of 30 micrometers which are equal in weight.

Weighing paraffin wax accounting for 22 percent of the total weight of the mixture and beeswax accounting for 2 percent of the total weight of the mixture, putting the mixture into a wax mixer for heating and melting into liquid, then gradually heating the preheated mixture into the wax mixer, and continuously stirring until the molten material and the mixture are completely and uniformly stirred to prepare slurry. Adding the slurry into a hot-press casting machine, continuously stirring, setting the temperature of the hot-press casting machine at 65 ℃, putting the pre-processed resistance circuit 1 with the electrode 2 into a mould, wherein the resistance value of the resistance circuit is 1.1 omega as shown in figure 2, and pressing the slurry into the mould by the hot-press casting machine for integral molding to obtain a green body.

Wherein, the resistance circuit adopts the arc transition design to the place that the energy is easily concentrated when the design circuit, can avoid local high temperature like this to avoid the harmful substance that leads to from this to generate.

Placing the green body in a sagger, covering the green body with the buried burning powder, putting the green body in a binder removal sintering furnace, heating the green body to 200 ℃ at the speed of 2 ℃/min, and preserving the heat for 120min at the temperature of 200 ℃; then raising the temperature to 450 ℃ at a speed of 3 ℃/min, and preserving the heat for 60min at 450 ℃; then raising the temperature to 650 ℃ at a speed of 3 ℃/min, and preserving the heat for 15min at 650 ℃; stopping heating, and cooling to room temperature along with the furnace.

In this example, 10 porous ceramic atomizing cores were prepared in the same batch according to the above specific formulation and sintering conditions, and the prepared 10 porous ceramic atomizing cores were subjected to porosity and water absorption tests. The test results are shown in table 1.

The existing porosity testing method mainly comprises the following steps: a microscopic analysis method, a direct mass-volume calculation method, a soaking medium method, a floating method and the like, wherein the soaking medium method, namely the Archimedes principle, is specifically adopted in the embodiment.

The water absorption test method comprises the steps of weighing the ceramic atomization core, wherein the weight mark is M1; soaking the ceramic atomizing core in a beaker filled with water, putting the ceramic atomizing core and the beaker into a container, vacuumizing until the vacuum degree reaches-100 Pa, maintaining for 5min, taking out, wiping off surface moisture, weighing again, and marking the weight as M2; the water absorption was calculated according to the following formula:

water absorption (M1-M2) ÷ M1X 100%

TABLE 1 porosity and Water absorption test results for the porous ceramic atomizing core of this example

Sample name	Weight of sample	Open porosity	Water absorption rate
				1#	0.1206g	55.19％	51.58％
2#	0.1207g	56.02％	53.6％
				3#	0.1207g	55.96％	53.27％
4#	0.1212g	55.94％	53.22％
				5#	0.1213g	55.72％	52.18％
6#	0.1205g	56％	53.03％
				7#	0.1206g	56.43％	54.23％
8#	0.12g	56.27％	53.83％
				9#	0.1207g	56.35％	53.69％
10#	0.1205g	56.48％	53.86％

The results in Table 1 show that the 10 porous ceramic atomizing cores prepared in this example have good consistency, and the open porosity is 55% or more and the water absorption is 51% or more. The porous ceramic atomizing core of this example is shown to have good permeability.

The porous ceramic atomizing core prepared in the example was observed by a scanning electron microscope, and the result is shown in fig. 3. The results in FIG. 3 show that the porous ceramic atomizing core prepared in this example has a uniform pore distribution. Further, the pore size and the distribution of the porous ceramic atomizing core prepared in this example were measured by a pore size analyzer (bubble point method), and the data graph of the measurement is shown in fig. 4. The results in fig. 4 show that the porous ceramic atomizing core prepared in this example has a pore size distribution of the through-holes ranging from 5 to 50 microns and a pore size distribution in the range of 10 to 20 microns in a proportion exceeding 80%.

The porous ceramic atomizing core prepared in the embodiment is assembled into an atomizer, a battery rod supplies power and outputs with constant power of 8W, and the aldehyde compounds and the heavy metal content in the flue gas are collected and measured according to the AFNOR standard. Wherein the aldehyde compound comprises formaldehyde, acetaldehyde and acrolein, and the heavy metal comprises lead, chromium, nickel, cadmium, arsenic and antimony. The specific collection and assay methods are referenced to the AFNOR standard.

The results were judged according to the TPD regulations and are shown in table 2.

Table 2 test results of harmful components in smoke generated from the atomizer of this example

Detecting items	CAS number	Test results (μ g/100puff)	Reference limit (μ g/100puff)
				Formaldehyde (I)	50-00-0	12	200
Acetaldehyde	75-07-0	87	3200
				Acrolein	107-02-8	Not detected out	16
Chromium (Cr)	7440-47-3	Not detected out	3
				Cadmium (Cd)	7440-43-9	Not detected out	2
Lead (Pb)	7439-92-1	Not detected out	5
				Nickel (Ni)	7440-02-0	Not detected out	5
Arsenic (As)	7440-38-2	Not detected out	2
				Copper (A), (B)Cu)	7440-50-8	Not detected out	—

The results in table 2 show that the atomizer using the porous ceramic atomizing core of the present example produced formaldehyde and acetaldehyde harmful components far below the reference limits of the TPD regulations, while none of the other harmful components were detected. It is demonstrated that the generation of harmful components can be effectively reduced by using the porous ceramic atomizing core of this example.

According to the above tests and results, the analysis considers that the local over-high temperature is the root cause for the cracking of organic matters in the tobacco tar to explain the emission of harmful substances, and the uniform oil guiding is the necessary condition for preventing the local over-high temperature of the atomizing core. The ceramic atomizing core prepared by the embodiment has uniform pore diameters, and the pore diameter distribution of the whole ceramic atomizing core is tested to be concentrated at 10-20 mu m by adopting the pore diameter analyzer, which means that the pores at each part of the ceramic core fluctuate in a narrower pore diameter range, so that the uniformity of the oil guiding speed of each position of the ceramic atomizing core is ensured, and the problems that the oil guiding is slow at local positions and the components in the tobacco tar are cracked to generate harmful substances due to overhigh local temperature in the atomizing process are avoided. The ceramic atomizing core prepared in the embodiment has relatively high open porosity and concentrated pore size distribution, so that the porosity of the ceramic atomizing core in the embodiment is high because the ceramic atomizing core is provided with a large number of pores instead of being provided with large pores; this means that the ceramic atomizing core of this example is a highly dense and uniformly distributed micro-pores, rather than non-uniformly dispersed pores; the oil guide device has the advantages that the oil guide of each part is ensured to be uniform, and the oil leakage caused by overlarge pore diameter can be avoided.

Example two

The preparation method of the embodiment has the same steps as those of the embodiment I, except that the specific formula is changed, and the specific steps are as follows:

in the concrete example, 60% of the total weight of the mixture is weighed to obtain fused quartz, 17% of the total weight of the mixture is weighed to obtain low-temperature glass powder with the particle size D50 of 8 microns, 23% of the total weight of the mixture is weighed to obtain a pore-forming agent, the mixture is placed into a V-shaped mixer to be mixed for 3 hours to prepare a mixture, and the mixture is placed into an oven to be dried at 80 ℃ and preheated in advance. Wherein the fused quartz also consists of fused quartz with the particle size D50 of 28 micrometers and fused quartz with the particle size D50 of 75 micrometers which are equal in weight; the pore-forming agent is PS powder with the particle size D50 of 20 microns.

Weighing paraffin wax accounting for 20 percent of the total weight of the mixture and beeswax accounting for 2 percent of the total weight of the mixture, putting the mixture into a wax mixer for heating and melting into liquid, then gradually heating the preheated mixture into the wax mixer, adding oleic acid according to one thousandth of the weight of the mixture, and continuously stirring until the molten material and the mixture are completely stirred uniformly to prepare the slurry. Adding the slurry into a hot-die casting machine, continuously stirring, setting the temperature of the hot-die casting machine at 65 ℃, putting the same resistance circuit as in the first embodiment into a mold, and pressing the slurry into the mold by using the hot-die casting machine to be integrally molded to obtain a green body.

In this example, 10 porous ceramic atomizing cores were prepared in the same batch according to the above specific formulation, and the porosity and water absorption of the 10 prepared porous ceramic atomizing cores were measured by the same method as in example one. The test results are shown in table 3.

TABLE 3 porosity and Water absorption test results for the porous ceramic atomizing core of this example

Sample name	Weight of sample	Open porosity	Water absorption rate
				11#	0.1151g	56.46％	54.65％
12#	0.1152g	56.76％	55.38％
				13#	0.1148g	57.71％	57.06％
14#	0.1150g	57.51％	56.61％
				15#	0.1150g	57.30％	56.0％
16#	0.1149g	57.40％	56.4％
				17#	0.1157g	57.29％	56.01％
18#	0.1147g	57.54％	56.58％
				19#	0.1139g	57.25％	56.19％
20#	0.1144g	57.63％	56.47％

The results in Table 3 show that the 10 porous ceramic atomizing cores prepared in this example have good consistency, and the open porosity is 56% or more and the water absorption is 54% or more. The porous ceramic atomizing core of this example is shown to have good permeability.

The porous ceramic atomizing core prepared in the example is observed by a scanning electron microscope image, and the result shows that the micropores of the porous ceramic atomizing core prepared in the example are uniformly distributed. Further, the pore size and the distribution thereof were measured by the same method as in example one, and the data graph of the measurement is shown in fig. 5. The results in FIG. 5 show that the porous ceramic atomizing core prepared in this example has a distribution of pore sizes ranging from 5 to 30 microns and a predominant distribution ranging from 10 to 15 microns.

The porous ceramic atomizing core of this example was assembled into an atomizer, and the aldehyde compound and heavy metal content were measured in the same manner as in example one. Similarly, the results were determined according to the TPD regulations and are shown in table 4.

Table 4 test results of harmful components in smoke generated from the atomizer of this example

Detecting items	CAS number	Test results (μ g/100puff)	Reference limit (μ g/100puff)
				Formaldehyde (I)	50-00-0	16	200
Acetaldehyde	75-07-0	67	3200
				Acrolein	107-02-8	2	16
Chromium (Cr)	7440-47-3	Not detected out	3
				Cadmium (Cd)	7440-43-9	Not detected out	2
Lead (Pb)	7439-92-1	Not detected out	5
				Nickel (Ni)	7440-02-0	Not detected out	5
Arsenic (As)	7440-38-2	Not detected out	2
				Copper (Cu)	7440-50-8	Not detected out	—

The results in Table 4 show that the atomizer using the porous ceramic atomizing core of the present example produced formaldehyde, acetaldehyde and acrolein harmful components far below the reference limits of TPD regulations, while no other harmful components were detected. It is demonstrated that the generation of harmful components can be effectively reduced by using the porous ceramic atomizing core of this example.

EXAMPLE III

In this example, the formulation of the porous ceramic atomizing core was further tested on the basis of example one. The components are mixed according to the same ratio as in the first embodiment.

Test one: weighing fused quartz according to 65% of the total weight of the mixture, weighing low-temperature glass powder according to 15% of the total weight of the mixture, and weighing pore-forming agent according to 20% of the total weight of the mixture to prepare the mixture; paraffin wax accounting for 18 percent of the total weight of the mixture and beeswax accounting for 1 percent of the total weight of the mixture are weighed as melting materials.

And (2) test II: weighing fused quartz according to 40% of the total weight of the mixture, weighing low-temperature glass powder according to 25% of the total weight of the mixture, and weighing pore-forming agent according to 35% of the total weight of the mixture to prepare the mixture; paraffin wax accounting for 18 percent of the total weight of the mixture and beeswax accounting for 1 percent of the total weight of the mixture are weighed as melting materials.

And (3) test III: weighing fused quartz according to 65% of the total weight of the mixture, weighing low-temperature glass powder according to 10% of the total weight of the mixture, and weighing pore-forming agent according to 25% of the total weight of the mixture to prepare the mixture; paraffin wax accounting for 18 percent of the total weight of the mixture and beeswax accounting for 1 percent of the total weight of the mixture are weighed as melting materials.

And (4) testing: weighing fused quartz according to 65% of the total weight of the mixture, weighing low-temperature glass powder according to 20% of the total weight of the mixture, and weighing pore-forming agent according to 15% of the total weight of the mixture to prepare the mixture; paraffin wax accounting for 25 percent of the total weight of the mixture and beeswax accounting for 3 percent of the total weight of the mixture are weighed as melting materials.

And (5) testing: weighing fused quartz according to 60% of the total weight of the mixture, weighing low-temperature glass powder according to 25% of the total weight of the mixture, and weighing pore-forming agent according to 15% of the total weight of the mixture to prepare the mixture; paraffin wax accounting for 30 percent of the total weight of the mixture and beeswax accounting for 5 percent of the total weight of the mixture are weighed as melting materials.

By adopting the sintering conditions of the first embodiment and according to the five formulas, 5 porous ceramic atomizing cores are respectively prepared, and the porosity and the water absorption of the prepared 5 porous ceramic atomizing cores are tested by adopting the same method of the first embodiment. The test results are shown in table 5.

TABLE 5 porosity and Water absorption test results for the porous ceramic atomizing core of this example

Sample name	Weight of sample	Open porosity	Water absorption rate
				Test No.)	0.1150	53.54％	51.20％
Test No. two	0.1147	59.83％	55.04％
				Experiment three	0.1148	56.70％	52.45％
Experiment four	0.1152	51.3％	47.61％
				Experiment five	0.1152	50.02％	47.30％

The results in Table 5 show that the 5 porous ceramic atomizing cores prepared in the example have good consistency, the open porosity is between 50% and 60%, and the water absorption is above 47%. The porous ceramic atomizing core of this example is shown to have good permeability.

The porous ceramic atomizing core prepared in the example is observed by a scanning electron microscope image, and the result shows that the micropores of the porous ceramic atomizing core prepared in the example are uniformly distributed. Further, the pore size and distribution thereof were measured in the same manner as in example one, and the test data are shown in tables 6 to 10.

TABLE 6 this example test-pore size distribution data of porous ceramic atomizing core test results

Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of
									21.405	0.222	100.000	14.031	8.436	84.109	6.658	0.372	3.555
20.483	0.598	99.804	13.109	14.809	75.673	5.736	0.627	3.182
									19.561	0.598	99.206	12.188	18.006	60.865	4.814	0.641	2.556
18.640	0.998	98.609	11.266	24.006	42.859	3.892	0.607	1.915
									17.718	1.727	97.610	10.344	8.604	18.853	2.971	0.298	1.308
16.796	1.727	95.884	9.423	3.763	10.249	2.049	0.937	1.010
									15.875	3.727	94.157	8.501	1.984	6.487	1.1273	0.0735	0.0735
14.953	6.320	90.430	7.579	0.948	4.503

TABLE 7 pore diameter distribution data of the second porous ceramic atomizing core of the present example

TABLE 8 test results of pore size distribution data of three porous ceramic atomizing cores in the present example

Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of
									25.703	0.184	100.000	16.92	22.611	65.291	8.136	0.043	1.194
24.605	0.881	99.849	15.822	15.848	42.681	7.039	0.127	1.151
									23.507	0.881	98.969	14.724	10.441	26.833	5.941	0.578	1.024
22.409	1.1	98.088	13.626	5.94	16.392	4.843	0.334	0.446
									21.311	1.883	96.988	12.528	3.78	10.451	3.745	0.016	0.112
20.213	2.984	95.105	11.43	0.982	6.672	2.647	0.081	0.096
									19.115	6.984	92.121	10.332	0.929	5.689	1.5493	0.0154	0.0154
18.018	19.847	85.138	9.234	3.566	4.76

TABLE 9 pore size distribution data of four porous ceramic atomizing cores in the present example

Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of
									19.572	0.221	99.956	12.965	13.61	36.718	6.358	0.396	1.755
18.746	1.292	99.735	12.139	6.739	23.108	5.532	0.913	1.36
									17.92	1.982	98.443	11.313	5.917	16.369	4.706	0.068	0.446
17.094	1.692	96.461	10.487	4.013	10.452	3.88	0.248	0.378
									16.268	4.972	94.769	9.661	2.727	6.439	3.054	0.006	0.13
15.442	10.992	89.797	8.835	1.647	3.712	2.228	0.12	0.124
									14.617	18.016	78.805	8.009	0.025	2.065	1.4021	0.0037	0.0037
13.791	24.071	60.789	7.183	0.285	2.04

TABLE 10 pore diameter distribution data of five porous ceramic atomizing cores in this example

Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of
									14.447	0.138	99.966	9.524	2.305	9.051	4.601	0.073	0.213
13.832	1.002	99.828	8.908	1.903	6.746	3.985	0.063	0.141
									13.216	5.002	98.826	8.293	1.595	4.843	3.37	0.026	0.078
12.601	16.002	93.824	7.678	0.94	3.249	2.754	0.035	0.052
									11.985	27.002	77.823	7.062	0.728	2.308	2.139	0.008	0.017
11.37	22.52	50.821	6.447	0.837	1.58	1.524	0.006	0.01
									10.755	14.105	28.3	5.831	0.436	0.743	0.908	0.004	0.004
10.139	5.145	14.196	5.216	0.094	0.307

The results in tables 6 to 10 show that the porous ceramic atomizing cores prepared in this example have a pore size distribution of the through-holes ranging from 5 to 30 μm, and the pore size distribution is relatively concentrated, exceeding 80% in the interval of 10 to 20 μm.

The porous ceramic atomizing core of this example was assembled into an atomizer, and the aldehyde compound and heavy metal content were measured in the same manner as in example one. Similarly, the results were judged according to TPD regulations, and the results showed that the atomizer using the 5 porous ceramic atomizing cores of this example produced formaldehyde, acetaldehyde and acrolein harmful components far below the reference limits of the TPD regulations, while no other harmful components were detected. It is demonstrated that the generation of harmful components can be effectively reduced by using the porous ceramic atomizing core of this example.

The test results show that the mixture comprises 40-65% of fused quartz, 10-25% of low-temperature glass powder and 15-35% of pore-forming agent according to the total weight percentage of the mixture; matching with a melting material consisting of paraffin wax accounting for 18-30% of the mass of the mixture and beeswax accounting for 1-5% of the mass of the mixture; the formula can prepare the porous ceramic atomizing core with the porosity of 50-60%, uniform micropore distribution, concentrated pore size, and good permeability, wherein the proportion of the pore size in the range of 10-20 microns is more than 80%. Such porous ceramic atomizing core can make tobacco tar permeate porous ceramic fast, transmits resistance circuit border, can supply the tobacco tar fast, prevents the high temperature to reduce harmful component and generate.

Example four

In this example, sintering conditions were tested based on the first example, and the same conditions were used as in the first example except that the sintering conditions were different.

Test one: heating to 180 deg.C at 1 deg.C/min, and maintaining at 180 deg.C for 100 min; then raising the temperature to 400 ℃ at the speed of 2 ℃/min, and preserving the heat for 100min at the temperature of 400 ℃; then rising to 680 ℃ at the speed of 8 ℃/min, and preserving the heat for 30min at 680 ℃; stopping heating, and cooling to room temperature along with the furnace.

And (2) test II: heating to 250 deg.C at 3 deg.C/min, and maintaining at 250 deg.C for 120 min; then raising the temperature to 400 ℃ at a speed of 5 ℃/min, and preserving the heat for 120min at 400 ℃; then raising the temperature to 600 ℃ at a speed of 5 ℃/min, and preserving the heat for 30min at the temperature of 600 ℃; stopping heating, and cooling to room temperature along with the furnace.

And (3) test III: heating to 250 deg.C at 1 deg.C/min, and maintaining at 250 deg.C for 30 min; then raising the temperature to 450 ℃ at the speed of 2 ℃/min, and preserving the heat for 30min at the temperature of 450 ℃; then raising the temperature to 680 ℃ at 3 ℃/min, and preserving the temperature for 5min at 680 ℃; stopping heating, and cooling to room temperature along with the furnace.

The same materials as in example one were used to prepare 3 porous ceramic atomizing cores respectively according to the above sintering conditions, and the porosity and water absorption of the prepared 3 porous ceramic atomizing cores were tested by the same method as in example one. The test results are shown in table 11.

TABLE 11 porosity and Water absorption test results for the porous ceramic atomizing core of this example

Sample name	Weight of sample	Open porosity	Water absorption rate
				Test No.)	0.1151	55.60％	52.11％
Test No. two	0.1149	56.24％	52.57％
				Experiment three	0.1148	55.32％	52.25％

The results in table 11 show that the 3 porous ceramic atomizing cores prepared in this example have good consistency, and the open porosity is above 55% and the water absorption is 52%. The porous ceramic atomizing core of this example is shown to have good permeability.

The porous ceramic atomizing core prepared in the example is observed by a scanning electron microscope image, and the result shows that the micropores of the porous ceramic atomizing core prepared in the example are uniformly distributed. Further, the pore size and distribution thereof were measured in the same manner as in example one, and the test data are shown in tables 12 to 14.

TABLE 12 this example test-porous ceramic atomizing core pore size distribution data test results

Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of
									24.428	0.196	100.03	16.137	11.03	78.845	7.847	0.58	1.167
23.391	0.133	99.834	15.101	17.395	67.815	6.81	0.315	0.587
									22.355	0.319	99.701	14.065	22.439	50.42	5.774	0.238	0.272
21.319	0.887	99.383	13.028	13.956	27.982	4.738	0.016	0.034
									20.282	1.887	98.495	11.992	7.756	14.026	3.702	0.009	0.018
19.246	2.887	96.608	10.956	3.404	6.27	2.665	0.003	0.009
									18.21	5.72	93.721	9.919	1.014	2.866	1.629	0.006	0.006
17.173	9.156	88.002	8.883	0.686	1.852

TABLE 13 pore diameter distribution data of the second porous ceramic atomizing core of the present example

Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of
									25.498	0.237	99.98	17.071	12.844	87.512	8.644	0.767	1.741
24.445	0.312	99.743	16.017	23.535	74.668	7.59	0.522	0.974
									23.391	0.513	99.431	14.964	16.969	51.133	6.537	0.357	0.452
22.338	0.912	98.918	13.911	14.2	34.164	5.483	0.079	0.095
									21.284	1.312	98.006	12.857	8.809	19.963	4.43	0.003	0.016
20.231	1.493	96.694	11.804	3.873	11.154	3.377	0.008	0.013
									19.178	2.344	95.2	10.75	3.77	7.281	2.323	0.005	0.005
18.124	5.344	92.856	9.697	1.77	3.511

TABLE 14 results of pore size distribution data of three porous ceramic atomizing cores in this example

Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of	Pore diameter/mum	Ratio of (a)/%	Cumulative percent of
									24.335	0.196	99.926	16.092	13.791	81.232	7.85	0.1	0.313
23.304	0.054	99.73	15.062	23.273	67.441	6.82	0.077	0.213
									22.274	0.651	99.676	14.032	20.369	44.168	5.789	0.069	0.136
21.244	1.051	99.025	13.001	14.048	23.799	4.759	0.048	0.067
									20.213	1.651	97.974	11.971	5.048	9.751	3.729	0.008	0.019
19.183	2.668	96.323	10.941	3.009	4.703	2.698	0.007	0.011
									18.153	4.346	93.655	9.91	0.666	1.694	1.668	0.004	0.004
17.123	8.077	89.308	8.88	0.715	1.028

The results in tables 12 to 14 show that the porous ceramic atomizing cores prepared in this example have a pore size distribution of the through-holes ranging from 5 to 25 μm, and the pore size distribution is relatively concentrated, exceeding 80% in the interval of 10 to 20 μm.

The porous ceramic atomizing core of this example was assembled into an atomizer, and the aldehyde compound and heavy metal content were measured in the same manner as in example one. Similarly, the results were judged according to TPD regulations, and the results showed that the atomizer using the 3 porous ceramic atomizing cores of this example produced formaldehyde and acetaldehyde harmful components far below the reference limits of TPD regulations, while no other harmful components were detected. It is demonstrated that the generation of harmful components can be effectively reduced by using the porous ceramic atomizing core of this example.

The test results show that the temperature is raised to 180 ℃ for 250 ℃ at the speed of 1-3 ℃/min, and the temperature is preserved for 30-120min to remove wax; then raising the temperature to 400-450 ℃ at the speed of 2-5 ℃/min, preserving the temperature for 30-120min, and removing the pore-forming agent; heating to 600-680 ℃ at the speed of 3-8 ℃/min, and preserving the heat for 5-30min to ensure that the low-temperature glass powder is partially or completely melted into a liquid phase to bond the fused quartz particles; the porous ceramic atomizing core with the porosity of more than 55 percent, uniform micropore distribution, concentrated pore size and good permeability is prepared under the sintering conditions, the proportion of the porous ceramic atomizing core in the 10-20 micron interval exceeds 80 percent, and the prepared porous ceramic atomizing core can reduce the generation of harmful components.

The foregoing is a more detailed description of the present application in connection with specific embodiments thereof, and it is not intended that the present application be limited to the specific embodiments thereof. It will be apparent to those skilled in the art from this disclosure that many more simple derivations or substitutions can be made without departing from the spirit of the disclosure.

Claims

1. A preparation method of a porous ceramic atomizing core is characterized by comprising the following steps: weighing a mixture and a melting material according to a mass ratio; uniformly mixing all components in the mixture, and preheating; heating and melting the molten material, adding the preheated mixture, and uniformly stirring to obtain slurry; placing a resistance circuit containing an electrode or a lead in a mould, injecting the slurry, and integrally forming by using the mould to prepare a green body; sintering the green body, and cleaning the green body after sintering to obtain the porous ceramic atomizing core;

the mixture comprises fused quartz accounting for 40-65% of the total mass of the mixture, low-temperature glass powder accounting for 10-25% of the total mass of the mixture and pore-forming agent accounting for 15-35% of the total mass of the mixture;

the melting material comprises paraffin and/or beeswax, and the amount of the melting material is 19-35% of the mass of the mixture.

2. The method of claim 1, wherein: the melting material consists of paraffin accounting for 18-30% of the mass of the mixture and beeswax accounting for 1-5% of the mass of the mixture.

3. The method of claim 1, wherein: the particle size D50 of the fused silica is 10-100 microns, the particle size D50 of the low-temperature glass powder is 3-20 microns, and the particle size D50 of the pore-forming agent is 15-70 microns.

4. The method of claim 1, wherein: the pore-forming agent is at least one of polymethyl methacrylate, polystyrene, flour, starch and wood chips.

5. The method of claim 1, wherein: the method also comprises the step of adding oleic acid accounting for one thousandth to three thousandth of the mass of the mixture in the stirring process after adding the preheated mixture into the molten material.

6. The production method according to any one of claims 1 to 5, characterized in that: the preheating temperature of the mixture is 70-90 ℃;

preferably, the slurry is stored at a constant temperature of 65-80 ℃ before being injected into a mold, and stirring is continuously carried out during the storage;

preferably, the resistance circuit is in an arc transition design.

7. The production method according to any one of claims 1 to 5, characterized in that: the sintering comprises the steps of putting the green body into a sagger, covering the green body with the buried burning powder, and then putting the green body into a binder removal sintering furnace for sintering;

preferably, the sintering condition is that the temperature is raised to 180 ℃ at the speed of 1-3 ℃/min, the temperature is kept for 30-120min, and wax is discharged; then raising the temperature to 400-450 ℃ at the speed of 2-5 ℃/min, preserving the temperature for 30-120min, and discharging the pore-forming agent; heating to 600-680 ℃ at the speed of 3-8 ℃/min, and preserving the heat for 5-30min to ensure that the low-temperature glass powder is partially or completely melted into a liquid phase to bond the fused quartz particles; then, cooling the mixture to below 50 ℃ along with the furnace to finish sintering;

preferably, the cleaning comprises removing the buried burning powder, cleaning by using ultrasonic waves, and drying to obtain the porous ceramic atomizing core.

8. The production method according to any one of claims 1 to 5, characterized in that: and after sintering, removing metal oxide skin formed on the surface of the electrode or the lead by laser etching to reduce contact resistance.

9. A ceramic atomizing core produced by the production method according to any one of claims 1 to 7.

10. An atomizer or electronic atomizing device employing the ceramic atomizing core of claim 9.