JPH0542255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filter element for cigarettes, the filter element comprising: a core through which tobacco smoke passes;
An inner sleeve attached around this core,
Surrounding the inner sleeve is a sleeve body made of an air permeable material. This filter element has a breathable jacket around it to form a filter, which, when joined to the tobacco rod, allows outside air to enter the sleeve body through the jacket in a direction transverse to the axis of the core. , directing most of the smoke stream along the core to the smoker's mouth, and most of the air inhaled through the outer jacket.
A filtered cigarette is formed that is arranged for delivery to a smoker's mouth along the region between the outer sleeve and the inner sleeve.

The jacket can be perforated or made of an air permeable material to allow air to pass through. The jacket is a fitted jacket by means of which the filter can be attached to the tobacco rod, and the jacket is usually made of an air-permeable material with ventilation holes.

The invention also relates to rod-shaped filter elements without such a jacket. In this way, a rod-shaped filter is produced, and filtered cigarettes are produced from this filter.

In fact, the jacket should be equal to the length of the filter,
It is installed during the manufacture of the filter, and the filter can be attached to the tobacco rod by means of a snap ring. The filter can also be attached to the tobacco rod as a breathable overlay.

The invention includes all types of filtered cigarettes.

Of the above-mentioned requirements for the filter core, the inner sleeve, the sleeve body of air-permeable material, and at least the breathable outer covering attached to the filtered cigarette, if not included in the originally manufactured filter, when used. , a wide variety of filter structures and compositions are possible that achieve the objectives of the present invention. The purpose is to restrict at least a major portion of the smoke flow to pass within the inner sleeve and to restrict at least a major portion of the permeated air flow to pass outside the inner sleeve;
This allows the smoke and the permeated air to flow largely separately within the filter and to mix with each other primarily within the smoker's mouth.

Thus, the core, which is the channel through which most of the smoke flows, can be any of a variety of materials that allow tobacco smoke to pass through. A cellulose acetate tow is preferred, but it may also be a filament tow, such as cellulose acetate or polyolefin, or a bonded or unbonded staple fiber, crepe paper, or smoke-permeable cellular material. The core may be uniform in structure and composition along its length, but it may also be a composite of plugs of distinct structure and/or composition with properties such as, for example, pressure drop or overeffect. The core runs the entire length of the filter.
Or, for example, the filter can extend only partially, leaving a recess at one or both ends.
Furthermore, when the core is a composite body in which two or more plug-like bodies are adjacent to each other, they may be butted against each other or may be separated from each other in the longitudinal direction. When the core extends only part of the length of the filter,
The inner sleeve has little or no air permeability, requiring the desired separation of permeated air and smoke in a filter during use.

The inner sleeve is typically the packaging member. The core or individual core plugs can be preformed with or without a wrapper. It can be subsequently packaged within a packaging member, or the core formation and packaging can be combined in one step. When the core is made of a suitable material, such as a heat or solvent softenable filament, fiber, or cellular material, the inner sleeve may be replaced by a skin that is part of the core that can be heat or solvent fused. can be used. This skin is normally impermeable to air. With controlled use of heat and/or solvents, it is also possible to form a skin that is partially fused but permeable and integrated with the core. Other forms of the inner sleeve may also be used, such as extrusion or liquid coating and drying.

The nature of the remainder of the filter, ie, the components other than the inner sleeve, determines the air or smoke permeability of the inner sleeve. The inner sleeve may or may not be permeable, provided that the nature of the remainder of the filter naturally separates the smoke stream and the permeating air during use. However, if the smoke stream and permeate air tend to mix excessively within the filter, the inner sleeve may need to have reduced or no permeability to reduce or prevent such mixing. be. The inner sleeve can be, for example, a paper, plastic or metal film or foil, or a laminate of such materials, for example a paper/plastic/paper laminate. Preferably, the inner sleeve and sleeve body are adhered or glued together to prevent separation of these composites. When forming the sleeve body by focusing solvent-plastic filaments or fibers around the core and the inner sleeve, the inner sleeve is made of a material softened by a plasticizer, and the inner sleeve and the sleeve body are brought into contact. It is appropriate to glue it when If the sleeve body is a filament or fiber of cellulose acetate plasticized, for example with triacetin, it is advantageous for the inner sleeve to be a cellulose acetate membrane. Generally, the materials of the inner sleeve and sleeve body are bonded together by applying an adhesive to one or both of them before they are brought into contact. If the inner sleeve needs to be permeable to air or smoke, this may be due to the inherent breathability of the material of the inner sleeve and/or by having large or small holes pierced through this material. As mentioned above, when the core extends only part of the length of the filter, it is necessary that the inner sleeve be impermeable to air and smoke, especially when leaving a recess at one or both ends of the filter.

The sleeve body around the inner sleeve may be a variety of air permeable materials, such as bonded or unbonded staple fiber or filament tow of cellulose acetate or polyolefin, or apertured cellular plastic. Generally, the sleeve body is inherently more air permeable than the core and/or has grooves or passageways in the body. This results in a relatively low pressure drop, but provides an overall arrangement in which the smoke stream flows along the core rather than toward the sleeve body during use.

The outer surface of the sleeve body may be flat or provided with one or more grooves extending longitudinally of the filter, the grooves extending from one end of the sleeve body to the other, or extending from one or both ends of the sleeve body. Slightly before. Such grooves reduce the pressure drop across the sleeve body and increase air flow in the region between the inner sleeve and the outer jacket. Preferably, at least a portion of the permeating air enters such grooves directly through the jacket. The surface of the groove is generally air permeable.

For the purpose of illustrating the invention, preferred embodiments will now be described with reference to the drawings. In the drawings, like numbers indicate like parts.

FIG. 1 shows a filtered cigarette in which the smoke permeable core 2 is a cellulose acetate filament tow and is surrounded by an air permeable inner sleeve 4 surrounding the plug-shaped core. The inner sleeve 4 is a paper/plastic/paper laminate with a sleeve body 6 surrounding the inner sleeve 4, the body 6 being an air permeable bonded cellulose acetate filament tow with grooves on its surface. 8 extends only partially from the mouth end towards the other end of the filter. The filter elements (hereinafter also referred to as composite elements) 2, 4, 6 of the present invention are attached to a wrapped tobacco rod 12 by means of a breathable jacket 10 to form a filtered cigarette. The sleeve 10 is made of air-permeable paper and has a ring-shaped array of ventilation holes 14, some of which open directly into the groove 8.

The nature and dimensions of the composite elements and parts of the filter shown in the figures ensure that, when smoking this filtered cigarette, the smoke is restricted to flow through the core 2, while the permeating air flows through the sleeve body 6 and its grooves. 8 to allow smoke and permeate air to mix only at the smoker's mouth.

FIG. 2 shows another composite element 2, 4, 6 of the invention, the core 2, inner sleeve 4 and sleeve body 6 being of the same material as the element of FIG. However, in this case the outside of the sleeve body 6 is corrugated with a number of grooves 8 extending longitudinally from one end of the element to the other. This element can be replaced with that of FIG. 1 and exhibits similar smoking characteristics.

As a variant of these two embodiments, the outer surface of the sleeve body 6 is flat except for the groove 8, as shown in FIG. 3, or the groove 8 of FIG.
can also extend over the entire length of the sleeve body as shown in FIG. However, it is necessary that they be dimensioned and numbered so that during use most of the smoke flows through the core 2. In FIG. 3 and all other embodiments, when the sleeve body 6 is a plasticized cellulose acetate filament tow or staple fiber, the cellulose acetate membrane or staple fiber is attached so that the inner sleeve 4 adheres to the body 6. It is appropriate to

As other embodiment variants, the inner sleeve 4 may have perforations or large through holes or be air and smoke permeable. However, this is limited to the case where the passage serves as a passage through which most of the smoke from the core 2 flows, and the sleeve body 6 serves as a passage through which most of the permeated air flows. Alternatively, the core 2 may terminate slightly short of one or both ends of the filter, but the inner sleeve 4 may be air impermeable, allowing most of the smoke flow to pass through until it reaches the smoker's mouth. is usually required.

As a variant of the illustrated embodiment, the length of the jacket 10 extends only to the length of the sleeve body 6, so that the enveloped filter and the wrapped tobacco rod are
The connection can be made by a ferrule or an all-over breathable ferrule. As in any case, but especially in the case of a fitted jacket, it is necessary that the jacket attached to the sleeve body be made of an air-permeable material. On the side shown in FIG. 5, a groove is provided over the entire length of the sleeve body.

The filter element of the invention is manufactured by forming the core in the form of a continuous rod, around which the inner sleeve is continuously molded, and over the core with the sleeve attached, the air permeable material is continuously passed through a ring molding machine. By advancing the core while feeding it, the sleeve body can be formed and filter elements can be manufactured continuously. Continuous application of a breathable jacket around the sleeve body may then occur at the time of forming the continuous composite rod, but may occur thereafter if desired or necessary. Before providing the outer covering in this way,
Continuous or discontinuous longitudinal grooves or corrugations can be formed in the outer circumferential surface of the sleeve body.
If the grooves or corrugations are continuous, the grooves or corrugations can be formed at the same time as the sleeve body is formed, for example using a ring forming machine with a suitable geometry. If they are discontinuous, they are usually indented into the surface of the sleeve body after forming the composite rod. The continuously formed composite rods, with or without grooves, with or without a jacket, are laterally cut into individual final lengths. The first cut is usually an even length of the rod, for example six times the length of the individual elements to be incorporated into a single filtered cigarette. If necessary, cut the initially manufactured long rod, say 6 times the length, into double length lengths and place them end to end between a pair of wrapped tobacco rods and attach the fitting ring. or joined to the tobacco rod by a breathable overlay. The conjugate is then cut at twice the length of the filter to produce two filtered cigarettes. If the individual filter elements are asymmetrical, as shown in FIG. 1, with grooves on one end but not on the other, the initially manufactured multiple length rod will be asymmetrical. That is, in the case of the structure shown in FIG. 1, there are no grooves at both ends. The present invention also includes first intermediate manufacturing multiple length filter elements and filters and their manufacture.

Example The filter shown in Figure 5 has a length of 25 mm and a circumference of 24.7 mm.
It was hot.

The 5.3 mm diameter hypercore 2 consists of tow bonded with 8 dpf (denier per filament) cellulose acetate crimped filaments, the filaments are bonded at the contact point to form the tow using a triacetin plasticizer before focusing. , rod-shaped. The pressure drop in the core was 100 mm of water.

Inner sleeve 4 was an air permeable cellulose acetate membrane.

The sleeve body 6 had four grooves 8 extending over its entire length and was made of a 15 dpf cellulose acetate crimped filament tow bonded at the contact points as well as the core. Note that the filament was previously treated with a triacetin plasticizer.

This plasticizer also coats the inner sleeve 4 and the core 2.
Then, it is also glued to the sleeve body 6.

The jacket 10 is a highly air permeable 300K paper and is used as part of the filter manufacturing. The illustrated filter includes elements 2, 4, 6 and a breathable jacket 1.
0, initially manufactured continuously and cut to final length upon exiting the filter making machine, as described above. The initial cutting length was an even number multiple of the length of the respective filter, for example 100 mm. As described above, this was cut into twice the length to produce filtered cigarettes. At this stage, a double length filter is butted between the tobacco rods so that the length of the breathable jacket 10 is equal to the axial length of the filter elements 2, 4, 6, as shown in FIG. If the length of the breathable jacket 10 is equal to is longer than the axial length of the filter elements 2, 4, 6, the breathable jacket 10 can be used as a fitting and joined to the tobacco rod 12. Note that these joining methods are well-known techniques. Individual filtered cigarettes were obtained by cutting at twice the length of the filter.

The pressure drop mentioned here is CORESTA (Centre
Cooperation pour les Recherches
Measurements were made according to dimensions recommended and accepted by the Scientifique Relatives au Tabac (Tobacco Scientific Research Association).

Air permeability, nk Filtrona, is expressed in air permeation rate n x 1000 ml/min.・10 cm ²・10 mm water column, and pressure P is measured in mm water column, and 10 cm ² of the sheet, membrane or foil is measured per minute. The pressure P generated by 1050 ml of air passing through was measured using the following formula.

Air permeability = 1050×100/P

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of one embodiment of the filter and filtered cigarette of the present invention, FIG. 2 is a sectional view of another embodiment of the filter of the present invention, and FIGS. FIG. 2 is a perspective view of another embodiment of the filter and filter-equipped cigarette of the present invention. 2...Core, 4...Inner sleeve, 6...Sleeve body, 8...Groove, 10...Outer cover, 12...
Wrapped tobacco rod, 14...ventilation hole.

Claims (1)

Claims: 1. A cigarette having a core 2 for filtering tobacco smoke, an air-permeable sleeve body 6 attached around the core 2, and an air-permeable outer jacket 10 attached around the sleeve body 6. A filter that filters smoke and a cigarette rod 1 connected to it
2, the filtered cigarette is capable of directing the smoke stream through the core 2 to the smoker's mouth on the one hand and the air introduced through the breathable jacket 10 to the smoker's mouth through the sleeve body 6 on the other hand. An inner sleeve 4 having gas impermeability effective to separate smoke passing through the core 2 from air passing through the sleeve body 6 is provided between the core 2 and the sleeve body 6. A cigarette with a filter. 2. The filtered cigarette according to claim 1, wherein the sleeve body 6 has at least one longitudinal groove, which groove extends over all or part of the axial length of the sleeve body 6. . 3. According to claim 1, the breathable jacket 10 fitted around the sleeve body 6 allows external air to be introduced into the sleeve body 6 in a direction perpendicular to the axis of the sleeve body 6. A cigarette with a filter.