EP1378182B1 - Ventilated paper for self-rolled cigarettes - Google Patents

Abstract

The cigarette paper sheet (100) has a zone of perforations (120) forming a band parallel to the long axis (130) of the cigarette. This band is sufficiently near the center of the sheet width to be outside the covering zone of the paper after rolling the cigarette.

Description

The present invention relates to a ventilated cigarette paper comprising a number of artificial holes for admitting fresh air into the cigarette when it is smoked. The role of this fresh air is to dilute the smoke inhaled by the smoker, the quantity of tars and nicotine delivered by the cigarette being diminished.

More specifically, the invention relates to a ventilated cigarette paper whose perforations are located in such a way that they remain effective in the case of cigarettes rolled by hand or with the aid of rolling machines.

The taste of the consumer and the legislation contribute for several years to the alleviation of the smoke of the cigarette. Thus, tar and nicotine levels of conventional cigarettes are regularly revised downward. If the situation is simple on conventional cigarettes, it is less so on cigarettes rolled by hand or using rolling machines. The trend towards lower and lower yields makes it necessary to develop paper that is ventilated.

The effectiveness of paper perforation has long been known to reduce the tars delivered by the smoke of the cigarette. Those skilled in the art know that the natural porosity of the cigarette paper (order of magnitude of the hole 10 microns), the electrostatic perforation of the cigarette paper (order of magnitude of the hole 100 microns) and the ventilation of the cigarette papers ( order of magnitude of the 300 micron hole) contribute to varying degrees to the reduction of tar and nicotine levels. On manufactured cigarettes, for example, the ventilation is carried out using lasers perforating one or more rows of holes a component of the end of the cigarette to be put in the mouth, the rows of perforation forming a circle around the tube of the cigarette.

The application of the same technique to paper for rolled cigarette poses two problems.

On the one hand, and contrary to what happens in manufactured cigarettes, the rolling paper is generally 50 to 100% wider than the perimeter of the rolled cigarette, which makes the perforations ineffective because they are covered by a second layer of paper during the making of the cigarette, second layer constituted by the additional margin that sticks on the opposite edge.

By way of example, the quantities of tar obtained will be compared with a sheet of unventilated cigarette paper of width 26 mm, a ventilated sheet of width 26 mm, and finally a ventilated sheet of width 38 mm.

In the following, the references to tar levels and their reduction are based on measurements made according to ISO / DIS 15592.

A manufactured cigarette has a conventional diameter of 7.2 mm and its perimeter is 22.6 mm. When the chosen paper is not ventilated, the cigarette delivers 2.87 mg of tar per puff.

Two circular rows of thirteen holes are made on one end of the sheet. When the width is 26 mm, the double sheet thickness is only 3.4 mm from the periphery and 12 holes per row are not covered. With 24 holes available, the cigarette delivers only 1.62 mg of tar by puff.

When the width is 38 mm, which is a classic width on the market, the double sheet thickness represents almost 70% of the periphery and only 3 holes per row are not covered. With 6 holes available, the cigarette delivers 2.58 mg of tar per puff.

It is clear from this example that the efficiency of ventilation as described and practiced today by those skilled in the art can be reduced or canceled in the case of cigarettes rolled by hand or at the using rolling machines, because of overlapping opposite edges.

The document FR-A-312 714 proposes for this a cigarette paper with groups of different sizes of porosity arranged in longitudinal strips on the surface of the paper, to ventilate the cigarette regardless of its diameter.

On the other hand, the paper being generally blank of any impression, the rolled cigarette will be brought to the mouth indifferently by one or the other of the two ends, which renders ineffective the row of perforation in the event that it is opposite the mouth, this row being burned in the first moments of combustion.

It is the object of the invention to solve the two problems related to the generalization of ventilation to cigarette papers to roll. The present invention must make it possible to overcome the problem of recovery, the efficiency of the ventilation remaining the same when the recovery following the rolling of the cigarette varies within the limits generally found on the market.

The present invention also aims to allow the smoker, either to get rid of the choice of the end by which he will take his cigarette in the mouth, the effectiveness of ventilation remaining the same regardless of the chosen end, or just know the end he has to put in his mouth.

Finally, the invention aims to overcome these disadvantages while keeping adequate ventilation efficiency, that is, by providing a sheet that is neither too waterproof nor too ventilated.

The object is achieved according to the invention by means of a sheet of cigarette paper according to claim 1.

• la figure 1 représente une feuille selon l'invention ;
• la figure 2 représente une autre feuille selon une variante de l'invention ;

Other characteristics, objects and advantages of the invention will appear on reading the detailed description which follows, made with reference to the appended figures in which:

• the figure 1 represents a sheet according to the invention;
• the figure 2 represents another sheet according to a variant of the invention;

In the case where the sense of grip of the cigarette has an importance, and where this band does not extend over the entire length of the cigarette, the object is achieved according to the invention by adding a distinctive sign to the end of the cigarette. the leaf to be taken in the mouth. This distinctive sign is one of the elements allowing the industrial production of the sheet of cigarette paper according to the invention.

The invention relates to a sheet of cigarette paper supplied in the form of a large-format board, in the form of individual sheets stacked, entangled or connected, in the form of rolls to be unwound, in the form of preformed tubes.

The following descriptions will better understand the advantage of the perforation parallel to the large side of the sheet rather than the short side, as is generally the case with non-rolled cigarettes. It will also be understood the advantage of the central position of the ventilation strip with respect to the width of the sheet of cigarette paper.

• la figure 1 représente une feuille de papier à cigarettes ventilée selon l'invention, la bande de ventilation étant perforée sur toute la longueur de la feuille de papier à cigarettes.
• la figure 2 représente une feuille de papier à cigarette ventilée selon l'invention, la bande de ventilation n'étant que partiellement perforée.

Two preferred embodiments are described in detail with reference to the appended figures in which:

• the figure 1 represents a sheet of ventilated cigarette paper according to the invention, the ventilation strip being perforated along the entire length of the sheet of cigarette paper.
• the figure 2 represents a sheet of ventilated cigarette paper according to the invention, the ventilation strip being only partially perforated.

The figure 1 represents an individual sheet of cigarette paper 100, provided with an adhesive rubber band 110, with a band formed by perforations extending along the entire length of the cigarette paper sheet 120, parallel to the large side of the leaf, centered on the axis 130 parallel to the large side of the sheet and passing through the middle of the small side of the sheet.

In the following, we will call "band reserved for ventilation", the band that remains uncovered by not covering the paper after rolling the cigarette.

The ventilation is, in this embodiment, symmetrical and does not depend on the end put in the mouth. On the other hand, whatever the percentage of overlap, it is the middle of the initial sheet which is reached last by the double thickness. In particular, on the cigarette of diameter 7.2 mm rolled with a sheet of width 38 mm, a band of 7.2 mm wide is free of cover and the perforations which are there find are available for ventilation. If the perforations were conventionally performed on circles perpendicular to the axis of the cigarette, only a small part of them would be available for ventilation, due to the obstruction of the holes by the second round of paper.

The figure 2 represents an individual sheet of cigarette paper 200, provided with an adhesive rubber band 210, a printed border 220 determining the side of the cigarette to be taken in the mouth, a band reserved for ventilation 240, parallel to the large side of the leaf, centered on the axis 230 parallel to the large side of the sheet, passing through the middle of the small side of the sheet and only one area has been perforated. The perforated zone 250 forms at this point a zone of perforations, which will be called perforation zone 250 here.

In this example, and compared to the example related to figure 1 , a higher density of holes is installed on the smoking side. The pavement of holes is located beyond the holding zone of the cigarette by the lips, and below the length of the butt, preferably between 13 and 27 mm. These holes are therefore available throughout the smoking period of the cigarette.

It is possible, from a desired reduction of tar, to define a number of holes weighted by the efficiency of each hole and consequently to define a width of the perforation band. The width of the sheet of cigarette paper can then be adjusted in knowledge of the necessary width of the perforation strip and in the knowledge of the consumer's driving practices. The advantage of the sheet of cigarette paper according to the invention is that the consumer in his practice no longer opposes the efficiency of the ventilation that was provided by the manufacturer of the sheet of cigarette paper. The scope of the invention will be better understood on the following two examples.

Example 1: Circular holes of 300 microns are made on the periphery of a cigarette, about 20 mm from the end brought to the mouth. The reduction of tars obtained when these holes are not covered by a second round of paper can determine the effectiveness of a hole of this size and in this area. In the example chosen, each hole contributes 1.3% to the overall decrease of tars per puff. It is desired that the tars delivered by the cigarette be halved. So you have to earn 50% tar per puff, which will be achieved by the presence of 39 holes.

The width of the cigarette paper sheet is 35 mm. The standard distance between two holes is 2.5 mm. If we leave 2.5 mm between the edge of the sheet and the first hole, we can place three rings of 13 holes at 17.5 mm, 20 mm, and 22.5 mm from the end of the sheet brought to the mouth However, and as this has It has been explained in the advantages of the invention, when the cigarette has been rolled to a diameter of 7 mm, only three holes per row will not be obstructed. Therefore, with only 9 holes available instead of 39, the proposed cigarette sheet is unable to lead to the desired 50% tar reduction. On the other hand, if the smoker carries the cigarette to the mouth by the non-perforated end, the efficiency will be even lower insofar as the perforations will have disappeared as of the third puff.

The cigarette sheet proposed according to the invention to achieve the desired goal which is a 50% decrease of tars per puff, has an identical width of 35 mm, a band reserved for ventilation centered on the middle of the sheet and width 9 mm, identical circular perforations of diameter 300 microns located in the band reserved for ventilation, over a width of 7.5 mm and over the entire length of the sheet, ie 70 mm.

Circular holes being 2.5 mm apart, 3 columns (parallel to the axis of the cigarette) by 22 rows (perpendicular to the leaf axis) of holes are available for ventilation. Indeed, the cigarette rolled to a diameter of 7 mm in a sheet of 35 mm has an overlap of 13 mm and thus leaves a band uncoated 9 mm that we call band reserved for ventilation. We do not take into account the holes that are covered by the lips of the smoker is the first thirteen millimeters of the length of the sheet of cigarette paper.

It is also considered that the holes beyond 13 mm and below 27 mm, which is the standardized length of the butt, are holes that will be present throughout the smoking operation with their efficiency of 1.3%. There are 5 rows of three holes in this area. Beyond this zone, there are 51 holes with 17 rows of 3.

Each row has a different efficiency in that it disappears more or less early in the smoking operation. Thus, we verified that the same 300 micron circular hole located 20 mm from the opposite end of the mouth had an efficiency of only 0.6%. As a first approximation, we can say that the efficiency of the holes decreases linearly between the value of 1.3% (located before the 27 mm dimension) and 0% (located at the 70 mm dimension, end of the cigarette).

By integrating these results on the 17 rows, we obtain an efficiency of 11.4% per column of 17. If we add the 5 rows to 1.3% located in the butt but beyond the lips, we obtain an efficiency of the column of 22 rows, equal to 17.9% .As there are three columns available in the ventilation band, the desired goal is achieved.

Example 2: Circular holes of 300 microns are made on the periphery of a cigarette, about 20 mm from the end brought to the mouth. Three rings of 13 holes are placed at 17.5 mm, 20 mm, and 22.5 mm from the end of the sheet brought to the mouth. As we saw in example 1, the cigarette being rolled to a diameter of 7 mm, the width of the sheet of cigarette paper being 35 mm, only three holes per row will not be obstructed. Therefore, with only 9 holes available instead of 39, the proposed cigarette sheet is unable to lead to a desired 50% tar reduction.

The cigarette sheet proposed according to the invention to achieve the desired purpose, has a width of 28 mm, a band reserved for ventilation centered on the middle of the sheet and 16 mm wide, a block of circular perforations located in the band reserved for ventilation, 15 mm wide and 14 mm long, between dimension 13 and dimension 27 mm measured from the end worn to the mouth, this end being indicated by a printed line on the sheet of cigarette paper. This trait is part of the invention and contributes to the purpose of the invention insofar as it is it that allows the perforator to position the block on the length of the sheet. In fact, the perforation and the eventual cutting of the sheet can be synchronized with the scrolling of the original sheet, thanks to this printed line. The block contains circular holes 2.5 mm apart, 7 columns (parallel to the axis of the cigarette) in 6 rows (perpendicular to the axis of the sheet). When the 7 mm diameter cigarette is rolled with the cigarette paper sheet according to the invention described in Example 2, 42 1.3% efficiency holes are available and the desired goal is achieved.

In the two examples treated, the diameter of the rolled cigarette is 7 mm, which is a value generally found and close to the value retained 7.2 mm in the future international standard. However, in some markets, consumers roll their cigarettes to smaller diameters, for example 5.5 mm. It is obvious that the present invention applies regardless of the diameter found on the market, the widths of the sheet of cigarette paper according to the invention can be adjusted to release a band reserved for ventilation of sufficient width. It is also clear that the size of the holes and the distance between the holes can be adjusted to achieve the desired efficiency.

According to one embodiment of the invention, the band reserved for ventilation extends over the entire length of the sheet and is centered on the axis passing through the middle of the short side of the sheet and parallel to the large side of the sheet. the sheet. Its width is that left free of recovery in an average cigarette as found on the target market.

According to one embodiment of the invention, the holes are not circular, but can take any geometric shape and have a particular orientation with respect to the axes of the cigarette.

According to one embodiment of the invention, the size of the holes is included in a nonlimiting manner between 50 and 500 microns. The distance between the holes can be any and limited only by criteria related to the physics of paper or the physics of perforation.

According to one embodiment, the sheet of cigarette paper is provided with a distinctive sign on the end to be put in the mouth. This distinctive sign may be, but not limited to, a notch, a thread, an impression, a punch.

According to one embodiment of the invention, the perforation zone may be perforated during the scrubbing or sizing operation of the cigarette paper sheets.

In another embodiment, the holes are not present in the making of the cigarette, but appear as the cigarette is smoked. For example and without limitation, a clog of the hole can melt under the effect of the heat of the cone of combustion or an obstructor of the hole can open under the effect of the aspiration of the smoker.

According to another embodiment, the width of the sheet of cigarette paper is deliberately reduced in the limit of rolling ability, so as to expand the band reserved for ventilation to the point that all the necessary holes can be accommodated.

The perforation sizes proposed above allow very significant reductions in tar levels of the order of 50%, while remaining in the field of smokable cigarettes.

Thanks to this technique, reductions in the order of 50% of the tar rates have been obtained, without increasing the number of flushes significantly, which is also an important advantage.

It is easy by non-selective perforation techniques to reduce tars of the order of 25%. But as soon as a stronger reduction is envisaged, it is more difficult to be content with natural porosity or electrostatic perforations. Laser perforations are prohibitively expensive and difficult to practice in the long direction of the cigarette.

We therefore preferentially adopt a mechanical perforation, which proves to be able to achieve significant reductions in tars without major obstacles. This mechanical perforation, preferably without removing paper, in practice by drilling with needles, for example, repels the paper rather than removing the paper pellet in the manner of a cookie cutter. After perforation, the sheet of paper has, around the perforation, a collar raised on a particular face of the paper.

An advantageous arrangement has been identified here, consisting in observing the appearance of this raised neck, and advantageously placing the latter in the outer part of the cigarette, so that the tobacco does not push back the neck in the direction of a obstruction of the perforation.

For this, it also turns out that the positioning to the outside is also possible in the context of a sheet of rolling paper having a gum net known per se. The raised part of paper is then placed on the face opposite to that carrying the gum net, thus inducing an adequate placement of the parts raised outside the cigarette during an ordinary rolling operation.

A preformed tube of cigarette paper preferably also has this arrangement, that is to say is preferentially a pre-perforated tube whose perforations have been made in a direction corresponding to the inner to outer direction of the tube.

Claims (14)

1. A cigarette paper sheet equipped with an area of perforations (120,250), the area of perforations forming a strip parallel to the longitudinal axis of the cigarette, this strip having a central axis placed sufficiently close to the centre of the width of the sheet (200) so that it is found outside the overlapping area of the paper after rolling of the cigarette, characterized in that the perforations (120,150) have a size comprised between 50 and 500 microns, and in that the perforations are of the embossed paper type, and in that the face of the paper sheet bearing the embossed portion of the perforations is the outer face.
2. The cigarette paper sheet according to claim 1, characterized in that the perforations have a size comprised between 250 and 350 microns.
3. The paper sheet according to claim 1 or claim 2, characterized in that the strip of perforations (120, 150) has its centre at half-length of the sheet.
4. The cigarette paper sheet (100) according to any of the preceding claims, characterized in that the strip of perforations (120, 150) is placed at half-width of the sheet.
5. The cigarette paper sheet (200) according to any of the preceding claims, characterized in that the area of perforations extends over only a portion of the length of the sheet and in that the mouth side of the paper is materialized by a mark (220) on the sheet itself.
6. The cigarette paper sheet according to the preceding claim, characterized in that the mark (220) is a notch, a thread, an imprint or a hallmark.
7. The cigarette paper sheet according to any of the preceding claims, characterized in that the width of the sheet (200) is sufficiently narrow for obtaining after rolling, a width without any overlapping which is larger than a quarter of the perimeter of the cigarette.
8. The cigarette paper sheet according to any of the preceding claims, characterized in that the perforations are covered with a blocking agent provided for melting under heat so as to be released when approaching the incandescence point of the cigarette.
9. The cigarette paper sheet according to any of the preceding claims, characterized in that the perforations were made during the gumming operation.
10. The cigarette paper sheet according to any of the preceding claims, characterized in that it has a thin line of gum, and in that the perforations are of the mechanically embossed type, the thin gum line being placed on a face opposite to the face having the embossed portion of the perforations.
11. A plate of cigarette papers, characterized in that it includes one or more cigarette paper sheets according to any of the preceding claims.
12. A package of stacked cigarette papers, characterized in that it includes one or more cigarette paper sheets according to any of claims 1 to 10.
13. A roll of cigarette paper, characterized in that it includes one or more cigarette paper sheets according to any of claims 1 to 10.
14. A preformed tube of cigarette paper, characterized in that it is formed by a cigarette paper sheet according to any of claims 1 to 10.

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