JPS641114B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention is a method for producing sheet materials such as sheet smoking articles, specifically, in the production of sheet materials by a slurry method, the present invention increases the strength of the obtained sheet materials, and improves the manufacturing process. The present invention relates to a method for producing a sheet-like material that is stabilized. (Prior Art) Conventionally, sheet-like materials such as sheet-like smoking articles (hereinafter also simply referred to as sheets) have been generally produced by the method described below using a slurry method. In the following description, tobacco will be taken up as an example of a seed-like material, and a method for producing the same will be explained, but the present invention can also be widely applied to the production of sheet-like materials from various materials in the food manufacturing field, etc. It is. In other words, the method for manufacturing sheet cigarettes involves blending appropriate amounts of binders, humectants, fragrances, fillers, etc. into tobacco waste powder produced and rotated from various tobacco manufacturing processes, and mixing the mixture with an appropriate amount of water to form a paste. The mixture (hereinafter simply referred to as paste) is
After kneading, the mixture is spread onto the surface of an endless belt made of stainless steel or the like using a roll coater or the like so as to have a uniform thickness, dried and moistened to form a continuous sheet cigarette. However, sheets manufactured by such conventional slurry methods generally have low strength and are easily crushed or broken, which not only hinders the sheet manufacturing process and reduces manufacturing efficiency, but also prevents the sheets from being used normally. When it is mixed into raw materials for shredding tobacco and subjected to processing such as shredding and rolling, or when transporting sheets to these processing steps, it is easily crushed and finely powdered, and when it is further finely ground, it cannot be rolled into cigarettes. There are drawbacks such as a decrease in the charging effect when In general, the strength of sheets produced by the slurry method is largely controlled by the type and proportion of the binder added. Typical binders used in the production of sheets include, for example, vegetable binders such as locust bingham gum, guar gum, tragacanth gum, konjac mannan, and corn starch; seaweed extracts such as faucerulan and sodium alginate; ethyl cellulose, methyl cellulose, and carboxymethyl cellulose; Examples include fibrillar derivatives such as carboxyethyl cellulose; sheet strength tends to be weak when natural products are used as is, and strength tends to be strong when synthetic binders such as fibrillar derivatives are used. can be seen. or,
It is known that the strength of these fibrillar derivatives as a binder varies greatly depending on the degree of polymerization, type of derivative group, reaction ratio, etc. For example, sodium salt of carboxymethylcellulose (CMC-Na), a type of fibrillar derivative, is commonly used as a binder, but the strength of the sheet when using this is due to the strength of CMC-Na itself. It is greatly influenced by the degree of polymerization and degree of etherification, and the higher the degree of polymerization, the more
The lower the degree of etherification, the higher the strength. but,
In order to obtain a sheet with high strength, the CMC
When Na is used, the viscosity of the paste made of the raw material mixture tends to increase. Thus, a positive correlation function is observed between the viscosity of the binder when it is made into a paste and the sheet strength. By the way, even if the viscosity of the binder is low, it is possible to increase the sheet strength by increasing the blending ratio of the binder, but increasing the blending ratio of the binder can significantly affect the flavor and taste of the product sheet cigarette. This is not preferable because it reduces the Therefore, in order to reduce the blending ratio of the binder as much as possible and to maintain sufficient sheet strength to prevent crushing in the above-mentioned sheet manufacturing process and cigarette manufacturing process, it is necessary to use a high viscosity binder. Must be used. However, when using high viscosity binders,
When turning the raw material mixture into a paste, it is necessary to increase the amount of water added to adjust the viscosity to an appropriate level that does not interfere with the manufacturing process, and the only disadvantage is that the load required for drying the sheet increases by the increased amount of water. First, high viscosity binders generally have a slow dissolution and dispersion rate in water, and have the drawback of being easily aggregated. When the binder is made into a paste with the raw material mixture in this way,
Even if the binder has a high bonding strength, it partially exists as a powder when it passes through the kneading machine as agglomerated without being sufficiently dissolved and dispersed and is spread on the belt surface with a roll coater. This may result in the binder not functioning at all. In addition, when a paste obtained by kneading the raw material mixture is spread on the belt surface by a roll coater, a strainer is generally installed in the supply piping system to the roll coater to separate foreign matter to prevent foreign matter from clogging the nip gap of the roll coater weir. However, binders in raw material formulations or tobacco powder, etc. (especially organic raw materials)
After passing through the strainer without being sufficiently dissolved or swelled in water, it swells and becomes larger.
This may cause the nip to become clogged. This nip clogging is extremely difficult to repair during operation, and even the presence of a single coarse particle can cause cracks in the sheet, degrading the quality and interfering with the smooth conveyance of the sheet on the belt surface. This may cause problems such as For this reason, conventionally, the binder is often pulverized in advance and then further classified before use. However, since it is difficult to achieve sufficient classification with air classification, sieve classification has been adopted. However, even with this sieve classification, it takes a long time for binders with strong adhesive and cohesive properties, resulting in high costs. Also, depending on the type of binder, there are some that need to be kept at a high moisture content due to their nature, and such binders have high viscoelasticity.
Since it is difficult to finely grind it, it must be used in a coarse state. However, such coarse-grained binders
Because the rate of water permeation into the interior of the particles, that is, the rate of swelling, is slow, a preliminary tank is usually installed and the particles are immersed in water for a long time to swell, but this method is not suitable for the continuous production of large quantities of sheets. In addition, there are other problems such as poor mixing accuracy with other blended raw materials and deterioration of the binder. (Problems to be Solved by the Invention) The present invention was made by focusing on the various drawbacks and problems of the conventional method as described above in the sheet manufacturing process using the slurry method. It is an object of the present invention to provide a method for producing a sheet material that solves the above-mentioned problems when using the present invention and produces a sheet with high strength, and in particular eliminates nip clogging in a roll coater and stabilizes the production process. purpose. (Means for Solving the Problems) That is, the present invention involves kneading a paste-like mixture of a powder raw material made of various materials, a binder, etc., and a liquid raw material made of water, a humectant, etc., and then spreading. This is a method for producing a sheet-like material, the gist of which is to include a step of swelling the paste-like mixture prior to a step of kneading the paste-like mixture in the step of producing the sheet-like material by drying. The present invention will be explained in detail below based on the accompanying drawings. That is, FIG. 1 is a schematic illustration of the sheet manufacturing process according to the present invention, and FIG. 2 is a schematic illustration of a swelling device used in the paste swelling process, which is the essential part of the present invention. First, in FIG. 1, reference numeral 1 denotes a mixing tank for powder raw materials among the raw materials to be mixed for sheet production, in which tobacco powder, binder powder, filler powder, etc. are mixed at predetermined mixing ratios. This powder raw material mixture is metered to a fixed amount by a powder metering feeder 2 and then fed to a continuous mixer 3.
is supplied to On the other hand, 4 is a mixing tank for liquid raw materials among the mixed raw materials for sheet manufacturing, and includes moisturizers,
Flavors and the like are mixed with water in a predetermined proportion. This liquid raw material mixture is supplied to the continuous mixer 3 by a metering pump 5, and is mixed with the powder raw material mixture to form a coarsely kneaded paste. This roughly kneaded paste is transferred to a swelling device 7 by a paste pump 6. The swelling device 7 is a roughly kneaded paste swelling device that is used in the sheet manufacturing method according to the present invention, and its details will be described later. In this swelling device 7, the tobacco powder, binder, etc. in the raw material mixture sufficiently absorb water, are swollen and dispersed, and then supplied to a continuous kneader 8 for kneading, and temporarily stored in a buffer tank 9. Continuous kneading machine 8
is equipped with a screw blade 8a inside, which performs the functions of kneading and conveying at the same time. This continuous kneading machine 8 is not operated all the time, but is operated on and off in accordance with requests for discharging paste in subsequent steps. Further, a level sensor is installed in the buffer tank 9, and when the paste in the tank reaches a predetermined upper and lower limit position, the transfer of the paste before the continuous kneading machine 8 and the supply of paste to the roll coater which is a subsequent process are controlled. be done. Note that 9a is a stirrer for stirring the paste in the buffer tank 9. The paste in the buffer tank 9 is transferred to a strainer 11 by a paste pump 10, filtered, and then transferred to a roll coater 12. The roll coater 12 has a weir 12a provided on a pair of opposing rolls, and a level sensor is also installed on the weir 12a to maintain the paste within the weir at a constant level. The paste supplied into the weir 12 is spread from the nip (roll gap) of the opposing rolls onto a belt 13 made of an endless stainless steel plate, etc., and while being transferred on the belt 13, it undergoes a drying and humidity conditioning process (not shown). It is then made into sheet cigarettes. Next, details of the swelling device 7 used in the present invention will be explained. That is, in FIG. 2, a swelling tank 7a, which is the main body of the swelling device 7, is equipped with a stirrer 14 provided with stirring blades 14a and 14b, a level sensor 15, and a converter 16. A jacket 17 is wrapped around the tank wall. This heating jacket 17 can be formed of steam piping that utilizes waste heat for sheet drying. Further, the heating jacket 17 is equipped with a temperature sensor 18.
and a converter 19 are attached. The level sensor 15 is installed to control the residence time of the paste in the tank to ensure the necessary swelling time of the substance in the paste, and to prevent overflow from the tank.
A non-contact type with good accuracy and water resistance is desirable. An ultrasonic sensor is most suitable for this type. The level control position of paste a by this level sensor 15 is mainly determined by the illustration of the swelling tank 7a.
It is set at positions _L1 to _L4 , and is configured to receive a sensing signal at the level position and convert it into a control current by a converter 16 to control the operation of devices in the upstream and downstream steps of the swelling device 7. There is. (Function) Next, the function of the swelling device 7 according to the present invention will be explained. First, at the start of operation, the paste roughly kneaded by the continuous mixer 3 is supplied to the swelling tank 7a via the pipe 20 by the paste pump 6, and storage is started. At this point, the devices after the continuous kneader 8 are in a stopped state. When the level of paste a stored in the swelling tank 7a reaches _L1 , the stirrer 1
4, start stirring paste a. Generally, a stirrer is easily damaged when operated under no load, so the mounting position of the stirring blade 14a at the lower end of the stirrer 14 is set at level _L1 . Next, when paste a is stored up to level L ₃ ,
The kneader 8 operates, and the paste that has been sufficiently swollen is kneaded by the kneader 8 and transferred to the buffer tank 9.
will be transferred to. The level position of paste a in the swelling tank 7a is set between levels L ₂ to _{L 4} during normal operation, and the level L ₂ is set at a position where the minimum swelling time of the paste is ensured. Therefore, if the level of paste a becomes below _L2 , mixer 8
is stopped and the transfer of paste is also stopped. Also, L ₄
is the maximum storage level of the paste in the swelling tank 7a, and when the paste reaches the _L4 level, the steps before the swelling step are stopped. Then, when the kneading and transfer by the kneader 8 progresses and the level drops to _L3 , the steps before the swelling step are operated again. In this way, the level of paste a in the swelling tank 7a is controlled by the level sensor 15 so as to maintain a steady state between _L1 and _L4 , and the roughly kneaded paste supplied to the swelling tank 7a has sufficient retention for swelling. time is given. In the above swelling process, the installation of the stirrer 14 can have two meanings as described below. Firstly, the rate at which organic substances such as binders absorb water and swell depends on their chemical properties;
Generally, it is obvious that the larger the particle size, the slower the swelling rate. Therefore, by removing the surface that has swelled and softened by absorbing water by successive stirring,
The second is that the paste with high viscosity has thixotropic properties, and if left without shearing, it will not gel and lose fluidity. The purpose is to prevent the paste from becoming difficult to transfer to the next process and from causing the above-mentioned residence time of the paste to become non-uniform, thereby causing variations in the quality of the sheet. Further, the reason why heating equipment such as a heating jacket 17 is added to the swelling device 7 is that the organic raw material in the paste generally swells faster at higher temperatures, and on the other hand, the viscosity of the paste decreases, making it easier to handle. This is to become. Therefore, it is desirable that the temperature of the paste in the swelling tank 7a is controlled to be as high as possible within a range that does not cause alteration, decomposition, or deterioration. (Example) Example 1 40 parts by weight of tobacco powder (yellow seed true leaf 1 grade, passed through an 80 mesh sieve), CMC-Na as a binder
(average degree of polymerization 500, average degree of substitution 0.76), 20 parts by weight of diatomaceous earth (classified through an 80 mesh sieve) as a filler, and 15 parts by weight of calcium carbonate powder, and 550 parts by weight of water. and a liquid mixed with 10 parts by weight of glycerin as a wetting agent were respectively supplied in fixed amounts and mixed in a continuous mixer to obtain a coarsely kneaded paste. This roughly kneaded paste was directly introduced into a continuous kneading machine without using a swelling tank, and the kneaded paste was spread on a stainless steel belt to a thickness of approximately 5 mm using a reverse roll coater, and then passed through a dryer.
It was dried for about 3 minutes in an atmosphere of 105°C to obtain a sheet, which was used as a control product. The time required for the powder raw material to reach the inlet of the kneader after being mixed with water was approximately 4 minutes. On the other hand, the same raw materials as in the case of the control product were used and mixed under the same proportions and conditions to obtain a coarsely kneaded paste. This coarsely kneaded paste was introduced into a swelling tank (capacity 140) according to the present invention, and stirred at 30 rpm using a stirrer.
While stirring at a rotational speed of , the average residence time in the tank was set to 10 minutes, 20 minutes, and 30 minutes, respectively. A sheet according to the present invention was obtained by kneading the mixture using a roll coater, spreading it onto a belt using a roll coater, and drying it. Note that the temperature of the paste in the swelling tank was set at 40°C. The relationship between the average residence time of the paste and the physical properties of the sheet was as shown in Table 1.

[Table] From the results in Table 1, the strength of the sheet produced by the present invention is significantly higher than that of the control product, and the longer the residence time of the paste in the swelling tank, the greater the strength of the sheet. it is obvious. Example 2 25 parts by weight of tobacco bone powder (local species, 60-mesh sieve-classified product), tobacco powder (yellow variety true leaf 1 grade, etc.)
35 parts by weight (classified product that passes through a 60-mesh sieve), 15 parts by weight of perlite powder as a filler (classified product that passes through a 60-mesh sieve)
Part by weight, CMC—NH ₄ as binder (average degree of polymerization
450, average degree of substitution 0.71, 3 mm sieve passed) powder mixed with 15 parts by weight and 10 parts by weight of corn starch, and a liquid mixed with 600 parts by weight of water and 5 parts by weight of propylene glycol as a wetting agent were supplied in fixed quantities. The mixture was mixed using a continuous mixer to obtain a coarsely kneaded paste. This coarsely kneaded paste was directly introduced into a continuous kneader without using a swelling tank, and the kneaded paste was spread on a stainless steel belt under the same conditions as in Example 1 and dried to obtain a control sheet. On the other hand, using the same raw materials as in the case of the control product, they were mixed under the same proportions and conditions to obtain a coarsely kneaded paste, which was then introduced into the same swelling tank according to the present invention as in Example 1, and the rotational speed of the stirrer was adjusted. 30rpm,
60rpm, temperature 30℃, 50℃ and average residence time 10
After the coarsely kneaded paste was allowed to stagnate in different settings for 30 minutes, 20 minutes, and 30 minutes, it was kneaded with a continuous kneader, spread with a roll coater, and dried under the same conditions as the control product. A sheet was obtained. The relationship between the swelling conditions such as the average residence time of the paste, temperature, and stirrer rotation speed and the physical properties of the sheet was as shown in Table 2.

【table】

[Table] From the results in Table 2, the strength of the sheet manufactured by the present invention is significantly stronger than that of the control product. It is clear that the greater the number, the greater the strength of the sheet. In the control product, granules were generated in the paste in the continuous kneading machine, clogging the strainer and at the same time clogging the roll coater's nip and causing tears in the sheet. However, in the case of the present invention, such trouble did not occur at all, and a uniform sheet without cracks etc. was obtained. (Effects of the Invention) As described in detail above, according to the present invention, a swelling step of the paste is provided before kneading the paste made of sheet compound raw materials, and a level sensor in a swelling tank is used to ensure sufficient swelling time of the paste. At the same time, it is possible to install a stirrer and heating equipment to promote swelling, which significantly improves the kneading effect in the next process, eliminates the presence of coarse particles in the paste, and improves the quality of the raw materials. The particles are sufficiently atomized to ensure uniform dispersion. Therefore, the paste supplied to the roll coater is uniformly spread on the belt without clogging the nips, and it does not break during the drying or humidity conditioning process, making the sheet manufacturing process extremely stable. At the same time, there is an advantage that a sheet with high strength can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the sheet manufacturing process according to the present invention, and FIG. 2 is a schematic explanatory diagram of a swelling device used in the paste swelling process, which is the essential part of the present invention. 1... Powder raw material mixing tank, 2... Powder quantitative feeder, 3
... Continuous mixer, 4... Liquid raw material mixing tank, 5... Metering pump, 6, 10... Paste pump, 7... Swelling device, 7a... Swelling tank, 8... Continuous kneading machine, 9... Buffer tank, 11... Strainer, 12... Roll coater, 12a... Weir, 13... Belt, 14... Stirrer, 15... Level sensor, 16... Converter, 17...
Heating jacket, 18... Temperature sensor, 19... Converter.

Claims (1)

[Claims] 1. Powder raw materials made of various materials, binders, etc.;
In the process of manufacturing a sheet material by kneading a paste mixture with a liquid raw material consisting of water, a humectant, etc., and then spreading and drying, the swelling of the paste mixture is performed prior to the kneading process of the paste mixture. 1. A method for producing a sheet-like material, characterized in that a step is involved. 2. The method for producing a sheet-like material according to claim 1, wherein the swelling step is carried out in a swelling tank equipped with a level sensor and a stirrer, respectively. 3. The method for producing a sheet-like material according to claim 1, wherein the swelling step is carried out in a swelling tank equipped with a level sensor, a stirrer, and heating equipment, respectively.