Full-tobacco type cigarette with core-shell structure and preparation method of full-tobacco type cigarette
By using steam puffing and extrusion molding with cross-linking aids, a core-shell structure of all-tobacco cigarettes was prepared, solving the problems of large usage of traditional cigarette auxiliary materials and poor self-adhesion, and achieving a low-carbon, environmentally friendly, and smooth-tobacco cigarette.
Patent Information
- Application Number
- CN202511718840.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-01-02
AI Technical Summary
Traditional cigarettes use a large amount of auxiliary materials, consume a lot of energy, and are non-degradable, resulting in high carbon emissions. In addition, all-tobacco cigarettes have poor self-adhesion, cannot be formed, and are too dense, making them difficult to smoke.
The tobacco shreds are steam-expanded to form self-adhesive expanded tobacco shreds, and then extruded with wet tobacco powder through cross-linking aids to form a core-shell structured whole tobacco cigarette, eliminating the need for cigarette paper and filter rod.
It achieves the "elimination of auxiliary materials" in all-tobacco cigarettes, reducing costs and energy consumption, improving the cigarette's formability and smoking smoothness, and enhancing the product's green brand recognition and safety.
Smart Images
Figure CN121242284A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of cigarette forming, and particularly relates to a full-tobacco cigarette with a core-shell structure and a preparation method thereof. BACKGROUND
[0002] The industrialized production of traditional cigarettes has been over a hundred years, and the structure thereof is composed of four units of "tobacco + cigarette paper + tipping paper + filter rod", the auxiliary material quality accounts for about 20%, the cost accounts for more than 30%, and the auxiliary material production chain is long, the energy consumption is high, and there are many non-degradable wastes. The additives and printing inks in the cigarette auxiliary material (filter rod, cigarette paper) have been included in the key supervision according to the 9th and 10th articles of the World Health Organization's Framework Convention on Tobacco Control (FCTC). Although the cigarette industry only accounts for 0.37% of the national carbon emission, the energy consumption of the auxiliary material section (papermaking, filter rod forming, printing) accounts for 28% of the whole process of the cigarette factory, and becomes a "hidden high-carbon area". Therefore, with the increasing of the global tobacco control convention (FCTC) and the increasing of the carbon emission reduction pressure, the tobacco industry urgently needs a bottom technology revolution of "de-auxiliary material".
[0003] The full-tobacco cigarette is proposed in this background. However, the tobacco is poor in self-adhesion and cannot be formed; the tobacco powder or tobacco paste can be formed by introducing a crosslinking agent, but the formed cigarette is relatively dense, and thus the smoking is not smooth. Therefore, there is no related literature or patent reporting the full-tobacco cigarette product without auxiliary materials such as cigarette paper.
[0004] Therefore, the present application is proposed. SUMMARY
[0005] The present application discloses a full-tobacco cigarette with a core-shell structure and a preparation method thereof. The full-tobacco cigarette with the core-shell structure of the present application does not need auxiliary materials such as cigarette paper, tipping paper and filter rod.
[0006] The first aspect of the present application discloses a full-tobacco cigarette with a core-shell structure, and the tobacco in the cigarette accounts for 95.0-99.5wt% of the total amount of the cigarette.
[0007] Preferably, the shell layer is a tobacco powder layer, and the core layer is a tobacco filler layer.
[0008] Preferably, the tobacco in the tobacco filler layer is crosslinked expanded tobacco, and the filling value of the expanded tobacco is increased by 10-40% compared with that of the tobacco before expansion.
[0009] Preferably, the shell layer is a layer formed by extruding wet tobacco powder, and the mass ratio of the shell layer to the core layer in the cigarette is (0.5-2.5) : 1.
[0010] The second aspect of the present application discloses a preparation method of the full-tobacco cigarette with the core-shell structure, comprising the following steps:
[0011] (1) Steam puffing treatment of tobacco raw material to obtain self-adhesive expanded tobacco; mixing and reacting the self-adhesive expanded tobacco with a natural polymer crosslinking aid solution or dispersion to obtain crosslinked expanded tobacco; the tobacco raw material includes one or more of upper, middle and lower tobacco, the moisture content of the tobacco is 10-14wt%, and the width of the tobacco is 0.8-1.2 mm; preferably, the tobacco is upper tobacco, the moisture content is 12wt%, and the width of the tobacco is 1.0 mm;
[0012] (2) Rolling the wet tobacco rod with a shell-core structure of full tobacco type;
[0013] (3) Drying and adjusting the moisture content of the wet tobacco rod to obtain the full tobacco type tobacco rod with a shell-core structure.
[0014] Preferably, the steam puffing treatment of the tobacco raw material in step (1) is carried out under the following conditions: the amount of water added is 0.5-4 times the dry weight of the tobacco raw material, the steam pressure is 0.1-0.5 MPa, and the holding time is 0.5-10 min; preferably, the amount of water added is 2 times the dry weight of the tobacco, the steam pressure is 0.25 MPa, and the holding time is 2 min.
[0015] Preferably, the natural polymer crosslinking aid in step (2) is one or more of water-soluble cellulose ether, starch, dextrin, guar gum, agar, pectin, gelatin, sodium alginate, and polyvinyl alcohol, and the amount of the crosslinking aid is 0.1-5wt% of the dry weight of the expanded tobacco.
[0016] Preferably, the preparation of the wet tobacco rod in step (2) is carried out by the following steps: the crosslinked expanded tobacco is input into a rolling machine through a spiral feeding system; at the same time, the wet tobacco powder is applied through a vibrating screen to form a tobacco powder wrapping layer by extrusion molding; thus, the wet tobacco rod with a shell-core structure of full tobacco type is obtained, in which the core layer is tobacco and the shell layer is tobacco powder; the particle size of the tobacco powder is 30-300 mesh, and the moisture content of the wet tobacco powder is 50-80wt%; the amount of the wet tobacco powder is: the mass ratio of dry tobacco powder to dry crosslinked expanded tobacco is (0.5-2.5)∶1; the wet tobacco powder is applied three times, and each time the amount of the wet tobacco powder is about 1 / 3 of the total amount of the tobacco powder.
[0017] Preferably, the extrusion molding is carried out under the following conditions: the pressure of the pressure roller is 0.3-0.5 MPa, the temperature of the pressure roller is 20-50℃, the extrusion time is 1-5 s, the interval between each feeding is 5-10 s, and the crimping line speed is 0.8-1.2 m / min.
[0018] Preferably, the drying and moisture adjusting in step (3) is carried out under the following conditions: the temperature is 15-25℃, the relative humidity is 50-65%, and the drying time is 2-10 h; the final moisture content of the tobacco rod is adjusted to 11wt%-13wt%, and preferably 12wt%.
[0019] The full-tobacco cigarette with the shell-core structure has the same shape as a common cigarette, has a length of 84 mm, a diameter of 7 mm, and a weight of about 0.8 g.
[0020] The beneficial effects of the present application are as follows:
[0021] 1. The full-tobacco cigarette with the shell-core structure of the present application does not contain auxiliary materials such as cigarette paper, tipping paper and filter rods, and realizes the technical route of full-tobacco and "auxiliary material removal"; the intuitive concept of "a cigarette containing only tobacco" improves the green recognition of the product and responds to the consumer's expectation of "natural, simple and low carbon".
[0022] 2. The preparation method of the full-tobacco cigarette with the shell-core structure of the present application obtains tobacco shreds with self-adhesion through steam puffing technology, and improves the formability and supportability of the tobacco shreds after physical cross-linking by a cross-linking agent. Meanwhile, the filling value of the puffed tobacco shreds is increased by 10-40%, the tar and nicotine contents of the tobacco shreds are reduced, the cost of the cigarette is reduced, and the safety of smoking is improved. The preparation method of the full-tobacco cigarette with the shell-core structure of the present application utilizes the self-adhesion and supportability of the expanded tobacco shreds and the compactness of the wet tobacco powder after extrusion, and develops the full-tobacco cigarette through the design of the shell-core structure. The preparation method of the present application breaks through the homogeneous structure of the traditional cigarette, and constructs a core-shell heterogeneous structure wet cigarette. The method is not only simple in process and low in energy consumption, but also reduces the cost of the cigarette, and breaks out of the "paper-rod" preparation inertia of the cigarette. The method provides a technical channel of "auxiliary material removal" for the tobacco industry, and brings a new growth point for the tobacco industry.
[0023] 3. The preparation method of the full-tobacco cigarette with the shell-core structure of the present application makes the tobacco shreds have self-adhesion through steam puffing treatment. The reason may be that the acetyl group on the hemicellulose in the tobacco shreds falls off to generate acetic acid under hydrothermal conditions, the acetic acid promotes the degradation of cellulose and hemicellulose into small molecular sugars, and the dissolved sugar components and natural high molecular cross-linking additives are used as adhesives to make the tobacco shreds have self-adhesion. Then, the tobacco powder is introduced, and the shell-core structure is designed to form. The cross-linked expanded tobacco shreds with self-adhesion, good porosity and good air permeability are used as the core layer, and the dense tobacco powder layer is used as the shell layer, so as to obtain a full-tobacco cigarette product which is easy to smoke and does not need auxiliary materials such as cigarette paper. Meanwhile, the steam puffing treatment can improve the filling value of the tobacco shreds and reduce the contents of tar and nicotine in the tobacco shreds, so as to reduce the cost of the obtained cigarette and improve the safety of smoking. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is a puffing tobacco shred photo obtained in Example 1.
[0025] Figure 2 It is a full-tobacco cigarette and smoking effect photo obtained in Example 1.
[0026] Figure 3 is a photo of the unswollen upper tobacco cut in Comparative Example 1.
[0027] Figure 4 is a photo of the forming effect of the unswollen tobacco cut in Comparative Example 1.
[0028] Figure 5 is a photo of the cigarette obtained by cross-linking the tobacco powder in Comparative Example 2 and the smoking effect.
[0029] Figure 6 is a photo of the wet cigarette obtained in Example 2.
[0030] Figure 7 is a photo of the full-tobacco cigarette obtained in Example 2 and the smoking effect. DETAILED DESCRIPTION
[0031] The present application is further described in detail by the specific embodiments below, but it should not be understood as limiting the scope of the present application to the following examples. Various substitutions and changes in accordance with ordinary technical knowledge and conventional means in the art without departing from the method idea of the present application should be included in the scope of the present application.
[0032] Example 1: Preparation of a full-tobacco cigarette with a core-shell structure, the steps are as follows:
[0033] Step 1: Add the upper tobacco cut with a moisture content of 12wt% and a width of 1.0 mm into water for steam swelling treatment, the treatment conditions are: water amount is 2 times the dry weight of the tobacco cut, steam pressure is 0.25 MPa, and holding time is 2 min; the swollen tobacco cut with self-adhesion obtained after swelling is shown in Figure 1 ;
[0034] Step 2: After stirring the pregelatinized starch solution and the swollen tobacco cut uniformly, input them into the cigarette maker through the spiral feeding system, the starch amount is 2% of the dry weight of the swollen tobacco cut; at the same time of curling the tobacco cut, apply the wet tobacco powder with 80% moisture content through the vibrating screen three times to perform extrusion forming, forming a dense tobacco powder wrapping layer, finally obtaining a wet cigarette with a core layer of tobacco cut and a shell layer of tobacco powder; the added tobacco powder is 30-50 mesh, the total amount is 1 times the dry weight of the tobacco cut, and the amount of each time is 1 / 3 of the total tobacco powder amount; the extrusion forming extrusion conditions are: pressure roller pressure is 0.3 MPa, pressure roller temperature is 20℃, extrusion time is 1 s, interval between each feeding is 5 s, and curling line speed is 0.8 m / min;
[0035] Step 3: Dry and adjust the moisture of the wet cigarette at 20℃ and 50% relative humidity for 5 h to obtain a full-tobacco cigarette with a core-shell structure with a moisture content of 12wt%.
[0036] By analysis, the filling value of the expanded tobacco is increased by 40%, the surface reducing sugar content is increased by 21%, the acetyl content is reduced by 5%, the tar content is reduced by 31.8%, and the nicotine content is reduced by 24.5%. This shows that during the steam expansion treatment, part of the acetyl in the tobacco falls off to generate acetic acid, which promotes the degradation of hemicellulose and cellulose in the tobacco into small molecule reducing sugars on the surface of the tobacco, thereby improving the self-adhesion of the tobacco. Finally, a cigarette with a length of 84 mm, a diameter of 7 mm, and a weight of 0.8 g is obtained, which has no suction resistance and good suction effect, as shown in Figure 2 .
[0037] Comparative Example 1: Preparation of tobacco without steam expansion treatment, the steps are as follows:
[0038] The upper tobacco with a water content of 12wt% and a width of 1.0 mm (as shown in Figure 3 ) is uniformly stirred with a pregelatinized starch solution, and then input into a cigarette maker through a screw feeding system, and the amount of starch is 2% of the dry weight of the tobacco; then, while the tobacco is curled, wet tobacco powder with a water content of 80% is applied through a vibrating screen three times for extrusion molding. The added tobacco powder is 30-50 mesh, and the total amount is 1 times the dry weight of the tobacco, and the amount of each time is 1 / 3 of the total amount of tobacco powder; the extrusion molding extrusion conditions are the same as those of Example 1. However, this method cannot form a cigarette, as shown in Figure 4 .
[0039] This shows that the cross-linked expanded tobacco with self-adhesion and loose pores participates in the formation of the shell. The tobacco without expansion treatment has no self-adhesion, and only by compounding the tobacco with the tobacco powder through a cross-linking agent, a full tobacco type cigarette with sufficient tightness can be obtained.
[0040] Comparative Example 2: Tobacco powder cross-linking molding.
[0041] The pregelatinized starch solution is uniformly stirred with 30-50 mesh wet tobacco powder with a water content of 80%, and then put into a cigarette maker, and the amount of pregelatinized starch is 2% of the dry weight of the tobacco powder, and a wet cigarette can be obtained by rolling the tobacco; then, the wet cigarette is dried and humidified at 20°C and 50% humidity for 5 h, and a cigarette with a water content of 12wt% is obtained.
[0042] The cigarette has no shell core structure, and the tobacco powder shrinks seriously after drying. By testing, the diameter of the cigarette is only 4.5 mm, the density is high, the suction resistance is high, and the suction is difficult, as shown in Figure 5 . This also shows that the cross-linking agent can be compounded with the tobacco powder to obtain a shell with sufficient tightness.
[0043] Example 2: Preparation of a full tobacco type cigarette with a shell core structure, the steps are as follows:
[0044] Step 1: the lower tobacco with water content of 10wt%, width of 0.8 mm is added into water for steam puffing treatment, the treatment conditions are as follows: water amount is 0.5 times of the dry weight of the tobacco, steam pressure is 0.1 MPa, and holding time is 10 min; the puffed tobacco with self-adhesion is obtained after puffing;
[0045] Step 2: the carboxymethyl cellulose solution is uniformly stirred with the puffed tobacco, and then is input into the cigarette maker through the screw feeding system, the amount of carboxymethyl cellulose is 0.1% of the dry weight of the puffed tobacco; then, the wet tobacco powder with water content of 50% is applied through the vibrating screen in three times while the tobacco is rolled, the extrusion molding is performed to form the dense tobacco powder wrapping layer, and finally the wet tobacco rod with tobacco as the core layer and tobacco powder as the shell layer is obtained as shown in Figure 6 ; wherein, the tobacco powder with 200-300 mesh is added, the total amount is 0.5 times of the dry weight of the tobacco, and the amount of each time is 1 / 3 of the total amount of the tobacco powder; the extrusion molding extrusion conditions are as follows: roller pressure is 0.5 MPa, roller temperature is 50℃, extrusion time is 5 s, interval of each feeding is 10 s, and the rolling line speed is 1.2 m / min;
[0046] Step 3: the wet tobacco rod is dried and humidified at 15℃ and 65% humidity for 10 h, and the full tobacco type tobacco rod with water content of 11wt% is obtained as shown in Figure 7 .
[0047] Through analysis, the filling value of the puffed tobacco is increased by 10%, the surface reducing sugar content is increased by 5%, and the acetyl content is reduced by 0.3%. The final obtained tobacco rod has a length of 84 mm, a diameter of 7 mm, a weight of about 0.8 g, no suction resistance, and good smoking effect, as shown in Figure 7 .
[0048] Example 3: preparation of full tobacco type tobacco rod with shell-core structure, the steps are as follows:
[0049] Step 1: the middle tobacco with water content of 14wt%, width of 1.2 mm is added into water for steam puffing treatment, the treatment conditions are as follows: water amount is 4 times of the dry weight of the tobacco, steam pressure is 0.5 MPa, and holding time is 2 min; the puffed tobacco with self-adhesion is obtained after puffing;
[0050] Step 2: After the guar gum solution is uniformly stirred with the expanded cut tobacco, it is input into the cigarette maker through a screw feeding system, and the amount of guar gum is 1% of the dry weight of the expanded cut tobacco. Then, while the cut tobacco is being curled, wet tobacco powder with a water content of 70% is applied through a vibrating screen in three times to perform extrusion molding to form a dense tobacco powder wrapping layer, and finally a wet tobacco rod with a core layer of cut tobacco and a shell layer of tobacco powder is obtained; wherein the added tobacco powder is 80-100 mesh, the total amount is 2.5 times the dry weight of the cut tobacco, and the amount of each time is 1 / 3 of the total amount of tobacco powder; the extrusion molding extrusion conditions are: roller pressure 0.4 MPa, roller temperature 25 ℃, extrusion time 3 s, interval between each time 8 s, and curling line speed 1.0 m / min;
[0051] Step 3: The wet tobacco rod is dried and conditioned at 25 ℃ and 55% humidity for 2 h to obtain a full-tobacco-type tobacco rod with a water content of 13wt%.
[0052] Through analysis, the filling value of the expanded cut tobacco is increased by 30%, and finally a tobacco rod with a length of 84 mm, a diameter of 7 mm, and a weight of about 0.8 g is obtained, which has no suction resistance and good smoking effect.
[0053] Example 4: Preparation of a full-tobacco-type tobacco rod with a shell-core structure, the steps are as follows:
[0054] Step 1: The upper cut tobacco with a water content of 11wt% and a width of 1.0 mm is added to water for steam expansion treatment, and the treatment conditions are: water amount is 1 times the dry weight of the cut tobacco, steam pressure is 0.2 MPa, and holding time is 4 min; after expansion, the expanded cut tobacco with self-adhesion is obtained;
[0055] Step 2: After the polyvinyl alcohol solution is uniformly stirred with the expanded cut tobacco, it is input into the cigarette maker through a screw feeding system, and the amount of polyvinyl alcohol is 5% of the dry weight of the expanded cut tobacco. Then, while the cut tobacco is being curled, wet tobacco powder with a water content of 60% is applied through a vibrating screen in three times to perform extrusion molding to form a dense tobacco powder wrapping layer, and finally a wet tobacco rod with a core layer of cut tobacco and a shell layer of tobacco powder is obtained; wherein the added tobacco powder is 100-150 mesh, the total amount (dry weight) is 0.9 times the dry weight of the cut tobacco, and the amount of each time is 1 / 3 of the total amount of tobacco powder; the extrusion molding extrusion conditions are: roller pressure 0.3 MPa, roller temperature 40 ℃, extrusion time 4 s, interval between each time 6 s, and curling line speed 1.1 m / min;
[0056] Step 3: The wet tobacco rod is dried and conditioned at 22 ℃ and 60% humidity for 8 h to obtain a full-tobacco-type tobacco rod with a water content of 12wt%.
[0057] Through analysis, the filling value of the cut tobacco after the puffing treatment is increased by 20%, and finally the cigarette with a length of 84 mm, a diameter of 7 mm, a weight of about 0.8 g, no suction resistance and good smoking effect is obtained.
[0058] Example 5: Preparation of a full-tobacco cigarette with a shell-core structure, the steps are as follows:
[0059] Step 1: The upper and lower cut tobaccos with a moisture content of 13wt%, a width of 1.1 mm (mass ratio 1:1) are added into water for steam puffing treatment, and the treatment conditions are as follows: water amount is 3 times of the dry weight of the cut tobacco, steam pressure is 0.4 MPa, and holding time is 3 min; after the puffing, the expanded cut tobacco with self-adhesion is obtained;
[0060] Step 2: After the gelatin solution is uniformly stirred with the expanded cut tobacco, the gelatin is input into a cigarette maker through a spiral feeding system, and the amount of the gelatin is 2% of the dry weight of the expanded cut tobacco. Then, while the cut tobacco is curled, the wet tobacco powder with a water content of 50% is added through a vibrating screen in three times to perform extrusion molding to form a dense tobacco powder wrapping layer, and finally the wet cigarette with a core layer of cut tobacco and a shell layer of tobacco powder is obtained; wherein the tobacco powder added is 200-300 mesh, the total amount is 2.2 times of the dry weight of the cut tobacco, and the amount of each time is 1 / 3 of the total amount of the tobacco powder; the extrusion molding extrusion conditions are as follows: pressure roller pressure is 0.5 MPa, pressure roller temperature is 30°C, extrusion time is 2 s, interval of each feeding is 9 s, and curling line speed is 0.9 m / min;
[0061] Step 3: The wet cigarette is dried and humidified at 23°C and 58% humidity for 7 h to obtain a full-tobacco cigarette with a water content of 12%.
[0062] Through analysis, the filling value of the cut tobacco after the puffing treatment is increased by 35%, and finally the cigarette with a length of 84 mm, a diameter of 7 mm, a weight of 0.8 g, no suction resistance and good smoking effect is obtained.
[0063] Example 6: Preparation of a full-tobacco cigarette with a shell-core structure, the steps are as follows:
[0064] Step 1: The upper, middle and lower cut tobaccos with a moisture content of 12%, a width of 0.9 mm (cut tobacco ratio 1:1:1) are added into water for steam puffing treatment, and the treatment conditions are as follows: water amount is 1.5 times of the dry weight of the cut tobacco, steam pressure is 0.35 MPa, and holding time is 7 min; after the puffing, the expanded cut tobacco with self-adhesion is obtained;
[0065] Step 2: After the pre-gelatinized starch and sodium alginate mixture is uniformly stirred with the expanded cut tobacco, the mixture is input into the cigarette maker through a screw feeding system, the total amount of pre-gelatinized starch and sodium alginate is 2.5% of the dry weight of the expanded cut tobacco, and the mass ratio of pre-gelatinized starch to sodium alginate is 4:1. Then, while the cut tobacco is being curled, wet tobacco powder containing 75% water is applied three times through a vibrating screen to perform extrusion molding, forming a dense tobacco powder wrapping layer, and finally obtaining a wet tobacco rod with a core layer of cut tobacco and a shell layer of tobacco powder; wherein the added tobacco powder is 50-100 mesh, the total amount is 1.4 times the dry weight of the cut tobacco, and the amount of each addition is 1 / 3 of the total tobacco powder amount; the extrusion molding extrusion conditions are: roller pressure 0.3 MPa, roller temperature 45℃, extrusion time 1 s, interval between each addition 5 s, and curling line speed 0.8 m / min;
[0066] Step 3: The wet tobacco rod is dried and conditioned at 18℃ and 55% humidity for 6 h to obtain a full-tobacco-type tobacco rod with a water content of 12%.
[0067] Through analysis, the filling value of the expanded cut tobacco increased by 19%, and the final tobacco rod had a length of 84 mm, a diameter of 7 mm, a weight of about 0.8 g, no suction resistance, and good smoking effect.
[0068] The above description is only used to specifically introduce the embodiments of the present application, but the technical solutions proposed by the present application are not limited to the above methods. Equivalent modifications and changes made by those skilled in the art to the technical solutions proposed by the present application without departing from the basic principles of the present technology should be covered in the scope of the claims of the present application.
Claims
1. A whole-tobacco cigarette with a core-shell structure, characterized in that, Tobacco accounts for 95.0-99.5 wt% of the total weight of cigarettes.
2. The whole-tobacco cigarette with a core-shell structure according to claim 1, characterized in that, Its outer shell is a tobacco powder layer, and its core layer is a tobacco shred filling layer.
3. The whole-tobacco cigarette with a core-shell structure according to claim 2, characterized in that, The tobacco in the tobacco filling layer is cross-linked expanded tobacco; the filling value of the expanded tobacco is 10-40% higher than that of the unexpanded tobacco.
4. The whole-tobacco cigarette with a core-shell structure according to claim 2, characterized in that, The shell is formed by extruding wet tobacco powder; the mass ratio of the shell to the core in the cigarette is (0.5-2.5):
1.
5. The method for preparing a whole-tobacco cigarette with a core-shell structure according to claim 1, characterized in that, Includes the following steps: (1) The tobacco raw material is steam-expanded to obtain self-adhesive expanded tobacco; the self-adhesive expanded tobacco is mixed with a solution or dispersion of natural polymer crosslinking aid to obtain crosslinked expanded tobacco; (2) Rolling whole tobacco-type wet cigarettes with a core-shell structure; (3) After drying and humidifying the wet cigarette, the whole tobacco type cigarette with the shell-core structure is obtained.
6. The preparation method according to claim 5, characterized in that, The conditions for steam puffing treatment of tobacco raw materials in step (1) are as follows: the amount of water added is 0.5-4 times that of the tobacco raw materials, the steam pressure is 0.1-0.5 MPa, the heat preservation time is 0.5-10 min, the moisture content of the tobacco raw materials is 10-14wt%, and the width of the tobacco is 0.8-1.2 mm.
7. The preparation method according to claim 5, characterized in that, Step (2) The natural polymer crosslinking agent is one or more of the following: water-soluble cellulose ether, starch, dextrin, guar gum, agar, pectin, gelatin, sodium alginate, and polyvinyl alcohol. The amount of the agent is 0.1-5 wt% of the dry weight of the expanded tobacco.
8. The preparation method according to claim 5, characterized in that, Step (2) The preparation steps of the wet cigarette are as follows: cross-linked expanded tobacco shreds are fed into the cigarette rolling machine through a spiral feeding system; at the same time, wet tobacco powder is applied multiple times through a vibrating screen to form a tobacco powder coating layer; that is, a whole tobacco type wet cigarette with a core layer of tobacco shreds and a shell layer of tobacco powder is obtained; the tobacco powder particle size is 30-300 mesh, the wet tobacco powder water content is 50-80wt%; the mass ratio of dry tobacco powder to dry cross-linked expanded tobacco shreds is (0.5-2.5):
1.
9. The preparation method according to claim 8, characterized in that, The extrusion conditions are as follows: pressure roller pressure 0.3-0.5MPa, pressure roller temperature 20-50℃, extrusion time 1-5s, feeding interval 5-10s, and roll speed 0.8-1.2m / min.
10. The preparation method according to claim 5, characterized in that, Step (3) Drying and humidification conditions are: temperature 15-25℃, relative humidity 50-65%, drying time 2-10 h; adjust the final moisture content of the cigarette to 11wt%-13wt%.