A slurry method of reconstituted tobacco leaf with a slow release cross-linking system

Abstract

The patent discloses a thick pulp method reconstituted tobacco with slow-release crosslinking system, which is characterized in that the slow-release crosslinking system comprises a functional crosslinking agent, a gelling agent and a crosslinking regulator; the crosslinking regulator is hydrolyzed in an aqueous phase to continuously release ions in the functional crosslinking agent, the ions are coordinated with the gelling agent to form an egg-box-shaped three-dimensional crosslinking network, so that the tensile strength of the thick pulp method reconstituted tobacco is greater than 0.7 kN / m, and the thermal diffusivity is greater than 0.15 mm 2 / s. The patent achieves the purpose of simultaneously enhancing the matrix strength and optimizing the thermal conductivity performance.

Description

Technical Field

[0001] This patent belongs to the field of tobacco sheet technology, specifically relating to a slurry-based reconstituted tobacco leaf with a slow-release crosslinking system. Background Technology

[0002] Thick slurry reconstituted tobacco (also known as tobacco sheet) is one of the key technologies in the tobacco industry to achieve efficient utilization of raw materials, reduce tar release, and regulate the composition of smoke. Its basic process involves dispersing tobacco raw materials, fibers, adhesives, fillers, and flavorings in water to form a homogeneous slurry, and then producing sheet-like substrates through processes such as casting, drying, and slitting.

[0003] Currently, there are two interrelated technical bottlenecks in the preparation of reconstituted tobacco using the slurry method: 1. Poor strength and integrity of the matrix structure Traditional paste-forming sheet production relies primarily on the physical bonding of adhesives (such as sodium carboxymethyl cellulose, guar gum, starch, and their derivatives) to maintain its structure. While these adhesives provide some dry strength, the sheets generally suffer from the following drawbacks: Poor wet strength: It is easy to soften and collapse when exposed to water or high humidity, which affects the stability of subsequent processing (such as flavoring and cutting); High brittleness and insufficient toughness: The dried sheets are brittle and are prone to cracking and fragmentation during cutting and conveying, resulting in a decrease in the yield of finished products; Lack of chemical cross-linking: The physical bonding network has limited strength, cannot form a stable three-dimensional structure, and is difficult to withstand the mechanical stress in subsequent processes.

[0004] 2. Thermophysical properties and uneven heat transfer issues

[0005] During the inhalation process, the heat transfer inside the thin film directly affects the volatilization of the fragrance, the formation of smoke, and the uniformity of combustion.

[0006] However, traditional formulas have the following problems: Lack of high thermal conductivity functional fillers: Commonly used fillers such as calcium carbonate (traditionally added in low proportion) or plant fibers generally have low thermal conductivity (e.g., the thermal conductivity of plant fibers is about 0.05–0.1 W / m·K), which cannot effectively establish a heat conduction network; Uneven distribution of fillers: Traditional mixing processes make it difficult to achieve highly uniform dispersion of fillers in the continuous phase of the adhesive, which can easily lead to the formation of local thermal resistance zones and hot spots; Dense structure hinders heat diffusion: The continuous dense film structure formed by the adhesive further impedes the rapid and uniform diffusion of heat within the matrix.

[0007] Current slurry-based reconstituted tobacco technology primarily relies on physically blended adhesives (such as CMC and starch) to maintain its structure. Due to the lack of chemical cross-linking, the molecular chains are bound only by hydrogen bonds or van der Waals forces, resulting in low bond energy and water sensitivity. This inherent structural characteristic leads to low mechanical strength, easy collapse in wet conditions, and brittleness and breakage during processing, affecting yield and product quality stability. Furthermore, in traditional formulations, fillers (such as calcium carbonate) are often added in low proportions through physical blending, primarily for cost adjustment or volume filling, failing to form chemical bonds with the adhesive. This results in weak filler-matrix interface bonding, making them prone to defects under stress and further weakening overall strength. In addition, the uneven dispersion and singular function of the fillers (lack of thermal conductivity design) lead to discontinuous heat conduction paths and uneven thermal resistance distribution within the matrix, preventing rapid and uniform heat transfer during absorption and causing localized overheating and cold zones. This unevenness in the thermal field directly causes differences in the rate at which the fragrance is released when heated, resulting in a sensory fluctuation of "strong at the beginning and weak at the end" where the fragrance is too strong in the early stages of vaping and then rapidly diminishes in the middle and later stages, which seriously affects the continuity and satisfaction of the vaping experience.

[0008] In summary, traditional slurry-based sheet fabrication suffers from insufficient matrix strength due to the lack of chemical cross-linking, while the limited functionality and uneven dispersion of fillers lead to heat transfer imbalance. Both factors contribute to poor sheet processing adaptability and unstable sensory release. Strength and heat transfer issues are intertwined; structural fragility is often accompanied by uneven pore distribution, further exacerbating the heat transfer imbalance. Conversely, uneven heat transfer leads to localized stress concentration, intensifying structural damage. Therefore, an integrated solution is needed that can simultaneously enhance matrix strength and optimize its thermal conductivity.

[0009] In existing technologies, such as Chinese patent CN119745104A, a method for preparing high-toughness reconstituted tobacco leaves using a slurry-based process for heated cigarettes is provided. This method effectively improves the compatibility and dispersibility of fibers in the reconstituted tobacco system by optimizing the formulation of the main crosslinking agent and gelatinizing the auxiliary crosslinking agent, thereby synergistically improving the overall elongation at break of the reconstituted tobacco leaves. The addition of inorganic fillers makes the reconstituted tobacco leaf structure more porous, improving overall softness while maintaining stable release characteristics of aroma substances. Using this existing technology, the preparation of reconstituted tobacco leaves for heated cigarettes can effectively improve the toughness and softness of slurry-based tobacco sheets, making them suitable for use in orderly arranged heated cigarettes and meeting the smoker's experience needs. However, this existing technology mainly relies on physical blending and process control (such as gelatinization and emulsification) to improve the toughness and softness of the sheets. The fillers (such as borax) are only used as inert fillers and fail to achieve chemical bonding and functionalization, thus failing to effectively solve the problems of low sheet strength and optimized heat conduction. Summary of the Invention

[0010] The purpose of this patent is to provide a slurry-based reconstituted tobacco leaf with a slow-release crosslinking system, so as to simultaneously enhance the matrix strength and optimize its thermal conductivity.

[0011] To solve the above-mentioned technical problems, this patent adopts the following technical solution: A slurry-based reconstituted tobacco leaf with a slow-release crosslinking system, characterized in that the slow-release crosslinking system includes a functional crosslinking agent, a gelling agent, and a crosslinking regulator; The hydrolysis of the crosslinking regulator in the aqueous phase leads to the continuous release of ions from the functional crosslinking agent. These ions coordinate with the gelling agent to form an egg-box-like three-dimensional crosslinked network, resulting in a tensile strength greater than 0.7 kN / m and a thermal diffusivity greater than 0.15 mm in the slurry-process reconstituted tobacco leaves. 2 / s.

[0012] Furthermore, the functional cross-linking agent is calcium carbonate; The ion is calcium ion; The gelling agent is sodium alginate; The cross-linking regulator is gluconolactone.

[0013] Furthermore, the slurry-based reconstituted tobacco process includes both tobacco raw materials and flavorings; Tobacco raw materials include tobacco stems or tobacco dust.

[0014] Furthermore, based on the total weight of the substances, the amount of crosslinking regulator added is 0.8-1.0%, 1.0-1.5%, or 1.5-2.5%; The amount of functional crosslinking agent added is 40-45%, 45-50%, 50-55%, or 55-60%; The amount of gelling agent added is 1.0-1.5%, 1.5-2.0%, 2.0-2.5%, or 2.5-3.0%; The amount of tobacco raw materials added is 25-30%, 30-35%, 35-40%, or 40-45%. The amount of spices added is 5-10%.

[0015] Furthermore, the preparation method of reconstituted tobacco using the slurry method includes the following steps: Step A: Grind the tobacco raw material to 200-400 mesh to obtain tobacco powder; add water to the gelling agent to prepare a glue solution; mix the tobacco powder, functional crosslinking agent and crosslinking regulator, add the glue solution and stir thoroughly to obtain a wet mixed slurry; Step B: The wet slurry undergoes a slow-release cross-linking maturation process under stirring. The temperature of the slow-release cross-linking maturation process is maintained at 30-40℃, and the time is 30-35 minutes, 35-40 minutes, 40-45 minutes, 45-50 minutes, or 50-60 minutes. Before the end of the slow-release cross-linking maturation process, the flavoring slurry is obtained. Step C: Add flavoring slurry and cast the mixture into a film. After drying, the resulting slurry-based reconstituted tobacco leaves are obtained.

[0016] Furthermore, step A includes the following steps: Step A1: Dry the tobacco raw material until the moisture content is ≤7%, then pulverize it to 200-400 mesh to obtain tobacco powder; Step A2: The functional crosslinking agent is activated for 80-100 minutes and then cooled to room temperature to obtain the activated functional crosslinking agent. The activation temperature is 100-110℃. Step A3: Slowly add the gelling agent to warm water at 40-50℃, stir and dissolve until completely transparent, to prepare a 2.0-2.5wt% gel solution.

[0017] Furthermore, step A also includes the following steps: Step A4: Add tobacco powder, activated functional crosslinking agent and crosslinking regulator into a high-speed mixer and dry mix at 45-60 rpm for 15-20 minutes to obtain dry mix; Step A5: Transfer the dry mixture to the mixing tank, add the adhesive liquid and start initial mixing. The initial mixing speed is 200-300 rpm and the initial mixing time is 3-10 minutes. Step A5: After the initial mixing is completed, the slurry is mixed at high speed. The high speed mixing speed is 800-1000 rpm and the high speed mixing time is 20-30 minutes. The solid content is adjusted to 20-25%. The slurry is then transferred to a high-pressure homogenizer for homogenization to obtain wet-mixed slurry.

[0018] Furthermore, step B includes the following steps: Step B1: The wet slurry undergoes a slow-release cross-linking maturation process under low-speed stirring. The stirring speed is 100-200 rpm, the temperature of the slow-release cross-linking maturation process is maintained at 30-40℃, and the time is 30-35 minutes, 35-40 minutes, 40-45 minutes, 45-50 minutes, or 50-60 minutes. Step B2: Add the flavoring 5-15 minutes before the end of the slow-release cross-linking and maturation process. The flavoring is added in the form of atomization. After adding the flavoring, stir at 60-80 rpm for 10-15 minutes to obtain the flavored slurry.

[0019] Furthermore, step C includes the following steps: Step C1: The flavored slurry is fed into the casting machine's feed trough for casting. The scraper gap in the casting machine's feed trough is 0.6-0.8 mm, 0.8-1.0 mm, or 1.0-1.2 mm; the steel belt speed in the casting machine's feed trough is 1.5-2.5 m / min; and the slurry flow rate in the casting machine's feed trough is 2.0-3.0 L / min, resulting in the cast material. Step C2: The cast material is subjected to pre-drying, main drying, shaping drying and cooling drying in sequence so that the moisture is removed in a gradient and the cross-linking network is solidified to obtain slurry reconstituted tobacco leaves.

[0020] Furthermore, in step C2, the pre-drying temperature is 75-85℃, the pre-drying relative humidity is 40-50%, and the pre-drying time is 2-3 minutes; The temperature for primary drying is 100-110℃, the relative humidity for primary drying is less than 15%, and the primary drying time is 4-5 minutes. The temperature for setting and drying is 65-75℃, the relative humidity for setting and drying is 25-30%, and the time for setting and drying is 2-3 minutes. The cooling and drying temperature is 20-30℃, the relative humidity is 25-30%, and the cooling and drying time is 1-2 minutes.

[0021] This patent provides a slurry-based reconstituted tobacco leaf with a slow-release crosslinking system. It innovatively proposes the core mechanism of "chemical slow-release crosslinking" and "multifunctional integration of fillers". By regulating the release of calcium ions by gluconolactone, calcium carbonate and sodium alginate are used to construct a stable "egg box" three-dimensional network, realizing a leap from physical mixing to chemical bonding. At the same time, calcium carbonate has the triple functions of crosslinking agent, high thermal conductivity filler and structural skeleton, which solves the correlation problems of low strength, uneven heat transfer and unstable flavor release of traditional thin sheets. Attached Figure Description

[0022] The above content of this patent and the following detailed embodiments will be better understood when read in conjunction with the accompanying drawings. It should be noted that the drawings are merely examples of the claimed technical solution.

[0023] Figure 1 This is a comparison diagram of the tensile strength of each embodiment and comparative example in this patent; Figure 2 This is a comparison diagram of the thermal diffusivity of the various embodiments and comparative examples in this patent; Figure 3 This is a comparison chart of the spice loading rates of various embodiments and comparative examples in this patent. Figure 4 This is a comparison chart of sensory ratings for each embodiment and comparative example in this patent; Figure 5This is a comparison diagram of the elongation at break of each embodiment and comparative example in this patent. Figure 6 This is a schematic diagram of the coordination structure of polymer segments and calcium ions in the slurry-based reconstituted tobacco leaf of this patent. Figure 7 This is a schematic diagram of the egg-box-shaped three-dimensional cross-linked network of reconstituted tobacco leaves using the slurry method in this patent. Detailed Implementation

[0024] The detailed features and advantages of this patent are described below in the specific embodiments. The content is sufficient to enable any person skilled in the art to understand the technical content of this patent and implement it accordingly. Based on the specification, claims and drawings disclosed in this specification, a person skilled in the art can easily understand the related objectives and advantages of this patent.

[0025] This specification also uses several compound terms to describe devices, components, equipment, etc. that include more than one function, or to assign additional functions to a corresponding device, component, equipment, etc. Those skilled in the art will understand that such compound terms can be implemented by a single or multiple devices, components, equipment, etc., as long as they are reasonable under the interpretation rules of this patent terminology.

[0026] It should be noted that in this specification, similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and interpreted in subsequent figures. In this specification and claims, several terms will be used, and unless otherwise indicated, these terms will be defined as having the following meanings: The terms “comprising” or “having” have the same meaning as “containing”, and also include other forms of the term, such as the gerund and singular forms in English, meaning including but not limited to, and not intended to exclude, for example, other elements, components, integers or steps. All other terms used herein for special definition are intended to have the general meaning understood by one of ordinary skill in the art, and in particular, meaning that one of ordinary skill in the art, upon reading the claims, specification and drawings of this patent, can directly and without doubt determine how the technical solution of this patent can be implemented.

[0027] Even if there are incomplete descriptions, omissions, or ambiguities in the grammar, words, punctuation, graphics, symbols, etc. of the claims, specification, and drawings of this patent, a person skilled in the art can still arrive at the only correct understanding by reading the claims, specification, and drawings as a whole without extensive reasoning or experimentation, and effectively exclude various incorrect interpretations that are not aimed at achieving the purpose of this patent.

[0028] Those skilled in the art would first choose to read the claims, specification, and drawings of this patent to reasonably interpret the terms; secondly, they would choose to refer to the relevant definitions in other documents published by the applicant before the filing date to reasonably interpret the terms; thirdly, they would choose the references cited in this patent to reasonably interpret the terms; and finally, they would choose to combine the technical dictionaries, technical manuals, reference books, textbooks, national or industry technical standards, etc., commonly used by those skilled in the art to reasonably interpret the terms.

[0029] All references cited in this application are incorporated herein by way of quotation, to the extent that they do not contradict the disclosure herein. It will be apparent to those skilled in the art that products (apparatus, components, devices, compounds, compositions, materials, etc.) and methods (processes, steps, conditions, parameters, equipment, and test methods, equipment, etc.) not specifically described herein can be applied to the implementation of the inventions fully disclosed herein without the need for excessive experimentation. This patent is intended to cover all functional equivalents known in the art of the methods, apparatus, apparatus components, materials, processes, and techniques specifically described herein. All cited references include: The following publications are included: Marks' Standard Handbook for Mechanical Engineers (11th edition and other editions prior to this patent application date), published by McGraw-Hill, Inc.; DeGarmo's Materials and Processes in Manufacturing (13th edition and other editions prior to this patent application date), published by Wiley; Machinery's Handbook (32nd edition and other editions prior to this patent application date), published by IndustrialPress Inc.; Mechanical Design Handbook (6th edition and other editions prior to this patent application date), edited by Cheng Daxian, published by Chemical Industry Press; and Modern Mechanical Design Handbook (6th edition and other editions prior to this patent application date), edited by Wen Bangchun, published by Machinery Industry Press.

[0030] This patent will now be described with reference to the accompanying drawings, in which similar reference numerals denote similar elements. While specific structures and arrangements are discussed, it should be understood that this is done merely for illustrative purposes. Those skilled in the art will recognize that other structures and arrangements can be used without departing from the spirit and scope of this patent. It will be clear to those skilled in the art that this patent can also be used in a variety of other applications.

[0031] This patent provides a method for preparing reconstituted tobacco leaves using the slurry method based on a sodium alginate-calcium carbonate slow-release crosslinking system, specifically including the following steps: S1: Raw material preparation and pretreatment Tobacco stems, tobacco dust, and other raw tobacco materials are dried to a moisture content of ≤7%. They are then pulverized to 200-400 mesh using an ultrafine pulverizer and sieved for later use.

[0032] Calcium carbonate pretreatment: Light calcium carbonate was selected and activated in an oven at 105±2℃ for 90 minutes. After cooling to room temperature, activated calcium carbonate was obtained for later use.

[0033] Preparation of sodium alginate solution: Slowly add sodium alginate (viscosity 300-800 mPa·s, M / G ratio > 1.5) to warm water at 40-50℃, stir until completely transparent, prepare a 2.0-2.5 wt% solution, and let it stand to remove bubbles for later use.

[0034] S2: Slurry preparation

[0035] Dry mixing: Weigh the treated tobacco powder, activated calcium carbonate and glucono-delta-lactone (GDL addition amount is 0.8-2.5% of the total dry weight) according to the weight ratio, put them into a high-speed mixer, and dry mix at 45-60 rpm for 15-20 minutes to ensure that the powder is evenly dispersed to obtain dry mixture.

[0036] Wet mixing: Transfer the dry mixture to a mixing vessel and add the pre-prepared sodium alginate solution. Start stirring and mix at a low initial speed (200-300 rpm) for 5 minutes to prevent dust from flying. Gradually increase the speed to 800-1000 rpm and continue stirring for 20-30 minutes to form a homogeneous slurry. Control the slurry temperature ≤35℃ and adjust the solid content to 20-25%. Transfer the slurry to a high-pressure homogenizer and circulate it twice under a pressure of 25MPa, controlling the slurry temperature ≤35℃ to obtain the wet-mixed slurry.

[0037] S3: Slow-release cross-linking maturation

[0038] Transfer the wet slurry to a jacketed reactor with online pH monitoring, start low-speed stirring (100-200 rpm), and maintain the temperature at 30-40℃.

[0039] The monitoring results of the sustained-release cross-linking and maturation process are as follows: Grinding time: 30-60 minutes (45 minutes preferred).

[0040] Real-time monitoring of pH changes: initial pH 6.8-7.2 until final pH 5.5-6.0.

[0041] Monitoring viscosity changes: The slurry viscosity steadily increased from the initial 200-400 cP to 1000-1300 cP and then stabilized, forming a gel network.

[0042] S4: Flavoring Addition

[0043] In the later stages of maturation (usually 25-40 minutes after the start of maturation, preferably 35-40 minutes, pH about 5.8-6.2), the flavoring is added in atomized form through a two-fluid atomizer.

[0044] Atomization pressure: 0.2-0.4 MPa; maintain slurry temperature ≤35℃. After adding, continue stirring at 60-80 rpm for 10-15 minutes to allow the fragrance to be adsorbed into the gel network, thus obtaining the flavored slurry.

[0045] S5: Casting

[0046] The fully matured slurry (i.e. flavored slurry) is fed into the casting machine feed trough, and gentle stirring is maintained to prevent settling.

[0047] The casting parameters are as follows: Scraper gap: 0.6-1.2 mm (preferably 0.8 mm); Steel belt speed: 1.5-2.5 m / min; Slurry flow rate: 2.0-3.0 L / min, maintain stable liquid level.

[0048] The surface of the slurry is smoothed using an oscillating leveler (frequency 50 Hz, amplitude 1 mm) to ensure uniform thickness and obtain cast material.

[0049] S6: Segmented drying and cross-linking curing

[0050] The cast material is dried in four stages: pre-drying, main drying, shaping drying and cooling drying, to achieve gradient removal of moisture and final curing of the cross-linked network.

[0051] Pre-drying: Temperature: 80±5℃; Relative humidity: 40-50%; Time: 2 minutes.

[0052] Main drying: Temperature: 105±3℃; Relative humidity: ≤15%; Time: 4 minutes.

[0053] Setting and drying: Temperature: 70±3℃; Relative humidity: 25-30%; Time: 2 minutes.

[0054] Cooling and drying: Cool at room temperature (20-30℃) for 1 minute with ventilation, then discharge to obtain dried sheets.

[0055] S7: Shred

[0056] The dried sheets are cut, rolled, or shredded to obtain the finished high-strength, high-thermal-conductivity, slow-release slurry-based reconstituted tobacco.

[0057] This patent addresses the problems of traditional reconstituted tobacco leaves, such as dense structure, insufficient strength, and uneven flavor release. It proposes using calcium carbonate as a functional crosslinking agent and filler, and sodium alginate to construct a slow-release crosslinked three-dimensional network in the slurry system. Specifically, the acidic environment generated by the hydrolysis of gluconolactone can controllably promote the release of calcium ions from calcium carbonate, achieving gentle, uniform, and gradual crosslinking of sodium alginate molecules. This crosslinking mechanism forms a stable "egg-box" structure, significantly enhancing the mechanical strength of the flakes, improving pore distribution, and increasing flavor loading and slow-release performance. The process is simple and controllable, suitable for large-scale production.

[0058] To further illustrate the advantages of this patent, embodiments 1-3 and comparative examples are given below.

[0059] Example 1

[0060] The raw material composition of this embodiment is shown in Table 1.

[0061] Table 1: Composition and Component Ratio Table

[0062] The total weight of the material refers to the total weight of all components except water, namely the total weight of tobacco raw materials, calcium carbonate, sodium alginate, glucono delta-lactone and blueberry flavoring, which is calculated as 100%.

[0063] According to the proportions in Table 1, the specific preparation steps for reconstituted tobacco using the slurry method are as follows: 1. Preprocessing Tobacco raw materials such as tobacco stems and tobacco dust are dried to a moisture content of 6.5% and then pulverized using an ultra-fine pulverizer to pass through a 300-mesh sieve.

[0064] Calcium carbonate was activated in an oven at 105°C for 90 minutes and then cooled to room temperature to obtain activated calcium carbonate for later use.

[0065] Slowly add sodium alginate (viscosity 300-800 mPa·s, M / G ratio > 1.5) to 40℃ warm water, stir until completely transparent, prepare a 2.0% sodium alginate solution, and let it stand to remove bubbles for later use.

[0066] 2. Dry mixing and wet mixing

[0067] Dry mixing: Add tobacco powder, calcium carbonate and GDL into a high-speed mixer and dry mix at 60 rpm for 20 minutes to obtain a dry mixture.

[0068] Wet mixing: Transfer the dry mixture to a mixing vessel, add the pre-prepared sodium alginate solution, and start stirring. Initially, mix at a low speed of 200 rpm for 5 minutes to prevent dust from flying. Gradually increase the speed to 800 rpm and wet mix for 25 minutes to form a uniform slurry. The slurry temperature should be ≤32℃, and the solid content should be adjusted to 22%. Transfer the slurry to a high-pressure homogenizer and circulate it twice under a pressure of 25MPa, controlling the slurry temperature to ≤32℃, to obtain the wet-mixed slurry.

[0069] 3. Slow-release cross-linking and maturation

[0070] The wet slurry was transferred to a jacketed reactor with online pH monitoring, and the mixture was stirred at a low speed of 150 rpm and aged at 35°C for 45 minutes.

[0071] pH monitoring: starting pH 7.0 → ending pH 5.9.

[0072] Viscosity change: increased from 280 cP to 1250 cP and then stabilized.

[0073] 4. Adding spices

[0074] After maturing for 40 minutes, flavoring is added by atomization at a pressure of 0.3 MPa, and stirring is continued for 10 minutes to obtain flavored slurry.

[0075] 5. Casting

[0076] The flavored slurry is fed into the casting machine's feed trough, and gentle stirring is maintained to prevent settling.

[0077] The casting parameters are as follows: The scraper gap is 0.8 mm; Steel belt speed: 2.0 m / min; Slurry flow rate: 2.5 L / min, maintain stable liquid level.

[0078] The surface of the slurry is smoothed using an oscillating leveler (frequency 50 Hz, amplitude 1 mm) to ensure uniform thickness and obtain cast material.

[0079] 6. Segmented drying and cross-linking curing

[0080] The cast material is subjected to pre-drying, main drying, shaping drying and cooling drying in sequence.

[0081] Pre-drying: Temperature 80℃; Relative humidity 40%; Time: 2 minutes.

[0082] Main drying: temperature 105℃; relative humidity: ≤15%; time: 4 minutes.

[0083] Setting and drying: temperature 70℃; relative humidity: 25-30%; time: 2 minutes.

[0084] Cooling and drying: Cool at room temperature (25℃) for 1 minute with ventilation, then discharge to obtain dried sheets.

[0085] 7. Shred

[0086] The dried sheets are cut, rolled, or shredded to obtain the finished high-strength, high-thermal-conductivity, slow-release slurry-based reconstituted tobacco.

[0087] Example 2

[0088] The raw material composition of this embodiment is shown in Table 2.

[0089] Table 2: Composition and Component Ratio Table

[0090] According to the proportions in Table 2, the specific preparation steps for reconstituted tobacco using the slurry method are as follows: 1. Preprocessing Tobacco raw materials such as tobacco stems and tobacco dust are dried to a moisture content of 6.5% and then pulverized using an ultra-fine pulverizer to pass through a 300-mesh sieve.

[0091] Calcium carbonate was activated in an oven at 105°C for 90 minutes and then cooled to room temperature to obtain activated calcium carbonate for later use.

[0092] Slowly add sodium alginate (viscosity 300-800 mPa·s, M / G ratio > 1.5) to 40℃ warm water, stir until completely transparent, prepare a 2.0% sodium alginate solution, and let it stand to remove bubbles for later use.

[0093] 2. Dry mixing and wet mixing

[0094] Dry mixing: Add tobacco powder, calcium carbonate and GDL into a high-speed mixer and dry mix at 60 rpm for 20 minutes to obtain a dry mixture.

[0095] Wet mixing: Transfer the dry mixture to a mixing vessel, add the pre-prepared sodium alginate solution, and start stirring. Initially, mix at a low speed of 200 rpm for 5 minutes to prevent dust from flying. Gradually increase the speed to 800 rpm and wet mix for 25 minutes to form a uniform slurry. The slurry temperature should be ≤32℃, and the solid content should be adjusted to 23%. Transfer the slurry to a high-pressure homogenizer and circulate it twice under a pressure of 25MPa, controlling the slurry temperature to ≤32℃, to obtain the wet-mixed slurry.

[0096] 3. Slow-release cross-linking and maturation

[0097] The wet slurry was transferred to a jacketed reactor with online pH monitoring, and the mixture was stirred at a low speed of 150 rpm and aged at 30°C for 40 minutes.

[0098] pH monitoring: starting at 6.9 → ending at 5.5 (faster decrease compared to Example 1).

[0099] Viscosity change: The viscosity rapidly increased to 1100 cP within 20 minutes, and then the rate of increase slowed down.

[0100] This embodiment adds a higher amount of GDL than in Embodiment 1 to achieve rapid crosslinking, and the amount of GDL added can be adaptively adjusted to suit the production plan.

[0101] 4. Adding spices

[0102] After maturing for 45 minutes, flavoring is added by atomization at a pressure of 0.3 MPa, and stirring is continued for 10 minutes to obtain flavored slurry.

[0103] 5. Casting

[0104] The flavored slurry is fed into the casting machine's feed trough, and gentle stirring is maintained to prevent settling.

[0105] The casting parameters are as follows: The scraper gap is 0.8 mm; Steel belt speed: 2.0 m / min; Slurry flow rate: 2.5 L / min, maintain stable liquid level.

[0106] The surface of the slurry is smoothed using an oscillating leveler (frequency 50 Hz, amplitude 1 mm) to ensure uniform thickness and obtain cast material.

[0107] 6. Segmented drying and cross-linking curing

[0108] The cast material is subjected to pre-drying, main drying, shaping drying and cooling drying in sequence.

[0109] Pre-drying: Temperature 80℃; Relative humidity 40%; Time: 2 minutes.

[0110] Main drying: temperature 105℃; relative humidity: ≤15%; time: 4 minutes.

[0111] Setting and drying: temperature 70℃; relative humidity: 25-30%; time: 2 minutes.

[0112] Cooling and drying: Cool at room temperature (25℃) for 1 minute with ventilation, then discharge to obtain dried sheets.

[0113] 7. Shred

[0114] The dried sheets are cut, rolled, or shredded to obtain the finished high-strength, high-thermal-conductivity, slow-release slurry-based reconstituted tobacco.

[0115] Example 3

[0116] The raw material composition of this embodiment is shown in Table 3.

[0117] Table 3: Composition and Component Ratio Table

[0118] According to the proportions in Table 3, the specific preparation steps for reconstituted tobacco using the slurry method are as follows: 1. Preprocessing Tobacco raw materials such as tobacco stems and tobacco dust are dried to a moisture content of 6.5% and then pulverized using an ultra-fine pulverizer to pass through a 300-mesh sieve.

[0119] Calcium carbonate was activated in an oven at 105°C for 90 minutes and then cooled to room temperature to obtain activated calcium carbonate for later use.

[0120] Slowly add sodium alginate (viscosity 300-800 mPa·s, M / G ratio > 1.5) to 40℃ warm water, stir until completely transparent, prepare a 2.0% sodium alginate solution, and let it stand to remove bubbles for later use.

[0121] 2. Dry mixing and wet mixing

[0122] Dry mixing: Add tobacco powder, calcium carbonate and GDL into a high-speed mixer and dry mix at 60 rpm for 20 minutes to obtain a dry mixture.

[0123] Wet mixing: Transfer the dry mixture to a mixing vessel, add the pre-prepared sodium alginate solution, and start stirring. Initially, mix at a low speed of 200 rpm for 5 minutes to prevent dust from flying. Gradually increase the speed to 800 rpm and wet mix for 25 minutes to form a uniform slurry. The slurry temperature should be ≤32℃, and the solid content should be adjusted to 21%. Transfer the slurry to a high-pressure homogenizer and circulate it twice under a pressure of 25MPa, controlling the slurry temperature to ≤32℃, to obtain the wet-mixed slurry.

[0124] 3. Slow-release cross-linking and maturation

[0125] The wet slurry was transferred to a jacketed reactor with online pH monitoring, and the mixture was stirred at a low speed of 150 rpm and aged at 30°C for 55 minutes.

[0126] pH change: starting at 7.1 → ending at 6.2 (slower decrease compared to Example 1).

[0127] Viscosity change: The viscosity began to rise significantly after 40 minutes, eventually reaching 1000 cP.

[0128] 4. Adding spices

[0129] After maturing for 50 minutes, flavoring is added by atomization at a pressure of 0.3 MPa, and stirring is continued for 10 minutes to obtain flavored slurry.

[0130] 5. Casting

[0131] The flavored slurry is fed into the casting machine's feed trough, and gentle stirring is maintained to prevent settling.

[0132] The casting parameters are as follows: The scraper gap is 0.8 mm; Steel belt speed: 2.0 m / min; Slurry flow rate: 2.5 L / min, maintain stable liquid level.

[0133] The surface of the slurry is smoothed using an oscillating leveler (frequency 50 Hz, amplitude 1 mm) to ensure uniform thickness and obtain cast material.

[0134] 6. Segmented drying and cross-linking curing

[0135] The cast material is subjected to pre-drying, main drying, shaping drying and cooling drying in sequence.

[0136] Pre-drying: Temperature 80℃; Relative humidity 40%; Time: 2 minutes.

[0137] Main drying: temperature 105℃; relative humidity: ≤15%; time: 4 minutes.

[0138] Setting and drying: temperature 70℃; relative humidity: 25-30%; time: 2 minutes.

[0139] Cooling and drying: Cool at room temperature (25℃) for 1 minute with ventilation, then discharge to obtain dried sheets.

[0140] 7. Shred

[0141] The dried sheets are cut, rolled, or shredded to obtain the finished high-strength, high-thermal-conductivity, slow-release slurry-based reconstituted tobacco.

[0142] This embodiment adds a lower amount of GDL than in Embodiment 1 to achieve slow crosslinking, and the amount of GDL added can be adaptively adjusted to suit the production plan.

[0143] Comparative Example

[0144] This comparative example uses a traditional physical mixing system without adding GDL. The raw material ratios for this comparative example are shown in Table 4.

[0145] Table 4: Composition and Component Ratio Table

[0146] The total weight of the material refers to the total weight of all components except water, namely the total weight of tobacco raw materials, calcium carbonate, sodium alginate and blueberry flavoring, which is calculated as 100%.

[0147] According to the proportions in Table 4, the specific preparation steps for reconstituted tobacco using the slurry method are as follows: 1. Preprocessing Tobacco raw materials such as tobacco stems and tobacco dust are dried to a moisture content of 6.5% and then pulverized using an ultra-fine pulverizer to pass through a 300-mesh sieve.

[0148] Calcium carbonate was activated in an oven at 105°C for 90 minutes and then cooled to room temperature to obtain activated calcium carbonate for later use.

[0149] Slowly add sodium alginate (viscosity 300-800 mPa·s, M / G ratio > 1.5) to 40℃ warm water, stir until completely transparent, prepare a 2.0% sodium alginate solution, and let it stand to remove bubbles for later use.

[0150] 2. Dry mixing and wet mixing

[0151] Dry mixing: Add tobacco powder and calcium carbonate to a high-speed mixer and dry mix at 60 rpm for 20 minutes to obtain a dry mixture.

[0152] Wet mixing: Transfer the dry mixture to a mixing vessel, add the pre-prepared sodium alginate solution, and start stirring. Initially, mix at a low speed of 200 rpm for 5 minutes to prevent dust from flying. Gradually increase the speed to 800 rpm and wet mix for 25 minutes to form a uniform slurry. The slurry temperature should be ≤32℃, and the solid content should be adjusted to 22%. Transfer the slurry to a high-pressure homogenizer and circulate it twice under a pressure of 25MPa, controlling the slurry temperature to ≤32℃, to obtain the wet-mixed slurry.

[0153] 3. Slow-release cross-linking and maturation

[0154] The wet slurry was transferred to a jacketed reactor with online pH monitoring, and the mixture was stirred at a low speed of 150 rpm and aged at 35°C for 45 minutes.

[0155] pH monitoring: After aging for 45 minutes, the pH remained unchanged at 7.0.

[0156] Viscosity change: The viscosity increased only from 280 cP to 320 cP (with no significant signs of crosslinking).

[0157] The slurry remained a relatively fluid suspension and did not form a gel network.

[0158] 4. Adding spices

[0159] After maturation for 40 minutes, flavoring was added via atomization at a pressure of 0.3 MPa, and stirring continued for 10 minutes to obtain the flavored slurry. 5. Casting The flavored slurry is fed into the casting machine's feed trough, and gentle stirring is maintained to prevent settling.

[0160] The casting parameters are as follows: The scraper gap is 0.8 mm; Steel belt speed: 2.0 m / min; Slurry flow rate: 2.5 L / min, maintain stable liquid level.

[0161] The surface of the slurry is smoothed using an oscillating leveler (frequency 50 Hz, amplitude 1 mm) to ensure uniform thickness and obtain cast material.

[0162] 6. Segmented drying and cross-linking curing

[0163] The cast material is subjected to pre-drying, main drying, shaping drying and cooling drying in sequence.

[0164] Pre-drying: Temperature 80℃; Relative humidity 40%; Time: 2 minutes.

[0165] Main drying: temperature 105℃; relative humidity: ≤15%; time: 4 minutes.

[0166] Setting and drying: temperature 70℃; relative humidity: 25-30%; time: 2 minutes.

[0167] Cooling and drying: Cool at room temperature (25℃) for 1 minute with ventilation, then discharge to obtain dried sheets.

[0168] 7. Shred

[0169] The dried sheets are cut, rolled, or shredded to obtain the finished high-strength, high-thermal-conductivity, slow-release slurry-based reconstituted tobacco.

[0170] The physical properties of the slurry-processed reconstituted tobacco leaves obtained in Examples 1-3 and the comparative example were tested. The test results are shown in Table 5. Figure 1-5 As shown.

[0171] Table 5: Results of Physical Performance Tests

[0172] As can be seen from Table 5, the slurry-based reconstituted tobacco leaves of Examples 1-3 constructed a ternary slow-release crosslinking system of "sodium alginate-calcium carbonate-gluconolactone" by using gluconolactone as a crosslinking regulator, which fundamentally changed the physicochemical structure of traditional slurry-based thin sheets, thereby achieving a systematic improvement in performance in multiple dimensions.

[0173] Compared with the prior art, this patent has the following advantages: Firstly, from the perspective of cross-linking mechanism and structural strength: due to the slow hydrolysis of gluconolactone in the aqueous phase, the pH of the system decreases gradually, allowing calcium ions in calcium carbonate to be released continuously at a controllable rate, rather than in an instantaneous burst. For example... Figure 6-7As shown, these calcium ions coordinate with the carboxyl groups on the sodium alginate molecular chain, gradually forming a uniform and stable "egg-box" shaped three-dimensional cross-linked network. Compared to traditional physical mixing or uncontrolled cross-linking, this mild and gradual cross-linking process avoids localized gelation and structural stress concentration, thus resulting in a network with high integrity and few defects. It can be directly deduced that the dry tensile strength and wet strength of the sheet are substantially improved, the brittle fracture and breakage rate during processing are significantly reduced, and the product's mechanical stability and yield are guaranteed.

[0174] This patent is the first to apply the "hydrolysis-acidification-solubilization" mechanism of gluconolactone to the sodium alginate-calcium carbonate crosslinking system, realizing active and precise control of crosslinking kinetics and solving the problem of uneven crosslinking caused by the traditional direct addition of calcium salts.

[0175] Secondly, from the perspective of filler function and thermal management: In this application, calcium carbonate is no longer just an inert filler, but also serves as a cross-linking ion source and a highly thermally conductive medium. When it is uniformly dispersed in the sodium alginate cross-linking network, the highly thermally conductive calcium carbonate particles form a continuous heat conduction pathway within the matrix. During suction heating, heat can be rapidly and uniformly diffused throughout the entire sheet through this network, avoiding localized overheating and cold zones caused by uneven thermal resistance in traditional materials. The homogenization of the thermal field directly leads to a more uniform evaporation rate of the fragrance, thus deriving that the thermal diffusion performance of the sheet is significantly improved, and the fragrance release curve changes from "strong at the beginning and weak at the end" to a stable and long-lasting one, greatly improving the consistency and satisfaction of the suction experience.

[0176] Finally, from the perspective of the synergy between network structure and release behavior: the three-dimensional network formed by slow-release cross-linking not only provides mechanical support, but also possesses a rich microporous structure and controllable porosity. Fragrance molecules can be effectively adsorbed and immobilized within the network pores. During thermal release, the cross-linked network, on the one hand, slows down the diffusion rate of fragrance molecules through physical barriers, and on the other hand, ensures synchronous and gentle desorption of the fragrance within the overall matrix through its uniform thermal conductivity. This synergistic effect of "structural slow release" and "uniform thermal field" further leads to the conclusion that: the fragrance loading rate is significantly improved (processing loss is reduced), release kinetics are controllable, and sensory consistency is excellent.

[0177] The three-dimensional network structure formed by the slow-release cross-linking of this patent is uniform and elastic, which increases the tensile strength of the sheet by more than 50%, the fragrance loading rate exceeds 90%, and the sensory release stability is significantly better than that of traditional processes.

[0178] In summary, this application systematically solves the inherent defects of traditional thin sheets in terms of strength, heat transfer, and sensory release through a triple synergistic mechanism of enhanced strength through chemical cross-linking, optimized thermal conductivity through functional fillers, and controlled release through network structure. It achieves integrated advantages of high strength, high thermal conductivity, high load capacity, and slow release. Moreover, the process is controllable and the raw material cost is low. This patent is fully compatible with existing slurry production lines, requires no equipment modification, and can achieve product upgrades through formula adjustment, thus possessing significant industrial competitiveness and market prospects.

[0179] The terms and expressions used in this specification are for illustrative purposes and not for limitation. Their use is not intended to exclude any equivalents of the features or portions thereof shown, but rather to facilitate the understanding that various modifications may be possible within the scope of this patent claim. Therefore, it should be understood that while this patent has been specifically disclosed through preferred embodiments, exemplary embodiments, and optional features, variations or modifications of the concepts disclosed herein may be adopted by those skilled in the art, and such variations and modifications are therefore considered to be within the scope of this patent as defined by the appended claims. The specific embodiments given in this specification are examples of useful embodiments of this patent, and it will be apparent to those skilled in the art that this patent can be implemented using many variations of the devices, device components, and method steps disclosed herein.

[0180] The foregoing description of specific embodiments fully discloses the general features of this patent, enabling others to easily modify and / or adapt such embodiments for various applications by applying knowledge within the scope of the art, without excessive experimentation or deviation from the general concept of this patent. Therefore, based on the teachings and guidance provided herein, it is intended that such modifications and alterations be included within the meaning and scope of equivalents of the disclosed embodiments. It should be understood that the wording or terminology used herein is for descriptive purposes and not intended to be limiting; thus, the wording or terminology in this specification will be interpreted by those skilled in the art based on the foregoing teachings and guidance.

[0181] Furthermore, the scope of this patent should not be limited to any of the exemplary embodiments described above, but only to the appended claims and their equivalents.

Claims

1. A slurry-based reconstituted tobacco leaf with a slow-release crosslinking system, characterized in that, The sustained-release crosslinking system includes a functional crosslinking agent, a gelling agent, and a crosslinking regulator; The crosslinking regulator hydrolyzes in the aqueous phase, causing the continuous release of ions from the functional crosslinking agent. These ions coordinate with the gelling agent to form an egg-box-like three-dimensional crosslinked network, resulting in a tensile strength greater than 0.7 kN / m and a thermal diffusivity greater than 0.15 mm² for the slurry-processed reconstituted tobacco leaves. 2 / s.

2. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 1, characterized in that, The functional crosslinking agent is calcium carbonate; The ion is a calcium ion; The gelling agent is sodium alginate; The crosslinking regulator is gluconolactone.

3. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 2, characterized in that, The slurry-based reconstituted tobacco leaf includes tobacco raw materials and flavorings; The tobacco raw materials include tobacco stems or tobacco dust.

4. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 3, characterized in that, The amount of the crosslinking regulator added, based on the total weight of the substances, is 0.8-1.0%, 1.0-1.5%, or 1.5-2.5%. The amount of the functional crosslinking agent added is 40-45%, 45-50%, 50-55%, or 55-60%. The amount of gelling agent added is 1.0-1.5%, 1.5-2.0%, 2.0-2.5%, or 2.5-3.0%. The amount of tobacco raw material added is 25-30%, 30-35%, 35-40%, or 40-45%. The amount of the added spices is 5-10%.

5. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to any one of claims 1-4, characterized in that, The method for preparing reconstituted tobacco using the slurry method includes the following steps: Step A: Grind the tobacco raw material to 200-400 mesh to obtain tobacco powder; add water to the gelling agent to prepare a glue solution; mix the tobacco powder, the functional crosslinking agent and the crosslinking regulator, add the glue solution and stir thoroughly to obtain a wet slurry; Step B: The wet mixed slurry undergoes a slow-release cross-linking maturation process under stirring. The temperature of the slow-release cross-linking maturation process is maintained at 30-40℃, and the time is 30-35 minutes, 35-40 minutes, 40-45 minutes, 45-50 minutes, or 50-60 minutes. Before the end of the slow-release cross-linking maturation process, the flavoring slurry is obtained. Step C: The flavored slurry is cast and dried to obtain the thickened slurry reconstituted tobacco.

6. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 5, characterized in that, Step A includes the following steps: Step A1: Dry the tobacco raw material to a moisture content of ≤7%, and pulverize it to 200-400 mesh to obtain the tobacco powder; Step A2: The functional crosslinking agent is activated for 80-100 minutes and then cooled to room temperature to obtain the activated functional crosslinking agent. The activation temperature is 100-110℃. Step A3: Slowly add the gelling agent to warm water at 40-50℃, stir and dissolve until completely transparent, to prepare a 2.0-2.5wt% gel solution.

7. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 6, characterized in that, Step A further includes the following steps: Step A4: Put the tobacco powder, the activated functional crosslinking agent and the crosslinking regulator into a high-speed mixer and dry mix at 45-60 rpm for 15-20 minutes to obtain a dry mix. Step A5: Transfer the dry mixture to a mixing tank, add the adhesive liquid and perform initial stirring. The initial stirring speed is 200-300 rpm and the initial stirring time is 3-10 minutes. Step A5: After the initial mixing is completed, the slurry is subjected to high-speed mixing at a speed of 800-1000 rpm for 20-30 minutes. The solid content is adjusted to 20-25%. The slurry is then transferred to a high-pressure homogenizer for homogenization to obtain a wet-mixed slurry.

8. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 5, characterized in that, Step B includes the following steps: Step B1: The wet slurry undergoes the slow-release cross-linking maturation process under low-speed stirring. The stirring speed is 100-200 rpm, the temperature of the slow-release cross-linking maturation process is maintained at 30-40℃, and the time is 30-35 minutes, 35-40 minutes, 40-45 minutes, 45-50 minutes, or 50-60 minutes. Step B2: Add the flavoring 5-15 minutes before the end of the slow-release cross-linking and maturation process. The flavoring is added in the form of atomization. After adding the flavoring, stir at 60-80 rpm for 10-15 minutes to obtain the flavored slurry.

9. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 5, characterized in that, Step C includes the following steps: Step C1: The flavored slurry is fed into the casting machine feed trough for casting. The scraper gap of the casting machine feed trough is 0.6-0.8 mm, 0.8-1.0 mm, or 1.0-1.2 mm; the steel belt speed of the casting machine feed trough is 1.5-2.5 m / min; and the slurry flow rate of the casting machine feed trough is 2.0-3.0 L / min, to obtain the cast material. Step C2: The cast material is subjected to pre-drying, main drying, shaping drying and cooling drying in sequence so that the moisture is removed by gradient and the cross-linking network is solidified to obtain the thick slurry reconstituted tobacco leaf.

10. The slurry-based reconstituted tobacco leaf with a slow-release crosslinking system according to claim 9, characterized in that, In step C2, the pre-drying temperature is 75-85℃, the pre-drying relative humidity is 40-50%, and the pre-drying time is 2-3 minutes. The temperature of the main drying is 100-110℃, the relative humidity of the main drying is less than 15%, and the main drying time is 4-5 minutes. The temperature for the shaping and drying process is 65-75℃, the relative humidity is 25-30%, and the drying time is 2-3 minutes. The cooling and drying temperature is 20-30℃, the relative humidity is 25-30%, and the cooling and drying time is 1-2 minutes.

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