EP4140321B1

EP4140321B1 - Reconstituted tobacco and process for manufacturing reconstituted tobacco

Info

Publication number: EP4140321B1
Application number: EP22191728.9A
Authority: EP
Inventors: Xu Wang; Wentao ZHAO; Jing Yang; Qi Feng
Original assignee: Shanghai Tobacco Group Co Ltd; Shanghai New Tobacco Products Research Institute Co Ltd
Current assignee: Shanghai Tobacco Group Co Ltd; Shanghai New Tobacco Products Research Institute Co Ltd
Priority date: 2021-08-25
Filing date: 2022-08-23
Publication date: 2024-06-05
Anticipated expiration: 2042-08-23
Also published as: CN115721040A; MY204446A; EP4140321C0; MA61987B1; EP4140321A1

Description

TECHNICAL FIELD

The present invention relates to the field of tobacco, and in particular relates to a heat-not-burn reconstituted tobacco and a process for manufacturing the reconstituted tobacco.

BACKGROUND

By comparing smoking of heat-not-burn tobacco products with smoking of traditional cigarettes, both smoked tobaccos include cut tobacco, tobacco fragments, tobacco particles, tobacco waste, and the like. However, a heat-not-burn type heating tobacco product is smoked with a lower temperature at a tobacco site, which only heats the tobacco and does not burn the tobacco, so that tar production can be greatly reduced. Particularly for an electric heating type heat-not-burn smoking set, the temperature control of tobacco product heating is more precise, which can be more effective in avoiding excessive temperatures of a smoke-generating article, and preventing the overflow of more harmful substances.
However, compared with traditional combustion-type smoke-generating articles, heat-not-burn smoke-generating articles still have a problem of insufficient smoke-generating amount when being electrically heated. In addition, the mechanical strength of current heat-not-burn smoke-generating substrates remains to be improved. Patent documents CA3135252A1 , CA2875167A1 and CZ291606B6 disclose reconstituted tobacco products that are used in devices for heating tobacco or in cigarettes.

SUMMARY

The present invention aims to provide a reconstituted tobacco to improve the smoke-generating amount and stability of the reconstituted tobacco.
It is disclosed a reconstituted tobacco, having a mass per unit area of 100-190 g/m², a thickness of 0.13-0.18 mm and a density of 700-1400 mg/cm³, wherein a mass percentage of an atomization agent in the reconstituted tobacco is 15-30% and wherein a mass percentage of a tobacco matter in the reconstituted tobacco is 65-80%.
The mass per unit area (represented by δ) in the present invention refers to the mass per unit area on the upper or lower surface of the reconstituted tobacco, and can be obtained through calculation by weighing the mass (represented by m) of the reconstituted tobacco, and measuring the upper or lower surface area (represented by S) of the reconstituted tobacco under the mass, wherein a calculation formula is shown in the following formula (1): $δ = m/S$
The thickness of the reconstituted tobacco refers to a dimension between the upper and lower surfaces of the reconstituted tobacco, and can be obtained by measurement. The density of the reconstituted tobacco can be obtained through calculation by measuring the mass and volume of the entire reconstituted tobacco prior to cutting into shreds.
For heat-not-burn smoke-generating articles, there are often problems of insufficient smoke-generating amount and poor smoking sense. A main reason is that heat-not-burn reconstituted tobacco has poor heat conduction effects when being electrically heated. In addition, a proportion of an atomization agent as a smoke-generating component is also an important factor for the smoke-generating effect.
A combination of the mass per unit area, thickness, density and atomization content of the reconstituted tobacco of the present invention can advantageously improve the heat conduction properties of the reconstituted tobacco, and enables liquid components of the reconstituted tobacco to be controlled within a reasonable range. When the reconstituted tobacco of the present invention is rolled into a smoke-generating body, the increase in water content can be slowed down, ensuring quality stability of a formed smoke-generating body, resulting in a more excellent smoke-generating effect of the final smoke-generating body.
The density of the reconstituted tobacco indicates the compactness of smoke-generating components of the reconstituted tobacco in a three-dimensional space, which has a large impact on thermodynamic performance. An increase in mass per unit volume means that there are fewer pores inside the sheet and less air is contained. Air has a much lower thermal conductivity than a general solid, so the sheet with fewer pores has a higher thermal conductivity, and conducts heat quickly, facilitating the reconstituted tobacco to absorb and transfer more heat when heated. However, the excessive density of the reconstituted tobacco can result in an increase in specific heat capacity, and even if more heat is absorbed, the temperature rise of the sheet is small, and it is difficult to release smoke. Thus, in the present invention, the density of the reconstituted tobacco is controlled to be 700-1400 mg/cm³.
The thickness of the reconstituted tobacco directly affects its processability resistance during subsequent processing of cigarettes. When the reconstituted tobacco with a large thickness is bent under stress, its folding resistance is reduced due to a large difference in the stress change between its two surfaces. In particular in rolled reconstituted tobacco or slurry processed reconstituted tobacco with low fiber content, if the thickness is too large, then when a sheet is processed into shreds or when cut reconstituted tobacco is rolled into cigarettes, it is easy to cause the fracture of the cut reconstituted tobacco, which affects the length of the cut reconstituted tobacco, produces more broken cut tobacco and tobacco waste, and in turn affects the filling properties of the cut reconstituted tobacco, and the integrity of the end face of the cut tobacco of the cigarette, resulting in reduced stability of the reconstituted tobacco, and meanwhile, also affecting the smoke-generating effects of the entire rolled smoke-generating body due to unguaranteed filling properties. Moreover, the thickness of the reconstituted tobacco also affects the degree of curling after the reconstituted tobacco is cut into shreds, which in turn affects the filling properties of the cut reconstituted tobacco. The smaller the thickness, the easier it is to cause curling after cutting into shreds, the elasticity increases, the filling force increases during rolling, and the filling weight per unit volume decreases, resulting in a decrease in the weight of the smoke-generating substrate in the cigarette, and the corresponding cigarette has too small smoking resistance, which makes it feel hollow and poor when smoking. The absolute content of a tobacco matter and an atomization agent is insufficient, which affects the smoke-generating amount of cigarettes and is not conducive to presenting a strong aroma. In the present invention, according to the requirements of density, the thickness of the reconstituted tobacco is set to 0.13-0.18mm, which can avoid the increase of the curvature after the reconstituted tobacco is cut into shreds, while ensuring folding resistance.
When the reconstituted tobacco is manufactured, the water content of the reconstituted tobacco is controlled. This is because moisture is detrimental to smoke formation and gaseous water produced after the reconstituted tobacco is heated affects the atomization effect of the atomization agent. Although the current manufacturing method has controlled the water content within a reasonable range before rolling the reconstituted tobacco, the reconstituted tobacco itself will absorb a certain amount of moisture in a short time before it is packaged, resulting in excessive water content of the smoke-generating body when it is rolled into a smoke-generating body.
The mass per unit area of the reconstituted tobacco indicates the compactness of smoke-generating components of the reconstituted tobacco on a plane. The inventors found through research that the mass per unit area on a flat surface has a greater influence on the rate of water absorption. If the reconstituted tobacco has a lower mass per unit area, higher in-plane filling power and roughness are caused, and the water absorption capacity is higher, which in turn affects the rate of water absorption. In addition to the atomization agent contained in the reconstituted tobacco, the water absorption capacity in the plane of the tobacco is further increased. On the other hand, if the mass per unit area of the reconstituted tobacco is too large, the effect of reducing the rate of water absorption is diminished, and it is also unfavorable for the release of nicotine and smoke. Through many experiments and explorations by the inventors, it is found that under the above-mentioned density and thickness range of the invention, the reconstituted tobacco of which the mass per unit area is controlled at 100-190g/m² has obvious smoke-generating effects and good stability.
In addition, in order to match the above mass per unit area, density and thickness of the reconstituted tobacco, the mass percentage of the atomization agent in the reconstituted tobacco needs to be controlled at 15-30%. Too low content results in insufficient smoke-generating amount, and too high content results in a higher specific heat capacity of cigarettes, and a slow temperature rise and also a large smoke volume cannot be achieved. In addition, too high content of the atomization agent can also accelerate the water absorption rate of the reconstituted tobacco.
In addition, in the present invention, by setting the mass per unit area of the reconstituted tobacco to be 100-190 g/m², the thickness to be 0.13-0.18 mm and the density to be 700-1400 mg/cm³, it is also beneficial to improve the tensile strength, thereby enabling a reduction in the production of broken cut tobacco.
Preferably, the reconstituted tobacco has a density of 900-1100 mg/cm³, and a better smoke-generating effect is achieved.
Preferably, the reconstituted tobacco has a mass per unit area of 150-190 g/m², and the water absorption rate of the reconstituted tobacco within this range is low, and generally the water content of the tobacco does not significantly change prior to rolling during production, leaving sufficient time for the rolling process of cigarettes. In addition, the nicotine release rate of the reconstituted tobacco within this mass per unit area range is significantly improved.
For the reconstituted tobacco of the present invention, it is more appropriate to control the water content of the reconstituted tobacco to be 4-8%. It is found through research that the higher the water content in the smoke formed is after the reconstituted tobacco is heated, the weaker the smoke visual effect of the aerosol formed is. If the water content of the reconstituted tobacco is too low, its brittleness will be enhanced and its folding resistance will be reduced. In the processing process, when the reconstituted tobacco is subjected to a force perpendicular to the plane of the sheet, it is easy to break, resulting in the increase of broken cut tobacco content. Preferably, the mass percentage of the atomization agent in the reconstituted tobacco is 20-25%. The reconstituted tobacco within this range can maintain sufficient smoke-generating amount while still maintaining significant smoke-generating amount after a number of puffs without making the cigarettes too moist. The atomization agent includes, but is not limited to, one or more of glycerol, and propylene glycol, more preferably the atomization agent employs glycerol. When glycerol is used as the atomization agent, less peculiar smell is produced.
The mass percentage of a tobacco matter in the reconstituted tobacco is 65-80%. The percent mass of the tobacco matter in the reconstituted tobacco directly affects the sensory quality of the reconstituted tobacco during smoking, and the content of the tobacco matter being 65-80% is conducive to the formation of smoke with strong tobacco flavor. The tobacco matter may be different types of tobacco raw materials such as flue-cured tobacco, air-cured tobacco, sun-cured tobacco, open-flame flue-cured tobacco, aromatic tobacco, and the like.
Preferably, the tobacco matter used may be de-stemmed leaves, and stems of the tobacco. More preferably, the tobacco matter used preferentially selects de-stemmed leaves, because the lignin content is less and the aroma substances are more in the leaves, which is advantageous for enhancing the smoking taste of the reconstituted tobacco.
In addition, the reconstituted tobacco may also include essence or spices. The essence and spices can be used as a supplement of aroma substances, and can be added according to the sensory quality design goal, generally 0-15%, to increase the tobacco flavor or give other flavor characteristics to the reconstituted tobacco.
The tensile strength of the reconstituted tobacco of the present invention can reach 0.4 kN/m or above. In addition, a water content increment within 1h is less than 0.6% at 22°C, and 65 RH%. Ensuring a tensile strength of 0.4 kN/m or above can significantly reduce the generation of broken cut tobacco. Further, the reconstituted tobacco of the present invention has a tensile strength of 0.4-0.5 kN/m. In general, it takes about an hour or above from unpacking and feeding of cut tobacco to the completion of cigarette rolling, whereas the reconstituted tobacco of the present invention has a water content increment of less than 0.6% within 1h after being unpacked under the temperature and humidity (22°C, 65 RH%) environment in a general cigarette production workshop, which is very beneficial to the control of the water content of cigarettes.
The present invention provides a smoke-generating body, including the reconstituted tobacco. The smoke-generating body has a better smoke-generating amount when used, debris is not likely to fall off at the end of the smoke-generating body, and the smoking experience is good.
The present invention also provides a process for manufacturing the reconstituted tobacco, including steps of preparing tobacco raw materials into tobacco powder; mixing water, an atomization agent and an adhesive to prepare a wet material; mixing the tobacco powder with the wet material to prepare a formed sheet; and drying the formed sheet to obtain the reconstituted tobacco. Wherein preparing the tobacco raw materials into the tobacco powder includes incoming material blending, impurity removal, moisture conditioning, coarse crushing, and fine grinding.
Incoming material blending refers to blending incoming materials well according to a formula proportion, and can be realized by quantitative feeding and stirring using a belt scale. Impurity removal refers to removal of non-tobacco substances such as metal, plastic, etc. in raw materials, and can be achieved by a metal detector or winnowing. Moisture conditioning means that ultra-fine tobacco powder should have a water content of 12% or less before crushing, if the water content is too high, the brittleness of the tobacco is insufficient, which is not conducive to crushing, if the crushing time is too long, it is easy to heat the tobacco material, and then the original flavor of the tobacco is changed. For example, there will be a burnt taste, which makes the sensory quality of the reconstituted tobacco poor. When an incoming tobacco sheet or stem has a moisture content of 12% or above, the incoming tobacco sheet or stem should be dried by drying equipment such as an oven or a drying barrel to reduce the moisture content to 12% or less, and then crushed. The crushing process includes coarse crushing and fine grinding to make the dry material into ultra-fine tobacco powder.
Preparing the wet material refers to uniformly mixing raw materials necessary for the formation of the reconstituted tobacco according to a certain proportion, mainly including mixing the water, the atomization agent and the adhesive. Generally, a stirring tank with a strong stirring function can be used for strong stirring to fully mix the three.
The dry material and the wet material are stirred by a mixer to ensure uniform mixing, and then prepared into a formed sheet. Generally, if a forming process adopts a rolling method, it is necessary to realize a solid mass or granular form after the dry material and the wet material are mixed, and then roll forming is carried out. If a forming process adopts a casting method, a mixture of the dry material and the wet material needs to be in a fluid state, which is convenient for casting.
The formed sheet formed after casting or rolling is further dried to obtain the reconstituted tobacco as a smoke-generating substrate for electrically heated cigarettes.
The manufacturing process of the present invention may manufacture the reconstituted tobacco that meets the requirements of parameters such as the density, mass per unit area, thickness, etc. of the present invention through selection of tobacco raw materials, adjustment of raw material ratios, adjustment of process parameters, etc. and the corresponding process parameters may be adjusted according to the actual production situation.

DETAILED DESCRIPTION

The embodiments of the present invention will be described below with reference to specific examples, and those skilled in the art can easily understand other advantages and effects of the invention from the contents disclosed in this specification.
In order to make the objects, technical solutions and advantages of the present invention become clearer, the embodiments of the present invention are further described in detail below.
In the following examples and comparative examples, the reconstituted tobacco is manufactured by using a similar process, including dry material preparation, wet material preparation, mixing of a dry material and a wet material, forming and drying.
Specific details include:
the dry material preparation includes incoming material blending, impurity removal, moisture conditioning, coarse crushing, and fine grinding.
Incoming material blending refers to blending incoming materials well according to a formula proportion, and can be realized by quantitative feeding and stirring using a belt scale. The tobacco raw materials employed in the following examples and comparative examples are the same.
Impurity removal refers to removal of non-tobacco substances such as metal, plastic, etc. in raw materials, and can be achieved by a metal detector or winnowing.
Incoming material moisture conditioning means that ultra-fine tobacco powder should have a water content of 12% or less before crushing, and the incoming material should be dried by drying equipment such as an oven or a drying barrel to reduce the moisture content to 12% or less.
Wet material preparation refers to uniformly mixing raw materials necessary for the formation of the reconstituted tobacco according to a certain proportion, mainly including mixing the water, the atomization agent and the adhesive. Generally, a stirring tank with a strong stirring function can be used for strong stirring to fully mix the three. The content of the atomization agent is formulated according to the design of the different examples and comparative examples.
Mixing of the dry material and the wet material refers to stirring the dry material and the wet material by a mixer until dry and wet material distribution is uniform, ensuring uniform mixing. Generally, if a forming process adopts a rolling method, it is necessary to realize a solid mass or granular form after the dry material and the wet material are mixed, and then roll forming is carried out. If a forming process adopts a casting method, a mixture of the dry material and the wet material needs to be in a fluid state, which is convenient for casting. The parameters of the mass per unit area, thickness, density and water content of the reconstituted tobacco in the following examples and comparative examples can be adjusted according to a specific forming process.
The formed sheet formed after casting or rolling is further dried to obtain the reconstituted tobacco in the following examples and comparative examples. The reconstituted tobacco is then rolled by using a same process to form a smoke-generating body, and the smoke-generating body is then tipped with a filter to form a heat-not-burn cigarette. The reconstituted tobacco in the following examples and comparative examples is manufactured by using a same rolling process, and the heat-not-burn cigarettes are formed by using a same cigarette manufacturing process. The smoke-generating body has a length of 13.5 mm and a diameter of 7.8 mm.
In the following examples and comparative examples, the mass per unit area of the reconstituted tobacco can be obtained through calculation using the above formula (1) by measuring its mass before cutting the reconstituted tobacco into shreds, and calculating the area of its upper or lower surface; the density of the reconstituted tobacco may be obtained through calculation according to a density formula by measuring its mass before cutting the reconstituted tobacco into shreds, and calculating its volume; and the thickness of the reconstituted tobacco may be obtained by measurement.
The water content of the reconstituted tobacco in the following examples and comparative examples is measured by prior known gas chromatography. The water content increment within 1h at 22°C and 65 RH% is determined by a weighing method, namely weighing a certain weight of reconstituted tobacco, placing the weighed reconstituted tobacco in a glass dish, placing the glass dish with the reconstituted tobacco in a constant-temperature constant-humidity chamber at 22°C and 65 RH% for moisture absorption, weighing after 1h, a weight gain portion being a weight of absorbed moisture, calculating the water content after moisture absorption, and subtracting the water content before moisture absorption to obtain the water content increment. By a sieving method, the percentage of short cut tobacco of 4mm or less produced by cut tobacco making is measured.
The total smoke particulate matter, nicotine mobility, smoking resistance, and smoke volume are determined by electrically heating heat-not-burn cigarettes in the following examples and comparative examples, and detecting the time required for the cigarettes from room temperature to 300°C. The total smoke particulate matter is determined by a weighing method using a Cambridge filter to capture particulate matters of each cigarette, the Cambridge filter weight difference being the total particulate matter weight. The nicotine mobility is determined by separately detecting the nicotine content in the smoke captured by the Cambridge filter and the nicotine content of cut reconstituted tobacco of each cigarette by using gas chromatography, a ratio of the two being the nicotine mobility; smoking resistance is determined by YC/T28.5, Testing of Cigarette Physical Properties, which is an industry standard in China; and the smoke volume is determined by electrically heating cigarettes manufactured from the smoke-generating body using a same smoking set and same heating conditions, and professional smoking evaluators are organized to evaluate and summarize the puff-by-puff smoke effects.
The following is a detailed description in combination with the examples and comparative examples in Tables 1 and 2:
in the evaluation of the smoke volume in the following examples and comparative examples, the order of the smoke volume from large to small is: large > relatively large > relatively small > small.
The reconstituted tobacco is made into cigarettes for testing, and it can be seen from Table 2 that in Examples 1 to 6, a relatively large smoke volume is achieved, the content of particulate matters in the smoke is higher, and the nicotine mobility is higher. In comparative examples 1 to 5, because a combination of various parameters does not meet the requirements, the total smoke particulate matter, nicotine mobility and smoke volume are low.

In comparative example 1, because the mass per unit area is too large and the thickness is large, the total surface area of cut reconstituted tobacco is too small under the same filling weight, that is, the release surface of the atomization agent is small, resulting in small smoke volume of the cigarette; in comparative example 2, due to its small thickness, poor elasticity of the cut reconstituted tobacco and insufficient support capacity, it is easy to fill too tightly in the process of rolling cigarettes, the smoking resistance is too large, and smoking is not smooth, resulting in low total smoke particulate matter, low nicotine mobility, low smoke volume, etc. In comparative example 3, because the density is too low, the inside of the reconstituted tobacco is relatively loose, when the cigarette is rolled, a fixed volume of a smoke-generating section of the cigarette is filled with less tobacco matters, resulting in insufficient ability to form smoke. In comparative example 4, due to its low mass per unit area and low thickness, the cut tobacco has a large specific surface area, it is easy to absorb moisture during the rolling process, the water content of cigarettes is increased, which affects the smoke volume, and in addition, the content of the atomization agent is low, which finally leads to a small smoke volume. In comparative example 5, due to its low thickness, large surface area, easy moisture absorption, too high density, poor toughness of cut tobacco, intolerance to processing, and easy breaking to form broken cut tobacco, high smoking resistance and poor smoking are caused. In addition, the content of the atomization agent is too high, and the specific heat capacity of the atomization agent is high, resulting in a slow heating rate when the cigarette is heated. Multiple reasons make the smoke volume low.

Table 1 Reconstituted tobacco parameters

Serial number	Mass per unit area/(g/m²)	Thickness/m m	Density/(mg/cm³ )	Atomizatio n agent content/%	Tobacco matter content/%	Water content/%
Example 1	150	0.14	1071	20	71.5	6
Example 2	160	0.16	1000	24	67.5	6
Example 3	152.6	0.14	1090	18	73	6.5
Example 4	190	0.18	1056	26	67.3	4.2
Example 5	106.3	0.13	818	20	70	7.5
Example 6	185	0.17	1088	20	71.5	6
Comparative Example 1	236.9	0.23	1030	25	67.5	5
Comparative Example 2	140	0.12	1167	27	59.9	10.6
Comparative Example 3	121.8	0.18	677	20	65.5	12
Comparative Example 4	90	0.11	818	12	82.5	3
Comparative Example 5	180	0.12	1500	38	54.5	5

Table 2 Reconstituted tobacco and formed smoke-generating body performance

Serial number	Time required for temperatu re rise from room temperatu re to 300°C/s	Water content increme nt within 1h at 22°C and 65 RH%/%	Percenta ge of short cut tobacco of 4mm or less produce d by cut tobacco making/ %	Smoking resistance/Pa	Total smoke particulate matter/mg	Nicotine mobility/%	Smoke volume
Example 1	15	0.4	10	900	45.6	37	Large
Example 2	16	0.38	11.7	890	42	35.2	Large
Example 3	15	0.4	10.5	910	45	38	Large
Example 4	17	0.35	12	920	47.3	40.4	Relative ly large
Example 5	12	0.59	8	850	40	34.3	Large
Example 6	16	0.35	11.8	920	44.4	40.2	Relative ly large
Comparative Example 1	16	0.33	16.8	920	42	27	Small
Comparative Example 2	19	0.45	11	1080	25.9	20	Relative ly small
Comparative Example 3	14	0.4	7	830	23	18	Relative ly small
Comparative Example 4	16	0.65	6	800	34	28.5	Relative ly small
Comparative Example 5	22	1.5	19	1150	23	25	Relative ly small

Claims

A reconstituted tobacco, having a mass per unit area of 100-190 g/m², a thickness of 0.13-0.18 mm and a density of 700-1400 mg/cm³, wherein a mass percentage of an atomization agent in the reconstituted tobacco is 15-30%, and wherein a mass percentage of a tobacco matter in the reconstituted tobacco is 65-80%.
The reconstituted tobacco according to claim 1, having a density of 900-1100 mg/cm³.
The reconstituted tobacco according to claim 1 or 2, having a mass per unit area of 150-190 g/m2.
The reconstituted tobacco according to any one of the previous claims, having a water content of 4-8%.
The reconstituted tobacco according to any one of the previous claims, wherein the mass percentage of the atomization agent in the reconstituted tobacco is 20-25%.
The reconstituted tobacco according to any one of the previous claims having a tensile strength of 0.4 kN/m or above.
The reconstituted tobacco according to any one of the previous claims, wherein the percentage water content increment within 1 hour after being unpacked is less than 0.6% when monitored in a constant-temperature constant-humidity at 22°C and 65 RH% in a general cigarette production workshop.
A smoke-generating body, comprising the reconstituted tobacco according to any one of claims 1 to 7.
A process for manufacturing the reconstituted tobacco according to any one of claims 1 to 7, comprising steps of:
preparing tobacco raw materials into tobacco powder;

mixing water, an atomization agent and an adhesive to prepare a wet material;

mixing the tobacco powder with the wet material to prepare a formed sheet; and

drying the formed sheet to obtain the reconstituted tobacco.
The process for manufacturing the reconstituted tobacco according to claim 9, wherein preparing the tobacco powder comprises adjusting a water content of the tobacco raw materials to 12% or below, followed by crushing.