CN114304729B - Electromagnetic induction heating cigarette and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of heating cigarettes, in particular to an electromagnetic induction heating cigarette and a preparation method thereof. The electromagnetic induction heating cigarette comprises a heating tobacco main body, wherein the heating tobacco main body is a paper roll structure formed by winding heating tobacco sheets; the heating tobacco sheet comprises a porous metal foil and plant fibers, wherein the plant fibers comprise a bonding section positioned on the front surface of the porous metal foil, a connecting section positioned in holes of the porous metal foil and a supporting section positioned on the back surface of the porous metal foil; the back surfaces of the supporting sections of the plant fibers and the porous metal foil are provided with metal oxide particles. In this application, through the structural design to the heating tobacco piece, make its arbitrary slice that winds the scroll structure of formation circle, be attached to the tip of the metal oxide granule of plant fiber support section can be opposite, even offset with the tobacco layer of its adjacent slice circle to form the bearing structure of flue gas passageway, can avoid flue gas passageway to seal, ensured the suction experience.

Description

An electromagnetic induction heating cigarette and its preparation method

technical field

The invention relates to the technical field of heated cigarettes, in particular to an electromagnetic induction heated cigarette and a preparation method thereof.

Background technique

Traditional tobacco maintains a smoldering state after being ignited, and uses the temperature generated by smoldering to heat the tobacco raw material near the burning area to release smoke that can be smoked. During this process, the temperature of the tobacco material at different positions is different according to the position difference from the combustion cone. The smoke release process of traditional tobacco tobacco products occurs in a system with a large temperature range and poor heating uniformity. The instability of temperature makes the composition of the compounds in the smoke composition very complex, which also affects the stability of the smoke quality of the smoke, and also makes it difficult to control the release of many harmful chemical components.

In recent years, scientific research has shown that effective control and reduction of the combustion temperature of cigarettes can significantly increase the release of harmful components in smoke and improve the safety of tobacco products. Based on this theory, heat-not-burn products have been developed. These heat-not-burn products use heating elements to heat and bake the tobacco material, and the heating temperature is controlled at about 300°C, so that the tobacco can release smoke but still remain in a non-combustible state. Compared with traditional burning and smoking cigarettes, heat-not-burn tobacco has greatly improved the temperature stability of the smoke released by tobacco, and thus reduced the hazard of the product.

Electromagnetic induction heating is to generate an alternating magnetic field through a high-frequency current, and cut the alternating magnetic force line corresponding to the metal surface to generate an alternating current (ie eddy current). The eddy current makes the metal atoms move at high speed and irregularly, and the atoms collide and rub against each other to generate heat energy. Play the effect of heating items. Because the iron container generates heat by itself, the heat conversion efficiency is much higher than the traditional contact heat transfer heating method. The patent document with the publication number CN108835707A discloses such an electromagnetic induction heating cigarette, which includes a tobacco section and a mouthpiece section. The tobacco section is wrapped by tobacco section cigarette paper, and the tobacco section is made of metal foil and tobacco. There is a certain gap between the layers in the cigarette-like structure.

In this application, firstly, the tobacco segment is formed by curling after the metal foil and tobacco are combined. Among them, the metal foil can be curled, and it must have good ductility and elasticity, which will cause it to be crimped after forming. When pinched by an external force, it is easy to deform, which leads to the closure of the gap between the layers for the circulation of smoke, which affects the flow of smoke. Second, the tobacco and the metal foil are pressed together. When the metal foil is deformed by an external force, the deformability of the tobacco and the metal foil is inconsistent, which will cause a gap between the tobacco and the metal foil, making the tobacco Comes off the foil easily.

Contents of the invention

To solve the above problems, the present invention provides an electromagnetic induction heating cigarette and a preparation method thereof.

The technical solution of the present invention to solve the problem is to firstly provide an electromagnetic induction heating cigarette, which includes a tobacco section, the tobacco section includes a heated tobacco body, and cigarette paper wrapped outside the heated tobacco body, and the heated tobacco body It is a paper roll structure formed by winding heated tobacco sheets, the paper roll structure includes several coils with successively increasing radii, and smoke channels are formed between adjacent coils; it is characterized in that the heated tobacco sheet includes porous Metal foil and plant fibers, the porous metal foil includes opposite fronts and backs, the plant fibers include a bonding section located on the front side of the porous metal foil, a connecting section located in the holes of the porous metal foil , and a support section located on the back of the porous metal foil; some of the bonding sections of the plant fibers are bonded by an adhesive; some of the support sections of the plant fibers, and the back of the porous metal foil are provided with metal oxide particles .

Based on the above structure, another object of the present invention is to provide a method for preparing electromagnetic induction heating cigarettes, comprising the following steps:

S1. After soaking the plant fiber in the tobacco liquid, take it out and dry it, and the tobacco liquid includes tobacco extract;

S2. Laying plant fibers on the front side of the porous metal foil, after vibration, spraying adhesive on the plant fibers, curing to form a tobacco layer;

S3. Cover the tobacco layer with a covering to obtain a porous metal foil with the front side covered and the back side exposed; the porous metal foil is added to the mixed solution of the metal precursor and the complexing agent, and then the precipitant is added dropwise to the mixed solution , taken out after reacting at 100-200°C to obtain heated tobacco sheets;

S4. Fix one end of the heated tobacco sheet as a fixed end, and continuously wind the other end around the fixed end to obtain a heated tobacco body, and wrap the heated tobacco body with cigarette paper to obtain a tobacco segment of a cigarette.

In the heated tobacco sheet used in this application to be wound into the main body of heated tobacco, on the front side, the tobacco layer formed by compounding the binder and the bonding section of the plant fiber can be obtained by compounding the plant fiber or/and the binder with the tobacco extract. Provides a tobacco smoking effect. On the back side, metal oxide particles are attached to the back body and the plant fiber support section extending from the back side. Based on this, when the heated tobacco sheet is wound, although a paper roll structure similar to the prior art is formed, However, in the present application, the end of the metal oxide particles attached to the plant fiber support section on any coil of the paper roll structure can be opposite to or even against the tobacco layer of its adjacent coil, thereby forming the smoke channel. The support structure can avoid the closure of the flue gas channel.

In addition, when the porous metal foil is wound and deformed, due to the existence of holes, the deformation of the holes can provide a buffer effect for the extension and stretching of the solid part, and avoid problems such as cracking of the porous metal foil during the deformation process. And after one end of the plant fiber is inserted into the hole of the porous metal foil, the tobacco layer and the porous metal foil are connected not only on the front, but also on a vertical surface perpendicular to the front, and the winding of the heated tobacco sheet has a great influence on the deformation of the front. However, the impact on the vertical plane is small, so the connection strength between the tobacco layer and the porous metal foil is guaranteed, and the falling off of the tobacco layer is avoided.

As a preference of the present invention, the porous metal foil is a ferromagnetic material, so that the porous metal foil can be used as a medium for electromagnetic induction heating.

As a preference of the present invention, the porous metal foil includes one or more of foamed stainless steel, foamed iron, and foamed iron alloy.

Based on the pore size of the metal foam, in order to ensure that the plant fibers pass through the holes. As a preference of the present invention, the outer diameter of the plant fiber does not exceed 1mm. At the same time, in the preparation process, as a preference of the present invention, in step S3, the vibration includes transverse vibration and longitudinal vibration, the vibration direction of the longitudinal vibration is perpendicular to the porous metal foil, and the vibration direction of the transverse vibration is perpendicular to the porous metal foil. The porous metal foils are parallel.

In order to improve the support effect, the particles are preferably particles with high hardness, good heat resistance, and not easily deformed. As a preference in the present invention, the metal oxide particles include one or more of alumina particles and magnesium oxide particles.

Based on this, in the preparation process, as a preference of the present invention, the metal precursor includes one or more of aluminum nitrate and magnesium nitrate.

As a preference of the present invention, the complexing agent includes one or a mixture of sodium edetate, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine.

As a preference of the present invention, the concentration of the complexing agent is 0.05-0.1 mol/L.

As a preference of the present invention, the precipitating agent includes one or more of ammonia water, sodium hydroxide and potassium hydroxide.

As a preference of the present invention, the concentration of the precipitation agent is 0.2-0.8 mol/L.

As a preference of the present invention, the dropping rate of the precipitating agent is 0.04-0.08mL/min.

As a preference of the present invention, the reaction is carried out at 100-200° C. for 1-3 hours.

The support of the flue gas channel in this application is based on the metal oxide particles attached to the plant fibers. In order to further improve the adhesion strength of the metal oxide particles on the plant fibers, as a preference of the present invention, the tobacco liquid also includes gluconic acid Lactone. Calcium ions will inevitably be contained in plant fibers. In plant fibers absorbed with gluconolactone, calcium ions can be released under the induction of gluconolactone, and under the above reaction conditions, with the metal in the metal precursor The ions form calcium-aluminum hydrotalcite, calcium-magnesium hydrotalcite, etc., which improve the adhesion strength of metal oxide particles on plant fibers.

As a preference of the present invention, the tobacco liquid also includes calcium chloride, so as to increase the calcium ion content in the plant fiber.

In addition, in the preparation process of the present application, since metal oxide particles do not need to be grown on the tobacco layer, a covering is covered on the tobacco layer of the porous metal foil.

As a preferred form of the cover of the present invention, the cover is a plastic film, and in step S4, the cover is peeled off before winding. Before rolling, when the heated tobacco sheet is stored, the cover can not be peeled off to avoid the volatilization of the flavor of the tobacco layer.

As another preference of the cover of the present invention, the cover is a chitosan film. The chitosan film not only provides a good covering protection effect, but also does not need to peel off the chitosan film during rolling, which can further reduce the harm of cigarette smoke.

Beneficial effects of the present invention:

In this application, through the structural design of the heated tobacco sheet, the end of the metal oxide particles attached to the plant fiber support segment on any lap of the paper roll structure formed by winding it can be separated from the tobacco of the adjacent lap. The layers are opposite or even offset to form a support structure for the smoke channel, which can avoid the closure of the smoke channel and ensure the smoking experience.

Description of drawings

Fig. 1 is a structural schematic diagram of a tobacco section of an electromagnetic induction heating cigarette;

In the figure: sheet circle 10, flue gas channel 101, porous metal foil 11, plant fiber 12, metal oxide particles 13.

Detailed ways

The following are specific embodiments of the present invention, and in conjunction with the accompanying drawings, further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

Example 1

An electromagnetic induction heating cigarette is prepared through the following steps:

S1. Prepare tobacco liquid: mix 10 parts of tobacco extract, 5 parts of tobacco essence and fragrance, and 15 parts of glycerin as an atomizing agent in parts by mass.

Tobacco fibers with an outer diameter of 1 mm were selected as plant fibers, and 5 parts of tobacco fibers were dipped in the above-mentioned tobacco liquid, soaked at 45°C for 3 hours, taken out, dried and dispersed under hot air at 50°C, and set aside.

S2. The porous metal foil is made of foamed iron-nickel sheet, with any side as the front and the opposite side as the back. A parallel frame is set on the vibrating device, and the edge of the porous metal foil is fixed on the frame, so that the body part in the middle of the porous metal foil is suspended, with the front facing up and the back facing down. The plant fibers obtained after the treatment in step S1 are laid on the front side. Start the vibrating device, so that the porous metal foil and the plant fibers alternately vibrate up and down and left and right together, the vibration frequency is 50 Hz, and vibrate until plant fibers extending from the back of the porous metal foil are observed.

Based on this step, the preliminary structure of the heated tobacco sheet can be obtained: as shown in Figure 1, although the heated tobacco sheet has been wound and processed in Figure 1, it can still be seen that the heated tobacco sheet includes a porous metal foil 11 and a plant The fiber 12, the porous metal foil 11 includes opposite front and back sides, the plant fiber 12 includes a bonding segment positioned at the front of the porous metal foil 11, a connecting segment positioned in the hole of the porous metal foil 11, and a bonding segment positioned at the porous metal foil 11. Support section on the back.

Then directly spray 20 parts of adhesive on the front of the porous metal foil 11, as shown in Figure 1, the adhesive binds the bonding section of the plant fiber 12 together and is bonded and fixed on the front of the porous metal foil 11, and forms tobacco after curing. layer.

S3. Cover the tobacco layer with a layer of plastic film to obtain a porous metal foil with the front side covered and the back side exposed, and set aside.

According to parts by mass, 20 parts of aluminum nitrate with a concentration of 0.1 mol/L and 20 parts of sodium ethylenediaminetetraacetate with a concentration of 0.08 mol/L were mixed uniformly to obtain a mixed solution, and the above-mentioned porous metal foil was added to the mixed solution, Under stirring, add 5 parts of ammonia water with a concentration of 0.5mol/L dropwise at a rate of 0.05mL/min into the mixed solution, then react at 150°C for 2 hours under stirring, take it out, peel off the plastic film, A heated tobacco sheet is obtained.

Based on this step, the final structure of the heated tobacco sheet can be obtained: as shown in Figure 1, on the exposed back side of the porous metal foil 11, and on the plant fiber 12 support section on the back side, aluminum oxide particles have been generated in situ, and the plant fiber 12 The longer supporting section provides a substrate for the massive growth of alumina, so that several large convex structures are formed on the back of the porous metal foil 11 (only a few are schematically drawn in FIG. 1 ).

S4. Fix one end of the heated tobacco sheet as a fixed end, and continuously wind the other end around the fixed end to obtain a heated tobacco body.

Based on this step, the structure of the heated tobacco body can be obtained: as shown in Figure 1, the heated tobacco body is a paper roll structure formed by winding heated tobacco sheets, and the paper roll structure includes several coils 10 with successively increasing radii. A flue gas channel 101 is formed between the rings 10 . Since the back of the heated tobacco sheet has several large convex structures, after winding, these large convex structures are just located between two adjacent coils 10, forming a support structure, which prevents the smoke channel 101 from being collapsed and closed by external force.

Finally, the heated tobacco body is wrapped with cigarette paper to obtain the tobacco section of the cigarette.

Example 2

The structure of the electromagnetic induction heating cigarette in this embodiment is basically the same as that in Embodiment 1, and only partly differs in the preparation method.

In this example:

S1. To prepare tobacco liquid, mix 10 parts of tobacco extract liquid, 5 parts of tobacco flavor and fragrance, 12 parts of glycerin as an atomizing agent, and 3 parts of gluconolactone according to parts by mass.

Example 3

The structure of the electromagnetic induction heating cigarette in this embodiment is basically the same as that in Embodiment 1, and only partly differs in the preparation method.

In this example:

S1. To prepare tobacco liquid, mix 10 parts of tobacco extract, 5 parts of tobacco flavor and fragrance, 12 parts of glycerin as an atomizer, and 3 parts of calcium chloride solution with a concentration of 0.1 mol/L according to parts by mass.

Example 4

The structure of the electromagnetic induction heating cigarette in this embodiment is basically the same as that in Embodiment 1, and only partly differs in the preparation method.

In this example:

S1. To prepare tobacco liquid, according to mass parts, 10 parts of tobacco extract, 5 parts of tobacco flavor and fragrance, 12 parts of glycerin as atomizer, 1 part of gluconolactone, and 2 parts of chlorine with a concentration of 0.1mol/L Calcium solution mixed evenly.

Example 5

The structure of the electromagnetic induction heating cigarette in this embodiment is basically the same as that in Embodiment 1, and only partly differs in the preparation method.

In this example:

S3. Cover the tobacco layer with a layer of chitosan film to obtain a porous metal foil with the front side covered and the back side exposed, and set aside.

According to parts by mass, 20 parts of aluminum nitrate with a concentration of 0.1 mol/L and 20 parts of sodium ethylenediaminetetraacetate with a concentration of 0.08 mol/L were mixed uniformly to obtain a mixed solution, and the above-mentioned porous metal foil was added to the mixed solution, Under stirring, 5 parts of ammonia water with a concentration of 0.5 mol/L was added dropwise to the mixed solution at a rate of 0.05 mL/min, then reacted at 150°C for 2 hours under stirring, and then taken out to obtain heated tobacco sheets.

Example 6

The structure of the electromagnetic induction heating cigarette in this embodiment is basically the same as that in Embodiment 1, and only partly differs in the preparation method.

In this example:

S1. To prepare tobacco liquid, according to parts by mass, 10 parts of tobacco extract, 10 parts of tobacco flavor and fragrance, 7 parts of citric acid as an atomizer, 1 part of gluconolactone, and 2 parts of 0.1mol/L The calcium chloride solution was mixed well.

The plant fibers are celery fibers with an outer diameter of 0.5 mm, 5 parts of celery fibers are immersed in the above tobacco liquid, soaked at 50°C for 1 hour, taken out, dried and dispersed under hot air at 60°C, and set aside.

S2. The porous metal foil is made of foamed stainless steel sheet, with any side as the front and the opposite side as the back. It is placed on a vibrating device, and the plant fiber obtained after processing in step S1 is laid on the front side. Start the vibrating device, so that the porous metal foil and the plant fibers alternately vibrate up and down and left and right, the vibration frequency is 100 Hz, and vibrate until plant fibers extending from the back of the porous metal foil are observed. Then directly spray 10 parts of adhesive on the front of the porous metal foil, and solidify to obtain the tobacco layer.

S3. Cover the tobacco layer with a layer of plastic film to obtain a porous metal foil with the front side covered and the back side exposed, and set aside.

According to parts by mass, 25 parts of magnesium nitrate with a concentration of 0.1 mol/L and 15 parts of sodium edetate with a concentration of 0.1 mol/L were mixed uniformly to obtain a mixed solution, and the above-mentioned porous metal foil was added to the mixed solution, Under stirring, 5 parts of ammonia water with a concentration of 0.8mol/L was added dropwise to the mixed solution at a rate of 0.08mL/min, and then reacted at 200°C for 1 hour under stirring, then removed, and the plastic film was peeled off. A heated tobacco sheet is obtained.

Example 7

The structure of the electromagnetic induction heating cigarette in this embodiment is basically the same as that in Embodiment 1, and only partly differs in the preparation method.

In this example:

S1. To prepare tobacco liquid, according to parts by mass, 15 parts of tobacco extract, 5 parts of tobacco flavor and fragrance, 7 parts of citric acid as atomizer, 2 parts of gluconolactone, 1 part of 0.1mol/L The calcium chloride solution was mixed well.

Tobacco fibers and celery fibers with an outer diameter of 0.1 mm were selected as plant fibers, and 5 parts of fibers were dipped in the above-mentioned tobacco liquid, soaked at 40°C for 5 hours, then taken out, dried under hot air at 50°C and dispersed, and set aside.

S2. The porous metal foil is made of foamed iron sheet, and any one side thereof is taken as the front side, and the opposite side is taken as the back side, which is placed on a vibrating device, and the plant fiber obtained in step S1 is laid on the front side. Start the vibrating device, so that the porous metal foil and the plant fibers alternately vibrate up and down and left and right together, the vibration frequency is 20 Hz, and vibrate until plant fibers extending from the back of the porous metal foil are observed. Then directly spray 30 parts of adhesive on the front of the porous metal foil, and solidify to obtain the tobacco layer.

S3. Cover the tobacco layer with a layer of chitosan film to obtain a porous metal foil with the front side covered and the back side exposed, and set aside.

In parts by mass, 25 parts of aluminum nitrate with a concentration of 0.1 mol/L and 15 parts of N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine with a concentration of 0.05 mol/L were uniformly mixed to obtain Mix the solution, add the above-mentioned porous metal foil to the mixed solution, and add 5 parts of sodium hydroxide with a concentration of 0.2mol/L dropwise to the mixed solution at a speed of 0.04mL/min under stirring, and then stir In the state, it was taken out after reacting at 100°C for 3 hours to obtain a heated tobacco sheet.

Comparative example 1

An electromagnetic induction heating cigarette is prepared through the following steps:

S1. To prepare the tobacco liquid, mix 5 parts of tobacco fibers with an outer diameter of 1 mm, 10 parts of tobacco extract, 5 parts of tobacco essence and spices, 15 parts of glycerin as an atomizer, and 20 parts of adhesive according to parts by mass, and set aside .

S2. Choose a solid iron-nickel sheet, take any side as the front and the opposite side as the back. Tobacco liquid is coated on the front and cured to form a tobacco layer.

S3. Cover the tobacco layer with a plastic film to obtain a solid iron-nickel sheet with the front side covered and the back side exposed, and set aside.

According to parts by mass, 20 parts of aluminum nitrate with a concentration of 0.1 mol/L and 20 parts of sodium edetate with a concentration of 0.08 mol/L were mixed uniformly to obtain a mixed solution, and the above-mentioned porous metal foil was added to the mixed solution, Under stirring, add 5 parts of ammonia water with a concentration of 0.5mol/L dropwise at a rate of 0.05mL/min into the mixed solution, then react at 150°C for 2 hours under stirring, take it out, peel off the plastic film, A heated tobacco sheet is obtained.

S4. Fix one end of the heated tobacco sheet as a fixed end, and continuously wind the other end around the fixed end to obtain a heated tobacco body.

[Determination of compressive strength of heated tobacco body]

The heated tobacco bodies prepared in Examples and Comparative Examples were used to test the compressive strength with a compression testing machine modeled as DE50A-2. During testing, the axial direction of the heated tobacco body is perpendicular to the pressure direction of the pressure testing machine, and the testing results are shown in Table 1 below.

Table 1.

From the comparison of Example 1 and Comparative Example 1 in Table 1, it can be seen that the compressive strength of the heated tobacco body is significantly increased through the support of the metal oxide, which can effectively avoid the sealing of the smoke passage.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (7)

1. A preparation method for electromagnetic induction heating cigarettes, characterized in that: The electromagnetic induction heating cigarette includes a tobacco section, the tobacco section includes a heated tobacco body, and cigarette paper wrapped outside the heated tobacco body, and the heated tobacco body is a paper roll structure formed by winding heated tobacco sheets , the paper roll structure includes several coils (10) with successively increasing radii, and smoke channels (101) are formed between adjacent coils (10); the heated tobacco sheet includes porous metal foils (11) and The plant fiber (12), the porous metal foil (11) includes opposite front and back sides, the plant fiber (12) includes a bonding section on the front of the porous metal foil (11), The connection section in the hole of the foil (11) and the support section located on the back of the porous metal foil (11); the bonding sections of several plant fibers (12) are bonded by adhesive; the several plant fibers (12) ) and the back of the porous metal foil (11) are provided with metal oxide particles (13); The porous metal foil (11) includes one or more of foamed stainless steel, foamed iron, and foamed iron alloy; The metal oxide particles (13) include one or both of alumina particles and magnesium oxide particles; The preparation method of the electromagnetic induction heating cigarette comprises the following steps: S1. The plant fiber (12) is soaked in the tobacco liquid and then taken out and dried, and the tobacco liquid includes tobacco extract; S2. laying plant fibers on the front surface of the porous metal foil (11), and spraying adhesive on the plant fibers (12) after vibration, curing to form a tobacco layer; S3. Cover the tobacco layer with a covering to obtain a porous metal foil (11) with the front covered and the back exposed; add the porous metal foil (11) to the mixed solution of the metal precursor and complexing agent, and then add the porous metal foil (11) to the mixture Add a precipitating agent dropwise into the solution, take it out after reacting at 100-200°C, and obtain heated tobacco sheets; S4. Fix one end of the heated tobacco sheet as a fixed end, and continuously wind the other end around the fixed end to obtain a heated tobacco body; wrap the heated tobacco body with cigarette paper to obtain a tobacco segment of a cigarette. 2. The method for preparing electromagnetic induction heating cigarettes according to claim 1, characterized in that: the outer diameter of the plant fibers (12) does not exceed 1 mm. 3 . The method for preparing electromagnetic induction heating cigarettes according to claim 1 , wherein the tobacco liquid further includes gluconolactone. 4 . 4 . The method for preparing electromagnetic induction heating cigarettes according to claim 1 , wherein the tobacco liquid further includes calcium chloride. 5 . The method for preparing electromagnetic induction heating cigarettes according to claim 1 , wherein the cover is a plastic film, and in step S4 , the cover is peeled off before winding. 6 . 6 . The method for preparing electromagnetic induction heating cigarettes according to claim 1 , wherein the covering is a chitosan film. 7 . 7. A method for preparing electromagnetic induction heating cigarettes according to claim 1, characterized in that in step S2, the vibration includes transverse vibration and longitudinal vibration, and the vibration direction of the longitudinal vibration is the same as that of the porous metal foil The sheet (11) is vertical, and the vibration direction of the transverse vibration is parallel to the porous metal foil (11).

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