JPH0330660A - Bulking up of tobacco material - Google Patents

Abstract

PURPOSE: To expand a tobacco material without varying the taste and flavor by impregnating an expanding agent made of sulfur hexafluoride into the tobacco material under a specified pressure and releasing the expanding material by heating. CONSTITUTION: An expanding agent made of sulfur hexafluoride is impregnated into a tobacco material 10 under 21.1kg/cm<2> , preferably 24.6kg/cm<2> pressure in an impregnation zone 12 until >=0.5wt.% sulfur hexafluoride is incorporated and then the expanding agent is released by heating preferably at 90-250 deg.C to expand the tobacco material in an expansion zone 48.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for bulking tobacco material, and in particular to a method for bulking tobacco material to reduce the bulk density of tobacco material and thereby increase its volume and replenishment capacity. This invention relates to a method for expanding materials. This bulking method is particularly suitable for processing shred refills for cigarettes.

Over the past 20 years, the tobacco material expansion process has become an important part of the cigarette manufacturing process. The tobacco material swelling process is used to restore the bulk density and/or volume of the tobacco material lost during tobacco drying and ripening (storage). Additionally, expanded tobacco material is an important component of many low tar and very low tar cigarettes.

A commercially important method of bulking tobacco material is disclosed in U.S. Pat.
No. 24,451 and No. 3,524,452. In the process described in these patents, tobacco material is contacted with a volatile organic impregnating agent, and then hot gas is applied to the impregnated tobacco material (tobacco material impregnated with the impregnating agent).
The tobacco material is expanded (expanded) by rapidly passing the current through it so as to bring it into contact with the tobacco material, thereby volatilizing the impregnating agent in the tobacco material. A variation of these methods is disclosed in U.S. Patent No. 3.68.
No. 3°937. In a variant of the method, tobacco material is impregnated with a volatile organic compound in a vapor phase free of liquid and solid phases, and then the impregnated tobacco material (
The tobacco material impregnated with the impregnating agent is expanded by heating or rapid depressurization.Heating can be carried out by means of a hot gas stream or by microwave treatment.

Even after the development and commercialization of the tobacco bulking method described above, extensive efforts have been made in the development and research of bulking agents and tobacco bulking methods.For example, U.S. Pat. Nos. 4,258,729 and 4,336,814 disclose the use of carbon dioxide as a tobacco bulking agent. These and related bulking methods involve contacting and impregnating tobacco material with gaseous or liquid carbon dioxide, and then rapidly heating the carbon dioxide-impregnated tobacco material to volatilize the carbon dioxide. , thereby expanding the smoking period. Carbon dioxide is contained in large amounts in the atmosphere and can be easily obtained. However, in this method of expanding tobacco material using carbon dioxide, the tobacco material must usually be heated excessively in order to achieve stable expansion. As a result, an excessive amount of tobacco fine powder is produced which may impair the flavor of the tobacco material. Furthermore, conventional commercial tobacco material swelling methods that use liquid carbon dioxide to impregnate tobacco material result in impregnated tobacco material in the form of solid blocks containing dry ice, making it difficult to heat treat. The solid blocks must be removed before hanging, which not only damages the tobacco material but also makes the process more complicated.

U.S. Patents 4,461,310 and 4,289,14
No. 8 discloses a tobacco material swelling method using supercritical nitrogen or argon as an impregnating agent for the tobacco material. When a nitrogen or argon impregnated tobacco material is rapidly depressurized, nitrogen or argon gas is released from the tobacco material, causing the tobacco material to expand by exposure to heated gas or microwaves.

However, in these methods, in order to achieve substantial bulking of tobacco material, a pressure of 140.6 kg/cm"
(2,000psi) or 281.2Kg/cm”
(4,000psi) or more, maximum 703Kg/cm”
Buffing materials must be processed at pressures of over 10,000 psi (10,000 psi).

U.S. Pat. No. 4,531,529 applies a low-boiling, high-volatility impregnating agent, such as a normally gaseous heroocarbon or hydrocarbon, to tobacco material above the critical pressure and temperature of the impregnating agent. or impregnated under similar processing conditions,
A method for increasing the replenishment capacity of tobacco material is disclosed in which the pressure is rapidly reduced to atmospheric pressure after impregnation to expand the tobacco material. This method does not require a heating step to expand the tobacco material or to secure the tobacco material in an expanded state.

Also, U.S. Patent No. 3,765,425, 3,842.8
No. 46 and No. 3,881,498, etc., disclose the use of microwave treatment in the expansion process of tobacco material.

In these methods, the tobacco material is treated to increase its moisture content, or the tobacco material is impregnated with an organic bulking agent that absorbs microwaves. Alternatively, the tobacco material is treated with water and an organic bulking agent that does not absorb microwaves, and then the tobacco material is exposed to microwave energy to volatilize the moisture and/or the organic bulking agent, and the tobacco material is then treated with water and an organic bulking agent that does not absorb microwaves. expand.

Various compounds such as alkanes, alkenes, alcohols, aldehydes, ketones, and ethers have been proposed as bulking agents for expanding tobacco materials. However, in most cases, the desired flavor is extracted from the tobacco material during the impregnation and/or swelling steps, insufficient swelling of the tobacco material is achieved, and the swelling is not uniform. , reaction between the bulking agent and components in the tobacco, harmful impact on tobacco processing equipment, excessive amount of bulking agent remaining in the final expanded tobacco material, accompanying bulking agent. There are various practical problems, such as the presence of flammability hazards.

SUMMARY OF THE INVENTION There is a need to improve the known tobacco bulking methods as described above and to provide new and improved tobacco bulking methods and bulking agents. However, despite considerable efforts in the past, commercial success in this area of tobacco bulking has still been limited. The present invention aims to solve this problem.

In order to solve the above problems, the present invention provides a method for expanding tobacco material using sulfur hexafluoride as a bulking agent. It is based on the knowledge that it can be used to expand tobacco material with little physical damage to the material and with little change in the taste and flavor of the tobacco material.

The tobacco material swelling method of the present invention provides tobacco material, preferably in a liquid phase, of about 21.1 Kg/cm" (300 ps
i) Higher pressure, preferably from about 24.6 to about 175.
This is done by impregnating with sulfur hexafluoride maintained at a pressure of 8 Kg/cm'' (350-2.500 psi).

The sulfur hexafluoride impregnated tobacco material is discharged from the impregnation zone at a temperature in the range of about -40 to 35°C, preferably about -25 to 20'C. Under such temperature conditions, the tobacco material is in a substantially pliable state and contains from about 0.50 to about 20% by weight, preferably from about 1.0 to about 10.0% by weight of sulfur hexafluoride. Hold. The impregnated tobacco material is then rapidly heated in the expansion zone to release the sulfur hexafluoride impregnated into the tobacco material, thereby expanding the tobacco. Relatively moderate heating conditions, e.g.
Temperatures of 00C, preferably 90 to 250C can be used.

The bulking agent used in the method of the present invention, sulfur hexafluoride, is
It is an odorless, tasteless, colorless and harmless gas at room temperature.
Sublimes from a solid to a gas at -64°C at atmospheric pressure. Also, despite the low sublimation temperature of sulfur hexafluoride, it has a temperature of -30~
30'C1 Hold the tobacco material for a short period of time, preferably at a temperature in the range -20 to 20°C, allowing time for conveying the impregnated tobacco material to the heated bulk zone; or
Allows time for temporary storage of the impregnated tobacco material in an insulated or cooled holding zone. Typically, sulfur hexafluoride is retained within the tobacco material in an amount of about 0.5% to about 20% by weight. Even though the triple point of sulfur hexafluoride is higher than atmospheric pressure (sulfur hexafluoride sublimates from a solid to a liquid at atmospheric pressure without passing through a liquid phase), it impregnates sulfur hexafluoride and produces approximately -30 Tobacco material having a temperature above 0.degree. C., preferably above about -20.degree. C., is substantially flexible, ie, does not contain large solid tobacco blocks that must be subsequently handled.

Impregnation of sulfur hexafluoride into tobacco material is carried out at a temperature of about -10 to about 45°C.
It has been found that the impregnation takes place quickly and completely at suitable impregnation temperatures, preferably above 10'C. Therefore, the impregnation time can be short, less than 15 minutes, for example in the range of 1 to 10 minutes. The impregnation pressure used in the process of the present invention is above atmospheric pressure, but not very high. The process of the present invention allows the use of relatively moderate temperatures to expand the impregnated tobacco material. Therefore, the generation of fine powder of tobacco material can be suppressed to a minimum, and the influence of heating on the flavor and taste of tobacco material can be avoided or minimized. Furthermore, little, if any, sulfur hexafluoride remains in the expanded tobacco material.

Yet another advantage of the bulking process of the invention is that at the impregnation temperatures and pressures used in the invention, there is little, if any, extraction of valuable flavor components from the tobacco material during the impregnation process. . Therefore, the tobacco material removed from the impregnation zone is substantially unextracted.

As a result, the flavor of the expanded tobacco material can be maintained, and the process of collecting the impregnating agent can be simplified. .

In a preferred embodiment of the invention, the sulfur hexafluoride impregnated tobacco material can be expanded using microwave treatment. In this embodiment, it is preferred that the tobacco material is treated prior to the impregnation step so that the moisture content of the tobacco material is greater than 15%, preferably in the range of about 25% to about 40%. , the tobacco material is rapidly conveyed through a microwave heating zone. Sulfur hexafluoride absorbs only a portion of the microwave energy, but the moisture in the tobacco material absorbs the microwave energy and generates heat, causing the bulking agent sulfur hexafluoride to volatilize rapidly. The volatilization of moisture and sulfur hexafluoride during the microwave heating process provides a cooling effect so that the tobacco material is maintained at a temperature below about 100° C. for the duration of the heating process. The expanded tobacco material is, for example, 7 to 1
It can be recovered at a moisture content of 3% by weight, thereby
Eliminating or minimizing the need for a separate readjustment process after the expansion process.

[K Blood] The tobacco material to be treated in the bulking method of the present invention can be supplied in any of a variety of forms, for example in the form of leaf tobacco, tobacco leaf strips, or shredded cigarette refill.
．． Shredded tobacco material shredded into 20 to 40 pieces per 54 cm (1 in) is preferred because the method of the invention is particularly efficient when applied to such relatively small tobacco material particles; This is because the unexpanded bulk tobacco material of tobacco or tobacco leaf strips will lose some of its increased replenishment capacity when it is later passed through a cutter or shredder. If desired, the tobacco material can be cased with various flavoring agents and humectants prior to the expansion step.

The tobacco material to be treated should be in a pliable state to minimize breaking or crushing of the tobacco material during processing. The traditional method of making tobacco wood pliable is to control moisture (moisture content).
in the range of about 10 to 30%, preferably about 20 to about 30%
It is to adjust it within the range of . In the process of the invention, higher moisture levels can be used, and may even be advantageous, especially when microwave treatment is used to expand the tobacco material.

Referring to FIG. 1, tobacco material 1o, preferably in the form of cigarette cut refill, is passed by conventional charging equipment, such as a conveyor 13, to a batch impregnation zone or impregnator 12. As shown in FIG. 1, impregnator 12 constitutes a batch high pressure vessel well known to those skilled in the art. Any of a variety of devices and accessories may be used in connection with the pressure vessel. It is preferable to provide a valve material outlet at the top or bottom of the pressure vessel for introducing sulfur hexafluoride, and a valve material outlet for discharging sulfur hexafluoride at the top or bottom of the pressure vessel. As shown, there may be multiple valve outlets at the top and bottom of the container;
Sulfur hexafluoride and tobacco material at about -10°C, preferably about 0
Heating or cooling means such as external heating jackets, heating coils, or cooling jackets can optionally be used to maintain an impregnation temperature of ~45°C.

Sulfur hexafluoride is supplied by conduit 16 from a sulfur hexafluoride source 14, such as a pressurized storage tank containing liquid sulfur hexafluoride, through valve 18 and filter 20 to heat exchanger 22.

Liquid sulfur hexafluoride is added to the heat exchanger 22 at a rate of 5 to 20% to prevent cavitation phenomena during subsequent pumping.
℃ cooled. The thus cooled liquid sulfur hexafluoride is sent to the heat exchanger 26 by the high pressure liquid pump 24,
Heat exchanger 26 heats or cools the sulfur hexafluoride to a desired temperature, for example, from about -10°C to about 90°C, preferably above about 10°C. The temperature of the sulfur hexafluoride exiting heat exchanger 26 is typically different from the desired impregnation temperature. Because the temperature of sulfur hexafluoride is
This is because it is affected by the temperature of the tobacco material when mixed with the tobacco material in the interior. Therefore, sulfur hexafluoride is, for example, 1
Advantageously, it is heated to a temperature of 0 to 75°C. When this sulfur hexafluoride is delivered to the impregnator 12 through valve 28 and added to the tobacco material, the system (tobacco material and sulfur hexafluoride) reaches an equilibrium temperature of, for example, 10-45C.

When the impregnator 12 is filled with sulfur hexafluoride and reaches equilibrium temperature, the sulfur hexafluoride in the impregnator is preferably maintained in a liquid state so that the tobacco material is completely immersed in the sulfur hexafluoride. Advantageously, sufficient sulfur hexafluoride is provided to impregnate the sulfur hexafluoride. The pressure within the impregnator is at a level sufficient to maintain the sulfur hexafluoride in a liquid state, and is between about 15.5 and about 21
0.9 Kg/am2 (220-3000 ps i) or more, 24.6-175.8 Kg
A pressure of between 350 and 2500 psi is preferred.The temperature during impregnation is advantageously above about 10°C, preferably above about 20°C; Short soak times are used, from 1 to about 30 minutes, preferably from about 2 to about 15 minutes.

After a suitable period of impregnation, valve 30 is opened to allow the sulfur hexafluoride liquid to exit the impregnator 12 through the lower discharge conduit 31. Evaporation within the impregnator reduces the temperature within the impregnator. If a heating operation is used during the impregnation process, it is preferable to stop the deterioration of the impregnated tobacco material (tobacco material impregnated with sulfur hexafluoride) as liquid sulfur hexafluoride is discharged from the impregnator. , a discharge conduit 32 is also provided at the top of the impregnator 12 . By opening valve 33, the sulfur hexafluoride can be removed in gaseous form, thereby effecting the desired cooling of the impregnated tobacco material. Depending on the impregnation temperature and pressure, the upper gas discharge conduit 3
2 and the lower liquid discharge conduit 31, or only one conduit can discharge sulfur hexafluoride. Upper discharge conduit 3
The sulfur hexafluoride exiting through 2 is directed to a conventional recovery zone (not shown), where it is liquefied and returned to the feed tank 14.

To prevent large solid blocks of tobacco material from forming, excessive cooling should be avoided when discharging the sulfur hexafluoride from the impregnator.

The temperature of the tobacco material after discharging the impregnating agent (sulfur hexafluoride) is between about -30 and 30°C, preferably between about -25 and 20°C.
In such a temperature range, most preferably maintained between about -20 and 0<0>C, the tobacco material remains substantially pliable. By "substantially soft" is meant that there are no large frozen blocks of tobacco material that must be broken up prior to heat treatment. However, small clumps of tobacco material may occur and conventional cracking may be required.

The liquid sulfur hexafluoride removed from the impregnator 12 is transferred to the pump 3
4 through a conduit 31 and returned to the supply tank 14 after any necessary treatment to remove solids and other contaminants.

The impregnated tobacco material is then removed from the impregnator 12 and the entire patch of impregnated tobacco material is preferably passed through an insulated or cooled holding tank 38 and then into a heating or expansion zone 42.4B as described below. send. However, if desired, the impregnated tobacco material may be delivered directly from the impregnator 12 to the heating zone. The tobacco material discharged from the impregnator is
It typically contains from about 1 to about 20% by weight sulfur hexafluoride, preferably less than 15% by weight. Sulfur hexafluoride is injected into the tobacco material in an amount sufficient to subsequently expand the tobacco material at a temperature of about -40 to about 30°C, preferably less than 20°C, without the need to cool or insulate the tobacco material. up to several minutes, e.g. 2
Hold for ~10 minutes or more. Without wishing to be bound by theory, the reason why sulfur hexafluoride is retained in tobacco material is that the molecular size of sulfur hexafluoride is relatively large, and the diffusion rate of sulfur hexafluoride from impregnated tobacco material is slow. This is probably because it is relatively slow. It is not known whether sulfur hexafluoride exists primarily as a solid, as a gas, or as a solute within the cellular structure of tobacco wood. It is known that at atmospheric pressure, sulfur hexafluoride sublimates directly from the solid phase to the gas phase without passing through the liquid phase. Therefore, sulfur hexafluoride may exist as small solid particles within the cellular structure of the tobacco material, but in any case, the method of the present invention does not require a special cracking operation before heat treatment. It has been found that this process can be carried out without producing large solid blocks of tobacco material.

Referring again to FIG. 1, it is advantageous to pass the entire batch of impregnated tobacco material to a holding tank 38, which is preferably adiabatic and/or cooled. The holding tank 38 is
The holding tank 38 is associated with various recovery means (not shown) for recovering sulfur hexafluoride gas escaping from the impregnated tobacco material during this holding period, which is preferably kept sealed during storage of the tobacco material. can be provided. Such recovery means may, for example, be a gas conduit connected to the top or bottom of the holding tank 38 for continuous removal of sulfur hexafluoride gas during the holding period.

Impregnated tobacco material is directly rotated from the holding tank 3 days to the star valve 4
0 to the lower portion 42 of the heating or expansion zone. In the lower portion 42 of the expansion zone, the impregnated tobacco material mixes with a high velocity flow of hot gas supplied via a heater (not shown) and fan 44. Source 4 of this hot gas stream
6 can be provided upstream of the lower part 42 of the expansion zone to mix with the gas recycled through the expansion zone.

The tobacco material is conveyed upwardly through an expansion zone or expander 48 by the force of the hot gas stream and into a cyclone separator 50.
sent inward. During the transport of the tobacco material through the expansion zone 42, 48, the sulfur hexafluoride is rapidly volatilized from the tobacco material, resulting in a stable expansion of the tobacco material.

The degree of heating of the tobacco material within the expansion zone 48 is advantageously designed to be minimal in order to avoid compromising the tobacco flavor and/or to avoid excessive pulverization of the tobacco material. . To prevent excessive evaporation of moisture from the tobacco material and to prevent overheating of the tobacco material, it is preferred that the temperature in the expansion zone not exceed 300°C. However, as will be apparent to those skilled in the art, if desired,
Temperatures above 300°C can also be used. The expansion zone has a temperature of about 90 to about 250°C, preferably about 100 to about 2
It is advantageous to pass heated gas at a temperature of 25°C, most preferably from about 100 to about 200°C.

Within the cyclone separator 50, expanded tobacco material 54 falls to its bottom, is continuously discharged by a rotating star valve 52, and is collected onto conventional tobacco material recovery equipment, such as a conveyor 54.

If desired, the expanded tobacco material may be passed to a reconditioning zone and/or a sulfur hexafluoride recovery zone. The reconditioning step, as is well known to those skilled in the art, is a moisture treatment in which the expanded tobacco material is steamed or steamed to increase the moisture content of the expanded tobacco material to a desired range of 10-13%. Process with etc. Usually, the expanded tobacco material discharged from the separator 50 contains a small amount of residual sulfur hexafluoride, for example less than 0.15% by weight. Because sulfur hexafluoride is highly volatile under expansion conditions, it is often included in the expanded bulk tobacco material as it exits expansion zone 48, depending on the expansion temperature and the composition of the expanding bulk gas. The amount of sulfur hexafluoride present is less than 0.10% by weight.

A portion of the hot or bulk gas from separator 50 containing sulfur hexafluoride volatilized from the tobacco material is passed through conduit 60 to a sulfur hexafluoride separation zone or sulfur hexafluoride recovery zone 62;
Sulfur hexafluoride recovered in separation zone 62 is sent to sulfur hexafluoride supply tank 14. Another portion of the hot gas or bulking gas from separator 50 containing sulfur hexafluoride volatilized from the tobacco material is recycled through pipe 66 and used to expand the newly impregnated tobacco material. do.

FIG. 2 shows another preferred embodiment of the invention, in which tobacco material 10 is introduced into conditioning drum 102 by conveyor 13. FIG. Tobacco material is usually 12 to 1
It has a moisture content of 5% by weight, and as mentioned above, it can be subjected to treatments such as casing treatment in advance. The conditioning drum 102 has a pipe 104 for introducing steam or moisture into the drum. Steam or atomized water is jetted from a plurality of nozzles 106 extending from a pipe 104 within the drum to treat the tobacco material within the drum. The drum is rotated so that all tobacco particles are evenly exposed to steam or moisture. It is preferable that a plurality of blades (not shown) protrude from the inner wall surface of the rotating adjustment drum 102 so that the tobacco material is slowly stirred and treated with steam or water. The equilibrium moisture content of the tobacco material is 20
% by weight, preferably greater than 25% by weight, most preferably in the range of about 30 to about 40% by weight.

Moisture enhancement within conditioning drum 102 is performed to provide sufficient moisture within the tobacco material to later absorb microwave energy. More than 15% by weight, maximum 50%
It has been found that the presence of moisture up to % by weight promotes tobacco material bulking in the process of the present invention when microwave energy is used to heat the tobacco material. Especially when increasing the moisture content of tobacco material to about 25% by weight or more,
The humidification step is carried out at a point close to the subsequent impregnation step, e.g. a few minutes to several days before the impregnation step, preferably less than 24 hours before the relief step, thereby eliminating mold in the damp tobacco material during storage up to the impregnation step. can be prevented from growing.

The humidified tobacco material 108 is removed from the drum 102 and conveyed to the impregnator 12 by a second conveyor 110 and subjected to the impregnating process in the manner described above.The tobacco material removed from the impregnator 12 is then transferred to the impregnator 12 in the manner described above. to a holding tank 38 such as

Microwave treatment zone 12 for heating and expanding tobacco material from holding tank 38 via rotating star valve 40
Send to within 0. Microwave treatment zone 120 is preferably disposed within a sealed chamber 122 so that sulfur hexafluoride volatilized during the heat treatment can be recovered through conduit 124.

Microwave processing band 120 has a magnetron 126 that generates microwaves, which are carried through a waveguide 128. Impregnated tobacco material is conveyor belt 1
30 through a waveguide 128 during which it is exposed to microwaves for a few seconds to about 1 minute, e.g. 5 to 20 seconds, thereby heating the moisture in the tobacco material, thereby heating the hexafluoride in the impregnated tobacco material. Excess microwave energy that is not absorbed by the tobacco material through the waveguide 128 volatilizes the sulfur and expands the tobacco material.
It is absorbed by a conventional water load 133.

The thus expanded tobacco material 54 is transported to the conveyor 1.
30 from the microwave processing zone 120 and via a rotating star valve 134 to conventional conveying means such as a conveyor belt 58. The expanded tobacco material removed from microwave processing zone 120 has a moisture content in the preferred range of about 7 to about 13 weight percent. The expanded tobacco material can be passed to a conventional reconditioning zone (not shown) and/or a sulfur hexafluoride separation zone, but typically the tobacco material is about 0.1
Since it contains less than 5% by weight of residual sulfur hexafluoride, there is often no need to recover residual sulfur hexafluoride.

Any of a variety of commercially available microwave heaters can be used to microwave the sulfur hexafluoride impregnated tobacco material. 0.113-0.226 kg (1/4-172 l) per minute
When treating tobacco material in b), for example, 2375MH
4,5-5 with a frequency of z and an efficiency of about 50%
．． Tobacco material is placed in the microwave treatment zone of 5 Kw.
Allow it to be exposed for 2 seconds. The depth of impregnated tobacco material is 1
If it is expected that the tobacco material will be larger than 0 cm (several inches), ensure that all the tobacco material is uniformly exposed to the microwave energy and that there is no excessive It is advantageous to arrange stirring means in the microwave treatment zone for stirring the tobacco material during treatment so that compaction of the tobacco material is avoided. As such stirring means, for example, a microwave-transparent rotating drum disposed within the waveguide, a gas jet tube for fluidizing the tobacco material within the waveguide, or the like can be used. Of course, the power of the microwave heater is selected depending on the amount of tobacco material to be treated. The exposure period is also varied depending on the amount of tobacco material to be treated. However, in order to achieve maximum expansion of the tobacco material, it is preferable to treat it with high energy for a short period of time.

In the method of the present invention where the moisture level of the tobacco material is adjusted to a level higher than about 20% prior to the impregnation step, particularly when microwave heating is used, the moisture content is controlled by controlling the moisture within the tobacco material. For example, simply increasing the moisture content by spraying moisture at ambient temperature onto tobacco material at ambient temperature will not allow the moisture to penetrate into the cells of the tobacco material. If such tobacco material were to be microwaved after only a few hours, the moisture on the surface of the tobacco material would simply evaporate, providing sufficient heat to the sulfur hexafluoride inside the tobacco material. Therefore, it is not possible to achieve the maximum expansion of the tobacco material that would be achieved if the moisture was equilibrated within the tobacco material. If the tobacco material is stored, for example, for 24 hours, the moisture will be completely equilibrated throughout the cellular structure of the tobacco material. Alternatively, as shown in FIG. 2, the tobacco material may be treated with moisture in the form of steam to increase the rate of moisture penetration into the tobacco material.

As mentioned earlier, the impregnation process of the present invention can be carried out over a wide range of temperatures and pressures, and the time required for complete impregnation is short (both 19 and 19) depending on the temperature and pressure used in the impregnation process. Dependent.

That is, the higher the temperature and pressure, the shorter the time required for impregnation, and the lower the temperature and pressure, the longer the time required for impregnation. Generally, the impregnation temperature is about 20°C or higher and the pressure is 52.7 to 175.8 kg/cm2 (750
~2.500 psi), the impregnation time is approximately 15
Less than a minute is sufficient.

The preferred impregnation temperature range is from about 20°C up to 44-45°C.
It is ℃. At these preferred temperatures, impregnation occurs rapidly. The preferred pressure range is from about 70.3 to about 175
．． 8K g/cm” (1,000~2゜50
0 ps i), more preferably about 84.4 to about 14
0.6Kg/cm” (1,200~2,000ps
i).

Advantageously, the temperature and pressure conditions within the impregnation zone are maintained such that all the sulfur hexafluoride remains in the liquid phase. Operating in the liquid phase ensures sufficient contact of the sulfur hexafluoride with the tobacco material, thereby promoting rapid and complete impregnation. Additionally, operation in the liquid phase is believed to increase the amount of sulfur hexafluoride absorbed by the tobacco material. However, according to the present invention, the tobacco material can also be impregnated with sulfur hexafluoride at a temperature and pressure such that some or all of the sulfur hexafluoride is maintained in the gas phase. In that case, in order to achieve a sufficient amount of sulfur hexafluoride impregnated into the tobacco material and/or to ensure sufficient retention of sulfur hexafluoride by the tobacco material, the impregnation time is increased and/or the impregnation step It may be necessary to increase the amount of subsequent cooling.

Heating the impregnated tobacco material for expansion can also be accomplished by means other than those described above. For example, the impregnated tobacco material can be heated by radiant means to expand it. In another preferred embodiment, the tobacco material can be heated in a fluidized bed at a temperature of 90 to 300C. Fluidized beds are well known in the art and are described, for example, in US Pat. No. 4,270,553. Fluidized beds can be used with or without the addition of hot particles as described in the Copper patent.

Various additives can be used in the process of the invention if desired. For example, the tobacco material can be pretreated with various alcohols, such as ethanol, or other additives, such as pentane or hexane, to promote better bulking.

Although the present invention has been described in connection with various batch-type embodiments, tobacco Continuous flow methods can be used if the device is provided with sealing plates made of ceramic material that slide relative to each other in the loading and unloading mechanisms.

Specific examples of the present invention are shown below for a better understanding of the present invention, but the present invention is not limited thereto. ) is expressed as the percentage loss in weight of the tobacco when heated for 5 minutes at a temperature of 92° C. in a convection oven. Expanded tobacco material samples and untreated (unexpanded)
Measurements of the replenishment volume of the tobacco material samples were made using a specially designed automatic electronically controlled replenishment volume measuring instrument.

This replenishment volume measurement meter has a diameter of 92.075 mm (3
, 625 in) is slidably disposed within the cylinder and applies a pressure of 1.8 Kg/cm" (26 psi) to the cylinder-loaded tobacco material sample. These parameters This simulates the compression filling conditions that the tobacco material is subjected to during the formation of tobacco rods in manufacturing equipment. Moisture in the tobacco material affects the replenishment capacity values measured by this method.

Therefore, the moisture content of all expanded and unexpanded tobacco material samples was measured, and by taking these values into consideration, the corrected refilling capacity for each tobacco material sample was calculated according to a correction table prepared in advance. . The measured amount of unexpanded tobacco material sample was 100 g and the measured amount of expanded bulk tobacco material sample was 50 g.

The percent increase in replenishment capacity (%), or swelling rate, shown in each of the specific examples below is calculated by subtracting the corrected refill capacity of the unexpanded tobacco material sample from the corrected refill capacity of the expanded tobacco material sample, and then calculate the difference by subtracting the corrected refill capacity of the unexpanded tobacco material sample. It was calculated by dividing by the corrected replenishment capacity of the bulk tobacco material sample and multiplying the resulting quotient by 100.

A sample of tobacco shredded replenisher (shredded replenisher made of tobacco material) was impregnated with an impregnating agent (sulfur hexafluoride) in a pressure vessel for impregnation having a volume of 2β.

A thermocouple for measuring the temperature of the contents of the pressure vessel (chop refill) and a pressure gauge for indicating the pressure within the pressure vessel were installed inside the vessel near the top. Sulfur hexafluoride is introduced into the container through a valve provided at the bottom of the container, and after impregnating the shredded replenishment material with sulfur hexafluoride in the container, two valves provided at the top of the container are opened. The sulfur hexafluoride was then discharged from the container by allowing the gas inside the container to escape. A thermostatically controlled heating jacket was placed around the vessel to heat the interior of the vessel during the impregnation process.

To be more specific, as a sample of the above-mentioned chopping refill, 1
Several samples of tobacco material ranging from 30 to 170 g were prepared. These tobacco material samples were flakes of a blend of Burle Type tobacco that had been dried in hot air and was in the form of chopped refills. The moisture content of these samples was measured and recorded as shown in Table I. These samples were then impregnated with sulfur hexafluoride at the temperature and pressure shown in the table for the time shown in the table. After the impregnation step, the tobacco material was removed from the pressure vessel and heated using a hot air gun. The obtained swelling ratios (%) are as shown in Table I.

Table-U1 33.7 44 60
17 322 142.7
27 60 19 653
210.9 25 60
18 604 210.9 45
45 21.5 575
210.9 45 45 21
．． 5 72 In heating with a hot air gun, the hot air can only be directed to a limited area of the tobacco material, and the temperature of the hot air when it comes into contact with the tobacco material is only about 50 to 70°C, so uniform heating cannot be achieved. There are various drawbacks such as not being able to do so. Despite this, it was possible to achieve the considerable expansion of tobacco material as described above.

black! Using the apparatus of JL-Dan Example 1, a tobacco material sample weighing approximately 150 g was impregnated with an impregnating agent (sulfur hexafluoride).

These tobacco material samples were flakes of the same hot air dried Burle Type 1 tobacco blend used in Example 1. These tobacco samples impregnated with the impregnating agent were removed from the impregnating pressure vessel and prepared as shown in FIG. The average transport time from the impregnation step to the microwave treatment by hand to a similar microwave heater was about 1.5 to about 2.5 minutes.

The length of the waveguide, that is, the microwave processing band, was approximately 1.2 m. The tobacco material was carried out on a moving belt disposed through the waveguide, and the exposure time of the tobacco material into the waveguide was 9 to 12 seconds. The maximum power of microwave is 6. O
It is variable in the range up to KW. The power settings for this microwave heater are as shown in Table II. It was measured and recorded as follows.

In addition to the parameters shown in Table I above, the temperature inside the impregnating pressure vessel was recorded after the sulfur hexafluoride was removed by opening a valve at the top of the vessel. These temperatures are shown as discharge temperatures in Table II below.

Table-1 121, 12115-15204, 530225, 32
315-26274, 549325, 32415-19
Similar tests were conducted using the same tobacco samples, pressure vessels, and microwave heaters as in Example 2, but at different impregnation temperatures and pressures as shown in Table 2.

1 28.1 16 15 -30
25 5 422 28.1 24
15 -23 27 5 583
28.1 20 15 -27 35 5
．． 5 In Test 1 in Table 62, one small piece of frozen tobacco material was observed. It is believed that the microwave energy used was insufficient to completely heat the tobacco material as evidenced by the presence of such frozen debris.

Similar tests were conducted using the same tobacco material samples, pressure vessels, and microwave heaters as in Example 2, but at different impregnation temperatures and pressures as shown in Table IV.

It is considered that this was insufficient. Furthermore, it is believed that the increased bulkiness in Test 3 is due, at least in part, to the high moisture content.

Similar tests were conducted using the same tobacco material samples, pressure vessels, and microwave heaters as in Example 2, but at different impregnation temperatures and pressures as shown in Table V.

(Kg/cm”) ('C) (min) ('C)
(%) to W (%) 1 35.2 24
15 -23 19 4.5 392
35.2 27 15 -10 19
4.5 503 35.2 31 15
+ 3 25 5.0 71 In Test 1 in Table 1, some small frozen tobacco lumps were observed. Therefore, the microwave energy used is (Kg/cm2) ('C) (min) ('C) (%) KW (%)1 4 to completely heat the tobacco material.
2.2 25 15 -10 19 4
゜5 382 49.2 31 15
+5 25 4.5 47 In this test,
It is believed that the increase in swelling ratio is due to the moisture content of the tobacco material and the high impregnation temperature.

Similar tests were conducted using the same tobacco material samples, pressure vessels, and microwave heaters as in Example 2, but at different impregnation temperatures and pressures as shown in Table 1.

(Kg/cm”) (”C) (min) (”C)
(%) to W (%) 1 49.2 33
15 +3 19 5.5 462
49.2 25 15 -22
23.5 5.5 463 49.2
28 15 -13 36 5.
5 67 In this test, the increase in bulk factor can again be attributed to the moisture content of the tobacco material and the high impregnation temperature.

and alcohol 1 63.3 28 15 -18
19 5.5 532 63.3 31
15 -15 25 4.7 463
63.3 30 15 -14 32
Similar tests were conducted using the same tobacco material sample, pressure vessel, and microwave heater as in Example 2, but at different impregnation temperatures and pressures as shown in Table 1. .

Similar tests were conducted using the same tobacco samples, pressure vessels, and microwave heaters as in IL-U Example 2, but at different impregnation temperatures and pressures as shown in Table 3.

(Kg/cm”) (”C) (min) (’C)
(%) KW (%) 77.3 38 7
-3 25 5.0 7177.3 3
7 15 -5 35 5.5 7777
．． 3 36 15 -5 31 5.0
Similar tests were conducted using the same tobacco material samples, pressure vessels, and microwave heaters as in Example 2, but at different impregnation temperatures and pressures as shown in Table 1.

(Kg/cm2) (℃) (min) ('C)
(%) KW (%)1 105.5 39
7 -6 19 5.0 582
105.5 36 7 -10 25
5.0 743 105°5 39 7
-7 35 5.5 804 105
．． 5 35 7 -5 39 5.5
Similar tests were conducted using the same tobacco material samples, pressure vessels, and microwave heaters as in Example 2, but at different impregnation temperatures and pressures as shown in Table X.

Table-■ (Kg/cm2) ('C) (min) (''C)
(%) to W (%) 1 119.5 43
15 -1 19 4.5 572 1
19.5 44 7 -2 19
4.5513 119.5 38 7
-10 23 5.0 764 119.
5 41 7 -5 35 5.0
84 As is clear from the above table, when the moisture content of the tobacco material is low, the swelling rate is low.6 Using the same tobacco material sample, pressure vessel, and microwave heater as in Example 2, However, similar tests were conducted at different impregnation temperatures and pressures as indicated in the surface layer. In this example,
In order to observe the effect of moisture when using microwave energy, the moisture content was set to a low value.

Table-A 1 119.5 44 7 -1
12.54.0362 +19.5 41
15 -6 16 5.039From this example,
It can be seen that the moisture content of the buffing material has a large effect on the swelling ratio of the tobacco material.

Similar tests were conducted using the same tobacco material sample, pressure vessel, and microwave heater as in Example 2, but at different impregnation temperatures and pressures as shown in Table 3.

Similar tests were conducted using the same tobacco material samples, pressure vessels, and microwave heaters as in Example 2, but at different impregnation temperatures and pressures as shown in Table 2.

(g/cm”) (”C) (min) (℃)
(%) KW (%) 1 175.8 43
7 -6 21 5.0682 175
．． 8 41 7 +3 30 5
．． 0793 175.8 43 15
-2 53 5.0 894 175.8
43 15 -2 35 5.0 8
95 175.8 44 7 +2
35 5.0 84 (Kg/cm2) ('C
) (min) (℃) (%) KW (%)14
0.6 44 7 0 25
5.079140.6 36 7 -4
35 5.082140.6 41 7
-4 21.5 5.0 60 m The test was conducted using the same tobacco sample, pressure vessel, and microwave heater as in Example 2. However, after the impregnation process, the sulfur hexafluoride is discharged as a liquid from the bottom of the container,
As a result, during the subsequent depressurization step (removal of sulfur hexafluoride gas), the temperature of the impregnated tobacco material is considerably high because the cooling effect due to evaporation of sulfur hexafluoride is small. The results of this test are shown in the table below.

Table-! (Kg/am2) ('C) (min), ('C)
C%) to W(%)1 119.5 43
7 23 35 5.5602 11
9.5 43 7 21 35
5.562 As is clear from the table above, in this specific example,
Even when the tobacco material is removed from the impregnation zone (pressure vessel) at high temperature, sufficient sulfur hexafluoride is retained in the tobacco material during the transport time from the impregnation zone to the microwave heating zone for about 1 degree, so that , a sufficient swelling ratio is achieved.

The tobacco material samples were then impregnated with sulfur hexafluoride and weighed immediately after the impregnation step. The difference in weight before and after impregnation is due to absorbed sulfur hexafluoride. The impregnation pressure was approximately 119.5 kg/cm2. The impregnation temperature and time were approximately 40° C. and 7 minutes, respectively. The pressure vessel for impregnation was depressurized (sulfur hexafluoride gas was removed from the vessel)
The discharge temperature at that time was -5°C to 0°C. The tobacco material samples immediately after impregnation were impregnated with 1.2 to 2.8% by weight of sulfur hexafluoride. These tobacco samples were exposed to the atmosphere at 25°C, left for 1 minute, and then weighed again. The results showed that approximately 35-40% of the sulfur hexafluoride retained in the tobacco material was lost through evaporation to the atmosphere. However, sufficient swelling could be achieved by heating the impregnated tobacco samples.

A tobacco sample was impregnated with sulfur hexafluoride as in Example 2, and a tobacco sample was impregnated with sulfur hexafluoride as in Example 2. Impregnation pressure is 119.5kg
/am'', the impregnation temperature and time are -3, respectively.
The temperature was 90°C for 9 minutes. , the entire batch of impregnated tobacco material was heated in a fluidized bed.

Hot air at a temperature of 90° C. was used as the fluidizing medium of the fluidized bed and the tobacco material sample was heated for about 50 seconds. After this heat treatment, the refill capacity of the expanded tobacco material sample increased by 52%. The moisture content of the recovered expanded tobacco material is approximately 12% by weight.
Met.

Although the present invention has been described above in connection with embodiments, the present invention is not limited to the structure and form of the embodiments illustrated herein, and may be modified in various ways without departing from the spirit and scope of the present invention. It should be understood that many different embodiments are possible and that various changes and modifications may be made.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus according to a preferred embodiment of the invention for impregnating tobacco material with sulfur hexafluoride, discharging the tobacco material from the impregnation zone and sending it to a hot air zone for bulking treatment. shows. FIG. 2 is a schematic diagram of an apparatus according to another preferred embodiment of the invention for expanding tobacco material impregnated with sulfur hexafluoride in a microwave heating zone. 10: Tobacco material 12; impregnating zone (impregnator) 1626 sulfur fluoride (impregnating agent) source (tank) 22: heat exchanger 38: holding tank 48; expansion zone (expander) 50: separator 62: Sulfur hexafluoride separation zone 102: Conditioning drum 120: Microwave processing zone 126: Magnetron 128: Waveguide 133: Water load

Claims (1)

[Claims] 1. (a) at least 21.1 Kg/cm within the impregnation zone;
(b) impregnating tobacco material containing at least about 0.5% by weight of sulfur hexafluoride; (c) discharging the impregnated tobacco material in the swelling zone under conditions that cause the release of sulfur hexafluoride contained in the tobacco material and cause the tobacco material to bulk up; A method for expanding tobacco material, comprising: a heating step of heating; 2. The pressure in the impregnation zone is about 35.2 to about 210.9
2. The tobacco material swelling method according to claim 1, wherein the tobacco material is in the range of Kg/cm^2 (500 to 3,000 psi). 3. The pressure in the impregnating zone is about 52.7 to about 140.6
2. The tobacco material expanding method according to claim 1, wherein the tobacco material is expanded in a range of Kg/cm^2 (750 to 2,000 psi). 4. During the impregnation step, the temperature in the impregnation zone is at least about 0.
2. The method for expanding tobacco material according to claim 1, wherein the tobacco material is maintained at a temperature of .degree. 5. During the impregnation step, the temperature in the impregnation zone is at least about 1
The method for expanding tobacco material according to claim 1, characterized in that the temperature is maintained at 0°C. 6. The method of claim 1, wherein the impregnated tobacco material discharged from the impregnation zone contains at least about 1% by weight of sulfur hexafluoride. 7. The impregnated tobacco material discharged from the impregnating zone is approximately -
A method for expanding tobacco material according to claim 1, characterized in that the temperature is in the range of 30 to +30°C. 8. The impregnated tobacco material discharged from the impregnation zone is about -
A method as claimed in claim 1, characterized in that the tobacco material is expanded at a temperature in the range of 20 to about +20C. 9. Tobacco material swelling according to claim 1, wherein the tobacco material impregnated with the impregnating agent in the impregnation zone has an initial moisture content of about 15 to about 50% by weight. Method. 10. Tobacco material swelling according to claim 1, wherein the tobacco material impregnated with the impregnating agent in the impregnation zone has an initial moisture content of about 20 to about 35% by weight. Method. 11. The tobacco material according to claim 1, wherein the impregnated tobacco material discharged from the impregnating zone is heated in the bulking zone to a temperature in the range of about 100 to about 250°C. Bulking method. 12. The method of expanding tobacco material according to claim 1, characterized in that the impregnated tobacco material is heated by treating it with a hot gas within the expansion zone. 13. The method of expanding tobacco material according to claim 1, characterized in that the impregnated tobacco material is heated by exposing it to microwaves within the expansion zone. 14. The method for expanding tobacco material according to claim 1, characterized in that before the heating step, the impregnated tobacco material is sent to a holding zone and held in the holding zone for about 10 to about 30 seconds. . 15. (a) an impregnation step of impregnating the tobacco material with a bulking agent comprising liquid sulfur hexafluoride in an impregnation zone; and (b) at least about 0.5% by weight of sulfur hexafluoride; Approximately -3
(c) discharging the impregnated tobacco material from the impregnating zone in a substantially flexible state at a temperature of 0 to 35°C; A method for expanding tobacco material, comprising: a heating step of heating under conditions such that sulfur hexafluoride is released and the tobacco material is expanded. 16. The pressure within the impregnating zone is from about 15.5 to about 140.
16. A method of expanding tobacco material according to claim 15, characterized in that the temperature within the impregnating zone is at least about 10° C. 17. A method for expanding tobacco material according to claim 16, characterized in that the temperature is maintained at an elevated temperature.18. 16. The method of bulking tobacco material according to claim 15, characterized in that the tobacco material treated in the impregnation zone has an initial moisture content of about 20 to about 35% by weight. 16. The method of bulking tobacco material according to claim 15, characterized in that the bulking method of tobacco material within the swelling zone ranges from about 100 to 20%.
16. A method as claimed in claim 15, characterized in that the tobacco material is heated to a temperature in the range of about 250<0>C. 21. Claim 2, characterized in that the impregnated tobacco material is heated in the expansion zone by a stream of hot gas.
The method for expanding tobacco material according to item 0. 22. The method of expanding tobacco material according to claim 20, characterized in that the impregnated tobacco material is heated by treatment with microwaves within the expansion zone. 23. The method of bulking tobacco material according to claim 15, characterized in that the tobacco material is processed as a batch within the impregnation zone. 24, (a) at least about 21.1 Kg/cm^2 (3
(b) an impregnating step of immersing tobacco material in the form of a cut filler in liquid sulfur hexafluoride in an impregnation zone maintained at a pressure of 00 psi) and a temperature of about -10 to 45°C; Contains at least about 0.5% by weight of sulfur hexafluoride absorbed within the cellular structure of the material, and contains about -30%
(c) recovering impregnated tobacco material from the impregnation zone that can have a substantially flexible state at temperatures of from about 35° C. to about 35° C.;
heating at a temperature of 0.000C, thereby releasing sulfur hexafluoride from the tobacco material and expanding the tobacco material by at least 50%. 25. The tobacco material in the form of cut refill treated in the impregnation zone has a moisture content of about 16 to about 50% by weight. The tobacco material swelling method described above. 26. The method of claim 25, wherein the moisture content is in the range of about 20 to about 35% by weight. 27. The pressure within the impregnating zone is about 52.7 to about 140.
26. The tobacco material expanding method according to claim 25, wherein the tobacco material is expanded at a pressure of 6 kg/cm^2 (750 to 2,000 psi). 28. During the impregnation step, the temperature in the impregnation zone is at least 1
28. The method for expanding tobacco material according to claim 27, wherein the temperature is maintained at 0°C or higher. 29. The method of claim 28, wherein the impregnated tobacco material discharged from the impregnation zone has a temperature of less than about 20<0>C. 30. The tobacco material of claim 29, wherein the impregnated tobacco material discharged from the impregnation zone has a sulfur hexafluoride content of at least about 1.0% by weight. Bulking method. 31. (a) treating the tobacco material in a moisture conditioning zone to increase its moisture content by about 20 to about 50% by weight; and (b) treating the treated tobacco material in an impregnation zone. (c) impregnating the impregnated tobacco material in a substantially pliable state and including at least about 0.5% by weight of sulfur hexafluoride in the impregnated zone; (c) heating the impregnated tobacco material in a microwave heating zone under conditions so as to release the sulfur hexafluoride contained in the impregnated tobacco material and cause the tobacco material to swell. A tobacco material swelling method comprising: 32. (a) an impregnating step of impregnating the tobacco material within the impregnation zone for at least about 1 minute under conditions sufficient to penetrate the tobacco material with a bulking agent comprising liquid sulfur hexafluoride; and (b) at least about (c) discharging from the impregnation zone impregnated tobacco material containing 0.5 wt. heating the impregnated tobacco material in a bulking zone under conditions that cause the release of sulfur hexafluoride contained in the tobacco material and cause the tobacco material to expand by at least about 50%; Tobacco material expansion method. 33. The method of claim 32, wherein the sulfur hexafluoride is maintained in a substantially liquid phase within the impregnation zone during the impregnation period of at least about 1 minute. 34. The tobacco material of claim 33, wherein the impregnated tobacco material discharged from the impregnation zone has a sulfur hexafluoride content of at least about 1.0% by weight. Bulking method. 35. During the impregnation time of about 1 minute or more, the pressure in the impregnation zone is set at about 21.1 to about 140.6 kg/cm^2 (30
35. The method of expanding tobacco material according to claim 34, wherein the tobacco material is expanded in a range of 0 to 2,000 psi. 36. The method of bulking tobacco material according to claim 35, wherein the tobacco material impregnated with the impregnating agent in the impregnation zone has a moisture content of about 16 to about 35% by weight. . 37. The method of claim 36, wherein the tobacco material is heated within the expansion zone to a temperature of less than about 300°C. 38. The method of bulking tobacco material according to claim 37, characterized in that the tobacco material is processed in batch mode within the impregnation zone. 39. The pressure in the impregnation zone is maintained at a pressure greater than about 750 psi during the impregnation time of about 1 minute or more. Tobacco material expansion method. 40. The method of claim 39, wherein the tobacco material is impregnated with an impregnation agent within the impregnation zone for less than about 15 minutes. 41, consisting of 100 parts by weight of tobacco material in the form of a shredded supplement, containing not less than about 0.5% by weight of sulfur hexafluoride, substantially pliable and in a substantially unextracted state. Intermediate tobacco products located in.