Method for preparing reconstituted tobacco leaves by secondary coating method

Abstract

The present invention discloses a method for preparing reconstituted tobacco leaves by a secondary coating method: (1) a primary coating process: a quantitative coating process is adopted, and a fixed amount of a first coating material is transferred to a coating roller by quantitative feeding. The coating roller transfers the material to a substrate by roller coating. The material passing through the primary coating process is dried at high temperature to remove excess moisture; (2) a secondary coating process: a second coating material is placed in a material trough, and a secondary coating is performed by a roller coating process. The material after the secondary coating is dried at low temperature and rolled to produce reconstituted tobacco leaves. The present invention adopts quantitative feeding for the first coating, controls the stability of the coating amount from the beginning to the end of the material, thereby improving the stability of the gram weight index of the tobacco core material, ensuring the stability of the chemical index of the tobacco core material from the beginning to the end of the material, and improving product quality. By combining the secondary coating with low-temperature drying, the loss of flavor is reduced, the cost is reduced, and the sensory evaluation of the product is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco products, and particularly relates to a method for preparing reconstituted tobacco leaves by a secondary coating method. Background Art

[0002] The papermaking composite method for producing reconstituted tobacco has good machine performance, but some problems still exist during the production process. The coating process is responsible for evenly transferring the coating liquid onto the substrate. The currently used roller coating process passes the substrate between two coating rollers immersed in the coating liquid. After absorption and extrusion, the uniformly coated reconstituted tobacco product is obtained. However, in actual production, the coating amount fluctuates. Samples prepared in the same batch often have a higher coating amount in the later stages than in the earlier stages. In addition, some formulations suffer from roller sticking, seriously affecting product yield and quality.

[0003] The coating rate has a great influence on the quality of composite papermaking method reconstituted tobacco products, so coating is a key process in the production process of composite papermaking method reconstituted tobacco.

[0004] At the same time, the traditional coating process is to coat through a circulating material trough. After the carrier material passes through the coating liquid, the solid material and liquid material in the coating liquid are transferred. However, the migration speed of the solid material and the liquid material is inconsistent, resulting in a large difference in the chemical composition of the head and tail of the finished cigarette core material.

[0005] CN114886139A discloses a method for flavoring reconstituted tobacco leaves using a papermaking process: a first flavoring application is performed on a wound basic sheet; the basic sheet is slit and rewound to form a rolled sheet; and the rolled sheet is then subjected to a second flavoring application. This method, through two flavoring applications, solves the problem of volatilization of flavoring substances and achieves a good flavoring effect. However, this method does not address the problem of quantitative fluctuations in the applied amount. Summary of the Invention

[0006] The object of the present invention is to provide a method for preparing reconstituted tobacco leaves by a secondary coating method, which reduces the quantitative fluctuation of the coating amount and improves the stability of product quality.

[0007] The technical solution adopted in the present invention is:

[0008] A method for preparing reconstituted tobacco leaves by a secondary coating method, the method comprising the following steps:

[0009] (1) One-time coating process: A quantitative coating process is used. A fixed amount of the first coating material is transferred to the coating roller by quantitative feeding. The coating roller transfers the material to the substrate by roller coating. The material that has passed the one-time coating process is dried at high temperature to remove excess moisture.

[0010] (2) Secondary coating process: the second coating material is placed in a material trough and is coated for the second time by a roller coating process. The material after the second coating is dried at low temperature and rolled to produce reconstituted tobacco leaves.

[0011] Furthermore, the quantitative feeding is carried out by a quantitative feeding device, which includes a storage tank, a quantitative pump, a feed main pipe, a feed branch pipe, a feed bin, a recovery pipe and a recovery bin;

[0012] During the quantitative feeding, the quantitative pump pumps out the first coating material from the storage tank, then pumps it into the feed bin through the feed main pipe and the feed branch pipe, discharges the material through the feed port of the feed bin, and transfers it to the coating roller.

[0013] Furthermore, the feed end of the feed main pipe is connected to the storage tank;

[0014] The metering pump is connected to the feed main pipe, and the metering pump pumps material from the storage tank to the feed bin;

[0015] At least two of the feed branch pipes are connected between the discharge end of the feed main pipe and the feed bin; the width of the feed bin gradually narrows from bottom to top, and the top of the feed bin forms a long feed opening; along the length direction of the feed opening, the discharge ends of multiple feed branch pipes are sequentially arranged;

[0016] The recovery pipe is connected between the recovery bin and the storage tank.

[0017] Optionally, one of the plurality of feed branch pipes is connected to the center of the feed main pipe, and the other plurality of feed branch pipes are arranged at equal angles in the circumferential direction of the feed main pipe.

[0018] Optionally, the feed branch pipe is connected to the lower part of the feed bin.

[0019] Optionally, the opening width of the feeding port is adjustable.

[0020] Optionally, the distance between the two ends of the recovery bin gradually decreases from top to bottom; the length direction of the recovery bin is the same as the length direction of the feeding port.

[0021] Optionally, the device further comprises a scraper for cleaning a coating roller of the coating machine.

[0022] Optionally, the tank body of the storage tank is cylindrical, and a stirring paddle is provided in the tank body. The first coating material in the storage tank is stirred at a constant temperature, and the temperature is controlled at 30-70°C.

[0023] Optionally, the stirring paddle includes a double-layer straight-line stirring blade.

[0024] Optionally, the device further includes a temperature control system, which can heat the temperature of the material in the storage tank to 100 degrees Celsius.

[0025] The present invention transfers a fixed amount of the first coating material to the coating roller for coating through a quantitative feeding device, which can accurately and quantitatively coat and improve the quantitative stability of the finished coating. The constant temperature stirring in the storage tank can improve the uniformity of the material.

[0026] The problem of some materials sticking to the roller can be solved by using a front scraper and cleaner. The front scraper and cleaner are precisely integrated, and the front scraper cleans the coating roller before it passes through the feed port. The rear scraper is detachable and height-adjustable, and can be used as either a baffle or a scraper. Generally, it is used only as a baffle.

[0027] In the step (1), the coating amount of one coating is 20-180 g / m2 in wet weight. 2 .

[0028] In the step (1), the high-temperature drying temperature is >70°C, preferably 85-95°C, and more preferably 90-95°C.

[0029] After high-temperature drying, the moisture content of the material is generally 10-20%.

[0030] The secondary coating process is a fragrance adding process, so a low-temperature drying process is adopted to ensure the fragrance retention rate. The temperature of the low-temperature drying process is ≤60°C, preferably 40-60°C.

[0031] After low-temperature drying, the moisture content of the material is generally 5-9%.

[0032] In the step (2), the coating amount of the secondary coating is 5-80 g / m2 in wet weight. 2 .

[0033] Furthermore, the second coating material includes low-boiling-point spices, which refer to fragrance raw materials with a boiling point lower than 180° C. Furthermore, the low-boiling-point spices can be tobacco oil or essential oils such as flower, grass, and fruit oils.

[0034] Furthermore, the low-boiling-point fragrance is usually mixed with an emulsifier and a solvent to prepare a second coating material.

[0035] The emulsifier is a mixture of one or more of soybean lecithin, sucrose fatty acid ester, and mono- and diglycerol fatty acid ester.

[0036] Preferably, the solvent in the second coating material is one or more of glycerol, propylene glycol, and triacetin, preferably a mixture of propylene glycol and triacetin, with a volume ratio of propylene glycol to triacetin being 5 to 50:1.

[0037] In the second coating material, the low-boiling point fragrance is usually 15 to 25 parts by mass, the emulsifier is usually 0.1 to 3 parts by mass, and the solvent is usually 75 to 85 parts by mass.

[0038] Furthermore, the first coating material is a coating liquid raw material excluding low-boiling-point fragrances, and its components may include one or more of smoke-generating agents, high-boiling-point fragrances, powder materials, water-blocking agents, and heat-conducting materials, and the solvent is water.

[0039] The mass usage of the solvent water of the first coating material is generally 20 to 30%.

[0040] Preferably, the high-boiling-point fragrance is one or more of tobacco water extract, tobacco alcohol extract, and synthetic fragrance raw materials with a boiling point higher than 180 degrees Celsius.

[0041] Preferably, the powder material is one or a mixture of tobacco powder, plant fragrance raw material powder, filler, and porous material.

[0042] The water-blocking agent is one or more of lipid substances and natural substances similar to beeswax.

[0043] The heat conductive material is one or more of aluminum nitride, boron nitride, and magnetic material.

[0044] The first coating material typically comprises 10-20 parts by mass of a smoke generating agent, 30-40 parts by mass of a high-boiling-point fragrance, 25-40 parts by mass of a powdered material, 1-3 parts by mass of a water-blocking agent, 1-2 parts by mass of a heat-conducting material, and 20-30 parts by mass of water. However, the formulation of the first coating material does not affect the process and scope of protection of this application.

[0045] The substrate is prepared by adopting a conventional reconstituted tobacco leaf substrate preparation method to obtain a sheet-like substrate.

[0046] The present invention also provides a reconstituted tobacco material prepared by the above-mentioned preparation method.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] This invention uses quantitative feeding for the first coating, controlling the stability of the coating amount from the beginning to the end of the material, thereby improving the stability of the tobacco core material's grammage index. Furthermore, quantitative feeding eliminates material return, ensuring the stability of the tobacco core material's chemical indicators from the beginning to the end of the material, thereby improving product quality. The second coating, combined with low-temperature drying, reduces flavor loss, lowers costs, and improves product sensory evaluation.

[0049] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present invention are not limited to the above specific descriptions, and the above and other purposes that can be achieved by the present invention will be more clearly understood based on the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a schematic diagram of a quantitative feeding device provided according to an embodiment from a first perspective.

[0051] Figure 2 This is a schematic diagram of a second viewing angle of a quantitative feeding device provided according to an embodiment.

[0052] Figure 3 This is a schematic diagram of a third viewing angle of a quantitative feeding device provided according to an embodiment.

[0053] Figure 4 The figure is a connection diagram of a main feed pipe and branch feed pipes of a quantitative feeding device provided according to an embodiment.

[0054] Explanation of the accompanying numbers: 1-feeding port, 2-feeding bin, 3-feeding branch pipe, 4-feeding main pipe, 5-storage tank, 6-recovery pipe, 7-recovery bin. DETAILED DESCRIPTION

[0055] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0056] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0057] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; and, unless otherwise specified, the numbering of each method step is merely a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of implementation of the present invention. Changes or adjustments in their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0058] The quantitative feeding device used in the present invention is as follows Figures 1 to 3As shown, it includes a storage tank 5, a metering pump, a feed main pipe 4, a feed branch pipe 3, a feed bin 2, a recovery pipe 6 and a recovery bin 7; the feed main pipe 4 and the feed main pipe 3 are both hoses, the diameter of the feed main pipe 4 is relatively thick, generally 10 to 20 cm, and the embodiment of the present invention uses a hose with a diameter of 15 cm, and the diameter of the feed branch pipe 3 is relatively thin, generally 10 to 50 mm, and the embodiment of the present invention uses a hose with a diameter of 25 mm;

[0059] The metering pump is connected to the feed main pipe 4, and the metering pump pumps materials from the storage tank 5 to the feed bin 2. The metering pump is adjustable.

[0060] The feed end of the feed main pipe 4 is connected to the storage tank 5;

[0061] The feed branch pipe 3 is connected between the discharge end of the feed main pipe 4 and the feed bin 2. In the embodiment of the present invention, five feed branch pipes 3 are provided, which are preferably arranged as follows:

[0062] A feed branch pipe 3 is connected to the center of the feed main pipe 4, and the other four feed branch pipes 3 are arranged at equal angles upward around the feed main pipe;

[0063] From bottom to top, the width of the feed bin 2 gradually narrows, and a long feed port 1 is formed at the top of the feed bin 2; along the length direction of the feed port 1, the discharge ends of the plurality of feed branch pipes 3 are sequentially arranged;

[0064] The recovery pipe 6 is connected between the recovery bin 7 and the storage tank 5 .

[0065] Furthermore, the feed branch pipe 3 is connected to the lower part of the feed bin 2, preferably the bottom.

[0066] Furthermore, the opening width of the feeding port 1 is adjustable within the range of 0.1 mm to 10 mm, and the minimum adjustment amount is 0.1 mm controlled by the gear adjustment lifting. The length of the feeding port 1 matches the length of the coating roller of the coating machine.

[0067] Furthermore, the distance between the two ends of the recovery bin 7 gradually decreases from top to bottom; the length direction of the recovery bin 7 is the same as the length direction of the feeding port 1. The liquid recovered by the recovery bin 7 can be pumped into the storage tank 5 from the bottom pipe through the pump, which is generally not used. It is designed to be used for recycling when the coating amount is too large.

[0068] Furthermore, the device also includes a front scraper and a rear scraper, wherein the front scraper and the cleaner are precisely fitted together. The front scraper cleans the coating roller before the coating roller passes through the feed port 1. The residue scraped from the front scraper is cleaned back and forth by the cleaner to ensure the front scraper is clean. The cleaner cleans the residue scraped from the scraper into the garbage collection bins on the left and right. The garbage collection bins are generally cleaned once a day. The rear scraper is a detachable scraper with adjustable height. It can be used as a baffle or a scraper. Generally, it is used only as a baffle.

[0069] Furthermore, the tank body of the storage tank 5 is cylindrical, and a stirring paddle is provided in the tank body.

[0070] Furthermore, the stirring paddle includes a double-layer straight-shaped stirring blade.

[0071] Furthermore, the device also includes a temperature control system, which can heat the temperature of the material in the storage tank 5 to 100 degrees Celsius.

[0072] How to use the quantitative feeding device:

[0073] After the first coating material is prepared, it is fully homogenized. After homogenization, the material is poured into the storage tank 5, stirred and preheated. The temperature is set to 45 to 55°C, and the coating machine is turned on to prepare the equipment and preheat the drying section. After the material in the storage tank 5 is stirred at a constant temperature for 1 to 2 hours, it is quantitatively fed. The opening and height of the feed port 1 and the position of the front scraper are adjusted. The rear scraper can be omitted. The base paper passes between the coating roller and the pressure roller of the coating machine. The coating roller is used in conjunction with a quantitative feeding device. The quantitative feeding device transfers the material to the coating roller through the feed port 1. The coating roller transfers the material to the base paper through roller coating. Some materials may stick to the roller. When sticking to the roller, the front scraper and cleaner can clean the residual material on the roller to ensure the cleanliness of the coating roller, thereby ensuring a stable coating amount.

[0074] The constant temperature material of the quantitative feeding device passes through the quantitative pump and enters the feed bin 2 through the feed main pipe 4 and the feed branch pipe 3 in turn, ensuring that the feeding material speed is relatively balanced. There is a certain pressure on the material in the feed bin 2, and the pressure squeezes the material to the feeding port 1. The feeding amount of the feeding port 1 is controlled by adjusting the quantitative pump, and the feeding amount is adjusted by adjusting the opening and closing degree of the feeding port 1.

[0075] Example 1

[0076] (1) The first coating material is prepared by mixing 15 parts by mass of a smoke generating agent, 32 parts by mass of a high-boiling-point flavoring (15 parts by mass of a tobacco aqueous extract, 10 parts by mass of a tobacco alcohol extract, and 7 parts by mass of a blended synthetic flavoring), 30 parts by mass of tobacco powder, 2 parts by mass of beeswax, 1 part by mass of boron nitride, and 20 parts by mass of water to obtain the first coating material, which is then loaded into a storage tank of a quantitative feeding device and stirred at 50°C for 1 hour.

[0077] (2) The second coating material is prepared by mixing 18 parts by mass of low-boiling point spices (10 parts by mass of 1% Virginia tobacco oil, 3 parts by mass of Zimbabwe tobacco oil, and 5 parts by mass of blended spices), 1 part by mass of emulsifier sucrose fatty acid ester, and 80 parts by mass of a solvent mixture of propylene glycol and triacetin (volume ratio 30:1). The mixture is mixed to obtain the second coating material, which is then loaded into a common material tank.

[0078] (3) The first coating process is a quantitative coating process, which uses a quantitative feeding device for quantitative feeding. The quantitative pump pumps a fixed amount of the first coating material from the storage tank, and then pumps it into the feed bin through the feed main pipe and the feed branch pipe. The material is discharged through the feed port of the feed bin and transferred to the coating roller, and then transferred to the substrate by the coating roller through roller coating. The coating amount is 104g / m2 wet weight. 2 .

[0079] In the quantitative feeding device, the opening of the feeding port 1 is 2.5 mm, and the height is 2 mm away from the coating roller. The front scraper is in contact with the coating roller to cut the residual material.

[0080] (4) Drying process: the material that has passed the first coating process is passed through a high-temperature drying section at a drying temperature of 90 degrees Celsius. The moisture content of the material after drying is 10-15%.

[0081] (5) Secondary coating process: the fragrance adding process, the second coating material is placed in the material tank, and the second coating is performed by roller coating process, and the coating amount is 26g / m2 wet weight. 2 .

[0082] (6) Low temperature drying process: A low temperature drying process is used to ensure the retention rate of spices. The drying temperature is 60°C and the moisture content of the material after drying is 5-9%.

[0083] (7) Roll up and vacuum seal the package.

[0084] Comparative Example 1

[0085] (1) Coating material preparation: The second coating material and the first coating material in Example 1 were mixed in a mass ratio of 1:4 to obtain a coating material.

[0086] (2) The primary coating process is a quantitative coating process in which a fixed amount of coating material is transferred to the coating roller by quantitative feeding, and then transferred to the substrate by the coating roller. The steps are the same as step (3) of Example 1. The coating amount is 130 g / m2 wet weight.2 .

[0087] (3) Drying process: the material after the first coating process goes through a high temperature drying section at a drying temperature of 90 degrees Celsius. The moisture content of the material after drying is 5-9%.

[0088] (4) Roll up and vacuum seal the package.

[0089] Comparative Example 2

[0090] (1) The coating material is prepared in the same manner as step (1) of Comparative Example 1.

[0091] (2) One-time coating process: using conventional circulating trough and roller coating process, the coating amount is 130g / m2 wet weight 2 .

[0092] (3) The drying process is the same as step (3) of Comparative Example 1.

[0093] (4) Roll up and vacuum seal the package.

[0094] Material evaluation

[0095] The materials prepared in Example 1, Comparative Example 1, and Comparative Example 2 were tested and compared for stability of various indicators. A total of 300 meters of samples were coated, with samples taken at 50-80 meters, 150-180 meters, and 250-280 meters, respectively. After sampling, the sample weights were measured, and the average value of 8 samples was calculated for each group. The weight results are shown in Table 1:

[0096] Table 1:

[0097]

[0098] The table above shows that the 300-meter samples in Example 1 and Comparative Example 1 have a low degree of dispersion in their grammage after coating, while the dispersion in Comparative Example 2 is relatively large. The dispersion can be used to characterize the stability of the sample coating weight. Comparative Example 2 uses a conventional coating process, resulting in uneven grammage, which seriously affects product quality.

[0099] The materials prepared in Example 1 and Comparative Examples 1 and 2 were rolled into heated cigarettes, and the samples were smoked. The results are shown in Table 2 below.

[0100] Table 2

[0101]

[0102] Note: + indicates positive enhancement, - indicates negative enhancement.

[0103] As can be seen from the table above, compared to Comparative Examples 1 and 2, the tobacco sample of Example 1 has a richer aroma, better richness, and better comfort. The tobacco samples of Comparative Examples 1 and 2 have acceptable aroma, slightly less richness, and poorer comfort. This indicates that low-boiling-point flavors tend to volatilize during high-temperature drying under conventional processes, affecting the sensory evaluation of the product. The present invention utilizes a secondary flavoring process combined with low-temperature drying to reduce the volatilization of low-boiling-point flavors and improve the sensory evaluation of the product.

[0104] The scope of protection of the present invention is not limited to the above-described embodiments. Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the scope and spirit of the present invention. If such modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. A method for preparing reconstituted tobacco by a secondary coating method, characterized in that The method comprises the following steps: (1) One-time coating process: A quantitative coating process is used. A fixed amount of the first coating material is transferred to the coating roller by quantitative feeding. The coating roller transfers the material to the substrate by roller coating. The material that has passed the one-time coating process is dried at high temperature to remove excess moisture. The temperature of high temperature drying is greater than 70°C. The quantitative feeding is carried out by a quantitative feeding device, which includes a storage tank, a quantitative pump, a feed main pipe, a feed branch pipe, a feed bin, a recovery pipe and a recovery bin; During the quantitative feeding, the quantitative pump pumps the first coating material out of the storage tank, then pumps it into the feed bin through the feed main pipe and the feed branch pipe, discharges the material through the feed port of the feed bin, and transfers it to the coating roller; The feed end of the feed main pipe is connected to the storage tank; The metering pump is connected to the feed main pipe, and the metering pump pumps material from the storage tank to the feed bin; The plurality of feed branch pipes are connected between the discharge end of the feed main pipe and the feed bin; the width of the feed bin gradually narrows from bottom to top, and the top of the feed bin forms a long feed opening; along the length direction of the feed opening, the discharge ends of the plurality of feed branch pipes are sequentially arranged; From top to bottom, the distance between the two ends of the recovery bin gradually decreases, and the recovery bin is arranged on the back of the feed bin; the length direction of the recovery port of the recovery bin is the same as the length direction of the feeding port; the recovery pipe is connected between the recovery bin and the storage tank; The device also includes a front scraper and a rear scraper. The front scraper and the cleaner are precisely fitted together. The front scraper cleans the coating roller before the coating roller passes through the feeding port. The residue scraped from the front scraper is cleaned back and forth by the cleaner to ensure that the front scraper is clean. The cleaner cleans the residue scraped from the scraper into garbage collection bins on both sides. The rear scraper is a detachable scraper and is used as a baffle or scraper. (2) Secondary coating process: the second coating material is placed in the material trough and coated for the second time through the roller coating process. The material after the second coating is dried at low temperature and rolled to produce reconstituted tobacco leaves; the temperature of the low temperature drying process is ≤60℃.

2. The method according to claim 1, wherein The first coating material in the storage tank is stirred at a constant temperature, and the temperature is controlled at 30-70°C.

3. The method according to claim 1, wherein In the step (1), the coating amount of one coating is 20-180g / m2 in wet weight. 2 .

4. The method according to claim 1, wherein In the step (2), the coating amount of the secondary coating is 5-80 g / m2 in wet weight. 2 .

5. The method according to claim 1, wherein The second coating material includes low-boiling-point fragrance, which refers to fragrance raw materials with a boiling point lower than 180°C.

6. The method according to claim 1, wherein The first coating material does not contain low-boiling-point fragrance.

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