阅读说明：本技术 多孔陶瓷体及其制备方法和应用该多孔陶瓷体的电子烟 (Porous ceramic body, preparation method thereof and electronic cigarette applying porous ceramic body ) 是由 武建 雷宝灵 徐中立 李永海 于 2020-05-28 设计创作，主要内容包括：本发明提出一种多孔陶瓷体及其制备方法和应用该多孔陶瓷体的电子烟。所述多孔陶瓷体的制备方法包括：制备混合原料,所述混合原料各成分及其质量百分数如下：陶瓷粉体35～65wt％、造孔纤维25～55wt％、胶黏剂10～25wt％；将所述混合原料成型形成坯体,使坯体内的造孔纤维沿预设方向排列,然后通过烧结工艺使造孔纤维分解挥发,从而制得具有定向贯通孔的多孔陶瓷体。本发明制备的多孔陶瓷体不仅结构强度较高,韧性好,降低了掉粉、掉渣的概率,还提高了导油速率和增加了有效导油路径。(The invention provides a porous ceramic body, a preparation method thereof and an electronic cigarette using the porous ceramic body. The method of making the porous ceramic body comprises: preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 35-65 wt% of ceramic powder, 25-55 wt% of pore-forming fiber and 10-25 wt% of adhesive; and forming the mixed raw materials to form a blank body, arranging pore-forming fibers in the blank body along a preset direction, and decomposing and volatilizing the pore-forming fibers through a sintering process to obtain the porous ceramic body with the directional through holes. The porous ceramic body prepared by the method has high structural strength and good toughness, reduces the probability of powder falling and slag falling, improves the oil guiding speed and increases the effective oil guiding path.)

1. A method of making a porous ceramic body, comprising the steps of:

preparing mixed raw materials, wherein the mixed raw materials comprise the following components in percentage by mass: 35-65 wt% of ceramic powder, 25-55 wt% of pore-forming fiber and 10-25 wt% of adhesive;

forming the mixed raw materials into a blank body, and enabling the pore-forming fibers in the blank body to be arranged along a preset direction approximately;

and sintering the green body in a preset temperature range to decompose and volatilize the pore-forming fiber, so as to prepare the porous ceramic body with oriented through holes, wherein the oriented through holes have the orientation consistent with the length direction of the pore-forming fiber.

2. The method of preparing a porous ceramic body of claim 1, wherein the method of forming the mixed feedstock comprises: and (3) forming by an extruder or an injection molding machine, wherein the forming pressure is 7-70 MPa.

3. The method of preparing a porous ceramic body of claim 2, wherein the forming pressure is 20 to 40 MPa.

4. The method of preparing a porous ceramic body of claim 1 or 2, wherein after shaping the mixed feedstock, the method further comprises: and carrying out isostatic compaction treatment on the formed blank.

5. The method of preparing a porous ceramic body according to claim 4, wherein the isostatic densification treatment is performed at a pressure of 100 to 200MPa and a dwell time of 5 to 10 min.

6. The method of preparing a porous ceramic body of claim 4, wherein prior to subjecting the shaped green body to isostatic compaction, the method further comprises: and carrying out vacuum packaging treatment on the formed blank.

7. The method of claim 2 or 3, further comprising, after the forming by the extruder or injection molding machine, further pressing the preform formed by the extruder or injection molding machine to form a preform of a predetermined shape, wherein the pressing is performed at a pressure of 10 to 50 MPa.

8. The method of preparing a porous ceramic body of claim 1, wherein the method of sintering comprises: and (3) feeding the blank into a sintering furnace, raising the temperature to 800-1400 ℃ at the speed of 1-2 ℃/min, preserving the heat for 5-10 hours, and then lowering the temperature to below 100 ℃ at the speed of 1-3 ℃/min.

9. The method of preparing a porous ceramic body of claim 8, further comprising a binder removal step prior to feeding the green body into the sintering furnace, comprising: and (3) feeding the formed blank into a glue discharging furnace, raising the temperature to 400-600 ℃ at the speed of 1-2 ℃/min, preserving the heat for 2-5 hours, and then lowering the temperature to below 100 ℃ at the speed of 1-3 ℃/min, so that the adhesive is discharged from the blank.

10. The method for preparing a porous ceramic body according to claim 1, wherein the ceramic powder is one or more of cordierite powder, zirconia powder, alumina powder, silicon carbide powder, silicon nitride powder, diatomaceous earth powder, and aluminum titanate powder; or the pore-forming fiber is one or more of polymethyl methacrylate, polyvinyl chloride and styrene-reduced fiber; or the adhesive is one or more of polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate and ethyl cellulose.

11. The method of preparing a porous ceramic body of claim 1 or 2, wherein the pore-forming fibers have a diameter of less than 100 μm.

12. A porous ceramic body produced by the method of producing a porous ceramic body according to any one of claims 1 to 11.

13. An electronic cigarette comprising the porous ceramic body of claim 12 having attached thereto an electrical heating element, the porous ceramic body for adsorbing a tobacco tar, the electrical heating element for atomizing the tobacco tar to produce an aerosol.

Technical Field

The invention relates to the technical field of electronic cigarettes, in particular to a porous ceramic body, a preparation method thereof and an electronic cigarette applying the porous ceramic body.

Background

An atomization core of an atomizer used in the existing electronic cigarette is composed of a porous ceramic carrier and a heating resistor printed on the surface of the porous ceramic carrier, but the taste of the porous ceramic atomization core and the problems of powder falling and slag falling of the ceramic carrier are in contradiction which is difficult to reconcile. Because the ceramic carrier is required to have larger pore diameter and higher porosity for good mouthfeel, the ceramic carrier has low strength and poor toughness, and the problems of powder falling, slag falling and the like can occur during use, thereby seriously threatening the health of users. In addition, referring to fig. 6, a large number of useless closed holes and semi-through holes exist in the conventional porous ceramic carrier, and the air holes cannot conduct the tobacco tar, so that the effective flow guide path of the tobacco tar is reduced, and the strength of the ceramic carrier is also seriously reduced. Ceramic carriers prepared by the existing porous ceramic preparation process (for example, a process of forming pores by using a pore-forming agent, a foaming agent, or the like) inevitably have a large number of closed pores and semi-through pores. Therefore, how to prepare a porous ceramic body suitable for an atomizing core has become an urgent problem to be solved by those skilled in the art.

Disclosure of Invention

In order to solve the above problems, the present invention provides a porous ceramic carrier for an electronic cigarette having oriented through holes and a method for preparing the same.

In a first aspect, the present invention provides a method of preparing a porous ceramic body, comprising the steps of:

preparing mixed raw materials, wherein the mixed raw materials comprise the following components in percentage by mass: 35-65 wt% of ceramic powder, 25-55 wt% of pore-forming fiber and 10-25 wt% of adhesive;

forming the mixed raw materials into a blank body, and enabling the pore-forming fibers in the blank body to be arranged along a preset direction approximately;

and sintering the blank in a preset temperature range to decompose and volatilize the pore-forming fiber, so as to prepare a porous ceramic body with oriented through holes, wherein the oriented through holes have the orientation consistent with the length direction of the pore-forming fiber.

Preferably, the method for forming the mixed raw material comprises the following steps: and (3) forming by an extruder or an injection molding machine, wherein the forming pressure is 7-70 MPa.

Preferably, the forming pressure is 20-40 MPa.

Preferably, after the mixed raw material is molded, the method further includes: and carrying out isostatic compaction treatment on the blank formed after the forming.

Preferably, the pressure of the isostatic compaction treatment is 100-200 MPa, and the pressure maintaining time is 5-10 min.

Preferably, before subjecting the blank formed after the forming to isostatic compaction treatment, the method further comprises: and carrying out vacuum packaging treatment on the blank formed after the forming.

Preferably, after the forming by the extruder or the injection molding machine, the method further comprises the step of performing compression molding on the blank formed by the forming by the extruder or the injection molding machine, wherein the compression molding pressure is 10-50 MPa.

Preferably, after the molding by the extruder or the injection molding machine, the method further comprises the following steps: cutting a rod-shaped blank formed by an extruder or an injection molding machine into sections; said press forming said blank comprising: and carrying out compression molding on the segment-shaped blank to form a green body.

Preferably, the sintering method comprises the following steps: feeding the formed green body into a glue discharging furnace, raising the temperature to 400-600 ℃ at the speed of 1-2 ℃/min, preserving the heat for 2-5 hours, and then lowering the temperature to below 100 ℃ at the speed of 1-3 ℃/min, so that the ceramic discharges the adhesive; and then, feeding the green block into a kiln, preserving the heat for 5-10 hours at 800-1400 ℃, and then reducing the temperature to be below 100 ℃ at the speed of 1-3 ℃/min.

Preferably, the ceramic powder is one or more of cordierite powder, zirconia powder, alumina powder, silicon carbide powder, silicon nitride powder, diatomite powder and aluminum titanate powder; or the pore-forming fiber is one or more of polymethyl methacrylate, polyvinyl chloride and styrene-reduced fiber; or the adhesive is one or more of polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate and ethyl cellulose.

Preferably, the pore-forming fiber has a diameter of less than 100 um.

In a second aspect, the present invention also provides a porous ceramic body produced according to the method for producing a porous ceramic body according to any one of the first aspects.

In a third aspect, the present invention further provides an electronic cigarette, comprising the porous ceramic body according to the second aspect, wherein an electric heating element is attached to the porous ceramic body, the porous ceramic body is used for adsorbing tobacco tar, and the electric heating element is used for atomizing the tobacco tar to generate aerosol.

In summary, the method for preparing the porous ceramic body comprises the following steps: preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 35-65 wt% of ceramic powder, 25-55 wt% of pore-forming fiber and 10-25 wt% of adhesive; and forming the mixed raw materials, arranging the pore-forming fibers along a preset direction, and sintering to obtain the porous ceramic body. That is to say, the pore-forming fibers are arranged in the preset direction as much as possible under the action of external force during molding, so that internal micropores formed after sintering the blank are arranged in the preset direction as much as possible to form directional through holes with the same orientation as the length direction of the pore-forming fibers, the probability of forming closed holes and semi-through holes is greatly reduced, more effective flow guide passages for tobacco tar are provided, and the oil guide efficiency is improved. In addition, the structure has higher strength and good toughness, and reduces the probability of powder and slag falling of the ceramic body.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

FIG. 1 is a flow chart of a method for preparing a porous ceramic body according to one embodiment of the present invention;

FIG. 2 is a scanning electron micrograph of a transverse cross-section of a porous ceramic body provided in accordance with an embodiment of the present invention;

FIG. 3 is a scanning electron micrograph of a longitudinal cross-section of a porous ceramic body provided in accordance with an embodiment of the present invention;

figure 4 is a schematic cross-sectional view of an electronic cigarette according to an embodiment of the present invention;

figure 5 is a schematic diagram of the configuration of the porous ceramic body of the electronic cigarette provided in figure 4 when mated with a heating wire and conductive leads;

FIG. 6 is a scanning electron micrograph of a cross-section of a prior art porous ceramic body.

Detailed Description

In order to facilitate an understanding of the invention, the invention is described in more detail below with reference to the accompanying drawings and detailed description.

Referring to fig. 1 and 2, an embodiment of the present invention provides a method for preparing a porous ceramic body, including the following steps:

s10, preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 35-65 wt% of ceramic powder, 25-55 wt% of pore-forming fiber and 10-25 wt% of adhesive;

the ceramic powder may be any ceramic powder, and for example, it may be one or more of cordierite powder, zirconia powder, alumina powder, silicon carbide powder, silicon nitride powder, diatomaceous earth powder, and aluminum titanate powder. The pore-forming fiber can be one or more of polymethyl methacrylate, polyvinyl chloride, styrene-reduced fiber and the like. In this example, the particle size of the ceramic powder is 30nm to 200. mu.m.

Preferably, the diameter of the pore-forming fiber is less than 100um, and preferably 50-100 um, so that the diameter of the micropores formed after sintering is also between 50-100 um. Therefore, the prepared micropores of the porous ceramic body can better adsorb the tobacco tar and better avoid the leakage and dry burning of the tobacco tar. The adhesive can be one or more of polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), ethyl cellulose and the like.

S20, forming the mixed raw materials into a blank, arranging the pore-forming fibers along a preset direction, and then sintering the blank in a sintering furnace within a preset temperature range to decompose and volatilize the pore-forming fibers in the blank to obtain the porous ceramic body with directional through holes. Referring to fig. 2 and 3, the oriented through-holes in the porous ceramic body have an orientation substantially coincident with the longitudinal direction of the pore-forming fibers.

The method for molding the mixed raw material may be molding by an extruder, an injection molding machine, or the like. The molding pressure is preferably 7-70 MPa, and preferably 20-40 MPa, so that the sintered ceramic body has a smaller shrinkage rate and a more uniform density, and the problems of hole blockage or less smoke oil adsorption and the like caused by too large shrinkage are better avoided. It can be understood that the mixed raw materials can be granulated after being uniformly mixed, and then the mixed raw materials are molded, wherein the shape of the granulated particles can be spherical or cylindrical, and the size of the granulated particles is generally less than 5mm, so that the problems of cavities, untight corners, layer cracks and the like of the molded part can be better avoided. The shape of the molded product obtained by the extrusion molding machine or the injection molding machine may be a columnar or block structure.

In order to make the formed blank body have high density, more uniform and isotropic, after the mixed raw materials are formed, the method further comprises the following steps: firstly, carrying out vacuum packaging treatment on a blank formed after molding, and then carrying out isostatic compaction treatment on the blank. Preferably, the pressure of the isostatic compaction treatment is 100-200 MPa, and the pressure maintaining time is 5-10 min, so that the production efficiency is high, and the density of the blank is well ensured.

And after the blank is molded by the extruder or the injection molding machine, further performing compression molding on the blank molded by the extruder or the injection molding machine, wherein the compression molding pressure is 10-50 MPa. That is, after the above-mentioned molding by an extruder or an injection molding machine, a rod-shaped material molded by the extruder or the injection molding machine is cut into a segment shape or the like, and then the segment-shaped material is press-molded to form a green compact. The green body is formed by compression molding, and is the final shape of the porous ceramic body, and the green body can be in a tubular, columnar, blocky, flaky and other structures, and the shape and the structure of the green body are not particularly limited.

The sintering method comprises the following steps: feeding the formed green body into a glue discharging furnace, raising the temperature to 400-600 ℃ at the speed of 1-2 ℃/min, preserving the heat for 2-5 hours, and then lowering the temperature to below 100 ℃ at the speed of 1-3 ℃/min, so that the ceramic discharges the adhesive; and then, feeding the green block into a kiln, preserving the heat for 5-10 hours at 800-1400 ℃, and then reducing the temperature to be below 100 ℃ at the speed of 1-3 ℃/min.

In order to make the details of the above method for preparing a porous ceramic body of the present invention more useful for those skilled in the art to understand and implement, and to highlight the effect of the porous body prepared in the present application on the improvement of performance and quality, the contents of the above method will be exemplified below by specific examples.

Example 1

S10, preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 3.5g of cordierite powder, 5g of polymethyl methacrylate and 1.5g of polyvinyl alcohol;

and S20, granulating the uniformly mixed raw materials to form a spherical shape, wherein the grain diameter is 2 mm. And then extruding the mixture by an extruder under the pressure of 20MPa to form a rod-shaped blank, then carrying out isostatic compaction treatment on the rod-shaped blank under the pressure of 150MPa, cutting the rod-shaped blank into sections, and then carrying out compression molding on the section-shaped blank under the pressure of 10MPa to form a green body. And finally sintering.

The sintering method comprises the following steps: feeding the formed green body into a glue discharging furnace, raising the temperature to 400 ℃ at the speed of 1 ℃/minute, preserving the temperature for 2 hours, and then lowering the temperature to 20 ℃ at the speed of 1 ℃/minute to discharge the adhesive from the ceramic; the green block is then fed into a kiln and held at 800 c for 5 hours and then ramped down to 20 c at a rate of 1 c/minute to achieve sufficient strength in the porous ceramic body.

Example 2

S10, preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 4g of cordierite powder, 4g of polymethyl methacrylate and 2g of polyvinyl alcohol;

and S20, granulating the uniformly mixed raw materials to form a spherical shape, wherein the grain diameter is 3 mm. Then, a bar-shaped blank is molded by an injection molding machine under the pressure of 30MPa, then isostatic compaction treatment is carried out on the bar-shaped blank under the pressure of 180MPa, the bar-shaped blank is cut into sections, and then the section-shaped blank is subjected to compression molding under the pressure of 20MPa to form a green body. And finally sintering.

The sintering method comprises the following steps: feeding the formed green body into a glue discharging furnace, raising the temperature to 450 ℃ at the speed of 1.2 ℃/min, preserving the temperature for 3 hours, and then lowering the temperature to 30 ℃ at the speed of 1.5 ℃/min to discharge the adhesive from the ceramic; the green block is then fed into a kiln and held at 900 c for 6 hours and then lowered to 30 c at a rate of 1.2 c/min to give the porous ceramic body sufficient strength.

Example 3

S10, preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 5g of silicon carbide powder, 2.5g of polyvinyl chloride and 2.5g of polyvinyl butyral;

and S20, granulating the uniformly mixed raw materials to form a cylindrical shape, wherein the grain diameter is 3.5 mm. Then, the rod-shaped billet is extruded by an extruder under a pressure of 50MPa, and then cut into segments, and then the segment-shaped billet is subjected to compression molding under a pressure of 30MPa to form a green compact. And finally sintering.

The sintering method comprises the following steps: feeding the formed green body into a glue discharging furnace, raising the temperature to 500 ℃ at the speed of 1.5 ℃/min, preserving the temperature for 4 hours, and then lowering the temperature to 50 ℃ at the speed of 2 ℃/min to discharge the adhesive from the ceramic; the green block is then fed into a kiln and held at 1100 c for 7.5 hours and then lowered to 50 c at a rate of 2 c/minute to give sufficient strength to the porous ceramic body.

Example 4

S10, preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 6g of cordierite powder, 3g of polymethyl methacrylate and 1g of polyvinyl alcohol;

and S20, granulating the uniformly mixed raw materials to form a spherical shape, wherein the grain diameter is 4 mm. Then, the rod-shaped billet is extruded by an extruder under a pressure of 60MPa, and then is cut into segments, and then the segment-shaped billet is subjected to compression molding under a pressure of 40MPa to form a green compact. And finally sintering.

The sintering method comprises the following steps: feeding the formed green body into a glue discharging furnace, raising the temperature to 500 ℃ at the speed of 1.8 ℃/min, preserving the temperature for 4 hours, and then lowering the temperature to 80 ℃ at the speed of 2 ℃/min so that the adhesive is discharged from the ceramic; the green block is then fed into a kiln and held at 1200 c for 8 hours and then lowered to 60 c at a rate of 2.5 c/min to achieve sufficient strength in the porous ceramic body.

Example 5

S10, preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 6.5g of aluminum titanate powder, 2.5g of reduced styrene fiber and 1g of polymethyl methacrylate;

and S20, granulating the uniformly mixed raw materials to form a spherical shape, wherein the grain diameter is 5 mm. Then, the rod-shaped billet is extruded by an extruder under a pressure of 70MPa, and then cut into segments, and then the segment-shaped billet is subjected to compression molding under a pressure of 50MPa to form a green compact. And finally sintering.

The sintering method comprises the following steps: feeding the formed green body into a glue discharging furnace, raising the temperature to 600 ℃ at the speed of 2 ℃/min, preserving the temperature for 5 hours, and then lowering the temperature to 90 ℃ at the speed of 3 ℃/min to discharge the adhesive from the ceramic; the green block is then fed into a kiln and held at 1400 c for 10 hours and then lowered to 70 c at a rate of 3 c/minute to give the porous ceramic body sufficient strength.

Example 6

Referring to fig. 3 and 4, an embodiment of the invention discloses an electronic cigarette, which includes an atomizing component 10 and a battery component 20, where the atomizing component 10 includes an oil cup 1, a seal seat 2, an oil absorbent cotton 3 and a porous ceramic body 4, the seal seat 2 is inserted into one end of the oil cup 1, the oil absorbent cotton 3 is inserted into a smoke passage of the oil cup 1 and is used for absorbing smoke oil in the oil cup 1, and the porous ceramic body 4 is inserted into the oil absorbent cotton 3. The porous ceramic body 4 is attached with an electric heating element 7, the porous ceramic body 4 is used for adsorbing tobacco tar, and the electric heating element 7 is used for atomizing the tobacco tar to generate aerosol. In the present embodiment, the electric heating element 7 is a heating wire, but it may also be a heating sheet or a conductive layer printed at the inner surface of the porous ceramic body 4. Wherein the porous ceramic body 4 is prepared according to the method for preparing a porous ceramic body 4 as described in any one of examples 1 to 5.

The battery assembly 20 comprises a shell 5, a battery 6 and a control module 8, wherein the battery 6 and the control module 8 are both positioned in the shell 5, and the battery 6 and a conductive lead 9 connected with the electric heating element 7 are both electrically connected with the control module 8. In operation, the control module 8 controls the battery 6 to supply power to the electric heating element 7 through the conductive lead 9, so that the electric heating element 7 generates heat to atomize the tobacco tar on the porous ceramic body 4, thereby generating aerosol.

In summary, the method for preparing the porous ceramic body comprises the following steps: preparing a mixed raw material, wherein the mixed raw material comprises the following components in percentage by mass: 35-65 wt% of ceramic powder, 25-55 wt% of pore-forming fiber and 10-25 wt% of adhesive; and forming the mixed raw materials, arranging the pore-forming fibers along a preset direction, and sintering to obtain the porous ceramic body. That is to say, pore-forming fibre can be arranged towards predetermined direction as far as possible under the exogenic action during the shaping, therefore, the micropore that forms after the sintering is arranged towards predetermined direction as far as possible, has greatly reduced the probability that forms closed hole, half perforating hole, and the effective water conservancy diversion passageway of tobacco tar is more, has improved and has led oily efficiency. In addition, the structure has higher strength and good toughness, and reduces the probability of powder falling and slag falling.

It should be noted that the preferred embodiments of the present invention are shown in the specification and the drawings, but the present invention is not limited to the embodiments described in the specification, and further, it will be apparent to those skilled in the art that modifications and changes can be made in the above description, and all such modifications and changes should fall within the protection scope of the appended claims.