JP6780919B2 - How to dry a cigarette strip and the resulting cigarette paper - Google Patents

Description

The present invention relates to the technical field of producing cigarette paper, more specifically to the drying process during production in order to improve the mechanical properties of the cigarette paper.

In conventional methods, the paper machine line, especially the cigarette paper production line, comprises a felt-based dehydration section at the outlet from the headbox, then a press section, and then a paper drying section leading to a winding section.

In the prior art, many papermaking methods, especially paper drying methods, have been proposed. For example, US Pat. No. 6,001,421 describes a strip-shaped paper dryer that includes, in particular, a pre-drying portion and a coating portion following the post-drying portion. Each pre-drying section or post-drying section comprises a series of groups of drying drums. Each group of drying drums comprises a plurality of drying drums and a drying felt provided to press the strips against the drying drums and support the strips against the transfer rolls. Although the techniques described in the patent allow control of the properties of wavy or curled strips, the patent is relatively fragile compared to other types of paper and makes cigarette paper No teaching for drying.

Similarly, U.S. Pat. No. 4,882,854 for the dry portion of a paper machine with dry felt, which presses the strip against a drying drum and supports the strip while passing it around a transfer roll. The guide roll device of is described in detail. The patent does not provide proper teaching for drying cigarette paper.

Usually, the cigarette paper undergoes additional processing in the size press in such a way that the dry portion is separated upstream and downstream with respect to the size press so as to form a pre-drying portion and a post-drying portion.

One of the characteristics of cigarette paper is its weight, that is, its size corresponding to its unit area mass. Usually, the cigarette paper weight in the range of 12 grams square meter ^{(g / m 2) ~45g /} m 2, and more precisely having a weight in the range of ^{12g / m 2 ~35g / m 2} .

Since cigarette paper is relatively fragile, the running speed of the strip is limited to avoid breakage during paper production. Unfortunately, the improvement in cigarette paper manufacturing costs depends especially on the increased running speed of the strips.

However, Applicant has increased running speed of the band of the cigarette paper leads to a reduction of the machine械的characteristics of cigarette paper, thereby found that adversely affect the subsequent operation of the cigarette paper produced in the process It was.

U.S. Pat. No. 6,001,421 U.S. Pat. No. 4,882,854

Accordingly, the present invention provides a novel technique for the manufacture of cigarette paper, which is capable of increasing the traveling speed of the strip paper while obtaining very good mechanical properties suitable for subsequent operations of the cigarette paper. By doing so, the purpose is to improve the shortcomings of the prior art.

In order to achieve the above object, what the present invention intends to provide is a drying method for drying a strip of cigarette paper in a drying portion of a cigarette paper manufacturing machine line, wherein the drying portion is A pre-drying section located between the outlet from the press section and the entrance to the size press, and a post-drying section located between the outlet from the size press and the entrance to the winding section. Has a drying drum, a transfer roll, and at least one dry felt, the method having a breaking elongation of 2.0% or more and a ratio of 2.0 kilonewton meters / square meter (kN.m / m ² ) or more. To form a single "Uno run" drying system in the pre-drying section that carries strips of cigarette paper at a substantially constant rate in order to obtain cigarette paper with a value of tensile energy absorption (TEA index). In addition, at least in the pre-drying section, it is a method of continuously supporting the band of cigarette paper by at least one drying felt running around all the drying drums provided in the pre-drying section and all the transfer rolls. ..

As another feature of the present invention, the drying method has a breaking elongation of 2.5% or more and 2.5 kN. A single "Uno" in the post-drying section carrying a strip of felt paper at a substantially constant rate to obtain a cigarette paper with a value of specific tensile energy absorption (TEA index) of m / m ² or greater. In the post-drying section, the post-drying section is continuously provided with at least one dry felt running around all the drying drums and all the transfer rolls to form a run "drying system of cigarette paper. It is a method of supporting the belt.

Another feature of the invention is that the method continuously runs around a drying drum and transfer roll in a pre-drying section and / or a post-drying section with one or more dry felts continuously cigarette. This is a method of supporting a band of paper.

Another feature of the present invention is the method of running a band of cigarette paper on a suction transfer roll provided between a size press and a first drying drum in the post-drying section.

Another object of the present invention is to propose a novel cigarette paper showing improved mechanical properties as compared with conventionally known cigarette papers, in particular, values of elongation at break and specific tensile energy absorption (TEA index). is there.

Another object of the present invention is a value of elongation at break of at least 2.0% and 2.0 kN. The purpose of the present invention is to propose a cigarette paper having a specific tensile energy absorption amount (TEA index) value of m / m ² or more.

Another object of the present invention is a value of elongation at break in the range of 2.5% to 3.5% and 2.5 to 3.0 kN. The purpose is to propose a cigarette paper showing a value of specific tensile energy absorption (TEA index) in the range of m / m ² .

Another object of the present invention is
Porosity is in the range of 10 Coresta units (CU) to 200 CU;
And weight is in the range of ^{12g / m 2 ~45g / m 2} ; in the content of and inorganic filler is proposed cigarette paper in the range of 20% to 40%.

Another object of the present invention is to allow the traveling speed of the strip paper to be increased up to 700 m / min or more, and all its mechanical properties for facilitating subsequent operations of the cigarette paper produced in this method. It is to provide a drying facility in a cigarette paper making machine line that can achieve a moving speed of even 1000 m / min while ensuring that it is preserved.

Equipment for drying cigarette paper strips in the drying section of the cigarette paper making machine line includes a pre-drying section provided between the outlet from the press section and the entrance to the size press, and an outlet from the size press. It comprises a post-drying section provided between the entrance to the take-up section, which drying section comprises a drying drum, a transfer roll, and at least one drying felt. The dry part
In the pre-drying section, only the first series of drying drums and transfer rolls form a single first "Uno run" drying system, around the drying system to the outlet from the press section and the size press. At least one dry felt runs to continuously support the band of cigarette paper between the entrances of the; and-in the post-drying section, with only a second series of drying drums and transfer rolls, a single first At least one dry felt to form two "Uno run" drying systems and to continuously support the strip between the exit from the size press and the entrance to the take-up section around the drying system. Passes.

Further, according to the present invention, the equipment performing the drying method also provides a combination with at least one and / or other additional properties:
One or more drying felts pass around each of the first series of drying drums and the second series of drying drums;
A suction drum is installed between the outlet from the size press and the first drying drum of the second series of drying drums;
-The "Uno run" drying system in the pre-drying section and the post-drying section is supported by a hard floor; and-The "Uno run" drying system in the pre-drying section and / or the post-drying section is a band of cigarette paper. Consisting of a group of drying drums that alternate with the bottom and top surfaces of the strip, the movement of strips between a series of drying drums to continuously support the strips of cigarette paper from start to finish of its run. , Provided by a series of pairs of transfer rolls.

Many other features will become apparent by reference to the following description along with the accompanying drawings showing embodiments of the invention given as non-limiting examples.

FIG. 1 shows a cross-sectional view of an example of a drying facility in which only the pre-drying section forms a "Uno run" drying system. FIG. 2 shows a cross-sectional view of another example of a drying facility in which the pre-drying section and the post-drying section form a "Uno run" drying system. FIG. 3 shows a cross-sectional view of another embodiment of the drying facility in which the post-drying section has a transfer roll attached to the entrance. FIG. 4 shows a cross-sectional view of another embodiment of a drying facility in which the pre-drying section has a single circuit for drying felt. FIG. 5 shows a cross-sectional view of another embodiment of a drying facility comprising a drying group in which the or each "Uno run" section alternately contacts the bottom and top surfaces of the felt to dry the felt symmetrically.

As shown in the figure, the subject matter of the present invention relates to the production of a band of cigarette paper 1 on a production line. FIG. 1 shows a first embodiment of a drying section 2 for drying a band of cigarette paper 1, which forms part of a well-known paper machine that is not shown.

In the conventional method, the drying portion 2 is placed between the discharge port from the press portion and the inflow port of the roll portion, which are known to those skilled in the art and are specifically a part of the subject matter of the present invention. These press and roll sections are not described in more detail because they do not form.

The drying section 2 includes a size press 3 for processing the band of the cigarette paper 1. Therefore, the drying section 2 is provided between the pre-drying section 4 provided between the discharge port of the press section and the inflow port of the size press 3, and between the discharge port of the size press 3 and the inflow port of the winding section (not shown). It is composed of a post-drying portion 5 provided in the above.

According to the present invention, the pre-drying section 4 comprises a single "Uno run" drying system so that at least 80% of the drying required for the cigarette paper strip can be obtained. The term "Uno run" drying system is defined as given in US Pat. No. 2,537,129 or US Pat. No. 4,882,854 with reference to embodiments shown in FIGS. 2 and 3. Point to. Therefore, the pre-drying section 4 forms the first series of drying drums 6, transfer rolls 7, and felt circuit, and runs between the cylinders of the felt circuit 9, at least one endless strip. Each includes one dry felt 8 (several dry felts 8 in the example shown in FIG. 1). The drying drum 6, transfer roll 7, and drying felt 8 will not be described in more detail as they are well known to those of skill in the art and can be implemented in a suitable manner.

In a known method, each dry felt 8 is a group of dry drums so that the dry felt 8 extends in contact with the band of cigarette paper 1 outside the dry drum 6 and inside the transfer roll 7. It runs around 6 and at least one transfer roll 7.

In the embodiment shown in FIG. 1, the "Uno run" drying system includes a group of four groups of drying drums in the pre-drying section 4, each having a group of drying felt 8 and two groups of drying drums 6. .. Of course, the pre-drying section 4 may have fewer or more groups of drying drums 6. Similarly, the use of a group of drying drums with a number of drying drums that may be in the range of one to two or more can be envisioned. In each group of drying drums, except for the first group of the pre-drying section 4, the number of drying drums 6 is the same as the number of transfer rolls 7, and the transfer roll has two drying drums 6 divided by the transfer roll 7. It is placed like this. In the first group of the pre-drying section 4, the entrance roll is not a transfer roll. In the first group of the pre-drying unit 4, when the number of drying drums 6 is n, the number of transfer rolls is n-1.

Thus, the "Uno run" drying system comprises a series of groups of drying drums that are associated to support the band of cigarette paper 1 in a continuous manner. Each drying drum group continuously supports the band of cigarette paper 1 outside the band as it passes through each drying drum 6 and inside the band as it passes through the transfer roll 7. The felt is provided with at least one drying drum 6 and at least one transfer roll 7.

In other words, each drying drum group in the "Uno run" drying system continuously supports a strip of cigarette paper, all drying drums are located outside the circuit of drying felt 8, and all transfer rolls 7 are dried. It comprises only one dry felt, which is provided to be located inside the felt 8 circuit.

Thus, the strip of cigarette paper 1 is in direct contact with all drying drums 6 so that it is placed between all drying drums 6 and dry felt, while the dry felt 8 is placed between the transfer roll 7 and the cigarette paper. Since it is placed between the band of 1 and the band of cigarette paper 1, the band of cigarette paper 1 indirectly contacts the transfer roll.

The "Uno run" drying system in the pre-drying section 4 has moisture in the strip (moisture causes loss of elongation at break and loss of specific tensile energy absorption (TEA index)) and the strip is still deformable. In the meantime, it is believed to serve to provide at least 80%, preferably 100% of the required drying, during the continuous support of the strip of cigarette paper 1 for the purpose of limiting its elongation.

Preferably, as shown in FIG. 1, the circuit of the drying felt 8 is provided so as to straddle the drying drum 6. As a result, all the elements that make up the pre-drying section 4 can rest directly on the hard floor S of the building that receives the paper production line, without the need for installation of a base.

As is clear from the above description, in order to form a single "Uno run" drying system in the pre-drying section, the band of cigarette paper 1 is provided with a set of drying drums 6 and a transfer roll provided in the pre-drying section 4. At least one dry felt 8 running around the set of 7 is continuously supported by the entire pre-drying section 4. In other words, the pre-drying section 4 comprises only one "Uno run" drying system suitable for obtaining at least 80% dryness of the cigarette paper 1 strip.

The use of a single "Uno run" drying system in the pre-drying section allows the strip of cigarette paper 1 to be supported through its path in the pre-drying section 4 and therefore "draws" between the drying drums 6. Instead of reducing the damage to the band called "(draw)", it eradicates it and eliminates the difference in speed. Therefore, the strip of cigarette paper 1 is carried at a substantially constant speed. The running speed is considered to have a substantially constant change in speed of 0.1% or less.

The reduced draw of the strip allows for greater elongation at break and specific tensile energy absorption (TEA index) in traction while the strip is still moist than can be obtained with prior art equipment.

In this way, the value of elongation at break of 2% or more and 2.0 kN. Cigarette paper showing a value of specific tensile energy absorption (TEA index) of m / m ² or more can be obtained. The specific tensile energy absorption can be measured according to the TAPPI standard T494 om-01, and the elongation at break is defined using the "stretch" magnitude of the same standard.

In the embodiment shown in FIG. 1, the post-drying portion 5 is composed of a drying drum 6 arranged at the uppermost stage and the lowermost stage, and the strip-shaped paper 1 is configured to run between them. While the strip 1 then travels through the drying section 5, the strip 1 is externally supported in connection with each drying drum 6 using dry felts 8 arranged above and below the drying drum.

FIG. 2 shows a modification of a preferred embodiment of the present invention, in which the post-drying section 5 also comprises only one second series of drying drums 6 and a series of transfer rolls 7 of cigarette paper. A single first dry felt 8 runs around to continuously support the strips in the post-drying section 5 to obtain at least 80% dryness required for the strips. Form 2 "Uno run" drying system. Of course, this second "Uno run" drying system is suitable as described for the first "Uno run" drying system, which uses the system 10 for refracting the web path of the band of cigarette paper 1. Manufactured by the method.

Therefore, the "Uno run" drying system comprises a set of related groups of drying drums to continuously support the band of cigarette paper 1. Each drying drum group is opposed to a dry felt that continuously supports the band of cigarette paper 1 on the outer surface of the band as it passes through each drying drum 6 and on the inner surface of the band as it passes through the transfer roll 7. It comprises at least one drying drum 6 and at least one transfer roll 7. In each group of drying drums, the number of drying drums 6 is the same as the number of transfer rolls 7, except for the first group of the post-drying part 5, and the transfer roll is divided into two drying drums 6 by the transfer roll 7. Placed to be. For the first group of post-drying sections 5, the entrance roll is not a transfer roll. For the first group of the post-drying unit 5, when the number of drying drums 6 is n, the number of transfer rolls is n-1.

In other words, each drying drum group in the "Uno run" drying system continuously supports a strip of cigarette paper, all drying drums are located outside the circuit of drying felt 8, and all transfer rolls 7 are dried. It comprises only one dry felt, which is provided to be located inside the felt 8 circuit.

Therefore, the strip of cigarette paper 1 is placed between the transfer roll 7 and the strip of cigarette paper 1 so that the dry felt 8 is in indirect contact with the transfer roll, while all the dry drums 6 and the dry felt. In direct contact with all drying drums 6 so that they are placed between.

By using only one "Uno run" drying system in the post-drying section 5, the band of cigarette paper 1 can be continuously supported on the entire path through the post-drying section 5. Cigarette strips are carried at a substantially constant rate that can practically eliminate differences in draw speed between the various drying drums.

The "Uno run" drying system in the post-drying section 5 limits the elongation of the strip while it is still deformable, as the strip is moist (moisture leads to loss of elongation at break and TEA index). For that purpose, it is believed that the cigarette paper strips provide at least 80%, preferably 100% of the required drying, for continued support.

As mentioned above, if the strips still contain moisture through the dry portion, the reduction in draw can result in better breaking elongation and specific tensile energy absorption (TEA index) than those obtained with prior art equipment. it can. Therefore, using a drying section 2 with only one "Uno run" drying system in the pre-drying section 4 and exclusively a single "Uno run" drying system in the post-drying section 5 is as shown in FIG. A value of elongation at break in the range of 2.5% to 3.5% and 2.5 kN. m / m ^{2 to} 3.0 kN. The value of the specific tensile energy absorption amount (TEA index) in the range of m / m ² can be obtained.

In this way, it is possible to obtain a cigarette paper that functions more easily and exhibits improved mechanical properties.

The term "cigarette paper" had a porosity of in the range of 10CU～200CU, weight is in the range of ^{12g / m 2 ~45g / m 2} , preferably in the range of ^{20g / m 2 ~35g / m 2} , And it is understood to mean paper having an inorganic filler content in the range of 20% to 40% (typically 30% calcium carbonate). Porosity, weight, and filler content are each measured using the following techniques:
Porosity ISO standard 2965; Weight TAPPI standard T410; Filler content TAPPI standard TR13.

In the embodiment shown in FIG. 2, in the post-drying section 5, the drying felt 8 is provided so as to straddle the drying drum. As a result, all the elements constituting the pre-drying section 4 and the post-drying section 5 can stand directly on the hard floor, and there is no need to prepare a base at least under the drying section 2.

In a preferred embodiment shown in FIG. 3, the post-drying section includes a suction transfer cylinder 15 at its inlet. Therefore, the suction cylinder 15 is arranged between the outlet from the size press 3 and the first drying drum 6 of the post-drying portion 5. The use of the suction drum 15 at the outlet from the size press is beneficial in further reducing the elongation of the strips of moist paper.

In FIGS. 1-3, the "Uno run" drying system of the pre-drying section 4 comprises a plurality of drying felts 8. FIG. 4 shows an example of an embodiment in which only one dry felt 8 is used. In a variant of this embodiment, the single dry felt 8 continuously affects the band of cigarette paper 1 through the pre-drying section 4. The dry felt 8 runs around all the drying drums 6 and all the transfer rolls 7. Such a form ensures that the band of cigarette paper 1 has a constant running speed through all pre-drying portions 4.

A second "Uno run" drying system may be provided to form part of the post-drying section with only one drying felt 8. A variant of this embodiment can be used when the "Uno run" drying system forming part of the pre-drying portion comprises either a single dry felt 8 or a plurality of dry felts 8.

In another preferred embodiment shown in FIG. 5, the "Uno run" drying system of the pre-drying section 4 and / or the post-drying section 5 is a drying drum that alternately contacts the bottom and top surfaces of the band of cigarette paper 1. It consists of 6 groups. The movement of the paper strip 1 between the groups of drying drums 6 is provided by two consecutive transfer rolls 7 to continuously support the cigarette paper strip during the run.

Therefore, a group of drying drums 6, each containing a common felt 8 circuit, alternates contact with the bottom and top surfaces of the cigarette paper 1 strips to obtain symmetrical drying of the cigarette paper 1 strips. It is arranged in a proper way. The movement of the cigarette paper 1 strip between the groups of drying drums 6 is provided by two consecutive transfer rolls 7 for the purpose of continuously supporting the cigarette paper 1 strip during running. This offer allows control of the degree of web curl specified by ISO standard 14968. Such a form can be applied to the pre-drying section 4 as it is, or can be applied to the pre-drying section 4 and the post-drying section 5.

Claims (5)

A method of drying a band of cigarette paper (1) in a drying section (2) of a cigarette paper manufacturing machine line, in which the drying section (2) is an outlet from a pressing section and an entrance to a size press (3). A pre-drying section (4) located between the two, and a post-drying section (5) located between the outlet of the size press (3) and the entrance to the winding section, the drying section (2). The method has a drying drum (6), wherein the drying portion (2) further has a transfer roll (7), and at least one dry felt (8), and has a breaking elongation value of 2.0% or more. And 2.0 kN. In order to obtain a cigarette paper having a value of specific tensile energy absorption (TEA index) of m / m ² or more, a band of the cigarette paper (1) is sewn at a substantially constant speed with a velocity change of 0.1% or less. All drying drums (6) and all transfers provided in the pre-drying section, at least in the pre-drying section (4), so that a single "Uno run" drying system to carry is formed in the pre-drying section (4). The "Uno run" drying system continuously supports the band of cigarette paper (1) by at least one dry felt (8) running around the roll (7), and the "Uno run" drying system is a band of cigarette paper (1). Each drying drum (6) group comprises at least one drying drum (6) and at least one group, comprising one or more groups of drying drums (6) associated to continuously support. It comprises one transfer roll (7) and only one dry felt (8) that continuously supports a band of cigarette paper (1), said dry felt (8) forming a circuit of felt. Arranged in the form of endless strips, all drying drums (6) in the group are located outside the circuit of dry felt (8), and all transfer rolls (7) in the group are dry felt (8). ) Is provided so as to be located inside the circuit. Fracture elongation of 2.5% or more and 2.5 kN. A single "Uno" carrying a band of cigarette paper (1) at a substantially constant rate of velocity change of 1% or less to obtain a cigarette paper with a specific tensile energy absorption value of m / m ² or greater. In the post-drying section (5), at least run around all drying drums (6) and all transfer rolls (7) provided in the post-drying section (5) so as to form a run "drying system. The drying method according to claim 1, wherein the band of the cigarette paper (1) is continuously supported by one drying felt (8). Cigarettes with one or more dry felts (8) running continuously around the drying drum (6) and transfer roll (7) in the pre-drying section (4) and / or the post-drying section (5). The drying method according to claim 1 or 2, wherein the strip of paper is continuously supported. The claim is characterized in that the band of the cigarette paper (1) is run on a suction transfer roll (15) located between the size press (3) and the first drying drum (6) of the post-drying portion. The drying method according to 2 or 3. In the pre-drying part (4) and / or the post-drying part (5), the bottom surface and the top surface of the band of the cigarette paper (1) are alternately contacted and replaced, so that the band of the cigarette paper (1) is dried symmetrically. The drying method according to any one of claims 1 to 4, wherein the drying method is carried out.

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