EP3629775B1

EP3629775B1 - An improved method for treating stems and/or leaf veins of tobacco

Info

Publication number: EP3629775B1
Application number: EP18732159.1A
Authority: EP
Inventors: Mario Martin; Francesco MATARAZZO
Original assignee: Comas SpA; Magg Consulting SRL
Current assignee: Comas SpA; Magg Consulting SRL
Priority date: 2017-05-29
Filing date: 2018-05-28
Publication date: 2023-01-25
Anticipated expiration: 2038-05-28
Also published as: WO2018220509A1; CN110678089A; KR20200014360A; IT201700058373A1; EP3629775A1

Description

The present invention relates to an improved method for treating, in particular by the expansion treatment, the stems of tobacco and/or the leaf veins of tobacco, preferably of those discarded by cigarette making machines.
Generally, the stems are the least valuable part of the mixture in the production of cut tobacco. In particular, they are different from the leaves both for the physical structure and for the chemical composition and therefore, they are to be treated in such a manner as to make the specific density and shape thereof similar to the features of the leaves.
In the current art, the processes for improving the quality of the stems provide a moistening step of the stems (to moisture ranging from 30 to 34% and temperature ranging from 50 to 60°C) and a successive laminating step in which the distance between the laminating rollers is of 0.4 to 0.8 mm in order to transform the stems into a structure similar to a leaf, also in terms of density; then there is provided a cutting step of the stems with a cutting width w_c = 0.1 to 0.2 mm.
A process is also known which provides - before the laminating and cutting steps - a washing step in water of the whole stems in order to extract the undesired products and improve the organoleptic qualities of the combustion products.
In any case, the cut stems are then subjected to a step of drying and/or expansion, which may occur in different types of dryers (rotating cylinders, fluid beds or flash dryers); in particular, the expansion of the stems may be obtained in such dryers.
Finally, the use is known of the stems and the leaves in the production of reconstituted tobacco. In particular, this production process provides the grinding of the stems and the leaves and a successive mixing of the powders with water and other substances, which are of natural origin or synthesis, and with chemical thickeners and additives so as to form a tobacco leaf having chemical-physical features similar to those of the leaves.
The cut material of the stems generated according to one of the aforesaid processes has physical sizes and features which are different from the cut material obtained from the leaves.
In particular, such sizes and features of the cut material of the stems limit and/or prevent the use thereof in the production of cigarettes having smaller diameter than 6.5 mm and in the cut tobacco generally used for hand-rolled cigarettes.
The term winnovers or winnowers in tobacco processing and generally in the production process of cigarettes, cigars and cut tobacco usually and generally identifies those parts of tobacco which cannot be used (mainly consisting of the aforesaid stems but also of the leaf veins) which are eliminated by the cigarette making machine.
Rejects as winnovers (or winnowers) in cigarette production represents about 2% of the total weight of the tobacco used.
Currently, the winnovers (or winnowers) generally are moved away from the production process as rejects which are not used again or are ground and added to the tobacco powder used for making reconstituted tobacco. In any case, the winnovers (or winnowers) are not currently used to obtain cut tobacco.
WO2016/005830 describes a method for treating stems of tobacco alone which, in sequence, provides:

a moistening step of the stems by means of adding water,
a mixing step of the moistened stems with a vegetable powder consisting of tobacco and/or other substances (cloves and/or vanilla and/or coffee and/or cinnamon),
a laminating step of the moistened stems mixed with the vegetable powder so as to induce the intrusion of the latter within the tissue of the stems themselves,
a drying step which, by inducing the contraction of the volume of the stems, allows the vegetable powder to be retained within the matrix of the stems themselves.

In essence, the method of WO2016/005830 specifically provides the addition of vegetable powder, after the moistening step, and this in order to improve the organoleptic features of the stems.
US4567903 describes the formation of tobacco feed material suitable for cigarette by blending shredded tobacco stem material and shredded tobacco lamina material while in partially-dried form and drying the blend to the final moisture content.
It is the object of the invention to suggest a method which allows a final product to be obtained having physical features as similar as possible to those of the leaf so as to then be able to be subjected to the same processing operations to which the leaves are traditionally subjected to.
It is another object of the invention to suggest a method which allows a final product to be obtained which may be used in making cigarettes having a diameter less than 6.5 mm, and also as cut tobacco for hand-rolled cigarettes.
It is another object of the invention to suggest a method which can be implemented in a simple, quick and affordable manner.
It is another object of the invention to suggest a method which allows suitable energy savings.
It is another object of the invention to suggest a method which allows the "winnovers" to be reused, and in particular which allows both the stems and the leaf veins which are discarded by the cigarette making machine during the cigarette production process, to be reused.
It is another object of the invention to suggest a method which does not cause any modification to the mechanical features of the incoming stems and/or leaf veins used.
It is another object of the invention to suggest a method which is alternative and/or improved with respect to traditional ones.
All these objects, both individually and in any combination thereof, and others which will become apparent from the description below, are achieved according to the invention, by a method for treating stems and/or leaf veins of tobacco, in particular the stems and/or leaf veins discarded by cigarette making machines with the features indicated in claim 1.In particular, the improved method according to the invention for treating, preferably by the expansion treatment, the stems of tobacco and/or leaf veins (1) of tobacco, in particular those discarded by cigarette making machines, comprises the sequence of the following steps:

a step (2) of moistening said stems and/or leaf veins (1) such that said stems and/or leaf veins (1) have a moisture at the end of said step, which is measured on moisture basis, ranging from 35 to 85% and a volume which is greater than the initial volume thereof before said moistening step (2),
at least one laminating step (4) of said previously moistened stems and/or leaf veins (1), such that the stems and/or the leaf veins have a thickness ranging from 0.07 to 1.7 mm at the end of the laminating,
at least one drying step (5) of said previously moistened and laminated stems and/or leaf veins (1), such that said stems and/or leaf veins (1) have a moisture ranging from 20 to 40% at the end of said step,

said at least one laminating step (4) is carried out immediately after said moistening step (2),
said at least one drying step (5) is carried out immediately after said at least one laminating step (4).

Advantageously, the water (3) is added to the stems and/or leaf veins (1) of tobacco during the moistening step (2) so that they have a moisture ranging from 35 to 85%, preferably ranging from 40 to 65%, at the end of said step.
Advantageously, the water (3) containing further liquid or solid substances to improve the chemical features of the stems and/or leaf veins (1) of tobacco is added to the stems and/or leaf veins (1) of tobacco during the moistening step (2).
Advantageously, the water (3) used in said moistening step (2) has a temperature ranging from T=10 to 70°C, and preferably ranging from T=10 to 40°C. Preferably, the water (3) used in said moistening step (2) is at room temperature. Preferably, the water (3) used in said moistening step (2) is at temperature ranging from T=10 to 30°C.
Advantageously, the length of the moistening step (2) is such that at the end of said moistening step (2), all the water (3) introduced is absorbed by the stems and/or leaf veins (1) of tobacco.
Advantageously, following to said moistening step (2), the final volume of the stems and/or of the leaf veins (1) has an increase equal to about 1.4 to 1.5 with respect to the initial volume thereof.
Advantageously, the distance between the laminating rolls in said laminating step (4) ranges from 0.07 to 1.7 mm, preferably ranges from 0.1 to 1.4 mm.
Advantageously, said at least one laminating step (4) is carried out so that said previously moistened stems and/or leaf veins (1) have a thickness ranging from 0.07 to 1.7 mm, preferably ranging from 0.1 to 1.4 mm, at the end of said laminating step (4).
Preferably, said laminating step (4) is carried out so that the volume of the stems and/or leaf veins output from such a step is greater than the initial volume thereof before said moistening step (2).
Advantageously, said drying step (5) is carried out by convection with a hot fluid, preferably with hot air. Preferably, said drying step (5) is carried out at a lower temperature as compared to those used in drying towers or cylinders.
Advantageously, the temperature of the fluid or of the fluids used in said drying step (5) ranges from T= 30 to 110°C. Preferably, the temperature of the fluid or of the fluids used in said drying step (5) ranges from T= 70 to 100°C.
Advantageously, said at least one drying step (5) of said previously moistened and laminated stems and/or leaf veins (1) is carried out in such a manner so that said stems and/or leaf veins (1) have a moisture ranging from 20 to 38% at the end of said step.
Advantageously, the method does not provide any intermediate step of mixing with vegetable powder.
Advantageously, the stems and/or leaf veins (1) obtained after said drying step (5) are subjected to a cutting step.
Advantageously, the stems and/or leaf veins (1) obtained after said drying step (5) are subjected to a further drying step. Preferably, said further drying step is carried out by using a convection and/or conduction dryer. Preferably, said further drying step is carried out by convection with a hot fluid, preferably with hot air. Preferably, said further drying step is carried out by convection with a hot fluid having temperature ranging from T= 30 to 110°C, preferably ranging from T= 70 to 100°C. Preferably, said further drying step is carried out by conduction with a hot fluid having pressure ranging from 2 to 3 absolute bars.
Advantageously, the stems and/or leaf veins (1) obtained after said drying step (5) are treated to obtain cut tobacco intended to make cigarettes having diameter less than about 6.5 mm.
Advantageously, the stems and/or leaf veins (1) obtained after said drying step (5) are treated to obtain cut tobacco to be used for hand-rolled cigarettes.
Advantageously, the invention further relates to a cut product to be used to make cigarettes, in particular cigarettes having diameter less than about 6.5 mm and/or tobacco to be used for hand-rolled cigarettes, characterized in that it is obtained by treating the stems and/or leaf veins (1) of tobacco, in particular those discarded by cigarette making machines, with a method having one or more of the above mentioned features.
Advantageously, the invention further relates to a product according to the preceding claim, characterized in that it has physical features which are substantially comparable with those of tobacco leaves.
Advantageously, the invention further relates to a cigarette characterized in that it comprises a cut product obtained by treating the stems and/or leaf veins (1) of tobacco, in particular those discarded by cigarette making machines, with a method having one or more of the above mentioned features.
The present invention is hereinbelow further clarified in a preferred embodiment thereof, which is described by mere way of non-limiting example, with reference to the only accompanying drawing, which diagrammatically shows a method for treating stems and/or leaf veins of tobacco according to the invention.
As shown in the drawing, the method according to the invention for treating, and preferably inducing the expansion of, stems and/or leaf veins of tobacco, comprises a moistening step 2 of the stems and/or leaf veins of tobacco, indicated overall with numeral "1".
In particular, "stem" hereinafter means the middle/main (generally thicker) vein of the tobacco leaf, while "leaf veins" mean the side (and generally thinner) veins of the tobacco leaf; in greater detail, the leaf veins comprise the veins which extend laterally from the middle vein which defines the stem.
Preferably, the input stems and/or leaf veins 1 used in the method according to the invention comprise the so-called "winnovers" (or winnowers), i.e. those pieces of tobacco - and in particular of stems and/or leaf veins - which are discarded by cigarette making machines.
Conveniently, such a moistening step 2 is carried out with traditional techniques, such as those which provide moistening the stems and/or the leaf veins 1 of tobacco in a suitable receptacle.
Conveniently, the moistening step 2 is carried out by adding water 3 to the stems and/or leaf veins 1 of tobacco so as to induce the expansion of volume of said stems and/or leaf veins 1 of tobacco.
Advantageously, water containing further liquid or solid substances (such as for example, monopropylene glycol, fructose and vegetable extracts in general) to improve the chemical features of the stems and/or leaf veins 1 of tobacco, is added to the stems and/or leaf veins 1 of tobacco during the moistening step.
In particular, water 3 is added to the stems and/or leaf veins 1 of tobacco during the moistening step 2 so that at the end of said step, they have a moisture ranging from 35 to 85%, preferably in the range from 40 to 65%. All the moisture values herein identified, also hereinbelow, are meant to be determined according to the Moisture Measurement System. In particular, the moisture values are defined as the percentage of water contained in the total mass of the corresponding product and in other words, it is the percentage ratio between the quantity of water and the total mass of the water and tobacco combination. Conveniently, such values are obtained using the traditional methods provided in literature for measuring the quantity of water in a product, such as for example those introduced in " Tobacco Moisture, Water and Oven Volatiles - A status report of common moisture methods used within the tobacco industry" by Nils Rose ET AL. in "Analytical and bioanalytical chemistry" (1 July 2014, pages 1-16).
Advantageously, the temperature of water 3, which is added during the moistening step 2, ranges from T=10 to 70°C, and in particular ranges from T=10 to 50°C.
Advantageously, water 3, which is added during the moistening step 2, is at room temperature and preferably, ranges from T = 10 to 30°C. Conveniently, the addition/use of water which is at room temperature is advantageous because it does not induce changes to the mechanical features or to the color of the stems and/or leaf veins of tobacco, and in particular it allows the features of resistance and flexibility of said stems and/or leaf veins 1 substantially to be kept unaltered.
Conveniently, the moistening step 2 carried out by adding water at room temperature (i.e., preferably with water ranging from T=10 to 30°C) induces a continuous and homogeneous expansion of the volume of the stems and/or leaf veins 1 of tobacco and such an expansion is obtained without modifying the mechanical features thereof and without thermal treatments.
Conveniently, the length of the moistening step 2 is such that at the end of said step, all the water introduced is absorbed - preferably completely - by the stems and/or leaf veins 1 of tobacco.
Conveniently, the moistening step 2 is such that during the step, the stems and/or the leaf veins 1 undergo an expansion due to the absorption of the water which induces a plastic deformation thereof.
In particular, the volume of the stems and/or leaf veins 1 at the end of the moistening step 2 is greater than the initial volume thereof before such a step, i.e. it is greater than the volume of the input stems and/or leaf veins 1 introduced in the method according to the invention. Advantageously, the final volume of the moistened stems and/or of the leaf veins 1 (i.e., output from the moistening step 2) has an increase equal to about 1.4 to 1.5 of the initial volume.
As depicted in figure 1, a laminating step 4 is carried out immediately after the moistening step 2, in which the stems and/or the leaf veins are subjected to laminating.
Conveniently, the laminating step 4 is carried out immediately after the moistening step 2, i.e. without further intermediate steps being between them.
Advantageously, the distance between the laminating rollers provided in said laminating step 4 is to be such that the output stems and/or leaf veins 1 have a thickness ranging from 0.07 to 1.7 mm, preferably ranging from 0.1 to 1.4 mm.
Conveniently, the laminating step 4 is carried out so that the volume of the stems and/or leaf veins output from this step is greater than the initial volume, preferably greater than the volume possessed by the stems and/or leaf veins before said moistening step 2 (i.e. input into the method according to the invention).
The measurement of the volume of the stems and/or of the leaf veins 1 is carried out by submerging the product in a glass cylinder containing n-Heptane.
Like all plant products, tobacco undergoes shrinkage during the drying step, caused by the leak of the water contained in the cells, and it has been noted that such a phenomenon is accentuated as the difference in temperature increases between drying fluid and product to be dried.
Conveniently, the previously moistened and laminated stems and/or leaf veins 1 are dried during a drying step 5 to reduce such a shrinkage.
Conveniently, the drying step 5 is carried out immediately after the laminating step 4, preferably without any further intermediate step.
Advantageously, the drying step 5 is carried out by convection with hot air.
Preferably, the drying step 5 is carried out at lower temperature as compared to those currently used in drying towers (which generally are of 160° to 220°C) or drying cylinders (in which generally they are of 110° of 160°C). In particular, the temperature of the air during the drying step 5 ranges from T= 30 to 110°C, and preferably from T= 70 to 100°C. Advantageously, such a drying step 5 with hot air allows the shrinkage of the previously moistened and laminated stems and/or leaf veins 1 to be avoided.
Advantageously, the drying step 5 carried out at lower temperatures as compared to those currently used in the known solutions allows an energy saving, and in particular allows decreasing the heat loss into the environment. Moreover, the heating fluid may also be hot water (energy waste).
Conveniently, the drying step 5 is configured so that the moisture of the stems and/or the leaf veins 1 at the end of the drying step 5 ranges from 20 to 40%, preferably from 20 to 38%.
Conveniently, the stems and/or the leaf veins 1 thus treated may then be cut, for example using any tobacco cutting machine already present on the market.
Conveniently, the cut stems and/or leaf veins may be further dried using a convection and/or conduction dryer. Preferably, the further drying is carried out by complying with the aforesaid values, and in particular the stem used when drying by conduction preferably has a pressure ranging from 2 to 3 absolute bars.
It is apparent the above that the method according to the invention is particularly advantageous, because:

the cut material obtained from the stems and/or leaf veins thus treated indeed is soft and without hard pieces of tobacco which could induce the perforation of the cigarette paper,
the product thus obtained is comparable to leaves and therefore may be added to/used in the production cycle of cigarettes of particularly small diameter without any limitation, in particular less than 6.5 mm (i.e., of the slim and super slim type), or it may be added to the leaf cut in the production of the tobacco to be used for hand-rolled cigarettes.

In greater detail, the method according to the present invention conveniently provides and aims to treat the stems and/or the leaf veins so as to induce the expansion thereof by means of adding water, and this allows a homogeneous expansion to be obtained in the whole plant tissue of said stems and/or the leaf veins. Contrarily, the expansion obtained with the application of heat according to the known art does not ensure such a homogeneity, and therefore the sizes of the stems and/or leaf veins in the final cut are different and not constant and homogeneous; in particular, such a difference prevents the unaltered use thereof in the production of cigarettes having smaller diameter than 6.5 mm and in the cut tobacco generally used for hand-rolled cigarettes.
Furthermore, unlike WO2016/053522 , the method according to the present invention provides cutting the stems and/or leaf veins of tobacco in order to induce the expansion thereof (and not to improve the organoleptic features thereof) and therefore provides for the laminating step to be carried out immediately after the moistening step and for the drying step to be carried out immediately after the laminating step, and in particular it does not provide any intermediate step of mixing with vegetable powder. Moreover, the initial step of moistening the stems in the method according to the present invention serves to induce the expansion thereof, while the initial step of moistening in the method of WO2016/005830 serves to allow the vegetable powder mixed with the moistened stems to remain adherent to the surface of the stems themselves.

Claims

A method for treating, preferably by the expansion treatment, the stems of tobacco and/or leaf veins (1) of tobacco, in particular those discarded by cigarette making machines, whereby it provides the sequence of the following steps:
- a step (2) of moistening said stems and/or leaf veins (1) such that said stems and/or leaf veins (1) have a moisture at the end of said step, which is measured on moisture basis, ranging from 35 to 85% and a volume which is greater than the initial volume thereof before said moistening step (2),

- at least one laminating step (4) of said previously moistened stems and/or leaf veins (1), such that the stems and/or the leaf veins have a thickness ranging from 0.07 to 1.7 mm at the end of the laminating,

- at least one drying step (5) of said previously moistened and laminated stems and/or leaf veins (1), such that said stems and/or leaf veins (1) have a moisture ranging from 20 to 40% at the end of said step,
and characterized in that:
- said at least one laminating step (4) is carried out immediately after said moistening step (2),

- said at least one drying step (5) is carried out immediately after said at least one laminating step (4).
A method according to claim 1, characterized in that water (3) is added to the stems and/or leaf veins (1) of tobacco during the moistening step (2) so that they have a moisture ranging from 35 to 85%, preferably ranging from 40 to 65%, at the end of said step.
A method according to one or more of the preceding claims, characterized in that water (3) containing further liquid or solid substances to improve the chemical features of the stems and/or leaf veins (1) of tobacco is added to the stems and/or leaf veins (1) of tobacco during the moistening step (2).
A method according to one or more of the preceding claims, characterized in that the length of the moistening step (2) is such that at the end of said moistening step (2), all the water (3) introduced is absorbed by the stems and/or leaf veins (1) of tobacco.
A method according to one or more of the preceding claims, characterized in that the distance between the laminating rolls in said laminating step (4) ranges from 0.07 to 1.7 mm, preferably ranges from 0.1 to 1.4 mm.
A method according to one or more of the preceding claims, characterized in that said laminating step (4) is carried out so that the volume of the stems and/or leaf veins output from such a step is greater than the initial volume thereof before said moistening step (2).
A method according to one or more of the preceding claims, characterized in that said drying step (5) is carried out by convection with a hot fluid, preferably with hot air.
A method according to one or more of the preceding claims, characterized in that the temperature of the fluid or of the fluids used in said drying step (5) ranges from T= 30 to 110°C, preferably ranges from T= 70 to 100°C.
A method according to one or more of the preceding claims, characterized in that said at least one drying step (5) of said previously moistened and laminated stems and/or leaf veins (1) is carried out in such a manner so that said stems and/or leaf veins (1) have a moisture ranging from 20 to 38% at the end of said step.
A method according to one or more of the preceding claims, characterized in that it does not provide any intermediate step of mixing with vegetable powder.
A method according to one or more of the preceding claims, characterized in that the stems and/or leaf veins (1) obtained after said drying step (5) are subjected to a cutting step.
A method according to one or more of the preceding claims, characterized in that the stems and/or leaf veins (1) obtained after said drying step (5) are subjected to a further drying step.
A method according to one or more of the preceding claims, characterized in that said further drying step is carried out by using a convection and/or conduction dryer.
A method according to one or more of the preceding claims, characterized in that the stems and/or leaf veins (1) obtained after said drying step (5) are treated to obtain cut tobacco intended to make cigarettes having diameter less than about 6.5 mm.
A method according to one or more of the preceding claims, characterized in that the stems and/or leaf veins (1) obtained after said drying step (5) are treated to obtain cut tobacco to be used for hand-rolled cigarettes.