Papermaking process reconstituted tobacco with improved combustion performance and method for preparing the same

Abstract

The present application relates to a kind of papermaking method reconstituted tobacco of improving combustion performance and preparation method thereof, and preparation raw materials include tobacco pulp, tobacco concentrate, combustion-modified wood fiber, porous forming aid and food-grade binder;The combustion-modified wood fiber is the coniferous wood fiber and / or broad-leaved wood fiber after low-temperature plasma activation treatment and load food-grade combustion improver;The porous forming aid is porous basic magnesium carbonate.The present application is first to wood fiber plasma activation modification, make fiber surface roughness high, pore structure is developed, improves oxygen conduction efficiency;Combustion improver is then loaded therein, avoid directly doped pulp to destroy reconstituted tobacco physical structure, also improve the compatibility and combination stability of combustion improver and fiber, improve the combustion stability and sufficiency, reduce harmful product release, and do not affect the physical strength and smoking taste of reconstituted tobacco;While porous basic magnesium carbonate constructs through micro-pore structure inside, further improves combustion performance.

Description

Technical Field

[0001] This invention belongs to the field of reconstituted tobacco preparation technology, and relates to a papermaking method for reconstituted tobacco with improved combustion performance and its preparation method. Background Technology

[0002] Reconstituted tobacco leaves produced by papermaking, as a core auxiliary material in cigarette formulation, can efficiently utilize tobacco waste such as tobacco stems and tobacco dust. At the same time, it plays a role in regulating cigarette smoke, optimizing combustion state, and reducing tar release. It is a key raw material for reducing tar and harm and improving the quality of cigarettes.

[0003] Currently, reconstituted tobacco produced using the papermaking method generally suffers from several technical defects in combustion performance: First, the internal structure of reconstituted tobacco is dense, with low porosity and poor air permeability, resulting in insufficient oxygen supply during cigarette smoking, incomplete combustion of the tobacco matrix, and problems such as flameout, smoldering, combustion cone detachment, and incomplete local carbonization. Second, conventional reconstituted tobacco has poor controllability in combustion rate, uneven heat release during combustion, and high levels of harmful components such as tar, carbon monoxide, and phenols in the smoke, leading to poor smoking safety and taste quality. Third, existing combustion improvers are directly added to the pulp, resulting in poor compatibility, uneven dispersion, and large addition amounts, which can easily damage the physical strength of reconstituted tobacco, while also producing off-flavors and deteriorating the sensory quality of the smoke, thus having limited improvement effects.

[0004] Existing technologies mostly improve combustion performance by simply adding combustion-enhancing salts or adjusting the quantitative amount of reconstituted tobacco leaves. These methods offer limited innovation and improvement, and fail to simultaneously enhance the physical properties, sensory quality, and combustion performance of the reconstituted tobacco leaves, resulting in significant technological bottlenecks. Furthermore, traditional methods using composite combustion-enhancing catalysts involve complex components, cumbersome preparation processes, and catalyst residues that can negatively impact the tobacco's aroma and smoke quality, making them unsuitable for high-end cigarette reconstituted tobacco production.

[0005] Therefore, developing a type of reconstituted tobacco leaf that combines complete combustion, stable flame retardancy, low toxicity release, excellent physical properties, and superior sensory quality is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a papermaking-based reconstituted tobacco leaf with improved combustion performance and its preparation method. This invention abandons the traditional composite combustion-supporting catalyst system and, through multiple innovations such as fiber plasma activation modification, combustion-supporting agent loading modification, precise control of porous structure, and optimized raw material compounding, produces reconstituted tobacco leaves that possess characteristics of complete combustion, low toxicity release, excellent physical properties, and superior sensory quality.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a paper-based reconstituted tobacco leaf with improved combustion performance. The raw materials for preparing the paper-based reconstituted tobacco leaf include: tobacco pulp, tobacco concentrate, combustion-enhancing modified wood fiber, porous forming aid, and food-grade binder. The combustion-enhancing modified wood fiber is coniferous wood fiber and / or broadleaf wood fiber that has been activated by low-temperature plasma and loaded with food-grade combustion enhancer. The porous forming aid is porous basic magnesium carbonate.

[0009] To address the technical shortcomings of existing reconstituted tobacco products that fail to simultaneously improve physical properties, sensory quality, and combustion performance, this invention first performs plasma-activated modification of wood fibers, resulting in high fiber surface roughness and a well-developed pore structure, thus enhancing oxygen conduction efficiency. Then, a combustion improver is uniformly loaded onto the interior and surface of the modified fibers. This avoids the direct mixing of pulp and damage to the physical structure of the reconstituted tobacco, resulting in a finished product with high physical strength, resistance to breakage, and good processing applicability. Furthermore, it significantly improves the compatibility and bonding stability between the combustion improver and the fibers, enhancing the combustion stability and completeness of the reconstituted tobacco, significantly reducing the release of harmful combustion byproducts, without affecting the physical strength and smoking taste of the reconstituted tobacco, making it suitable for continuous industrial production. Simultaneously, porous basic magnesium carbonate can construct a continuous microporous structure within the reconstituted tobacco, balancing oxygen diffusion, preventing localized incomplete combustion, and further improving oxygen conduction efficiency and combustion performance.

[0010] Preferably, the raw materials for preparing the papermaking reconstituted tobacco leaf, by oven-dry weight, include: 45-50 parts of tobacco pulp, 35-44 parts of tobacco concentrate, 7-10 parts of combustion-enhancing modified wood fiber, 5-9 parts of porous forming aid, and 0.1-0.5 parts of food-grade binder.

[0011] The oven-dry weight percentages of the tobacco pulp can be selected from 45, 46, 47, 48, 49, 50, etc.; the oven-dry weight percentages of the tobacco concentrate can be selected from 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, etc.; the oven-dry weight percentages of the combustion-enhancing modified wood fiber can be selected from 7, 7.5, 8, 8.5, 9, 10, etc.; the oven-dry weight percentages of the porous forming aid can be selected from 5, 5.5, 6, 6.5, 7, 7.5, 8, 9, 10, etc.; the oven-dry weight percentages of the food-grade binder can be selected from 0.1, 0.2, 0.3, 0.4, 0.5, etc.; other specific values ​​not listed within the above ranges can be selected, and will not be elaborated here.

[0012] Preferably, the combustion-supporting modified wood fiber is prepared by a method comprising the following steps:

[0013] (1) Using coniferous wood fiber and / or broadleaf wood fiber as the base wood fiber, the wood fiber pulp is prepared by pulping, dried and cooled;

[0014] (2) The dried wood fibers are subjected to low-temperature plasma treatment to obtain activated modified wood fibers;

[0015] (3) The activated modified wood fiber is immersed in a food-grade combustion aid dispersion for impregnation treatment. After impregnation, it is filtered and dried to obtain combustion aid modified wood fiber.

[0016] Preferably, the beating degree in step (1) is controlled at 22-28°SR, such as 22°SR, 24°SR, 25°SR, 27°SR, 28°SR, etc.

[0017] Preferably, the drying in step (1) is carried out at 60-70℃ (e.g., 60℃, 62℃, 63℃, 64℃, 66℃, 68℃, 70℃, etc.) for 1-2 hours (e.g., 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, etc.).

[0018] Preferably, the low-temperature plasma treatment in step (2) is carried out in an oxygen atmosphere with an oxygen purity ≥99.9%, a vacuum degree of 10-50 Pa (e.g., 10 Pa, 20 Pa, 30 Pa, 40 Pa, 50 Pa, etc.), a discharge power of 100-150 W (e.g., 100 W, 110 W, 120 W, 130 W, 140 W, 150 W), an operating temperature of 30-50℃ (e.g., 30℃, 35℃, 40℃, 45℃, 50℃, etc.), and a treatment time of 3-5 min (e.g., 3 min, 3.5 min, 4 min, 4.5 min, 5 min, etc.).

[0019] All other point values ​​not listed above within the above ranges can be selected, and will not be elaborated on here.

[0020] Preferably, the food-grade combustion aid in step (3) is potassium malate and / or potassium citrate.

[0021] Preferably, the food-grade combustion aid in step (3) is a combination of potassium malate and potassium citrate, wherein the mass ratio of potassium malate to potassium citrate is 1:2-2:1.

[0022] Preferably, the mass concentration of the food-grade combustion aid dispersion is 5-10%, such as 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0023] Preferably, the mass ratio of the activated modified lignocellulose to the food-grade combustion aid dispersion is 1:(2-5), such as 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, etc.

[0024] Preferably, the impregnation treatment is carried out at 40-50°C (e.g., 40°C, 42°C, 43°C, 44°C, 46°C, 48°C, 50°C, etc.) for 1-2 hours (e.g., 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, etc.).

[0025] Preferably, the drying in step (3) is carried out at 70-80℃ (e.g., 70℃, 72℃, 73℃, 74℃, 76℃, 78℃, 80℃, etc.) for 1.5-2.5 h (e.g., 90 min, 100 min, 110 min, 120 min, 130 min, 140 min, 150 min, etc.).

[0026] All other point values ​​not listed above within the above ranges can be selected, and will not be elaborated on here.

[0027] Preferably, the tobacco pulp and tobacco concentrate are prepared by a method comprising the following steps:

[0028] Tobacco stems and tobacco dust are used as raw materials, and they are mixed with water for hot extraction. After extraction, they are centrifuged to obtain tobacco extract and tobacco fiber residue. The tobacco extract is concentrated to obtain tobacco concentrate. The tobacco fiber residue is pulped to obtain tobacco pulp.

[0029] Preferably, the mass ratio of the raw material to water is 1:(5-10), such as 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc. Other specific values ​​not listed within this range can be selected, and will not be elaborated here.

[0030] Preferably, the hot extraction is carried out at 55-65℃ (e.g., 55℃, 57℃, 58℃, 60℃, 62℃, 64℃, 65℃, etc.) for 30-50 min (e.g., 30 min, 35 min, 40 min, 45 min, 50 min, etc.); other specific point values ​​not listed above within the above range can be selected, and will not be elaborated here.

[0031] Preferably, the density of the tobacco concentrate is 1.18-1.20 g / cm³. 3 For example, 1.18 g / cm³ 3 1.19 g / cm 3 1.20 g / cm 3Other unlisted point values ​​within this range can also be selected, and will not be elaborated on here.

[0032] Preferably, the degree of beating of the tobacco pulp is 22-28°SR, such as 18°SR, 19°SR, 20°SR, 22°SR, 24°SR, 25°SR, 27°SR, 28°SR, etc. Other specific values ​​not listed in this range can be selected, and will not be elaborated here.

[0033] Preferably, the food-grade binder is selected from any one or a combination of at least two of starch, guar gum, or carboxymethyl cellulose.

[0034] In a second aspect, the present invention provides a method for preparing reconstituted tobacco leaves according to the papermaking method described in the first aspect, the method comprising the following steps:

[0035] (1) Mix tobacco pulp, combustion-enhancing modified wood fiber, porous molding agent and food-grade binder, stir and disperse to obtain a mixed pulp;

[0036] (2) The mixed slurry is formed into shape, and tobacco concentrate is coated on the surface of the wet substrate sheet after forming;

[0037] (3) After coating, the tobacco leaves are dried, cut and rolled to obtain reconstituted tobacco leaves.

[0038] The reconstituted tobacco preparation method of this invention avoids complex catalyst preparation processes, integrates coating and drying into a single process, simplifies the production flow, and optimizes existing papermaking reconstituted tobacco processes. It is easy to modify, consumes little energy, produces no waste, and exhibits high production stability, making it suitable for large-scale industrial production. This invention makes full use of tobacco waste, reduces production costs, and combines environmental and economic benefits, meeting the requirements of green, low-carbon, and high-quality development in the cigarette industry.

[0039] Preferably, the concentration of the mixed slurry is controlled at 0.3-0.4%, such as 0.3%, 0.32%, 0.33%, 0.35%, 0.36%, 0.37%, 0.38%, 0.4%, etc.

[0040] Preferably, the controlled quantitative amount in the copying process is 55-58 g / m³. 2 For example, 55 g / m 2 56 g / m 2 57 g / m 2 58 g / m 2 wait.

[0041] Preferably, the coating control coating rate is 39-40%.

[0042] Preferably, the drying process employs a two-stage gradient drying method:

[0043] First stage: Dry at 85-95℃ (e.g., 85℃, 87℃, 90℃, 93℃, 95℃, etc.) until the moisture content is 22-28% (e.g., 22%, 23%, 24%, 25%, 26%, 27%, 28%, etc.).

[0044] Second stage: Dry at 95-105℃ (e.g., 95℃, 98℃, 100℃, 102℃, 105℃, etc.) until the moisture content is 11-13% (e.g., 11%, 12%, 13%, etc.).

[0045] All other point values ​​not listed above within the above ranges can be selected, and will not be elaborated on here.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] To address the technical shortcomings of existing reconstituted tobacco products that fail to simultaneously improve physical properties, sensory quality, and combustion performance, this invention first performs plasma-activated modification of wood fibers, resulting in high fiber surface roughness and a well-developed pore structure, thus enhancing oxygen conduction efficiency. Then, a combustion improver is uniformly loaded onto the interior and surface of the modified fibers. This avoids the direct mixing of pulp and damage to the physical structure of the reconstituted tobacco, resulting in a finished product with high physical strength, resistance to breakage, and good processing applicability. Furthermore, it significantly improves the compatibility and bonding stability between the combustion improver and the fibers, enhancing the combustion stability and completeness of the reconstituted tobacco, significantly reducing the release of harmful combustion byproducts, without affecting the physical strength and smoking taste of the reconstituted tobacco, making it suitable for continuous industrial production. Simultaneously, porous basic magnesium carbonate can construct a continuous microporous structure within the reconstituted tobacco, balancing oxygen diffusion, preventing localized incomplete combustion, and further improving oxygen conduction efficiency and combustion performance. Detailed Implementation

[0048] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0049] The sources of some of the raw materials used in the following examples or comparative examples are as follows:

[0050]

[0051] All other raw materials are commercially available in this field.

[0052] Example 1

[0053] This embodiment provides a reconstituted tobacco leaf, the raw materials of which, by oven-dry weight, are: 50 parts tobacco pulp, 40 parts tobacco concentrate, 8 parts combustion-enhancing modified wood fiber, 6 parts porous basic magnesium carbonate, and 0.4 parts guar gum.

[0054] The combustion-supporting modified wood fiber is prepared by the following method:

[0055] (1) Select coniferous wood fiber as the base wood fiber, pulp it, with a pulping degree of 25°SR, dry it at 70℃ for 1 hour, and cool it for later use;

[0056] (2) Dry fibers are spread in a plasma chamber, in a high-purity oxygen atmosphere with an oxygen purity ≥99.9%, a vacuum degree of 30Pa, a power of 120W, and a treatment time of 4 min. The working temperature is 45℃, and activated modified wood fibers are obtained.

[0057] (3) Prepare a dispersion of 8% (mass ratio of potassium malate and potassium citrate) combustion aid, stir at 25°C for 12 min at a speed of 450 r / min.

[0058] (4) The activated modified wood fiber was immersed in the dispersion at a solid-liquid mass ratio of 1:3.5, and impregnated at 45℃ and 350r / min for 1.5h. After filtration, it was dried at 75℃ for 2h to obtain the combustion-supporting modified wood fiber.

[0059] Its preparation method is as follows:

[0060] (1) Mix tobacco stems and tobacco dust at a mass ratio of 3.5:6.5; add deionized water at a material-to-liquid mass ratio of 1:8, and extract at 60℃ for 40 min; after extraction, centrifuge to obtain tobacco extract and tobacco fiber residue; concentrate the tobacco extract under reduced pressure to obtain a density of 1.19 g / cm³. 3 The tobacco concentrate; the tobacco fiber residue is milled in multiple stages to prepare a tobacco pulp with a beating degree of 25°SR, for later use.

[0061] (2) The tobacco pulp, combustion-enhancing modified wood fiber, porous basic magnesium carbonate and guar gum were put into a dispersion device and stirred for 35 min to obtain a homogeneous mixed pulp with a concentration of 0.35%.

[0062] (3) The mixed slurry is formed into a sheet with a basis weight of 56 g / m³. 2 After molding, tobacco concentrate is coated onto the surface of the wet substrate sheet, with the coating rate controlled at 39.5%.

[0063] (4) After coating, the first section is dried at 85°C to 28% moisture content, and the second section is dried at 95°C to 12% moisture content. The tobacco leaves are then cut and rolled up to obtain reconstituted tobacco leaves.

[0064] Example 2

[0065] This embodiment provides a reconstituted tobacco leaf, the raw materials of which, by dry weight, are: 48 parts tobacco pulp, 44 parts tobacco concentrate, 7 parts combustion-enhancing modified wood fiber, 9 parts porous basic magnesium carbonate, and 0.5 parts starch.

[0066] The combustion-supporting modified wood fiber is prepared by the following method:

[0067] (1) Select coniferous and broad-leaved wood fibers as the base wood fibers, pulp them to a pulping degree of 26°SR, dry them at 65℃ for 1.5h, and cool them for later use;

[0068] (2) Dry fibers are spread in a plasma chamber under a high-purity oxygen atmosphere with an oxygen purity ≥99.9%, a vacuum degree of 25 Pa, a power of 140 W, and a treatment time of 3.5 min at a working temperature of 40℃ to obtain activated and modified wood fibers.

[0069] (3) Prepare a 6% mass concentration combustion aid (potassium malate and potassium citrate in a mass ratio of 2:1), stir at 25°C for 15 min at a speed of 400 r / min;

[0070] (4) The activated modified wood fiber was immersed in the dispersion at a solid-liquid mass ratio of 1:3, and impregnated at 48℃ and 400r / min for 1.2 h. After filtration, it was dried at 78℃ for 2 h to obtain the combustion-supporting modified wood fiber.

[0071] Its preparation method is as follows:

[0072] (1) Mix tobacco stems and tobacco dust at a mass ratio of 3.5:6.5; add deionized water at a material-to-liquid mass ratio of 1:8, and extract at 62℃ for 45 min; after extraction, centrifuge to obtain tobacco extract and tobacco fiber residue; concentrate the tobacco extract under reduced pressure to obtain a density of 1.20 g / cm³. 3 The tobacco concentrate; the tobacco fiber residue is milled in multiple stages to prepare a tobacco pulp with a beating degree of 26°SR, for later use.

[0073] (2) The tobacco pulp, combustion-enhancing modified wood fiber, porous basic magnesium carbonate and starch were put into a dispersion device and stirred for 40 min to obtain a homogeneous mixed pulp with a concentration of 0.38%.

[0074] (3) The mixed slurry is formed into a sheet with a basis weight of 57 g / m³. 2 After molding, tobacco concentrate is coated on the surface of the wet substrate sheet, with the coating rate controlled at 40%.

[0075] (4) After coating, the tobacco leaves are dried in stages: the first stage is dried at 87°C to 26% moisture content, and the second stage is dried at 98°C to 11.5% moisture content. The leaves are then cut and rolled up to obtain reconstituted tobacco leaves.

[0076] Example 3

[0077] This embodiment provides a reconstituted tobacco leaf, the raw materials of which, by oven-dry weight, are: 45 parts tobacco pulp, 38 parts tobacco concentrate, 10 parts combustion-enhancing modified wood fiber, 5 parts porous basic magnesium carbonate, and 0.3 parts carboxymethyl fiber.

[0078] The combustion-supporting modified wood fiber is prepared by the following method:

[0079] (1) Select coniferous wood fiber and broadleaf wood fiber with a mass ratio of 1:1 as the base wood fiber, and after pulping treatment, the pulping degree is 28°SR, dry at 60℃ for 2h, and cool for later use;

[0080] (2) Dry fibers are spread in a plasma chamber, in a high-purity oxygen atmosphere with an oxygen purity ≥99.9%, a vacuum degree of 35Pa, a power of 120W, and a treatment time of 5 minutes. The working temperature is 35℃, and activated modified wood fibers are obtained.

[0081] (3) Prepare a 10% mass concentration combustion aid (potassium malate and potassium citrate in a mass ratio of 1:2), stir at 25°C for 15 min at a speed of 400 r / min;

[0082] (4) The activated modified wood fiber was immersed in the dispersion at a solid-liquid mass ratio of 1:4, soaked at 43℃ and 400r / min for 2 h, filtered, and dried at 70℃ for 2.5 h to obtain the combustion-supporting modified wood fiber.

[0083] Its preparation method is as follows:

[0084] (1) Mix tobacco stems and tobacco dust at a mass ratio of 3.5:6.5; add deionized water at a material-to-liquid mass ratio of 1:10, and extract at 58℃ for 50 min; after extraction, centrifuge to obtain tobacco extract and tobacco fiber residue; concentrate the tobacco extract under reduced pressure to obtain a density of 1.18 g / cm³. 3 The tobacco concentrate; the tobacco fiber residue is milled in multiple stages to prepare a tobacco pulp with a beating degree of 28°SR, for later use.

[0085] (2) The tobacco pulp, combustion-modified wood fiber, porous basic magnesium carbonate and carboxymethyl fiber were put into a dispersion device and stirred for 40 min to obtain a homogeneous mixed pulp with a concentration of 0.4%.

[0086] (3) The mixed slurry is formed into a sheet with a basis weight of 58 g / m³. 2 After molding, tobacco concentrate is coated onto the surface of the wet substrate sheet, with the coating rate controlled at 39%.

[0087] (4) After coating, the first section is dried at 90°C to 24% moisture content, and the second section is dried at 100°C to 11% moisture content. The tobacco leaves are then cut and rolled up to obtain reconstituted tobacco leaves.

[0088] Example 4

[0089] This embodiment provides a reconstituted tobacco leaf, the only difference between its preparation raw materials and those of Example 1 is that a combustion aid (potassium malate) with a mass concentration of 10% is prepared in step (3), while the others remain unchanged. The preparation method is the same as in Example 1.

[0090] Example 5

[0091] This embodiment provides a reconstituted tobacco leaf, the only difference between its preparation raw materials and those of Example 1 is that a combustion aid (potassium citrate) with a mass concentration of 10% is prepared in step (3), while the others remain unchanged. The preparation method is the same as in Example 1.

[0092] Comparative Example 1

[0093] This comparative example provides a reconstituted tobacco leaf, the only difference between its preparation raw materials and those of Example 1 being: the porous basic magnesium carbonate is replaced by nanoporous diatomaceous earth, while all other aspects remain unchanged. The preparation method is the same as in Example 1.

[0094] Comparative Example 2

[0095] This comparative example provides a reconstituted tobacco leaf, the only difference between its preparation raw materials and those of Example 1 being: porous basic magnesium carbonate is replaced by precipitated calcium carbonate (PCC) in equal mass, while all other aspects remain unchanged. The preparation method is the same as in Example 1.

[0096] Comparative Example 3

[0097] This comparative example provides a reconstituted tobacco leaf, the only difference between its preparation materials and those of Example 1 being the absence of porous basic magnesium carbonate; all other aspects remain unchanged. The preparation method is the same as in Example 1.

[0098] Comparative Example 4

[0099] This comparative example provides a reconstituted tobacco leaf, the only difference between its preparation raw materials and those of Example 1 being that the combustion-enhancing modified lignocellulose is obtained by the following method:

[0100] (1) Select coniferous wood fiber as the base wood fiber, pulp it, with a pulping degree of 25°SR, dry it at 70℃ for 1 hour, and cool it for later use;

[0101] (2) Prepare a dispersion of 8% (mass ratio of potassium malate and potassium citrate) combustion aid, stir at 25°C for 12 min at a speed of 450 r / min.

[0102] (3) The dried fiber was immersed in the dispersion at a solid-liquid mass ratio of 1:3.5, and impregnated at 45℃ and 350r / min for 1.5 h. After filtration, it was dried at 75℃ for 2 h to obtain the combustion-supporting modified wood fiber.

[0103] Everything else remains unchanged. The preparation method is the same as in Example 1.

[0104] Comparative Example 5

[0105] This comparative example provides a reconstituted tobacco leaf, the only difference between its preparation raw materials and those of Example 1 is the absence of combustion-enhancing modified lignocellulose; all other aspects remain unchanged. The preparation method is the same as in Example 1.

[0106] Comparative Example 6

[0107] This comparative example provides a reconstituted tobacco leaf, the raw materials of which, by oven-dry weight, are: 50 parts tobacco pulp, 40 parts tobacco concentrate, 6 parts precipitated calcium carbonate (PCC) and 0.4 parts guar gum.

[0108] Its preparation method is as follows:

[0109] (1) Mix tobacco stems and tobacco dust at a mass ratio of 3.5:6.5; add deionized water at a material-to-liquid mass ratio of 1:8, and extract at 60℃ for 40 min; after extraction, centrifuge to obtain tobacco extract and tobacco fiber residue; concentrate the tobacco extract under reduced pressure to obtain a density of 1.19 g / cm³. 3 The tobacco concentrate; the tobacco fiber residue is milled in multiple stages to prepare a tobacco pulp with a beating degree of 25°SR, for later use.

[0110] (2) Add tobacco pulp, precipitated calcium carbonate PCC and guar gum into a dispersion device and stir for 35 min to obtain a homogeneous mixed pulp with a concentration of 0.35%;

[0111] (3) The mixed slurry is formed into a sheet with a basis weight of 56 g / m³. 2 After molding, tobacco concentrate is coated onto the surface of the wet substrate sheet, with the coating rate controlled at 39.5%.

[0112] (4) After coating, the first section is dried at 85°C to 28% moisture content, and the second section is dried at 95°C to 12% moisture content. The tobacco leaves are then cut and rolled up to obtain reconstituted tobacco leaves.

[0113] Test Example 1

[0114] (1) Evaluation of porosity (%) of reconstituted tobacco leaves:

[0115] The porosity (%) of the reconstituted tobacco leaves obtained in Examples 1-5 and Comparative Examples 1-6 was evaluated. The evaluation method was as follows: 50 mm × 50 mm reconstituted tobacco leaf samples were cut, dried at 105°C to constant weight, and the oven-dry mass m0 was measured; the length, width, and thickness were measured with vernier calipers, and the apparent total volume V was calculated. 总 The sample was vacuum impregnated with deionized water to fully fill the pores. After wiping off the surface water, the saturated water mass m1 was measured. Pore volume V 孔 =(m1-m0) / ρ水 Porosity = V 孔 / V总 ×100%, ρ 水 Take 1.00 g / cm 3 Each group underwent three parallel tests, and the average value was taken. The higher the porosity, the more developed the pore structure of the thin sheet, and the better the combustion performance.

[0116] (2) Evaluation of the combustion failure rate (%) of reconstituted tobacco:

[0117] The extinguishing rate (%) of the reconstituted tobacco leaves prepared in Examples 1-5 and Comparative Examples 1-6 was evaluated. The evaluation method was as follows: reconstituted tobacco leaves were cut into 100 mm × 30 mm standard samples and equilibrated for 48 h at a temperature of (22±2)℃ and a relative humidity of (60±5)% to ensure sample moisture stability. A total of 50 samples were tested in each group. The samples were horizontally fixed to a combustion support, and the end was continuously ignited for 3 s to ensure stable smoldering. The ignition source was then removed, and the samples were allowed to extinguish spontaneously. The number of samples that extinguished spontaneously was recorded. The extinguishing rate was calculated using the formula: extinguishing rate (%) = (number of extinguished samples / total number of tested samples) × 100%. A lower extinguishing rate indicates better smoldering stability and combustion continuity of the reconstituted tobacco leaves, making them less prone to flameout and exhibiting better combustion uniformity.

[0118] (3) Evaluation of carbon monoxide emissions from reconstituted tobacco:

[0119] The carbon monoxide release (mg / cigarette) and tar release (mg / cigarette) of the reconstituted tobacco leaves prepared in Examples 1-5 and Comparative Examples 1-6 were evaluated. The evaluation method was as follows: Based on the total mass of cigarette tobacco, a mixed tobacco shred containing 9% reconstituted tobacco and 91% natural tobacco was prepared. The reconstituted tobacco was subjected to impurity removal, slicing, rehydration, pre-addition, and storage balancing. The natural tobacco was subjected to leaf threshing, re-drying, shredding, rehydration, and pre-addition. The tobacco shreds were then uniformly mixed at a mass ratio of 9:91 using a precise metering system. After mixing, drying, flavoring, and a second storage balancing, the finished mixed tobacco shreds were obtained. Standard cigarettes were rolled using uniform process parameters, ensuring consistent tobacco filling in each cigarette. The prepared cigarettes were then placed in an environment at 22°C and 60% relative humidity for 48 hours to equilibrate, yielding the cigarette samples to be tested.

[0120] According to the standard testing conditions specified in GB / T 19609-2004 and GB / T 23356-2009, the carbon monoxide release of mainstream cigarette smoke was tested using a conventional analytical smoking machine and a non-dispersive infrared carbon monoxide detector. The smoking volume was 35 mL, the smoking duration was 2 s, and the smoking interval was 60 s. Multiple parallel tests were conducted for each group, and the average value was taken.

[0121] According to GB / T 19609-2004, tar detection of mainstream smoke was carried out using a standard linear smoke extraction machine. The extraction conditions were: extraction volume of 35 mL, extraction time of 2 s, and extraction interval of 60 s. Cambridge filters were used to capture particulate matter in the smoke. The tar content was calculated after weighing and deducting moisture and nicotine. Multiple parallel tests were conducted for each group of samples, and the arithmetic mean was taken.

[0122] (4) Evaluation of tensile strength (kN / m) of reconstituted tobacco leaves:

[0123] The tensile strength (kN / m) of the reconstituted tobacco leaves obtained in Examples 1-5 and Comparative Examples 1-6 was evaluated according to the YC / T 426 standard for testing the physical properties of reconstituted tobacco leaves. Samples were cut into 150 mm × 15 mm strips and equilibrated under standard temperature and humidity conditions for 24 hours. A paper tensile strength tester was used, with a clamping distance of 100 mm and a tensile speed of 20 mm / min. Ten samples were tested in each group, and the average value was taken. The formula for calculating tensile strength is: Tensile strength (kN / m) = F / b, where F is the maximum tensile force and b is the sample width. Higher tensile strength indicates stronger interweaving and bonding of the substrate fibers, making it less prone to brittleness during drying and resulting in better adaptability for finished product processing.

[0124] The test results for the above indicators are shown in Table 1.

[0125] Table 1

[0126]

[0127] As shown in Table 1, compared with the reconstituted tobacco products of Comparative Examples 1-6, the reconstituted tobacco products prepared by the present invention first complete the plasma activation modification of wood fibers, then uniformly load the combustion aid into the interior and surface of the modified fibers, and at the same time, the porous basic magnesium carbonate constructs a through-hole microporous structure inside, so that the reconstituted tobacco products have better combustion stability and combustion completeness, reduce the release of harmful combustion products, and do not affect the physical strength of the reconstituted tobacco.

[0128] Test Example 2

[0129] Cigarettes were made from the reconstituted tobacco leaves obtained in Examples 1-5 and Comparative Examples 1-6 using the same preparation process. The cigarettes were then sealed and stored for at least 48 hours at a temperature of (22±1)℃ and a relative humidity of (60%±2)%. Seven certified professional smoke testers conducted blind tastings under standardized atmospheric conditions. Evaluation indicators included aroma, flavor, off-flavors, burning sensation, dryness, and residue. The maximum scores for each indicator were 15, 25, 15, 15, 15, and 15 points respectively. The scores for each indicator were summed to obtain the overall sensory score. (A higher score indicates a better sensory effect for that indicator; the average value was taken and rounded to one decimal place.) The results are shown in Table 2.

[0130] Table 2

[0131]

[0132] As shown in Table 2, compared with the reconstituted tobacco products of Comparative Examples 1-6, the reconstituted tobacco products obtained by the present invention have superior sensory qualities because they first complete the plasma activation modification of wood fibers, then uniformly load the combustion aid into the interior and surface of the modified fibers, and at the same time, the porous basic magnesium carbonate constructs a through-hole microporous structure inside.

[0133] The applicant declares that the technical solution of this invention is illustrated by the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

[0134] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0135] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A papermaking method for reconstituted tobacco with improved combustion performance, characterized in that, The raw materials for preparing reconstituted tobacco by the papermaking method include: tobacco pulp, tobacco concentrate, combustion-enhancing modified wood fiber, porous forming aid, and food-grade binder; the combustion-enhancing modified wood fiber is coniferous wood fiber and / or hardwood fiber that has been activated by low-temperature plasma and loaded with food-grade combustion-enhancing agent; the porous forming aid is porous basic magnesium carbonate.

2. The papermaking method for reconstituted tobacco leaves according to claim 1, characterized in that, The raw materials for preparing reconstituted tobacco by the papermaking method include, by oven-dry weight, 45-50 parts of tobacco pulp, 35-44 parts of tobacco concentrate, 7-10 parts of combustion-enhancing modified wood fiber, 5-9 parts of porous forming aid, and 0.1-0.5 parts of food-grade binder.

3. The papermaking method for reconstituted tobacco leaves according to claim 1 or 2, characterized in that, The combustion-supporting modified wood fiber is prepared by a method comprising the following steps: (1) Using coniferous wood fiber and / or broadleaf wood fiber as the base wood fiber, the wood fiber pulp is prepared by pulping, dried and cooled; (2) The dried wood fibers are subjected to low-temperature plasma treatment to obtain activated modified wood fibers; (3) The activated modified wood fiber is immersed in a food-grade combustion aid dispersion for impregnation treatment. After impregnation, it is filtered and dried to obtain combustion aid modified wood fiber.

4. The papermaking method for reconstituted tobacco leaves according to claim 3, characterized in that, In step (1), the beating degree is controlled at 22-28°SR. Preferably, the drying in step (1) is carried out at 60-70°C for 1-2 hours.

5. The papermaking method for reconstituted tobacco leaves according to claim 3, characterized in that, The low-temperature plasma treatment in step (2) is carried out in an oxygen atmosphere with an oxygen purity ≥99.9%, a vacuum degree of 10-50 Pa, a discharge power of 100-150 W, a working temperature of 30-50℃, and a treatment time of 3-5 min.

6. The papermaking method for reconstituted tobacco leaves according to claim 3, characterized in that, The food-grade combustion aid mentioned in step (3) is potassium malate and / or potassium citrate; Preferably, the mass concentration of the food-grade combustion aid dispersion is 5-10%; Preferably, the mass ratio of the activated modified lignocellulose to the food-grade combustion aid dispersion is 1:(2-5); Preferably, the impregnation treatment is carried out at 40-50°C for 1-2 hours; Preferably, the drying in step (3) is carried out at 70-80°C for 1.5-2.5 h.

7. The papermaking method for reconstituted tobacco leaves according to any one of claims 1-6, characterized in that, The tobacco pulp and tobacco concentrate are prepared by a method comprising the following steps: Tobacco stems and tobacco dust are used as raw materials. They are mixed with water and hot-extracted. After extraction, they are centrifuged to obtain tobacco extract and tobacco fiber residue. The tobacco extract is concentrated to obtain tobacco concentrate. The tobacco fiber residue is pulped to obtain tobacco pulp. Preferably, the mass ratio of the raw material to water is 1:(5-10); Preferably, the hot extraction is carried out at 55-65°C for 30-50 minutes; Preferably, the density of the tobacco concentrate is 1.18-1.20 g / cm³. 3 ; Preferably, the beating degree of the tobacco pulp is 22-28°SR.

8. The papermaking method for reconstituted tobacco leaves according to any one of claims 1-7, characterized in that, The food-grade binder is selected from any one or a combination of at least two of starch, guar gum, or carboxymethyl cellulose.

9. The method for preparing reconstituted tobacco by papermaking according to any one of claims 1-8, characterized in that, The preparation method includes the following steps: (1) Mix tobacco pulp, combustion-enhancing modified wood fiber, porous molding agent and food-grade binder, stir and disperse to obtain a mixed pulp; (2) The mixed slurry is formed into shape, and tobacco concentrate is coated on the surface of the wet substrate sheet after forming; (3) After coating, the tobacco leaves are dried, cut and rolled to obtain reconstituted tobacco leaves.

10. The method for preparing reconstituted tobacco using the papermaking process according to claim 9, characterized in that, The concentration of the mixed slurry is controlled at 0.3-0.4%; Preferably, the controlled quantitative amount in the copying process is 55-58 g / m³. 2 ; Preferably, the coating control coating rate is 39-40%; Preferably, the drying process employs a two-stage gradient drying method: First stage: Dry at 85-95℃ until moisture content reaches 22-28%; Second stage: Dry at 95-105℃ until the moisture content is 11-13%.

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