Method for improving retention rate of pulp by blending and grinding tobacco raw materials and medium and long fibers
By blending and grinding tobacco raw materials with medium and long fibers to form a three-dimensional network framework, the pulping process is optimized, solving the problem of low pulp retention rate in reconstituted tobacco production. This achieves resource conservation and reduced water treatment load, resulting in cost reduction and efficiency improvement.
Patent Information
- Application Number
- CN202511257388.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-04
- Publication Date
- 2025-11-07
AI Technical Summary
In the current reconstituted tobacco production, the pulp retention rate is low, resulting in resource waste and a large load on downstream water treatment. In addition, commonly used functional additives are expensive and have complex processes, making it difficult to meet the safety and sensory quality requirements of cigarettes.
By blending tobacco raw materials with medium and long fibers and grinding them together, a three-dimensional network framework is formed, which enhances the hydrogen bonding between fibers. The pulp retention rate is monitored step by step, and the pulping process is optimized to improve the pulp retention rate.
Without introducing new functional additives, it significantly improves the slurry retention rate by 5.0% to 30.0% and reduces the concentration of concentrated white water under the wire by 5.0% to 60.0%, achieving cost reduction and efficiency improvement.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a method for improving the retention rate of pulp of tobacco raw materials and medium-length fibers, belonging to the technical field of papermaking reconstituted tobacco. BACKGROUND
[0002] Papermaking reconstituted tobacco (hereinafter referred to as reconstituted tobacco) is a kind of reconstituted tobacco product made from tobacco byproducts such as tobacco stems and tobacco shreds through extraction, concentration, pulping, papermaking, coating and drying processes, etc. using the principle and process of wet papermaking. Because of its unique style characteristics, flexible and controllable components, harm reduction function, and low cost, reconstituted tobacco has become an important part of cigarette raw materials.
[0003] At present, most domestic reconstituted tobacco enterprises use tobacco raw materials (stem group and leaf group) to make low-concentration pulp separately, with a pulp concentration of 3% to 7%. The low-concentration tobacco pulp is mixed with additional fibers (needle leaf pulp, broadleaf pulp, etc.) after being dispersed by beating, and then the reconstituted tobacco sheet is made. In the process of sheet forming, the single-pass retention rate of the pulp is about 50% to 65%, and the fine components and fillers in the pulp are lost seriously, resulting in waste of resources and low product yield. At the same time, the high-concentration white water in the net brings a heavy burden to the water treatment in the back end.
[0004] Pulp flow is a key link in the production process of reconstituted tobacco, and the retention of pulp directly affects the quality of the sheet and the production cost. In recent years, the use of functional additives and functional materials has significantly improved the retention rate of pulp, and also improved the distribution of fibers and fillers. At present, the commonly used and mature method applied in the production of reconstituted tobacco is to use cationic additives such as guar gum and chitosan to promote the flocculation of fine components by charge neutralization and ionic interaction, thereby improving the retention of pulp. In addition, the methods that can improve the retention of pulp mainly focus on cationic micro-nano cellulose and multi-component retention system. Nano-cellulose, due to its high specific surface area and hydroxyl activity, can adsorb fine components and form a dense network structure. Multi-component composite retention system achieves better retention effect through synergistic effect. Through the modification of calcium carbonate, titanium dioxide, diatomite, etc. by guar gum, chitosan, polyacrylamide epichlorohydrin, etc., the retention of fillers and fine components is promoted.
[0005] The above means for improving the retention of pulp focus on the use of functional additives and functional materials, most of which have high cost and complex process. In addition, as an important component of cigarettes, reconstituted tobacco has high requirements for safety and sensory quality, which greatly restricts the widespread application of most functional additives and functional materials. Therefore, based on the characteristics of the components of reconstituted tobacco, it is particularly important to improve the retention effect of pulp by improving and optimizing the pulping process. SUMMARY
[0006] In order to improve the effect of papermaking method for tobacco leaf pulp, so as to reduce the waste of raw materials, reduce the load of water treatment in the back end, and realize cost reduction and benefit increase, the present application provides a method for improving the pulp retention rate of tobacco raw materials and long fibers by blending and grinding, which improves the pulp effect by adsorption, interception and combination between different types of pulp. The pulp retention rate of the method is improved by 5.0%~30.0%, and the white water concentration under the screen is reduced by 5.0%~60.0%.
[0007] A method for improving the pulp retention rate of tobacco raw materials and long fibers by blending and grinding, the specific steps are as follows: (1) uniformly mixing the extracted tobacco raw materials and long fibers to obtain a mixture; (2) uniformly coarse grinding the mixture at a dryness of 30%~50% by disc mill to obtain a coarse grinding product; (3) gradually preparing pulp with medium concentration and high concentration by disc mill, and monitoring the pulp retention rate.
[0008] Preferably, the tobacco raw material in step (1) is one or more of tobacco stem, stem plug, tobacco leaf, tobacco scrap, tobacco dust and tobacco ash.
[0009] Preferably, the extraction method in step (1) is: mixing the tobacco raw materials and water uniformly according to the solid-liquid mass ratio of 1:5~10, and extracting at a temperature of 50~90℃ for 1~4 stages, with each stage of extraction time being 30min, and solid-liquid separation after each stage of extraction is completed.
[0010] Preferably, the length of the long fiber in step (1) is not less than 1.5mm.
[0011] More preferably, the long fiber is one or more of bamboo pulp, conifer pulp and hemp pulp.
[0012] Preferably, the extracted tobacco raw material in the mixture in step (1) accounts for 50%~80% (by absolute dry weight).
[0013] Preferably, the grinding plate of the disc mill in step (2) is a straight-through type grinding plate, which can ensure the dispersion of the material while reducing the excessive grinding of the tobacco raw material by mechanical force, and realize flexible dissociation.
[0014] Preferably, the coarse grinding method in step (2) is 1~3 stages of progressive knife coarse grinding.
[0015] Preferably, the grinding plate of the disc mill in step (3) is a semi-closed type grinding plate, which reduces the excessive cutting and grinding of the fiber.
[0016] Preferably, the pulp preparation method in step (3) is 1~8 stages of progressive knife pulp preparation.
[0017] Preferably, the pulp concentration of the step (3) pulping is 5% to 15%.
[0018] The mechanism of the tobacco raw material and the medium-length fiber blending and pulping for improving the pulp retention rate is that the medium-length fiber interweaves to form a three-dimensional network skeleton, the large pores are formed between the fibers, the micro-pores are formed between the tobacco pulp short fibers, the voids are filled to reduce the filtration channels, and the loss of fine components is significantly reduced. The pulping makes the medium-length fiber moderately flossed, the specific surface area of the fiber is increased, more hydroxyl groups are exposed, and the hydrogen bond combination is enhanced.
[0019] The beneficial effects of the present application are: (1) The present application improves the pulp retention rate of the reconstituted tobacco under the premise of not introducing new functional additives and functional materials from the aspect of pulping process improvement; (2) The present application monitors the pulp retention rate step by step to realize online real-time monitoring and mastering of the pulp retention rate; (3) The present application improves the pulp retention rate to reduce the waste of raw materials, reduce the load of the downstream water treatment, and finally realizes the purpose of cost reduction and efficiency increase. DETAILED DESCRIPTION
[0020] The present application will be further described in detail in combination with specific embodiments, but the protection scope of the present application is not limited to the content described.
[0021] Embodiment 1: A method for improving the pulp retention rate of tobacco raw material and medium-length fiber blending and pulping, the specific steps are as follows: (1) The extracted tobacco raw material (tobacco stem and tobacco leaf) and medium-length fiber (conifer pulp or bamboo pulp) are uniformly mixed to obtain a mixture; the extraction method is: the tobacco raw material and water are uniformly mixed according to the solid-liquid mass ratio of 1:5, and then 4-stage extraction is carried out at a temperature of 90℃, and the extraction time of each stage is 30min, and the solid-liquid separation is carried out after each stage of extraction is completed; Experimental group 1: The mass ratio of the extracted tobacco stem, the extracted tobacco leaf, and the conifer pulp (fiber length 2.3mm) is 17%:67%:16% (according to the absolute dry mass); Experimental group 2: The mass ratio of the extracted tobacco stem, the extracted tobacco leaf, and the bamboo pulp (fiber length 1.7mm) is 17%:67%:16% (according to the absolute dry mass); (2) The mixture is uniformly coarsely disintegrated by disc mill at a dryness of 30% to obtain a coarsely disintegrated product; the disc mill is a straight-through type grinding plate, which can ensure that the material is fully dispersed while reducing the excessive grinding of the tobacco raw material by mechanical force, and realizes flexible disintegration; (3) using disc grinder to gradually carry out 2, 4, 6, 8 stages of pulping on the coarse solution product after adding water with a concentration of 5%, and adding 15% CaCO3 (based on the absolute dry mass of the pulp) and 0.1% guar gum (based on the absolute dry mass of the pulp) in each stage of pulp; The mass ratio of the extracted tobacco stems and the extracted tobacco leaves is 17:67, and the extracted tobacco stems and the extracted tobacco leaves are uniformly mixed to obtain a mixture; the mixture is uniformly coarsely solved by disc grinding at a dryness of 30% to obtain a coarse solution product; the disc grinding plate is a straight-through type grinding plate, which can ensure that the material is fully dispersed while reducing the excessive grinding of the tobacco raw material by mechanical force, and realizes flexible dissociation; the coarse solution product is gradually pulped by disc grinding at a concentration of 5% after adding water, and the same mass of initial beating degree of needle leaf pulp, CaCO3 and guar gum in the experimental group is added as control group 1, and the same mass of initial beating degree of bamboo pulp, CaCO3 and guar gum in the experimental group is added as control group 2; The 2, 4, 6, 8 stage pulps in the experimental group 1, the experimental group 2, the control group 1 and the control group 2 are respectively taken for retention rate and white water concentration determination (see Tables 1-1 and 1-2); Table 1-1 Retention rate (%) of pulp under 5% concentration pulping condition
[0022] Table 1-2 White water concentration (%) under 5% concentration pulping condition
[0024] The retention rate of the 2, 4, 6, 8 stage tobacco pulp in the control group 1 and the control group 2 gradually decreases, while the sample of the tobacco raw material blended with the needle leaf pulp and the bamboo pulp gradually increases with the increase of the degree of pulping, and the sample added with the needle leaf pulp is higher than the sample added with the bamboo pulp; wherein the retention rate of the experimental group 1 is increased by about 4.8%~15.7%, and the retention rate of the experimental group 2 is increased by about 1.4%~9.8%; The white water concentration of the 2, 4, 6, 8 stage tobacco pulp in the control group 1 and the control group 2 gradually increases, while the sample of the tobacco raw material blended with the needle leaf pulp and the bamboo pulp gradually decreases with the increase of the degree of pulping, and the sample added with the needle leaf pulp is lower than the sample added with the bamboo pulp; wherein the white water concentration of the experimental group 1 is decreased by about 4.8%~33.3%, and the white water concentration of the experimental group 2 is decreased by about 8.3%~26.9%.
[0025] Example 2: A method for improving the retention rate of pulp by blending and pulping tobacco raw materials with medium and long fibers, the specific steps are as follows: (1) The extracted tobacco raw material (tobacco stem and tobacco leaf) is mixed with medium-length fibers (conifer pulp or bamboo pulp) to obtain a mixture; the extraction method is as follows: the tobacco raw material is mixed with water at a solid-liquid mass ratio of 1:7, and then uniformly mixed and extracted at 60 DEG C for 3 stages, with each stage lasting for 30 min; after each stage of extraction, the solid and liquid are separated; Experiment group 1: the mass ratio of the extracted tobacco stem, the extracted tobacco leaf, and the conifer pulp (fiber length of 2.3 mm) is 23:54:23 (based on the absolute dry mass); Experiment group 2: the mass ratio of the extracted tobacco stem, the extracted tobacco leaf, and the bamboo pulp (fiber length of 1.7 mm) is 23:54:23 (based on the absolute dry mass); (2) The mixture is uniformly coarsely disintegrated by disc refining at a dryness of 40% to obtain a coarsely disintegrated product; the disc refining plate is a straight-through type plate, which can ensure that the material is fully dispersed while reducing the excessive grinding of the tobacco raw material by mechanical force, and realizes flexible disintegration; (3) The coarsely disintegrated product is gradually pulped at 2, 4, 6, and 8 stages after being supplemented with water at a concentration of 10%; 15% CaCO3 (based on the absolute dry mass of the pulp) and 0.1% guar gum (based on the absolute dry mass of the pulp) are added to each stage of pulp; Control group: the mass ratio of the extracted tobacco stem and the extracted tobacco leaf is 23:54; the extracted tobacco stem and the extracted tobacco leaf are uniformly mixed to obtain a mixture; the mixture is uniformly coarsely disintegrated by disc refining at a dryness of 40% to obtain a coarsely disintegrated product; the disc refining plate is a straight-through type plate, which can ensure that the material is fully dispersed while reducing the excessive grinding of the tobacco raw material by mechanical force, and realizes flexible disintegration; the coarsely disintegrated product is gradually pulped at 2, 4, 6, and 8 stages after being supplemented with water at a concentration of 10%; the conifer pulp and CaCO3 and guar gum of the same initial beating degree as the experimental group are added as control group 1, and the bamboo pulp and CaCO3 and guar gum of the same initial beating degree as the experimental group are added as control group 2; The 2, 4, 6, and 8 stages of pulp in the experimental group 1, the experimental group 2, the control group 1, and the control group 2 are taken for retention rate and white water concentration determination (see Tables 2-1 and 2-2); Table 2-1 Retention rate of pulp under 10% concentration pulping conditions (%)
[0026] Table 2-2 White water concentration under 10% concentration pulping conditions (%)
[0027] The retention rate of the tobacco pulp of grades 2, 4, 6 and 8 in the control group 1 and the control group 2 gradually decreases, while the retention rate of the samples of the tobacco raw material blended with the needle pulp and the bamboo pulp gradually increases with the increase of the degree of refining, and the sample added with the needle pulp is higher than the sample added with the bamboo pulp; wherein the retention rate of the experimental group 1 increases by about 12.8% to 22.8%, and the retention rate of the experimental group 2 increases by about 9.9% to 22.1%. The white water concentration of the tobacco pulp of grades 2, 4, 6 and 8 in the control group 1 and the control group 2 gradually increases, while the white water concentration of the samples of the tobacco raw material blended with the needle pulp and the bamboo pulp gradually decreases with the increase of the degree of refining, and the sample added with the needle pulp is lower than the sample added with the bamboo pulp; wherein the white water concentration of the experimental group 1 decreases by about 10.0% to 48.0%, and the white water concentration of the experimental group 2 decreases by about 12.5% to 34.6%.
[0028] Embodiment 3: A method for improving the retention rate of pulp by blending and refining a tobacco raw material with a medium-long fiber, and the specific steps are as follows: (1) mixing the extracted tobacco raw material (tobacco stems and tobacco leaves) with a medium-long fiber (needle pulp or bamboo pulp) to obtain a mixture; the extraction method is as follows: mixing the tobacco raw material with water at a solid-liquid mass ratio of 1:10, uniformly, and then performing 4-stage extraction at a temperature of 50°C, with each stage of extraction lasting for 30 minutes, and then performing solid-liquid separation after each stage of extraction; Experimental group 1: the mass ratio of the extracted tobacco stems, the extracted tobacco leaves and the needle pulp (fiber length of 2.3 mm) is 29:43:28 (according to the absolute dry mass); Experimental group 2: the mass ratio of the extracted tobacco stems, the extracted tobacco leaves and the bamboo pulp (fiber length of 1.7 mm) is 29:43:28 (according to the absolute dry mass); (2) uniformly coarsely disintegrating the mixture at a dryness of 50% by disc refining to obtain a coarsely disintegrated product; the disc refining plate is a straight-through type plate, which can ensure the sufficient dispersion of the material while reducing the excessive grinding of the tobacco raw material by mechanical force, and realizes flexible disintegration; (3) gradually performing 2, 4, 6 and 8-stage pulping on the coarsely disintegrated product by disc refining after adding water at a concentration of 15%, and adding 15% CaCO3 (based on the absolute dry mass of the pulp) and 0.1% guar gum (based on the absolute dry mass of the pulp) in each stage of pulp; The mass ratio of the extracted tobacco stems and the extracted tobacco leaves is 29:43, the extracted tobacco stems and the extracted tobacco leaves are uniformly mixed to obtain a mixture; the mixture is uniformly coarsely disintegrated by disc milling in three stages under a dryness of 50% to obtain a coarsely disintegrated product; the disc mill is provided with straight-through grinding plates, which can ensure that the material is fully dispersed while reducing the excessive grinding of the tobacco raw material by mechanical force, and realize flexible disintegration; the coarsely disintegrated product is gradually disintegrated into 2, 4, 6 and 8 stages after being supplemented with water at a concentration of 15%; after the disintegration is completed, the same mass of initial beating degree of needle pulp, CaCO3 and guar gum in the experimental group is added as control group 1, and the same mass of initial beating degree of bamboo pulp, CaCO3 and guar gum in the experimental group is added as control group 2; The 2, 4, 6 and 8 stage pulps in the experimental group 1, the experimental group 2, the control group 1 and the control group 2 are respectively taken for retention rate and white water concentration determination (see Tables 3-1 and 3-2); Table 3-1 Retention rate (%) of pulp under 15% concentration disintegration condition
[0029] Table 3-2 White water concentration (%) under 15% concentration disintegration condition
[0030] The retention rate of the 2, 4, 6 and 8 stage tobacco pulps in the control group 1 and the control group 2 gradually decreases, while the retention rate of the samples of the tobacco raw material mixed and disintegrated with the needle pulp and the bamboo pulp gradually increases with the increase of the disintegration degree, and the sample added with the needle pulp is higher than the sample added with the bamboo pulp; wherein the retention rate of the experimental group 1 is increased by about 22.8%~28.2%, and the retention rate of the experimental group 2 is increased by about 21.7%~28.0%. The white water concentration of the 2, 4, 6 and 8 stage tobacco pulps in the control group 1 and the control group 2 gradually increases, while the white water concentration of the samples of the tobacco raw material mixed and disintegrated with the needle pulp and the bamboo pulp gradually decreases with the increase of the disintegration degree, and the sample added with the needle pulp is lower than the sample added with the bamboo pulp; wherein the white water concentration of the experimental group 1 is decreased by about 34.8%~64.0%, and the white water concentration of the experimental group 2 is decreased by about 30.8%~46.7%.
[0031] The specific embodiments of the present application are described in detail above, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.
Claims
1. A method for improving pulp retention of tobacco raw material and medium-long fiber blended pulp, characterized in that, The specific steps are as follows: (1) mixing the extracted tobacco raw material with the medium-length fiber to obtain a mixture; (2) uniformly coarsely grinding the mixture by disc mill at a dryness of 30%-50% to obtain a coarsely ground product; (3) gradually performing medium-concentration and high-concentration pulping on the coarsely ground product by disc mill, and monitoring the retention rate of the pulp.
2. The method according to claim 1, wherein the tobacco raw material and the medium-long fiber are blended and ground to improve the retention of the pulp. The tobacco raw material in step (1) is one or more of tobacco stem, stem segment, tobacco leaf, tobacco scrap, tobacco dust, and tobacco ash.
3. The method according to claim 1, wherein the tobacco raw material and the medium-long fiber are blended and ground to improve the retention of the pulp. The extraction method in step (1) is as follows: the tobacco raw material is mixed with water at a solid-liquid mass ratio of 1:5-10, and then uniformly mixed and extracted at a temperature of 50-90°C for 1-4 stages, with each stage of extraction lasting for 30 min, and solid-liquid separation being performed after each stage of extraction.
4. The method according to claim 1, wherein the tobacco raw material and the medium-long fiber are blended and ground to improve the retention of the pulp. The fiber length of the medium-length fiber in step (1) is not less than 1.5 mm.
5. The method according to claim 4, wherein the tobacco raw material and the medium-long fiber are blended and ground to improve the retention of the pulp. The medium-length fiber is one or more of bamboo pulp, conifer pulp, and hemp pulp.
6. The method of claim 1, wherein the tobacco material and the medium-long fibers are blended and ground to improve the retention of the pulp. The extracted tobacco raw material in the mixture in step (1) accounts for 50%-80% by weight of the absolute dry weight.
7. The method according to claim 1, wherein the tobacco raw material and the medium-long fiber are blended and ground to improve the retention of the pulp. The grinding plate of the disc mill in step (2) is a straight-through grinding plate, and the coarsely grinding method is 1-3 stages of gradually increasing the knife feed.
8. The method according to claim 1, wherein the tobacco raw material and the medium-long fiber are blended and ground to improve the retention of the pulp. The grinding plate of the disc mill in step (3) is a semi-closed grinding plate.
9. The method according to claim 1, wherein the tobacco raw material and the medium-long fiber are blended and ground to improve the retention of the pulp. The pulp concentration for pulping in step (3) is 5%-15%.