CN100358447C - Cigarette filter - Google Patents

Abstract

A thermoformed filter rod having a tubular body of tobacco smoke filtering material which is open at one end and closed at the other end by a filtering plug of said tobacco smoke filtering material integral with the tubular body. The filter rod may be thermoformed from filamentary tow of plasticised cellulose acetate.

Description

cigarette filter

The present invention relates to a filter suitable for example for papirosi type cigarettes.

Previous attempts in the industry to join a filter to a rigid cigarette or a tube were unsuccessful because the combination could not be reliably produced in the actual manufacturing process.

The present invention solves this problem by providing a cigarette filter comprising a thermoformed filter rod. The filter rod includes a tube body made of cigarette filter material, the tube body is provided with an opening at least at one end, and the tube body is closed by a filter plug integrated with the tube body, and the filter plug is made of the cigarette filter material production. The pipe body can be provided with an opening at one end, and the other end is closed with a filter plug. Alternatively, openings may be provided at both ends of the body, closed by filter plugs positioned between the two ends, in which case there are two end portions on the body, which pass through and form a Integral filter plugs merge into one unit. In all cases, the length of the filter rod body is at least equal to the length of the filter plug, preferably longer than the filter plug, for example, two to three times or more times the length of the filter plug; therefore the length of the body The length ratio to the filter plug can be 6:1 or about 4:1, but usually 5:2 is suitable, especially for filter rods with a total length of 70 mm.

Superficially, the entire thermoformed filter rod has generally the same perimeter and shape from one end to the other; the most common is a cylindrical outer surface from one end to the other. The cross-section of the inner cavity of the tube can be circular or non-circular, such as triangular, or other polygonal, cross-shaped, or star-shaped (for example, with 4, 5 or 6 vertices).

When the filter rod of the present invention is applied to a filter cigarette, the integral filter plug ends at the mouth end of the cigarette, and the open end on the pipe body faces the cigarette. A filter rod with an integral end filter plug or an integral internal filter plug is joined to a rolled cigarette preferably with the open end of the tube forming the mouth end to form a papirosi filter cigarette. Combining a short cigarette (e.g., 25-50 mm) with a long filter rod (e.g., 50-80 mm) with a short filter plug (e.g., 10-20 mm, or about 15 mm), such that The formed filter cigarettes are suitable for smokers who only want to take a few puffs of cigarettes in a short period of time, such as only 2-5 puffs, preferably 3-4 puffs. The tar retention of this cigarette is low (because the smoked cigarettes are short), And it provides the smoker with satisfactory smoke (because the filtration is mainly limited to the filter plug part).

The filter plug is preferably thermoplastically formed from fibers or plasticized cellulose acetate bundles, but other heat-formable fibers or filaments (such as polyolefin materials) or other heat-formable filter materials can also be used, such as Thermoformable open-cell foam. Since the filter rod is thermoformed, it is ensured that the tube remains sufficiently strong during subsequent handling (such as packaging and/or assembly with the cigarette) or during smoking.

Thermoformed filter rods can be produced stably at high speed and in large batches using a single-pass inline process. In this production process, thermoformable filter material (such as plasticized fiber bundles or mixtures of fiber bundles) is fed and passed through a rod forming device, which heats the filter material, and the device has a central The mandrel repeatedly reciprocates along the axial direction, and the complete rod body made of cigarette filter material is continuously discharged from the outlet of the device. In the axial direction of the rod body, the tube part made of filter material and the filter material The manufactured filter plugs are distributed alternately. A conventional rod jacket can be fed into and passed through the rod forming device at the same time to produce a rod with a rod jacket, although of course the rod is strong even without a jacket. Then the continuously discharged rod body with jacket or without jacket is cut laterally, the cutting position is in the middle of the pipe body part and the middle of the filter plug part, to form a single papirosi type filter rod, and the filter rod An integral filter plug is located at one end. It is best to cut only the tube part of the discharged rod so that there is a distance between the integral filter plug and the two open ends on the tube; the advantage of this embodiment is that it facilitates the production of pressure Filter rods with constant difference and retention and reproducible production because the initially formed one-piece filter plug remains intact and uncut and in the example cut from the filter plug, the cut is misplaced (in actual production It is difficult to avoid) the length of the filter plug of each filter rod produced continuously will be inconsistent, so the pressure difference and retention are also inconsistent.

Rod sheathing is part of the rod forming process, and individual filter rods cut in this manner directly from the raw rod produced in series are usually jacketed, usually with an end wrap. A filter rod with a jacket is connected to the cigarette. Having both ends of a single filter rod be the open ends of the body parts, with the filter plug being internal and integral between the open ends of the two body parts, this form of filter rod has another advantage, Since the two ends are the same, it is not necessary to align the filter rods before connecting them to the cigarette; on the contrary, for filter rods with filter plugs at the ends, they must be aligned before they are assembled with the cigarette, so that Make sure that the filter plugs of all filter rods are on the same end relative to the rods to be connected.

The continuously produced rods can be cut into complete rods twice or more in length, and then the rods can be further cut into individual filter rods. For example, when using a sheath to connect with cigarettes, a double-length entire rod can be placed close to and between the two cigarettes so that they are aligned on the same axis, and then the sheath is extended and wrapped around the double-length rod. The rod body and the end portion of the cigarette adjacent to it, so that the double-length rod body is connected with the two cigarette rods, and then cut from the center of the double-length rod body to form two filter-tip cigarettes. If the double-length rod has a filter plug at each end, and the double-length tube is positioned between the two filter plugs and forms one piece with them, the resulting filter cigarette will be a papirosi-type filter cigarette , the open end of the tube body of this filter cigarette is at the mouth end. There is also a filter plug with a double-length rod body that is double-length, and is located between two pipe bodies. The tube body and a filter plug form an integral body, the filter plug of the filter cigarette made in this way is at the mouth end, and the open end of the tube body is connected with the cigarette. In order to avoid cutting on the complete filter plug to achieve the above advantages, it is best to place all the cutting positions on the tube part, from cutting the continuous output of the original rod to cutting the double length rod to make The filter cigarettes are all the same, the filter cigarette made in this way has the open end of the tube body at the mouth end, and the upstream end is also formed by the open end of the tube body, and the integrated filter plug is between the mouth end and the upstream end.

When the sheath is applied, the initially produced double-length or multiple-length rods may or may not have a rod jacket attached to the rod itself. Individual filter rods can be cut from the integral double or multiple length rods, and these double or multiple length rods are also included in the protection scope of the present invention. These multiple-length rods are composed of several individual filter rods, and the ends of these filter rods are connected in a mirror image manner to form a whole. The unit may have a filter plug at each end or a body open end at each end.

The length of the body portion or the filter plug portion can be selected according to needs to produce papirosi type filter cigarettes with desired filtering effect. The degree of filtration also depends on the characteristics and compactness of the smoke filter material, and is less affected by the surface area of the lumen of the tube.

The length of the filter rod of the present invention is generally about 70 mm, but the range of variation is very large, for example from 20 mm to 90 mm. The length of the filter plug portion is generally from 8 or 10 mm to 50 mm, but is preferably shorter than the body portion as already indicated above. The filter plug part is generally not less than 8 or 10 mm long (otherwise the filtering effect is too low), generally not longer than 20 or 25 or 30 mm (otherwise the filtering effect or resistance to smoking is too strong); especially for papirosi filter cigarettes , the length of the pipe body generally has no technical significance, and can be determined according to the total length required by the final product, so as pointed out above, it can be 2 or 3 (for example, about 2-5) times the length of the filter plug.

The tube wall of the tube portion of the present invention is preferably relatively thin, for example, from about one-quarter to one-eighth of the filter rod diameter or less, so that the lumen of the tube is about half to about the outside diameter of the rod. three quarters or more. The tube wall of the filter rod should have sufficient strength to prevent dents during production, operation, storage and use. For example, the thickness of the wall of the body portion may be from 1 to 2 mm, preferably around 1.5 mm. The outer diameter of the filter rod is preferably between 7 and 9 mm, the same as that of a usual papirosi cigarette.

A filter rod manufactured according to the present invention has a total length of 74 mm, an 18 mm long filter plug at the end, and a 56 mm long integral tube with a wall thickness of about 1.5 mm. Its differential pressure is 64 mm water column (this value is conventionally obtained by testing a closed filter rod). The filter rod has a circumference of 24.5 mm, is connected with a 50 mm long cigarette, and the filter plug withstands the cigarette to form a non-ventilated filter cigarette, which has 40% tar retention and 38% nicotine retention.

The thermoformed filter rods produced according to the invention can be provided without a jacket or with their own rod jacket which is tightly connected to the rod in the longitudinal direction. If there is a coat on the filter rod, the end wrapping ring can be used to connect the filter rod to the cigarette to form a filter cigarette. The rod coat of the filter rod of the filter cigarette formed in this way is exposed, and it is best to be waterproof or non-absorbent to prevent smoking. When the stick body coat sticks to the lips. Regardless of whether the filter rod is not covered with a jacket or has its own rod jacket, it is possible to use a common jacket to join the filter rod to the cigarette to form a filter cigarette without the end ring, which wraps the entire filter rod and The adjacent end of the cigarette is wrapped, and the wrapping is preferably non-absorbent or waterproof. The rods of the filter cigarettes are generally 30 or 40 mm long, but can also be increased to 90 mm long. Cigarettes are generally rolled with ordinary cigarette paper.

Tar emissions from filter cigarettes can be reduced if the rod jacket of a thermoformed filter rod is ventilated. For example, when end wraps are used, the rod casing can be pre-perforated so that air can enter the filter rod during smoking, thereby diluting it. Similarly, when using the wrapper, holes can be pre-punched on the part of the filter rod (if there is a rod coat between the wrapper and the filter rod, the rod coat should also be air-permeable). It is also possible to use laser technology to punch vent holes in the jacket that wraps the thermoformed filter rod when assembling filter-tip cigarettes.

Tar emissions from filter cigarettes depend on the tar yield within the tobacco composition, the filter effectiveness of the filter rod and the degree of ventilation (if ventilation is available). Under the standard conditions of the World Standard Organization ISO, the amount of tar discharge can be from 1 to 65 mg, but it can be controlled within 15 mg. Regardless of the tar output of the papirosi filter cigarettes of the present invention, contamination of the mouth end of the filter rod is minimized.

Filter rods and filter cigarettes of the present invention are depicted in the accompanying drawings, which are not drawn to scale.

Fig. 1 is a schematic side view sectional view of a thermoformed filter rod of the present invention;

Figure 2 is a schematic side view of a papirosi filter cigarette, which is formed by joining a filter rod to a cigarette by an end ring;

Fig. 3 is a schematic side view sectional view of a papirosi filter cigarette, which is formed by joining the filter rod to the cigarette by the wrapper;

Figure 4 is a schematic side view of a filter cigarette, which is formed by joining a filter rod and a cigarette, with a filter plug at the mouth end; and

Figure 5 is a schematic sectional side view of another thermoformed filter rod.

The thermoformed filter rod 2 shown in FIG. 1 comprises a tubular body 4 of filter material and a filter plug 6 of said filter material. The entire thermoformed filter rod 2 is made of plasticized cellulose acetate filamentary tow. The total length 1 of the filter rod is generally 70 millimeters, and the length t of the pipe body 4 is 50 millimeters. The tube wall 8 is 1.5 mm thick. Along the entire length of the filter rod, the cross-section of the outer surface 10 of the filter rod is uniformly circular with a diameter of about 8 mm. The section of the inner cavity 12 of the tubular body is also circular.

FIG. 2 shows the filter rod shown in FIG. 1 , the filter rod is closely connected longitudinally to the rod casing 20 , and the filter rod is engaged with the cigarette 14 through the end ring 16 . Fig. 3 shows the filter rod shown in Fig. 1. There is no rod body jacket 20 on the rod body, and it is engaged with the cigarette 14 through the wrapper 18, and the length of the cigarette rod is about 40 mm.

The thermoformed filter rod 2 in FIG. 4 is placed in the opposite direction to that of the filter rod in FIG. 3 , and is joined with the cigarette 14 through the sheath 18 , the open end of the pipe body bears against the cigarette, and the filter plug is at the mouth end. Dimensions are shown in Figures 1 to 3.

The rod housing 20 and wrapping 18 in FIGS. 2 to 4 are not gas-tight, but they can also be made gas-permeable if desired.

The thermoformed filter rod 3 shown in Fig. 5 is basically the same as the filter rod 2, except that the two open ends of its two tube parts 5 are located at the two ends of the filter rod respectively, and the filter plug 6 is connected with the two tubes. The body parts are integrated and located at an intermediate position between them. The filter rod is made of plasticized cellulose acetate tow, with a total length of 70 millimeters, a filter plug 6 about 20 millimeters long, and a pipe body part with a total length of 50 millimeters, and each pipe body part 5 with a length of about 25 millimeters. The tube wall 8 has a thickness of about 1.5 mm and an outer diameter of about 8 mm. The cross-section of the outer surface 10 is circular, and the cross-section of the inner cavity 12 is also circular.

The filter rod 3 shown in FIG. 5 may have a rod casing tightly connected to it in the axial direction, and the filter rod is joined to the cigarette through an end ring, as shown in FIG. 2 . If the filter rod 3 is not tightly connected with the rod body jacket, it can be joined with the cigarette through the sheath (ventilated or non-ventilated), and the sheath wraps the entire filter rod and the downstream end of the cigarette, as shown in the figure 3.

Example

Various physical properties of various thermoformed filter rods and filter cigarettes of the present invention are listed in the table below.

Example Length (mm) Circumference (mm) Differential pressure (mm water column) hardness Weight / grams) tube shape A 70 24.10 174.9 95.9 0.913 round B 70 24.09 145.3 96.2 0.954 star C 70 24.21 181.9 95.7 0.937 star

Example Length (mm) Circumference (mm) Differential pressure (mm water column) Weight / grams)  Plasticizer content (%) Tar retention (%) Nicotine retention (%) T 70 24.16 84.6 0.824 16.5 42.2 39.1 L 70 24.20 87.4 0.845 16.5 42.5 42.0 X 74 24.4 114 0.75 16 44 41 Y 74 24.5 80 0.72 16 41 38

Embodiments A to C are various types of filter rods shown in FIG. 1 , the filter rods are all 70 mm long, and consist of a tube body approximately 50 mm long and a filter plug approximately 20 mm long.

Examples A, B and C were made using a 50/50 blend of "5Y40" and "7Y34" cellulose acetate tows, "dYn" tow indicating n x ¹⁰³ denier cross-section "Y "Shaped fiber, "d" represents the denier number of each fiber. The plasticized fiber bundle and the airtight rod jacket are sent longitudinally into the preheated rod forming device, which has the above-mentioned reciprocating mandrel, and the complete fiber bundle thermoformed with the rod jacket is produced. The rod body made, the 100 mm long pipe body part and the 40 mm long filter plug part on the rod body are alternately distributed. The cross-sectional shape of the lumen of the tube depends on the shape of the cross-sectional shape of the mandrel. The continuously produced rods are then cut transversely from the center of the tubular portion to produce individual papirosi-type filter rods. The hardness measurement is carried out on the filter plug part, and the hardness of the pipe wall part is slightly higher than that of the filter plug part.

The filter rods in Examples L and T are manufactured in the same manner as in Examples A to C, but are all made of 7Y/34 cellulose acetate tow; Connect, and make the filter plug close to the cigarette, the open end of the pipe body part is the mouth end, and produce the papirosi filter tip cigarette. Under standard conditions, the retention of tar and nicotine was measured, and the discharge of tar was reduced to about 13 mg. With the exception of retention, the other data listed are for the filter rod without a cigarette attached.

Examples X and Y are the filter rods shown in Figure 5. This type of filter rod is made entirely of 8Y/39 cellulose acetate tow. The manufacturing process is essentially the same as described in Examples A, B and C. , except that on the original rod body produced continuously, the 50 mm long pipe body part and the filter plug part on the 20 mm are distributed alternately, and the rod body is only cut at the center of the pipe body part. The advantage of this manufacturing method is that the lengths of the filter plugs of each filter rod produced continuously are consistent (so the pressure difference and retention are basically the same), the filter rods produced are symmetrical, and there is no need for any filter plugs when producing filter cigarettes. Specialized techniques and equipment align them in direction. The jacketed filter rods X and L were joined to tobacco rods in the manner described in Examples L and T to produce filter cigarettes (the properties of the filter rods and filter cigarettes were measured and reported). The output dropped to around 13 mg.

Examples D and E describe a "puff only" filter cigarette for short periods of time, with a short cigarette and a long filter rod. The long filter rod, in addition to its cooling effect, also ensures a comfortable distance between the end of the cigarette and the smoker's nose and face when lighting. In these embodiments, the length of the cigarette rolled with common cigarette paper is 30 mm, and the length of the filter rod is 51 mm. The filter rod is connected with the cigarette with a common wrapper, and the wrapper in embodiment D is airtight. The bag in Example E was pre-perforated to allow ventilation. These filter rods are integral thermoformed plasticized cellulose acetate tows of 5 fiber deniers, having a tubular body extending from the open mouth end to a 17mm long filter plug which abuts the cigarette, And seal the upstream end of the pipe body. The outer diameters of both the cigarette roll and the filter rod are 24.5 mm, and the tube wall thickness of the filter rod is 1.5 mm.

Other data of embodiment D and E see following table:

Example D Example E Suction resistance (mm water column) 192 133 Filter rod ventilation rate (%) 0 69 Tar yield (mg/1 cigarette) 6.4 1.7 Nicotine production (mg/1 cigarette) 0.3 0.12 Carbon monoxide (CO) production (mg/1 cigarette) 6.7 1.2 number of smoking ports 2.8 3.0

A preferred embodiment of the invention involves thermoforming filter material, preferably bundled fibers or fibrous material, to produce a complete unit with a relatively long, thin-walled tube body that The body (at the end or in the middle of the pipe section) is closed by a relatively short filter plug. The combination of these parts provides an industrially valuable filter that can be produced quickly, has sufficient strength to ensure that it will not be damaged during production, processing, storage and use, and allows people to breathe cool, satisfying Smoke with a controlled filtering effect, especially suitable for joining with relatively short cigarettes (for the smoker to smoke only two or three or four puffs).

Claims (11)

1. A cigarette filter comprising an integral thermoformed filter rod having a uniform structure and outer peripheral shape between its two ends, and having a tube body made of tobacco filter material, the tube The body has an opening at one end of the smoking body, and is closed at the other end by a filter plug made of the tobacco filter material and integrally formed with the pipe body. 2. A filter according to claim 1, characterized in that it is combined with a rod casing surrounding the filter rod, the rod casing being longitudinally connected to the filter rod. 3. The filter of claim 2, wherein the rod casing is a vented casing. 4. The filter according to claim 1 or 2, characterized in that the length of the filter plug is not less than 8mm. 5. A filter according to claim 1 or 2, wherein the filter plug is shorter than the rest of the filter rod. 6. The filter according to claim 1 or 2, characterized in that it is thermoformed from plasticized cellulose acetate tow or fibers. 7. A filter as claimed in claim 1 or 2, characterized in that the filter is attached to a cigarette. 8. A filter as claimed in claim 7, characterized in that the filter is joined to the cigarette rod by an end wrap. 9. A filter as claimed in claim 7, characterized in that the filter is joined to the cigarette by a wrapper. 10. The filter of claim 9, wherein the filter is vented. 11. An integral multiple-length filter rod, characterized in that the filter according to claim 1 or 2 can be cut therefrom, and each end of the multiple-length filter rod has a filter plug.

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