A method of reducing the degree of reconstituted tobacco cake formation

Abstract

The present application belongs to the technical field of papermaking method reconstituted tobacco production and processing, and particularly relates to a method for reducing the caking degree of reconstituted tobacco. The method comprises: spraying a surface viscosity regulator on the upper surface and the lower surface of the reconstituted tobacco respectively; the surface viscosity regulator comprises: chitosan and nanocellulose. The present application is characterized in that a specific surface viscosity regulator combination-chitosan and nanocellulose is sprayed on the front and back surfaces of the reconstituted tobacco in different amounts, a relatively dense film-shaped structure is formed on the front and back surfaces of the reconstituted tobacco, the surface adhesion of the reconstituted tobacco can be effectively regulated, and the caking risk of the reconstituted tobacco can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of papermaking reconstituted tobacco production and processing technology, specifically relating to a method for reducing the degree of clumping in reconstituted tobacco. Background Technology

[0002] Currently, reconstituted tobacco produced through papermaking has evolved from its initial primary functions as a waste tobacco material and filler to a crucial raw material unit that also reduces harm and tar content and shapes the style and characteristics of cigarettes. However, because the surface of reconstituted tobacco contains a large amount of macromolecules such as sugars, proteins, and pectin, its hygroscopicity and stickiness are easily altered by changes in the external environment, affecting its surface viscosity. This leads to adhesion and clumping during transportation and storage, which in turn affects the feeding and processing of reconstituted tobacco. Therefore, research on surface viscosity control technology for reconstituted tobacco is needed to provide technical support for reducing or solving the clumping and adhesion problems, and to fully leverage the "stabilizer" function of reconstituted tobacco in cigarette quality.

[0003] Currently, there is considerable research on moisture-proofing and anti-caking of reconstituted tobacco leaves. For example, invention patent application CN112369645A discloses "a method for preparing moisture-proof reconstituted tobacco leaves," which involves adding moisture-proof additives to a coating solution to prepare moisture-proof reconstituted tobacco leaves. The additives include at least one of methyl palmitate, candelilla wax, beeswax, and tamarind gum, and the mass percentage of the additives in the coating solution is 2wt%-3wt%, with a coating rate of 38wt%-42wt%. Invention patent application CN 107692300A discloses "a method for reducing the degree of clumping in papermaking reconstituted tobacco products". The method involves weighing a dispersant (lecithin) at 0.5‰ to 2.5wt% of the weight of the papermaking reconstituted tobacco product after the papermaking reconstituted tobacco has been formed, adding the dispersant to the coating solution, and coating the coating solution with the added dispersant onto the formed paper base; or spraying the dispersant onto the coated papermaking reconstituted tobacco.

[0004] The two patent applications mentioned above involve adding 0.5‰–2.5wt% lecithin or 2wt%–3wt% of at least one additive such as methyl palmitate, candelilla wax, beeswax, and tamarind gum to the coating solution for reconstituted tobacco. While this can improve the moisture resistance of reconstituted tobacco and reduce the risk of clumping, the coating method is a traditional dip-coating method. The reconstituted tobacco leaves pass directly through the coating solution, which is distributed on the upper and lower surfaces of the leaves and in the leaf base. The distribution of these macromolecular additives in the leaf base affects the absorption of flavorings and other components in the coating solution, as well as the uniformity of the longitudinal distribution of the coating solution within the leaf base. Furthermore, the addition of lecithin to the reconstituted tobacco also has a certain impact on the sensory evaluation quality.

[0005] To address the above problems, this invention is proposed. Summary of the Invention

[0006] This invention discloses a method for reducing the degree of clumping in reconstituted tobacco leaves, the method comprising:

[0007] A surface viscosity modifier was sprayed onto the upper and lower surfaces of the reconstituted tobacco leaves.

[0008] The surface viscosity modifier comprises chitosan and nanocellulose.

[0009] Preferably, the amount of surface viscosity modifier sprayed on the upper surface of the reconstituted tobacco leaf is greater than the amount of surface viscosity modifier sprayed on the lower surface of the reconstituted tobacco leaf.

[0010] Preferably, the amount of surface viscosity modifier sprayed on the upper surface of the reconstituted tobacco leaf is 0-1.0 wt%, and the amount of surface viscosity modifier sprayed on the lower surface of the reconstituted tobacco leaf is 0-0.5 wt%.

[0011] The percentages mentioned above are based on the oven-dry weight of the reconstituted tobacco product.

[0012] Preferably, the surface viscosity modifier further comprises water, the mass of which is 10-30 times the sum of the masses of the chitosan and nanocellulose.

[0013] Preferably, before spraying the surface viscosity modifier onto the upper and lower surfaces of the reconstituted tobacco leaves, the moisture content of the reconstituted tobacco leaves is controlled at 8wt%-9.5wt%, the above percentages being based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0014] Preferably, the moisture content of the reconstituted tobacco leaves after the surface viscosity regulator is sprayed onto the upper and lower surfaces is controlled to be 11wt%-13wt%, the above percentages being based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0015] Preferably, the method specifically includes the following steps:

[0016] Step 1, Preparation of surface viscosity regulator: Chitosan and nanocellulose are mixed and then mixed with water to obtain a surface viscosity regulator. The mass of the water is 10-30 times the sum of the masses of the chitosan and nanocellulose.

[0017] The chitosan content is 0.1 wt%-1 wt%, and the nanocellulose content is 0.1 wt%-0.5 wt%.

[0018] Step 2, Moisture control of reconstituted tobacco leaves: Control the moisture content of reconstituted tobacco leaves to 8.0wt%-9.5wt%;

[0019] Step 3, spraying the upper surface of the reconstituted tobacco leaf: spraying the surface viscosity modifier obtained in step 1 onto the upper surface of the reconstituted tobacco leaf, wherein the amount of the surface viscosity modifier is 0-1.0 wt%.

[0020] Step 4, Moisture adjustment: Control the moisture content of the reconstituted tobacco leaves to 8.5wt%-9.5wt%;

[0021] Step 5, spraying the lower surface of the reconstituted tobacco: spray the surface viscosity modifier obtained in step 1 onto the lower surface of the reconstituted tobacco, with the amount of surface viscosity modifier being 0-0.5 wt%.

[0022] Step 6, Moisture adjustment: Control the moisture content of the reconstituted tobacco leaves to 11wt%-13wt% to obtain the finished reconstituted tobacco leaves;

[0023] The percentages mentioned above are based on the oven-dry weight of the reconstituted tobacco product.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This application unexpectedly discovered that chitosan and nanocellulose have a synergistic effect. When a chitosan and nanocellulose composition is sprayed onto the surface of reconstituted tobacco leaves, the nanocellulose can make the membrane structure on the surface of the tobacco leaves have a certain roughness, thus preventing the reconstituted tobacco leaves from sticking together.

[0026] The reason may be that the surface of reconstituted tobacco leaves coated only with chitosan is too smooth, making it easy for the reconstituted tobacco leaves to stick together. Coating only with nanocellulose cannot effectively reduce dilution properties and moisture resistance, thus failing to reduce clumping.

[0027] 2. In the process of realizing this invention, the applicant discovered that due to the significant structural differences between the two sides of the reconstituted tobacco leaf (the front side is looser, absorbs more coating liquid, and is prone to adhesion and clumping; the back side has more fine fibers during molding, and is therefore denser, absorbing relatively less coating liquid), it is necessary to consider the differences in structure and surface adhesion, and spray different amounts of surface viscosity modifier to minimize the impact on sensory quality, while achieving the purpose of controlling the surface adhesion of the reconstituted tobacco leaf.

[0028] Therefore, the present invention is characterized by spraying a specific combination of surface viscosity modifiers—chitosan and nanocellulose—on both sides of reconstituted tobacco leaves in different amounts, which can form a relatively dense film structure on both sides of the reconstituted tobacco leaves, effectively control the surface adhesion of the reconstituted tobacco leaves, and thus reduce the risk of reconstituted tobacco leaves clumping. Attached Figure Description

[0029] Figure 1 The image shows a frontal electron microscope image of the reconstituted tobacco product (SEM magnification 200×). a is the sample of Comparative Example 1, and b is the sample of Example 1.

[0030] Figure 2 The images are reverse electron microscope images of the reconstructed tobacco leaves (SEM magnification 200×). a is the sample of Comparative Example 1, and b is the sample of Example 1. Detailed Implementation

[0031] The present invention will be described below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Experimental methods not specifically described in the embodiments generally use conventional conditions and conditions described in the manual, or conditions recommended by the manufacturer. The general equipment, materials, reagents, etc., used are all commercially available unless otherwise specified. The raw materials used in the following embodiments and comparative examples are all commercially available.

[0032] This invention provides a method for regulating the adhesion force on the surface of reconstituted tobacco leaves, the modulation method comprising the following steps:

[0033] Step 1, preparation of surface viscosity modifier. The additives are chitosan and nanocellulose, wherein the chitosan addition ratio is 0.1wt%-1wt% and the nanocellulose addition ratio is 0.1wt%-0.5wt%, the percentages are based on the oven-dry weight of the reconstituted tobacco leaves; the above materials are mixed and prepared according to the proportions, and then mixed with 10-30 times the oven-dry weight of water at 60-65℃ for 10-15 min, with a stirring speed of 1000-2000 rpm; the surface viscosity modifier of reconstituted tobacco leaves is stirred and dissolved in a mixing tank until uniform, and the viscosity of the spray solution does not exceed 60 mPa·s to ensure uniform atomization.

[0034] Step 2, Moisture control of reconstituted tobacco leaves. The moisture content at the outlet of the reconstituted tobacco drying process is controlled at 8.0wt%-9.5wt%.

[0035] Step 3: Spraying the upper surface of the reconstituted tobacco leaves (the surface that does not contact the felt during sheet forming). Spraying the upper surface of the reconstituted tobacco leaves is performed at the exit of the reconstituted tobacco drying process. Ultrasonic atomizing nozzles are used for spraying, with an atomized particle size of 15-100 μm, an atomization temperature of 60-65℃, and a distance of approximately 20-30 cm between the atomizing nozzle and the conveyor belt. The spraying ratio of the reconstituted tobacco leaf surface viscosity modifier ranges from 0-1.0 wt%, and the increase in moisture content of the reconstituted tobacco leaves ranges from 1.0 wt% to 2.0 wt%. These percentages are based on the oven-dried weight of the finished reconstituted tobacco leaves.

[0036] Step 4, Moisture Adjustment. After spraying, infrared drying is used to adjust the moisture content of the reconstituted tobacco leaves. After adjustment, the moisture content of the reconstituted tobacco leaves is controlled within the range of 8.5wt%-9.5wt%. The above percentages are based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0037] Step 5: Spraying the lower surface of the reconstituted tobacco leaves (the surface in contact with the felt during sheet forming). At the exit of the reconstituted tobacco moisture adjustment process, the reconstituted tobacco leaves are first flipped over, and then the lower surface is sprayed. Ultrasonic atomizing nozzles are used for spraying, with an atomization particle size of 15-100 μm, an atomization temperature of 60-65℃, and a distance of approximately 20-30 cm between the atomizing nozzle and the conveyor belt. The proportion of the reconstituted tobacco surface viscosity regulator is 0-0.5 wt%, and the moisture increase range is 0.5 wt%-1.5 wt%. These percentages are based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0038] Step 6, Moisture Adjustment. After spraying, infrared drying is used to adjust the moisture content of the reconstituted tobacco leaves. After adjustment, the moisture content of the reconstituted tobacco leaves is controlled within the range of 11wt%-13wt%. The above percentages are based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0039] Step 7: After the moisture content has been adjusted, the reconstituted tobacco leaves can be directly cut and packaged.

[0040] In step 2, the process before the reconstituted tobacco drying process exits is a routine operation in the field, and this application only provides an example as follows:

[0041] Step A: Select raw materials of a certain specification of reconstituted tobacco leaves. Mix tobacco leaves and tobacco stems at a mass ratio of 7:3 to prepare 2.5t (octane-dry weight) of mixed raw materials, with an expected production of 2.0t of oven-dry reconstituted tobacco leaf product. Add 200kg of wood pulp fiber at an oven-dry weight percentage of 8%. Mix the tobacco stems, leaves, and wood pulp fiber evenly, add 7 times the mass of water of the mixture, and extract at 60℃ for 40min. Perform solid-liquid separation to obtain residue and extract. Repeat the above steps to extract the residue again under the same conditions to obtain residue and extract.

[0042] Step B involves combining the residues from both extractions, pulping the mixture to a freeness of 32°SR, and then forming an oven-dry weight of (60±2) g / m³. 2 The film base.

[0043] Step C: Combine the extracts from the two extractions and adjust them to a density of (1.180±0.005) g / cm³. 3 The coating solution was prepared at a temperature of (44.0±4.0)℃ and the coating rate was (45.0±2.0)%.

[0044] Step D involves drying using a tunnel dryer. The setpoints for sections 1-5 of the tunnel dryer are (90 / 95 / 102 / 108 / 115) ± 0.3℃. The moisture content at the outlet of the reconstituted tobacco drying process is controlled at 8.5 wt%.

[0045] This invention is an improvement upon existing technology. The equipment used in this invention is all general tobacco equipment, specifically including: reconstituted tobacco leaf production equipment, mainly comprising a feeding device, an extraction device, and a sheet forming device. To demonstrate the superior effects of this invention, comparative experiments are conducted below.

[0046] Comparative Example 1

[0047] The reconstituted tobacco product of Comparative Example 1 was not coated with the surface viscosity regulator of the present invention. Instead, the product with the moisture content at the outlet of the reconstituted tobacco drying process in step 2 of Example 1 controlled at 8.0wt%-9.5wt% was directly used as the reconstituted tobacco product of Comparative Example 1.

[0048] Take fragments of the reconstituted tobacco product prepared above after slicing, and take one sample every 3 minutes, for a total of 20 samples. Then mix them and evaluate them by electron microscopy, contact angle, moisture absorption performance and sensory quality.

[0049] Comparative Example 2

[0050] A method for reducing the degree of clumping in reconstituted tobacco leaves includes the following steps:

[0051] Step 1: Preparation of surface viscosity modifier. The additive was chitosan, added at a ratio of 0.20 wt% (4 kg), the percentage based on the oven-dry weight of the reconstituted tobacco product. Chitosan and water were mixed and stirred at a mass ratio of 1:10 at 63°C. The stirring time was 15 min, and the stirring speed was 1600 rpm. The viscosity of the resulting spray solution was 55 mPa·s. Finally, 40 kg of surface viscosity modifier was obtained.

[0052] Step 2, Moisture control of reconstituted tobacco leaves. The moisture content at the outlet of the reconstituted tobacco leaf drying process is controlled at 8.5 wt%.

[0053] Step 3: Spraying the upper surface of the reconstituted tobacco leaves (the surface that does not contact the felt during sheet forming). Spraying of the upper surface of the reconstituted tobacco leaves is performed at the exit of the reconstituted tobacco drying process. An ultrasonic atomizing nozzle is used for spraying, with an atomized particle size of 80μm, an atomization temperature of 63℃, and a distance of approximately 25cm between the atomizing nozzle and the conveyor belt. The spraying ratio of the reconstituted tobacco leaf surface viscosity modifier is 1.2wt%, and the moisture content of the reconstituted tobacco leaves increases by 1.12wt% (actual measured value).

[0054] Step 4, Moisture Adjustment. After spraying, infrared drying is used to adjust the moisture content of the reconstituted tobacco leaves. After moisture adjustment, the moisture content of the reconstituted tobacco leaves is 9.51 wt%.

[0055] The adhesion and contact angle of the reconstituted tobacco leaves obtained in step 4 are tested. The results are shown in Tables 1 and 2, and the front spraying results are shown in Comparative Example 2.

[0056] Step 5: Spraying the lower surface of the reconstituted tobacco leaf (the surface in contact with the felt during sheet forming). At the exit of the reconstituted tobacco leaf moisture adjustment process, the upper and lower surfaces of the reconstituted tobacco leaf are first turned over, and then the lower surface of the reconstituted tobacco leaf is sprayed. Ultrasonic atomizing nozzles are used for spraying, with an atomization particle size of 80μm, an atomization temperature of 63℃, and the distance between the atomizing nozzle and the conveyor belt is approximately 25cm. The surface viscosity regulator of the reconstituted tobacco leaf is applied at a ratio of 0.80wt%, increasing the moisture content of the reconstituted tobacco leaf by 0.71wt%.

[0057] Step 6, Moisture Adjustment. After spraying, infrared drying is used to adjust the moisture content of the reconstituted tobacco leaves. After moisture adjustment, the moisture content of the reconstituted tobacco leaves is controlled at 11.9 wt%, resulting in the finished reconstituted tobacco product.

[0058] The percentages mentioned above are based on the oven-dry weight of the reconstituted tobacco product.

[0059] The adhesion and contact angle of the reconstituted tobacco leaf obtained in step 6 are shown in Tables 1 and 2, and the reverse side spraying results are shown in Comparative Example 2.

[0060] Comparative Example 3

[0061] Replace the chitosan in step 1 of Comparative Example 2 with tamarind gum, keeping all other operations unchanged.

[0062] The adhesion and contact angle of the reconstituted tobacco leaf obtained in step 4 are shown in Tables 1 and 2, and the front spraying results are shown in Comparative Example 3.

[0063] The adhesion force and contact angle of the reconstituted tobacco leaf obtained in step 6 are shown in Tables 1 and 2, and the reverse side spraying results are shown in Comparative Example 3.

[0064] Comparative Example 4

[0065] Replace the chitosan in step 1 of Comparative Example 2 with beeswax, while keeping other operations unchanged.

[0066] The adhesion and contact angle of the reconstituted tobacco leaf obtained in step 4 are shown in Tables 1 and 2, and the results of the front spraying are compared in Comparative Example 4.

[0067] The adhesion and contact angle of the reconstituted tobacco leaf obtained in step 6 are shown in Tables 1 and 2, and the results of reverse spraying in Comparative Example 4 are also shown.

[0068] Comparative Example 5

[0069] Replace the chitosan in step 1 of Comparative Example 2 with nanofibers, while keeping other operations unchanged.

[0070] The adhesion and contact angle of the reconstituted tobacco leaf obtained in step 4 are shown in Tables 1 and 2, and the front spraying results are shown in Comparative Example 5.

[0071] The adhesion and contact angle of the reconstituted tobacco leaf obtained in step 6 are shown in Tables 1 and 2, and the results of reverse spraying in Comparative Example 5 are also shown.

[0072] Comparative Example 6

[0073] Preparation of front-coated samples for hygroscopicity testing of reconstituted tobacco leaves:

[0074] Step 1: Preparation of surface viscosity modifier. The additive is chitosan, added at a ratio of 0.20 wt%, based on the oven-dry weight of the reconstituted tobacco leaf, i.e., 4 kg. Chitosan and water are mixed and stirred at a mass ratio of 1:10 at 63℃. The stirring time is 15 min, and the stirring speed is 1600 rpm. The viscosity of the resulting spray solution is 55 mPa·s. Finally, 40 kg of surface viscosity modifier is obtained.

[0075] Step 2, Moisture control of reconstituted tobacco leaves. The moisture content at the outlet of the reconstituted tobacco leaf drying process is controlled at 8.5 wt%.

[0076] Step 3: Spraying the upper surface of the reconstituted tobacco leaves (the surface that does not contact the felt during sheet forming). Spraying of the upper surface of the reconstituted tobacco leaves is performed at the exit of the reconstituted tobacco drying process. An ultrasonic atomizing nozzle is used for spraying, with an atomized particle size of 80 μm, an atomization temperature of 63℃, and a distance of approximately 25 cm between the atomizing nozzle and the conveyor belt. The surface viscosity modifier spraying ratio is 1.2 wt%, and the moisture content of the reconstituted tobacco leaves increases by 1.12 wt% (measured value). These percentages are based on the oven-dried weight of the finished reconstituted tobacco leaves.

[0077] Step 4, Moisture Adjustment. After spraying, infrared drying is used to adjust the moisture content of the reconstituted tobacco leaves. After adjustment, the moisture content of the reconstituted tobacco leaves is 9.51 wt%. The above percentages are based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0078] The hygroscopicity of the reconstituted tobacco obtained in step 4 is tested, and the results are shown in Table 3, with the results of the front spraying in Comparative Example 6.

[0079] Preparation of reverse-side sprayed samples for hygroscopicity testing of reconstituted tobacco leaves:

[0080] Step 01: Preparation of surface viscosity modifier. The additive is chitosan, added at a ratio of 0.20 wt%, based on the oven-dry weight of the reconstituted tobacco product. Chitosan and water are mixed and stirred at a mass ratio of 1:10 at 63°C. The stirring time is 15 min, and the stirring speed is 1600 rpm. The viscosity of the resulting spray solution is 55 mPa·s. Finally, 5 kg of surface viscosity modifier is obtained.

[0081] Step 02, Moisture control of reconstituted tobacco leaves. The moisture content at the outlet of the reconstituted tobacco leaf drying process is controlled at 9.51 wt%.

[0082] Step 03: Spraying the lower surface of the reconstituted tobacco leaves (the surface that does not contact the felt during sheet forming). Spraying of the lower surface of the reconstituted tobacco leaves is performed at the exit of the reconstituted tobacco drying process. An ultrasonic atomizing nozzle is used for spraying, with an atomized particle size of 80 μm, an atomization temperature of 63°C, and a distance of approximately 25 cm between the atomizing nozzle and the conveyor belt. The reconstituted tobacco leaf surface viscosity modifier is applied at a ratio of 0.80 wt%, increasing the moisture content of the reconstituted tobacco leaves by 0.71 wt%. These percentages are based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0083] Step 04, Moisture Adjustment. After spraying, infrared drying is used to adjust the moisture content of the reconstituted tobacco leaves. After moisture adjustment, the moisture content of the reconstituted tobacco leaves is controlled at 11.9 wt%. The above percentage is based on the oven-dry weight of the finished reconstituted tobacco leaves.

[0084] The reconstituted tobacco obtained in step 04 was tested for hygroscopicity. The results are shown in Table 3, and the reverse side spraying results are shown in Comparative Example 6.

[0085] Comparative Example 7

[0086] Preparation of the front-coated sample for the hygroscopicity test of reconstituted tobacco: The chitosan in step 01 of Comparative Example 6 was replaced with tamarind gum, while other operations remained unchanged. The hygroscopicity test results of the reconstituted tobacco obtained in step 4 are shown in Table 3, along with the front-coated results from Comparative Example 7.

[0087] Preparation of reverse-side sprayed samples for hygroscopicity testing of reconstituted tobacco: Replace the chitosan in step 1 of Comparative Example 6 with tamarind gum, keeping other operations unchanged. The hygroscopicity test results of the reconstituted tobacco obtained in step 04 are shown in Figure 3, the reverse-side spraying results in Comparative Example 7.

[0088] Comparative Example 8

[0089] Preparation of the front-coated sample for the hygroscopicity test of reconstituted tobacco: Replace the chitosan in step 01 of Comparative Example 6 with beeswax, keeping other operations unchanged. The hygroscopicity test results of the reconstituted tobacco obtained in step 4 are shown in Table 3, along with the front-coated results from Comparative Example 8.

[0090] Preparation of reverse-side sprayed samples for hygroscopicity testing of reconstituted tobacco: In Comparative Example 6, chitosan in step 01 was replaced with beeswax, while other operations remained unchanged. The hygroscopicity test results of the reconstituted tobacco obtained in step 04 are shown in Table 3, along with the reverse-side spraying results in Comparative Example 8.

[0091] Comparative Example 9

[0092] Preparation of the front-coated sample for the hygroscopicity test of reconstituted tobacco: The chitosan in step 01 of Comparative Example 6 was replaced with nanofibers, while other operations remained unchanged. The hygroscopicity test results of the reconstituted tobacco obtained in step 4 are shown in Table 3, along with the front-coated results from Comparative Example 9.

[0093] Preparation of reverse-side sprayed samples for hygroscopicity testing of reconstituted tobacco: In Comparative Example 6, chitosan in step 1 was replaced with nanofibers, while other operations remained unchanged. The hygroscopicity test results of the reconstituted tobacco obtained in step 04 are shown in Table 3, along with the reverse-side spraying results in Comparative Example 9.

[0094] Example 1A: Preparation of front-side sample:

[0095] In Comparative Example 6, the 0.20 wt% chitosan added in step 1 was replaced with 0.15 wt% chitosan and 0.05 wt% nanocellulose, with other operations remaining unchanged; that is, the mass of chitosan was 3 kg and the mass of nanocellulose was 1 kg. The hygroscopicity of the reconstituted tobacco leaves obtained in step 4 was tested, and the results are shown in Table 3, which shows the results of spraying the front side in Example 1.

[0096] Example 1A: Preparation of the reverse side sample:

[0097] Preparation of the reverse-side sprayed sample for the hygroscopicity test of reconstituted tobacco: In Comparative Example 6, the 0.20 wt% chitosan added in step 01 was replaced with 0.15 wt% chitosan and 0.05 wt% nanocellulose, i.e., 3 kg chitosan and 1 kg nanocellulose, with other operations remaining unchanged. The hygroscopicity test results of the reconstituted tobacco obtained in step 04 are shown in Table 3, the results of the reverse-side spraying in Example 1.

[0098] The sample with double-sided spraying in Example 1 in Table 3 is the same sample as that in Example 1.

[0099] Performance testing:

[0100] Performance tests were conducted on the reconstituted tobacco products of Example 1 and Comparative Examples 1-5. The method for each performance test was as follows: one sample was taken every 3 minutes, for a total of 20 samples, which were then mixed and evaluated by electron microscopy, adhesion, contact angle, moisture absorption, and sensory quality.

[0101] Under electron microscopy at 200x magnification, the following was observed: Figure 1 , 2 It can be seen that after the reconstituted tobacco leaves in Example 1 were sprayed on both sides, a relatively dense coating was formed on the surface.

[0102] Under the conditions of temperature 22±2℃ and humidity of 40wt%, 50wt%, 60wt%, 70wt%, and 80wt%, the reconstituted tobacco leaves were equilibrated for 48h. The surface adhesion of the reconstituted tobacco leaves was tested according to the method described in the literature "Hu Mengyan, Song Chengjian, Li Degui, et al. Establishment and verification of the method for detecting the surface adhesion of reconstituted tobacco leaves by papermaking [J]. Tobacco Science and Technology, 2019, 52(2): 96-100." The results are shown in Table 1.

[0103] As shown in Table 1, compared with the comparative example of not spraying surface viscosity modifier or spraying chitosan, tamarind gum, beeswax or nanofiber surface viscosity modifier alone, spraying the surface viscosity modifier of chitosan and nanocellulose combination in Example 1 can significantly reduce the surface adhesion of reconstituted tobacco leaves under humidity conditions of 40wt% to 60wt%.

[0104] Table 1. Changes in adhesion (N) of reconstituted tobacco leaves under different humidity conditions after adding surface viscosity modifiers.

[0105]

[0106]

[0107] Test on the change in contact angle of reconstituted tobacco leaves before and after the addition of surface viscosity modifier:

[0108] Water droplets of the same size were dropped onto the front and back of the samples of Example 1 and Comparative Examples 1-5 respectively. The changes in the contact angle of the water droplets were detected and analyzed according to the method described in the literature "Lu Hongliang, Li Yuefeng, Li Yifei, et al. Evaluation of the dynamic absorption performance of reconstituted tobacco coating liquid by contact angle technology [J]. Tobacco Science and Technology, 2019, 52(9): 96-101." The results are shown in Table 2.

[0109] As shown in Table 2, compared with Comparative Examples 1 to 5, in Example 1, the surface viscosity modifier composed of chitosan and nanocellulose sprayed can significantly increase the contact angle between the front and back sides of the reconstituted tobacco leaves within 2s to 6s and prolong the penetration time, indicating that it can effectively reduce the water absorption performance of the reconstituted tobacco leaves.

[0110] Table 2. Changes in contact angle (°) before and after adding surface viscosity modifier.

[0111]

[0112] Test on the change in hygroscopicity of reconstituted tobacco leaves before and after the addition of surface viscosity modifier:

[0113] The samples were equilibrated for 48 hours at a temperature of 22±2℃ and humidity of 40wt%, 50wt%, 60wt%, 70wt%, and 80wt%, and were tested according to the "YC / T 31-1996 Preparation of Tobacco and Tobacco Products Samples and Determination of Moisture Content by Oven Method" (results are shown in Table 3).

[0114] As shown in Table 3, compared with the comparative example without surface viscosity modifier, spraying chitosan, tamarind gum, beeswax, nanofibers, or a combination of chitosan and nanocellulose on the front or back alone, and spraying the surface viscosity modifier of the combination of chitosan and nanocellulose in Example 1 on both sides can significantly reduce the water absorption properties of reconstituted tobacco leaves.

[0115] Table 3. Changes in the hygroscopicity of reconstituted tobacco leaves after the addition of surface viscosity modifiers.

[0116]

[0117] Sensory quality analysis:

[0118] According to "YC / T 498-2014 Sensory Evaluation Method for Reconstituted Tobacco (Papermaking Method)", nine experts with sensory evaluation qualifications were invited to conduct sensory quality evaluations on samples of reconstituted tobacco products, shredded and rolled into cigarettes. The results are shown in Table 4. As can be seen from Table 4, the sensory quality of Example 1 after double-sided spraying with the surface viscosity modifier of this application showed little change.

[0119] Table 4 Sensory Quality Analysis

[0120]

Claims

1. A method for reducing the degree of clumping in reconstituted tobacco leaves, characterized in that, The method includes: A surface viscosity modifier was sprayed onto the upper and lower surfaces of the reconstituted tobacco leaves. The surface viscosity modifier comprises: chitosan and nanocellulose; The mass ratio of chitosan to nanocellulose is 1-2; The amount of surface viscosity modifier sprayed on the upper surface of the reconstituted tobacco leaf is greater than the amount of surface viscosity modifier sprayed on the lower surface of the reconstituted tobacco leaf; The method specifically includes the following steps: Step 1, Preparation of surface viscosity regulator: The additives are chitosan and nanocellulose, wherein the chitosan addition ratio is 0.1wt%-1wt% and the nanocellulose addition ratio is 0.1wt%-0.5wt%, the percentages are based on the oven-dry weight of the reconstituted tobacco leaves; the chitosan and nanocellulose are mixed and prepared according to the above ratio, and then mixed with 10-30 times their oven-dry weight of water at 60-65℃ for 10-15 min, with a stirring speed of 1000-2000 rpm; the surface viscosity regulator of the reconstituted tobacco leaves is stirred and dissolved in a mixing tank until uniform, and the viscosity of the spray solution does not exceed 60 mPa.s to ensure uniform atomization; Step 2, Moisture control of reconstituted tobacco leaves: The moisture content of the reconstituted tobacco leaves should be controlled between 8.0 wt% and 9.5 wt%. Step 3, spraying the upper surface of reconstituted tobacco leaves: spraying the surface viscosity modifier obtained in step 1 onto the upper surface of the reconstituted tobacco leaves, wherein the amount of the surface viscosity modifier is 0-1.0 wt%, excluding 0 wt%; wherein the spraying is performed using an ultrasonic atomizing nozzle, with an atomization particle size of 15-100 μm, an atomization temperature of 60-65℃, and a distance of 20-30 cm between the atomizing nozzle and the conveyor belt; Step 4, Moisture Adjustment: Control the moisture content of the reconstituted tobacco leaves to 8.5wt%-9.5wt%; Step 5, spraying the lower surface of the reconstituted tobacco: spray the surface viscosity modifier obtained in step 1 onto the lower surface of the reconstituted tobacco. The amount of surface viscosity modifier is 0-0.5 wt%, excluding 0 wt%. The spraying is performed using an ultrasonic atomizing nozzle with an atomization particle size of 15-100 μm, an atomization temperature of 60-65℃, and a distance of 20-30 cm between the atomizing nozzle and the conveyor belt. Step 6, Moisture adjustment: Control the moisture content of the reconstituted tobacco leaves to 11wt%-13wt% to obtain the finished reconstituted tobacco leaves; The percentages mentioned above are based on the oven-dry weight of the reconstituted tobacco product.

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