KR20160007689A - Cellulose acetate tow band for use in cigarette filters, cigarette filter, tow band production apparatus, and tow band production method - Google Patents

Abstract

(S / A) of the filament denier in the tow band of the cellulose acetate for cigarette filter is 5.0 or more, and the filet area of the filament is 0.5 or more and / or the cross-sectional area S of the filament cross- L) is 5 or more. The filament denier may be 10 denier or less, the pellet area may be 0.9 or less, and the ratio (S / L) may be 9 or less. In the manufacturing apparatus or the manufacturing method of the tow band, a circular radiating hole 10 having a diameter of 50 탆 or more is used. The diameter of the circular radiation hole 10 may be 100 占 퐉 or less.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cigarette filter, a cigarette filter, a toe band manufacturing apparatus, and a method for manufacturing a toe band,

The present invention relates to a tow band of cellulose acetate, a cigarette filter made of the tow band, and an apparatus and a method for producing the tow band.

The tow band of cellulose acetate is well known as the material of the cigarette filter. In the manufacture of the tow band, cellulose acetate is dissolved in an organic solvent to adjust the stock solution. The radiator has a plurality of radiation tubes, each radiating tube having a spinneret having a plurality of radiators. In each radiation cylinder, a plurality of filaments are formed by discharging the fiberizable liquid from a plurality of radiation holes, and a plurality of filaments are gathered to form a yarn. The tow band is produced by crimping the yarns from the entire spinning cylinder together. In the manufacture of a cigarette filter, the filter rod is made of a tow band. The filter rod is manufactured by opening a tow band, adding a plasticizer such as triacetin to the filter rod, shaping it into a cylindrical shape, and wrapping it with a wrapping paper. The cigarette filter is manufactured by cutting the filter rod to a predetermined length.

In this document, "filament" is a single fiber (short fiber) extruded from one radiation hole. The term " yarn " refers to a fiber bundle (a collection of short fibers) formed by combining a plurality of filaments formed in one radiation tube. The " tow band " is a fiber bundle which combines a considerable number of yarns of a total number of yarns, that is, all the filaments formed by the yarn bundle. The tow band, in a narrow sense, represents a collection of a plurality of crimped filaments. In the technology related to the prior art, the fiber bundle or the aggregate thus defined may be referred to as "filter tow" or simply "tow" instead of "tow band".

The " filament denier " is the fineness of the filament represented by the mass (g) per unit length (9000 m), and may be hereinafter abbreviated as " FD ". That is, the FD of the tow band means the fineness of one filament constituting the tow band. Quot; total denier " is a fineness of the toe band represented by the mass (g) per unit length (9000 m), hereinafter sometimes abbreviated as " TD ". The " amount of injection " is the net weight of the tow band charged in one filter rod.

Previously, Y-shaped and other deformed shapes have been preferred as the cross-sectional shape of the filament. For example, in Patent Document 1, an H-type filament is manufactured using a spinneret having a rectangular orifice, and the bundle is used in a cigarette filter or the like.

Recently, a thin cigarette called "slim type" or "super slim type" is on the market. When a filter of a thin cigarette is made of a conventional material as disclosed in Patent Document 1, the ventilation resistance becomes excessively high. Recently, a cigarette having a filter in which a capsule containing a flavor ingredient is embedded is also commercially available. The capsule is a factor of increasing the ventilation resistance. If the ventilation resistance is high, it becomes difficult for the smoker to drink the cigarette. Therefore, there is a demand for a material capable of lowering the ventilation resistance even when it is practiced in the cigarette filter as described above.

For example, Patent Document 2 discloses a cigarette having a small size only. The cigarette includes a filter including a filter member and a reel to be wound around the filter member, and a chip paper adhered on the cigarette rod and the filter to connect the cigarette rod and the filter. A through hole is formed to penetrate the chip paper and the winding paper, and air is introduced at the time of smoking. The filter member includes a tow, and the tow has an FD larger than 8.0 denier and a TD smaller than 15000 denier, thereby lowering the ventilation resistance along with the through-hole. Further, it is presumed that the injection amount is lowered to lower the ventilation resistance.

U.S. Patent No. 2825120 International Publication No. 2013/042609

Lowering the injection amount can lower the ventilation resistance. At the same time, however, the hardness of the cigarette filter is lowered. Then, the cigarette filter is easily deformed during smoking, so that it is difficult for the smoker to drink the cigarette. Further, the amount of air inflow from the tip of the cigarette is reduced instead of the amount of inflow of air from the through-hole, so that there is a problem that the amount of tar generated by smoking is reduced.

In addition, in Patent Document 2, the TD is made small in order to provide a volume suitable for the super-slim type, and the FD is made large in order to lower the rising air resistance by being tapered. As a result, the number of filaments constituting the tow necessarily becomes small. However, if the TD is small and the filament is small, it is difficult to uniformly crimp the tow in the longitudinal direction and the width direction, and it is difficult to stabilize the quality of the tow. If the crimp is not constant, the ventilation resistance of the cigarette filter also fluctuates, making it difficult to stabilize the quality of the cigarette filter.

Therefore, the present invention relates to a cigarette filter capable of suppressing aeration resistance and fluctuation thereof while maintaining a hardness, a toe band of cellulose acetate exhibiting such action when used as a cigarette filter, and an apparatus and a method for producing such a toe band And to provide the above objects.

According to one aspect of the present invention, a tow band of cellulose acetate for a cigarette filter is formed by crimping a plurality of filaments discharged from each of a plurality of radiation holes into a single filament and crimping one filament, wherein the filament denier is 5.0 denier or more, The pellet area is 0.5 or more.

The " Feret area " is an index that can be used to evaluate the releasability of the filament cross section. At the time of drawing out the pellet area, the filament is cut perpendicularly to the longitudinal direction of the filament at an arbitrary point, and a parallelogram contiguous to the end face is imagined (see Fig. 5). In this virtual parallelogram, one of the two pairs of stools is two parallel lines circumscribing the cross section, and the other line is the two lines having the maximum line-to-line distance (so-called maximum feret diameter) Parallel lines in which the line-to-line distance is the minimum value (the so-called minimum Feret diameter). The pellet area is the area ratio obtained by dividing the cross-sectional area of the filament by the area of the virtual parallelogram, in other words, the occupancy of the filament cross section in the virtual parallelogram.

The technical significance of the filet area of the filament in the field of cigarette filters will be described below. Generally, in the cigarette filter, the major axis direction of the filament is substantially perpendicular to the flow of the mainstream smoke of the cigarette (see Fig. 6). The mainstream smoke is blocked by the filament thus arranged, and the droplets contained in the mainstream smoke collide with the filament and are collected. In view of this cross flow, the blocking ability of the filament can be said to be substantially equal to the blocking ability of the virtual filament having the cross-sectional shape of the parallelogram imagined at the time of deriving the pellet area. Therefore, the smaller the pellet area, the higher the ability of the filament to stop against the cross-sectional area of the filament. Since the cross-sectional area of the filament is positively correlated with the mass of the tow band (tow injection weight), a small pellet area indicates that a large tow band mass can block many mainstream smoke.

For example, in the case of a filament with a full cross section, the length of one side of the imaginary parallelogram becomes equal to the diameter of the end circle, so that the pellet area becomes πr ² / 4r ² , ie, about 0.785 (r, The filament has been considered to be an inefficient material that does not have excellent collection performance as compared with the mass, and it has been tried to reduce the pellet area. As a part of this, the sectioning of the cross section has been attempted and, as described above, the cross-sectioning and cross-sectioning has been preferred. For example, in a filament having a Y-shaped cross section formed by using a triangular radiating hole or a Y-type radiating hole, the Y-shaped cross section corresponds to a shape obtained by partially shrinking and deforming the triangle, so that the pellet area becomes less than 0.5. When the releasability of the cross section is remarkable as described above, the pellet area becomes small.

In order to achieve the above-described object, the inventor of the present invention has developed a tow band of a cellulose acetate for a cigarette filter, contrary to the conventional development, when a tow band is constituted by a filament of a relatively large pellet area, , It was conceived that even under the same mass condition as that of the conventional tow band composed of filaments having a deformed cross section, the blocking ability could be further lowered and the ventilation resistance could be lowered accordingly.

According to the tow band related to this embodiment of the present invention, since the filament is relatively large at 5.0 or more, the ventilation resistance can be suppressed. In addition, the pellet area of the filament is 0.5 or more, which is larger than the pellet area of the filament having the Y- or H-shaped cross section which has been generally used before, and the releasability is suppressed. Therefore, when the toe band cigarette filter is practically used, the ventilation resistance can be suppressed compared with the mass (even when the tow injection weight is increased). When the tow band is used as a cigarette filter, air flows smoothly along the outer surface of the filament in the cigarette filter, and the air flow resistance is suppressed. As the ventilation resistance is suppressed, it is possible to maintain a large number of filaments.

By using the filament of a relatively large pellet area in this way, when used as a cigarette filter, the ventilation resistance can be suppressed. Therefore, the injection amount is not reduced, and the hardness of the cigarette filter can be kept high. In addition, the total denier need not be made small in size, so that the number of filaments constituting the tow band is not reduced, and the crimping process can be stably performed on the tow band. Therefore, the quality and productivity of the tow band can be enhanced. When the cigarette filter is manufactured using the toe band as a material, the air resistance and fluctuation thereof can be suppressed while maintaining a high hardness.

The filament denier may be 10 denier or less. The feret area may be 0.9 or less.

The total denier may be 14,000 denier or more. The total denier may be 22,000 denier or less. Preferably, the total denier is 15000 to 21000 denier, more preferably 15000 to 20000 denier.

According to another aspect of the present invention, a tow band of cellulose acetate for a cigarette filter is formed by crimping a plurality of filaments discharged from each of a plurality of radiation holes into a single filament and crimping the filaments, wherein the filament denier is 5.0 denier or more, (S / L) of the area and the circumferential length when the circumferential length of the cross section is L is 5 or more.

The " ratio (S / L) " is an index used for evaluating the releasability of the filament cross section, like the pellet area. If the droplets contained in the mainstream smoke are regarded as aerosols, the surface of the filaments can be considered to collect them. In this case, the smaller the ratio (S / L), the higher the collection performance of the filament cross-sectional area and hence the tow injection weight. If the releasability of the filament cross section is remarkable, the ratio (S / L) becomes small. The present inventor has found that the ratio (S / L) can be controlled within an appropriate range by setting the filament denier to a specific range.

According to the toe band according to the other aspect of the present invention, the ventilation resistance can be suppressed because the filament denier is relatively large at 5.0 or more, and the filament denier is in such a range, . Further, since the ratio (S / L) is 5 or more, when this tow band is used as a cigarette filter, the ventilation resistance can be suppressed compared to the weight of the tow injection. Therefore, the amount of injection, the total denier and the number of filaments need not be lowered. Therefore, the productivity of the tow band can be increased, and when the cigarette filter is manufactured using the tow band, the air resistance and fluctuation thereof can be suppressed while maintaining the high hardness.

The filament denier may be 10 denier or less, and the ratio (S / L) may be 9 or less.

The cigarette filter according to one aspect of the present invention is made of the toe band and has a circumferential length of 14 to 18 mm, preferably 14 to 17 mm, more preferably 14 to 15 mm. Thus, even when the cigarette is a thin cigarette, the ventilation resistance and the variation thereof can be suppressed while maintaining the hardness of the cigarette filter at a high level.

An apparatus for producing a cellulose acetate toe band for a cigarette filter according to an aspect of the present invention is a device for producing a toe band of a cellulose acetate for a cigarette filter comprising a plurality of filaments discharged from a plurality of radiation holes, And a spinneret having the plurality of spin holes, wherein the spinneret is circular and has a diameter of 50 mu m or more.

A method for producing a tobacco of cellulose acetate for a cigarette filter according to an embodiment of the present invention includes the steps of forming a plurality of filaments by discharging a spinning solution from each of a plurality of radiating holes, And the band is circular, and the diameter of the spinning hole is 50 占 퐉 or more.

With such a size of the spinneret, the filament denier becomes larger and the sectional shape becomes larger, so that the spinning hole has a circular shape. Therefore, filaments having a relatively smooth cross-sectional shape with a pellet area of 0.5 or more and a ratio (S / L) of 5 or more can be formed as filaments having a filament denier of 5.0 denier or more.

The above-mentioned spinneret may have a circular shape and its diameter may be 100 mu m or less. As a result, filaments having a filet area of 0.9 or less and / or a ratio (S / L) of 9 or less can be formed as filaments having a filament denier of 10 denier or less.

According to the present invention, it is possible to provide a cigarette filter capable of suppressing the ventilation resistance and the variation thereof while maintaining the hardness, and a toe band of cellulose acetate exhibiting such action when used as a cigarette filter. It is also possible to provide an apparatus and a method for manufacturing such a tow band.

1 is a conceptual diagram showing an apparatus and a method for producing a tow band of cellulose acetate for a cigarette filter according to an embodiment.
2 is a bottom view of the spinneret according to the embodiment.
Fig. 3 is a view showing a section of a filament according to the embodiment. Fig.
4 is an explanatory diagram of an index for evaluating the releasability of the filament cross section. Fig. 4 (a) shows an example of a section of the filament according to the embodiment, and Fig. 4 (b) shows a comparative example.
Fig. 5 is a view for explaining the method of deriving the pellet area.
6 is a view showing an example of the flow of cigarette mainstream smoke in the cigarette filter.

Hereinafter, embodiments will be described with reference to the drawings. The same or corresponding elements are denoted by the same reference numerals throughout the drawings, and redundant description thereof is omitted.

1 is a conceptual diagram showing an apparatus and a method for producing a tow band (TB) of cellulose acetate for a cigarette filter according to an embodiment. 1, the toe band manufacturing apparatus 1 includes a mixer 2, a filter 3, a radiator 4, a winding unit 5, a drier 6 and a baler 7 . In the manufacture of the tow band, a spinning stock solution (hereinafter sometimes simply referred to as " dope ") is prepared (raw stock preparation step). (For example, a weight concentration of 20 wt% or more and 30 wt% or less, preferably 26 wt%) by dissolving cellulose acetate in an organic solvent such as acetone by a mixer 2, Is adjusted. The solution is then filtered by a filter (3). This filtrate is used as a spinning stock solution.

After the raw liquid preparation process, the tow band (TB) of cellulose acetate is prepared as a spinning solution using the radiator 4, the winding device 5 and the drier 6 (spinning process). The tow band TB is compressed and packed by a baler 7 (packing process).

Although the detailed illustration is omitted, the cigarette filter is manufactured using the toe band (TB) as a material. In the production of the cigarette filter, the filter rod is manufactured as a middle product. In short, the tow band (TB) is opened and a plasticizer such as triacetin is added. The tow band TB is formed into a cylindrical shape suitable for the size (diameter and circumferential length) of the target cigarette using a plug traction machine, and the wrapper is wound around the filter rod. The filter rod thus manufactured is cut to a predetermined length corresponding to the target cigarette. Thereby, a plurality of cigarette filters are manufactured as one filter rod.

The toe band TB according to the present embodiment is preferable for a material of a cigarette filter mounted on a thin cigarette such as a so-called slim type or super slim type. The cigarette filter has, for example, a circumferential length of 14 mm or more and 18 mm or less (preferably, a circumferential length of 14 to 17 mm, more preferably 14 to 15 mm or less).

The spinning processes and the devices (4 to 6) used in the spinning process will be described. The radiator 4 is provided with a plurality of radiation tubes 11 and a plurality of spinnerets 12 corresponding to the radiation tubes 11, respectively. The spinneret 11 is formed as a long cylindrical body in the vertical direction and the spinneret 12 is formed at the upper end of the spinneret 11. [ The spinneret 12 has a plurality of spinning holes 10 (see Fig. 2).

The spinning stock solution is delivered to the plurality of spinnerets 12 by the spinning pump 13. The spinning stock solution is discharged downward into the radiation tube 11 from each of the plurality of radiation holes of the spinneret 12 so that a plurality of filaments F are formed by the dry spinning method. As the plurality of filaments (F) face downward, the distance between them decreases, thereby forming one yarn (Y). The yarn (Y) is discharged downward from the bottom of the corresponding radiation cylinder (11). In the radiator 4, a plurality of yarns Y are discharged from each of the plurality of radiation tubes 11.

Each yarn Y is fed from the oil ring device 14 with an oil emulsion containing a fiber emulsion and water and passes through the periphery of the high-defect roller 15 and is sent to the winding device 5. The plurality of yarns Y are joined to each other in the course of going from the high-deflection roller 15 to the winding machine 5, thereby forming the tow band TB. The winding machine 5 is, for example, a known stepping box type. The tow band (TB) is conveyed to a stuffer box while being pressed by a press roll. Thus, the crimping of the waveform is imparted to the tow band TB. The crimped tow band TB (tow band in a narrow sense) is sent from the winding unit 5 to the dryer 6. [ In the dryer (6), the residual solvent and moisture are removed from the tow band (TB).

The process of forming filaments of cellulose acetate by dry spinning will be described. The spinning liquid travels downward in the radiation tube 11 until it is discharged from a radiation hole and then discharged from the radiation tube 11. At the time of starting the running of the dope (that is, when the dope is discharged from the radiation hole), the dope is in a liquid phase. During running of the dope, the solvent evaporates from the dope to form filaments, and the dope becomes a solid phase in the liquid phase. The solvent evaporates from the dope surface immediately after the start of running.

The cross-sectional shape of the filament is characterized by the relationship between the evaporation rate, which is the rate at which the solvent evaporates from the dope surface, and the diffusion rate, which is the rate at which the solvent diffuses from the dope center to the surface. The evaporation rate is determined by the following equation: (1) solvent retention force of cellulose acetate, (2) vapor pressure of solvent at ambient temperature, (3) saturation degree of solvent vapor of atmosphere gas at each run point, (4) And (5) evaporation surface area. The diffusion rate is in accordance with the second law of the pick.

Immediately after the start of running of the dope, the diffusion from the dope center portion does not reach the evaporation on the dope surface, and the surface layer of the dope is solidified to form the skin. When the skin is formed, the peripheral length of the filament is determined to some extent. The solvent in the center of the dope diffuses into the skin and evaporates. Therefore, the volume in the skin (i.e., the cross-sectional area of the filament) after the formation of the skin is reduced, and the skin is deformed in the radial direction. Therefore, the cross section of the filament shows a deformed shape from the shape of the radiation hole.

The present inventors have found out as follows. That is, when the diameter of the radiation hole is small, most of the solvent in the center of the dope diffuses into the skin and evaporates at the stage where the skin is formed. Therefore, the cross-sectional shape of the filament does not largely change from the shape of the radiating hole. For example, if the spinning hole is circular, the filament cross section becomes approximately circular, and its releasability is small. If the releasability of the cross section is small, it is difficult to secure filtration performance. In the past, filtration performance has been ensured by adopting a release shape for the radiation hole and adopting a release type such as Y-shape or H-shape on the filament end face.

The factors (1) to (4) are almost determined by the process. That is, (1) depends on the solvent to be used, (2) the atmospheric temperature depends on the drying temperature in the process, (3) is determined by the drying air volume, and (4) On the other hand, with respect to the factor (5), if the diameter of the radiating hole is large, the sectional area of the filament becomes large and the evaporated surface area becomes large. If the evaporation surface area is large, the evaporation rate is increased and the releasability of the filament section becomes strong. When the diameter of the spinning hole is large, the volume of the solvent trapped in the skin also becomes large. From this point as well, the releasability of the filament cross section becomes strong.

Therefore, when the diameter of the radiating hole is within a specific range to make the shape of the radiating hole circular, it is possible to control the releasability of the filament cross section to ensure a constant filtration performance. That is, when a bulb having a small diameter is used, if a Y-shaped or H-shaped modified cross section is not used and a circular hole having a diameter in a specific range is used, appropriate releasability can be exhibited in the cross section of the filament , And the ventilation resistance is appropriately controlled by the filament having the specific FD having such releasability.

2 is a bottom view of the spinneret 12 according to the embodiment. As shown in Fig. 2, the plurality of radiation holes 10 are opened in the bottom surface 12a of the spinneret 12 facing in the radiation tube 11. As shown in Fig. As an example, the bottom surface 12a may be circular and the plurality of radiating holes 10 may be arranged on a trapezium on the bottom surface 12a. The shape of the bottom surface 12a and the arrangement of the radiating apertures 10 you can change it. The radiation hole 10 is circular and has a diameter of 50 탆 or more and 100 탆 or less. More preferably, it is 50 占 퐉 or more and 90 占 퐉 or less.

Fig. 3 is a view showing a section of the filament F according to the embodiment. Fig. This cross-section is obtained by cutting the filament F perpendicularly to the longitudinal direction of the filament. The FD of the filament (F) is 5.0 denier or more and 10 denier or less. More preferably, it is 5.5 denier or more and 9.0 denier or less. By using the above-described radiation hole 10, the FD of the tow band TB can be included within the numerical range as described above.

Since the diameter of the radiating hole 10 is included in the above-mentioned specific range, the releasability of the cross-sectional shape of the filament F discharged therefrom is controlled to a suitable range. The cross-sectional shape of the filament F is suppressed in comparison with the Y-type or H-type rather than the true circle, and the shape approximates to a circle.

4 is an explanatory diagram of an index for evaluating the releasability of the filament cross section. Fig. 4 (a) is an example of a cross-section of the filament F according to the embodiment, Fig. 4 (b) is a comparative example, As shown in Fig. The indicator is, for example, "Pellet Area" or "S / L".

The "pellet area" is defined as the ratio S (S) to the area (SVP) of the area S when the cross-sectional area of the filament F is S and the area of the virtual parallelogram VP that contacts the cross- / SVP). In this virtual parallelogram, one of the two pairs of stools is the two parallel lines circumscribing the cross section, and the line-to-line distance is the maximum pellet diameter. The other side is the two parallel lines circumscribing the cross section, and the line distance becomes the minimum pellet diameter. Therefore, when the cross section of the filament F is taken at an arbitrary point and the pellet area of the cross section is obtained, the pellet area becomes a value irrespective of the posture of the cross section around the normal line. If the cross section is full circle, the pellet area is 0.785 [-], and if it is triangular, the pellet area is 0.5 [-] or less.

The cross section of the filament F is minute. However, by setting electronic data of an image photographed through a microscope by using a known image processing technique or by calculating (manually calculating) based on the photographed image, setting of a virtual parallelogram VP , The cross-sectional area (S), the area (SVP) and the peripheral length (L) can be measured.

As shown in Fig. 4 (b), in the Y-type filament Fy related to the comparative example, a region of the cross section excluding the inscribed circle ICy is divided into a plurality of points (three points) on the circumference of the inscribed circle ICy, So that the plurality of points are spaced apart in the circumferential direction. On the other hand, the virtual parallelogram VPy must be set so that the area also surrounds. Therefore, the imaginary parallelogram VPy is away from the inscribed circle ICy in the radial direction, and becomes much larger than the size of the inscribed circle ICy. This area occupies only a very small part of the space excluding the inscribed circle (ICy) from the virtual parallelogram (VPy). Therefore, in the Y-type filament related to the comparative example, the pellet area becomes a small value. Since the Y-shape is the contraction of the triangle of the radiation hole, the pellet area is less than 0.5. Also, since the degree of the concavities and convexities of the outer peripheral edge portion is large, the peripheral peripheral length L becomes larger than the sectional area S, and the ratio S / L becomes small.

On the other hand, as shown in Fig. 5 (a), in the filament F according to the present embodiment, a circular radiating hole is used, and the irregularities at the outer edge of the end face are small. A region of the cross section of the filament F excluding the inscribed circle (IC) is formed substantially over the entire periphery. The amount of protrusion from the inscribed circle (IC) to the outside does not largely fluctuate with respect to the circumferential direction of the inscribed circle (IC). Therefore, the virtual parallelogram VP becomes closer to the inscribed circle IC in the radial direction. As described above, in the filament F according to the embodiment, since the releasability of the cross-sectional shape of the filament F is suppressed, the pellet area becomes a relatively large value. Also, the unevenness of the outer peripheral edge portion is small, and the ratio (S / L) becomes large.

In the present embodiment, the radiation hole 10 having a diameter of 40 占 퐉 or more is used and the FD of the toe band TB is 5.0 denier or more, which is larger than that of the conventional one. When the FD is large, the air resistance can be suppressed when the toe band TB is used as a cigarette filter.

In this embodiment, a circular radiation hole 10 is used, and the filet area of the filament F is 0.5 or more and 0.9 or less. The ratio (S / L) is 5 or more and 9 or less. When the toe band TB is used as a cigarette filter, the ventilation resistance can be suppressed even if the TD is large.

As described above, if the diameter of the radiation hole 10 and the FD of the toe band TB become too large, the releasability becomes remarkable. If the FD of the toe band TB becomes excessively large, it is necessary to reduce the number of filaments constituting the toe band TB for TD adjustment of the toe band TB.

Therefore, the diameter of the radiation hole 10 is set to 100 占 퐉 or less and the FD of the tow band TB is set to 10 denier or less. More preferably, the diameter of the radiation hole 10 is 50 占 퐉 or more and 90 占 퐉 or less, and the FD of the tow band TB is more preferably 15,000 denier or more and 22,000 denier or less. Thereby, the pellet area can be set to 0.6 or more and 0.8 or less. Also, the ratio (S / L) can be set to 5.5 or more and 8.0 or less.

As described above, in the present invention, the FD is limited to a predetermined size, and the releasability is suppressed, so that an increase in the ventilation resistance can be suppressed. Further, in the present invention, even if the injection amount of the filter is increased, the degree of increase of the ventilation resistance is low. Therefore, fluctuation of the ventilation resistance of the cigarette filter due to fluctuation of the injection amount of the cigarette filter can be suppressed. Therefore, the injection amount of the cigarette filter can be increased, and the filter hardness can be maintained. Thus, the manufacturer of the cigarette filter can manufacture the cigarette filter without changing the manufacturing conditions according to the type of the cigarette, thereby improving the productivity of the cigarette filter.

Further, in the present invention, TD of the toe band (TB) can be kept high. For example, the TD of the tow band TB may be 14,000 denier or more and 22,000 denier or less, preferably 15,000 denier or more and 21,000 denier or less. Even when the TD is kept high as described above, the ventilation resistance can be suppressed when used as a cigarette filter. Further, since the TD of the tow band TB is kept high, the volume of the tow T fed to the winding unit 5 per unit time is also increased. Therefore, the tow T can be stably supplied in the crimper box, and the tow T can be easily given crimp. As described above, in the present invention, fluctuations in the air flow resistance due to the variation of the winding number of the toe band (TB) can also be suppressed.

In the toe band TB according to the present embodiment, by forming the toe band TB with the pellet area and / or the ratio (S / L) satisfying the above numerical range so that the FD satisfies the above numerical range, The fluctuation of the ventilation resistance accompanied by the variation of the weight can be suppressed well. The fluctuation of the air flow resistance of the cigarette filter (plug) using the toe band TB according to the present embodiment may be 4.0%, preferably 3.8, more preferably 3.5, and still more preferably 3.2% or less.

As described above, it is possible to manufacture the toe band (TB) suppressing fluctuation of the TD and the crimp number while suppressing the ventilation resistance while maintaining the hardness when used as a cigarette filter without strict production control. By manufacturing the cigarette filter using this toe band (TB), the hardness of the cigarette filter can be kept high and fluctuations in the ventilation resistance can be suppressed. Particularly, this cigarette filter can be suitably employed in recent "slim type" and "super slim type" cigarette filters, or in a capsule-embedded filter.

Example

EXAMPLES Hereinafter, examples will be described, but the present invention is not limited to the following examples. In the Examples and Comparative Examples, the pellet area, the ratio (S / L), the ventilation resistance, the variation of the ventilation resistance, and the filter hardness were measured by the following methods.

(Pellet Area)

A pencil-like filament sample was prepared from the tow band associated with the Examples or Comparative Examples. That is, a part of the fiber was taken out from the toe band, and the inside of the fiber was wrapped with paraffin so that the inside of the fiber was located at a portion corresponding to the pencil lead. The thus-prepared filament sample was sliced to a thickness of 1 占 퐉 to 10 占 퐉 using a microtome to obtain a sample slice. The sample slice was observed with an optical microscope ("BX-51" manufactured by Olympus Corporation), and the image obtained by observation was introduced into an image processing apparatus. The image processing apparatus was set to set a virtual parallelogram (VP) circumscribing one filament end face included in the image, and to measure the cross-sectional area of the filament and the area of the virtual parallelogram (VP). The pellet area was calculated by dividing the sectional area of the filament by the area of the virtual parallelogram.

(Ratio (S / L))

The sample slice was observed with the optical microscope, and the image obtained by the observation was introduced into the image processing apparatus, and the cross-sectional area and the circumferential length of the one filament cross section included in the image were measured Respectively. The ratio (S / L) was calculated by dividing the cross-sectional area by the circumferential length.

(Ventilation resistance)

A filter rod sample was prepared from the tow band related to Example or Comparative Example. That is, a filter rod sample having a predetermined length and a predetermined injection amount (nominal tow weight) was prepared by focusing the tow band to a predetermined diameter using a conventional manufacturing apparatus and fixing the tow band with a filter paper using a filter winding machine . Air having a temperature of 22 ± 1 ° C and a humidity of 60 ± 10% was passed through the filter rod sample at a flow rate of 17.5 cc / sec, and the pressure difference [mmWG] (millimeter water gauge) at both ends of the filter was measured. Further, in both of the examples and the comparative examples, the filter rod sample does not have a through hole penetrating the wrapper.

(Variation value of the ventilation resistance)

A total of 300 filter load samples are sampled at intervals of 15 samples. The change value was expressed as a percentage from the measurement value of each of the 300 aeration resistances.

(Filter hardness)

The filter hardness was measured using a durometer ("QTM7" manufactured by Filtrona) for a filter rod sample shaped to have a plug length of 120 mm, a circumference of 16.70 mm and a ventilation resistance of 350 mm WG. During the measurement of the hardness of the filter, a load of 300 g was applied vertically to the side of the filter rod sample. The filter hardness was calculated from the following formula.

Filter hardness [%] = d / d0 x 100

d is the diameter of the filter rod sample in the load direction after deformation due to the load, and d0 is the diameter of the filter rod sample before deformation. If there is no deformation at all, the hardness is 100%, and when the hardness is close to 100%, it means hard.

(Examples 1 and 2)

The tow band related to Example 1 was prepared as follows. That is, a cellulose diacetate having an average degree of acetalization of 55.2% was dissolved in acetone to prepare a spinning solution having a concentration of about 25 mass%. A spinning stock solution having a temperature of 50 to 60 ° C was supplied to the spinneret. Each radiation hole is circular with a diameter of 71 탆. The spinning stock solution was discharged from each spinneret into the spinning cylinder to form a filament of FD: 8.6 denier. In the spinneret, heated air of 120 to 150 ° C was blown onto the filaments to evaporate the acetone. An oil emulsion was applied to a bundle-shaped aggregate (yarn) discharged from the spinneret, which was wound with a high-precision roller. The yarns were combined to form a toe band having a TD of 21,000 denier. The toe band was crimped, and the toe band was dried with a drier. The tow band related to Example 2 was produced in the same manner as in Example 1 except that a filament of FD: 6.0 denier was formed using a circular spray hole having a diameter of 59 탆.

(Comparative Examples 1 to 7)

The tow band related to Comparative Example 1 was produced in the same manner as in Example 1, except that a filament of FD of 2.0 denier was formed using a triangular radiating hole of about 45 占 퐉 on one side. The tow band related to Comparative Example 2 was produced in the same manner as in Example 1 except that a filament of FD of 3.0 denier was formed by using a triangular radiating hole of about 55 占 퐉 on one side. The tow band related to Comparative Example 3 was produced in the same manner as in Example 1 except that a filament of FD of 6.0 denier was formed using a triangular radiating hole of about 80 탆 on one side. The tow band related to Comparative Example 4 was produced in the same manner as in Example 1, except that a filament of FD of 7.0 denier was formed using a triangular radiating hole of 85 占 퐉 on one side. The tow band related to Comparative Example 5 was produced in the same manner as in Example 1 except that a filament of FD: 8.6 denier was formed by using a triangular radiating hole of about 95 탆 on one side. The tow band related to Comparative Example 6 was produced in the same manner as in Comparative Example 3 except that the TD was 17,000. The tow band related to Comparative Example 7 was produced in the same manner as in Example 1 except that a filament of FD of 8.0 denier was formed using a triangular radiating hole of about 95 탆 on one side and the TD was 15000.

From the tow band related to Examples 1 to 2 and Comparative Examples 1 to 7, a filter rod sample having a plug length of 120 mm, a circumference of 16.70 mm, a tow injection weight of 0.35 g / rod was prepared, The humidity was kept for 24 hours in an air-conditioning room at a temperature of 20 ° C and a humidity of 65%.

With respect to the obtained sample, the aeration resistance and the variation thereof were measured by the aforementioned measuring method. For the samples related to Example 1 and Comparative Example 7, the filter hardness was measured by the measurement method described above. Table 1 shows the measurement results.

From the tow band related to Examples 1 to 2 and Comparative Examples 1 to 5, a filter rod sample having a tow injection weight of 0.33 g / rod was also prepared. From the tow band related to Comparative Example 6, a filter rod sample having a tow infusion weight of 0.33, 0.28 g / rod was also prepared. From the tow band related to Comparative Example 7, a filter rod sample having a tow injection weight of 0.33, 0.28, and 0.24 g / rod was also prepared. The air resistance of the obtained sample was measured by the above measuring method. Table 2 shows the measurement results.

As is apparent from the comparison between Example 1 (8.6R21000) and Comparative Example 5 (8.6Y21000), in the triangular radiating hole, even if the TD is 21,000 denier and the FD is thickened to 8.6 denier, the plug length is 120 mm, the circumference is 16.70 mm Is about 430 mm WG.

In order to achieve a ventilation resistance of about 300 mm WG, it is necessary to make the TD smaller in the triangular radiating hole. In the case of TD 15,000 denier and FD 8.0 denier, as in Comparative Example 7 (8.0 Y 15000), the ventilation resistance becomes 530 mmWG. Therefore, by reducing the indentation weight, it is necessary to lower the ventilation resistance. When the indentation weight is between 0.25 g and 0.28 g, a ventilation resistance of about 300 mm WG can be achieved. However, as shown in Table 2, the hardness decreases as the indentation weight decreases (Comparative Example 7).

On the other hand, filaments having a large pellet area can be obtained by increasing the size of the filament denier by making the shape of the radiation hole circular. Even if the total denier is kept high by such a tow band, the ventilation resistance is not increased.

As can be seen from the comparison between Example 1 and Comparative Example 7, when the total denier is maintained at a high level, the variation width of the ventilation resistance of the plug can be reduced.

Further, the change in the ventilation resistance due to the weight change is smaller than that in Comparative Example 7, and the rate of change in the ventilation resistance is small even when the press-in weight is changed, as is clear from Example 1.

Therefore, for example, it is possible to lower the airflow resistance by about 30% while maintaining the indentation weight in the TD large toe band using a filament having a large FD and a large pellet area using a circular radiating hole. Thereby, the possibility of the hardness problem can be reduced, and the variation of the ventilation resistance due to the variation of the injection weight at the time of plug winding can be reduced.

Industrial availability

The present invention is advantageous for use in tow band of cellulose acetate for cigarette filter.

F: filament
TB: Toe band
1: Tow band manufacturing device
4: radiator
5: winding machine
10: Fireworks
11: Radiation canal
12: spinning detention

Claims (8)

1. A tow band of cellulose acetate for cigarette filters, comprising a plurality of filaments discharged from a plurality of radiating holes,
The filament denier is 5.0 denier or more,
The toe band of cellulose acetate for cigarette filter having a pellet area of the filament of at least 0.5. The method according to claim 1,
The toe band of cellulose acetate for a cigarette filter having a filament denier of 10 denier or less. 3. The method according to claim 1 or 2,
The toe band of cellulose acetate for cigarette filter having a pellet area of 0.9 or less. 4. The method according to any one of claims 1 to 3,
Toe band of cellulose acetate for cigarette filter with total denier of over 14,000 denier. 5. The method of claim 4,
The toe band of cellulose acetate for a cigarette filter wherein the total denier is less than or equal to 22,000 denier. 1. A tow band of cellulose acetate for cigarette filters, comprising a plurality of filaments discharged from a plurality of radiating holes,
The filament denier is 5.0 denier or more,
(S / L) of the area and the circumferential length when the cross-sectional area of the filament is S and the circumferential length of the cross-section is L, is not less than 5, the toe band of the cellulose acetate for cigarette filter. The method according to claim 6,
The toe band of the cellulose acetate for the cigarette filter having the filament denier of 10 denier or less and the ratio (S / L) of 9 or less. A cigarette filter made of the toe band of any one of claims 1 to 7 and having a circumferential length of 14 to 18 mm.

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