MXPA98005505A - Wrapping papers of high and low porosity for articles of smoking and process for the elaboration of the mis - Google Patents

Abstract

The present invention relates to a method for controlling the permeability of wrapping paper for smoking articles. Specifically, the permeability of the paper is varied by incorporating a filler material having a particular particle size into the paper. In one embodiment, for example, a filler having a larger size than conventional sized fillers is incorporated into the wrapping paper to significantly increase the permeability of the wrapping paper. For example, the wrapping papers can be made according to the present invention having a permeability greater than 80 CORESTA units without having to perforate the paper

Description

«Fe 1 HIGH AND LOW POROSITY WRAPPING PAPERS FOR SMOKING ARTICLES AND PROCESS FOR THE ELABORATION OF THEM Field of the Invention The present invention relates in general to a method for controlling and adjusting the permeability of wrapping papers for smoking articles. More particularly, the present invention relates to a method for producing high porosity cigar papers by incorporating into the wrapping paper 10 a filler having a relatively large particle size. In an alternative embodiment, the present invention also relates to a method for producing low porosity cigarette wrapping papers using smaller size filler particles.

BACKGROUND OF THE INVENTION Smoking articles such as cigars are conventionally made by wrapping a column of tobacco on white wrapping paper. At one extreme, the smoking article usually includes a filter through which the article is smoked. The filters are attached to the smoking articles using a pointed paper which is attached to the paper of REF: 27058 white wrap. The wrapping papers and the pointed papers used to make smoking articles are typically made from linen or other cellulosic fibers and contain a filler, such as a calcium or magnesium compound.

Apart from being used to hold the cigar together and to provide the cigar with an aesthetic appearance, the cigarette wrapping papers also contribute or control many physical properties or characteristics of the cigar. For example, the cigarette wrapping paper can be used to control the speed at which the cigar is burned, the number of puffs per cigar, and the tar released per puff. Cigarette paper can also be used to limit the amount of smoke that emanates from the burning end of the cigar when it stops burning. In addition, cigarette paper is still used to reduce the tendency of cigars to ignite surfaces that come in contact with the cigar and to cause the cigar itself to turn off when smoking is stopped.

One of the most important properties of the cigarette wrapping paper used to control the characteristics described above of a cigar is the permeability of the paper. Increasing or decreasing the permeability of a wrapping paper, for example, varies the rate of burning, the release of tar, and the number of puffs of a cigar made with paper. Problems have been experienced in the past, however, in the ability to widely vary the permeability of a wrapping paper without adversely affecting other paper properties or the overall flavor of the cigar.

One method that is used to control the permeability of a wrapping paper is to vary the fiber supply that is used to make the paper. In general, it is known that if longer fibers are used to make the wrapping paper, the paper will have a higher permeability.

Another method for controlling the permeability of a wrapping paper is either to increase or decrease the refining of the fiber supply. In general, refining the fiber supply to a greater degree causes a reduction in permeability. More particularly, the refining of the cellulosic material used to make the paper into smaller sizes creates more surface area, which reduces permeability and leads to better formation.

Another method to alter the permeability of a wrapping paper is to change the amount of filler added to the paper. Increasing or decreasing the filler load of the paper causes an increase or decrease in permeability respectively. As more filler is added to the paper, the filler tends to interfere with the hydrogen bond between the fibers creating the increase in permeability. Unfortunately, however, altering the levels of filler in the cigarette paper also affects the rate of cigarette burn regardless of permeability, which could be an undesirable result.

Other problems are also experienced when the filler levels are altered. For example, as the filler content is increased, the paper strength is compromised. On the contrary, when not enough filler is incorporated in the paper, the opacity of the paper decreases significantly, adversely affecting the appearance of the cigar. As such, there is increased pressure to maintain the levels of filler in the cigarette paper constant or at least within a set range.

In some applications, it is desirable to create a wrapping paper having a high natural permeability. For example, highly permeable wrapping papers are needed in some applications to produce cigars having a rapid burn rate and / or a low release of tar. Some of the methods and processes described above for varying the permeability of a wrapping paper can be used, under some circumstances, to produce papers with highly natural permeability characteristics.

To increase the permeability of the wrapping papers, it is more common, however, to perforate the papers using a laser or using or electrostatic charging. Unfortunately, the perforation of the wrapping paper requires an additional step and thus increases the production cost of the papers.

Thus, there is a need for a method of naturally adjusting the permeability of a cigarette paper without adversely affecting other characteristics of the paper. There is also a need for a method of altering the permeability of a wrapping paper without having to significantly alter the amount of filler contained within the paper. There is an additional need for a method of producing wrapping papers with a high permeability that does not have to be perforated.

Description of the invention The present invention recognizes and addresses the above disadvantages, and other constructions and methods of the prior art.

Therefore, it is an object of the present invention to provide an improved method of making cigar wrapping papers.

Another object of the present invention is to provide a method for controlling the permeability of a cigar wrap.

It is another object of the present invention to provide a process for producing wrapping papers having a naturally high permeability.

It is still another object of the present invention to provide a process for producing wrapping papers with a high permeability without having to perforate the papers.

It is another object of the present invention to provide a process for increasing the permeability of a wrapping paper by incorporating into the wrapper a filler having a relatively large average particle size, such as a size of at least 2.3 microns.

It is still another object of the present invention to provide a process for increasing the permeability of a wrapping paper without significantly varying the total content of the filler.

Another objective of the present invention, in an alternative embodiment, is to provide a process for producing paper wrappers having low permeability by incorporating into the wrappers a filler having a relatively small particle size.

In general, the present invention relates to a process for increasing the permeability of a wrapping paper for a smoking article. The process includes the step of adding a wrapping paper to a filler. The filler has an average particle size of at least 2.3 microns and is added to the paper in a sufficient amount such that the paper has a permeability of at least 60 CORESTA units, and more particularly at least 80 CORESTA units. For example, in one embodiment of the present invention the wrapping paper can have a permeability from about 100 CORESTA units to about 200 CORESTA units.

As described above, the permeability of the wrapping paper is increased by adding a filler having an average particle size of at least 2.3 microns, particularly from about 2.3 microns to about 12 microns. In one embodiment, the average particle size of the filler can be from about 2.3 microns to about 9 microns and in a preferred embodiment of the present invention, the average particle size of the filler is from about 3 microns to about 4 microns. The filler may be added to the paper so that the paper has a total filler level from about 20% by weight to about 45% is weight, and more particularly from about 30% by weight to about 40% is weight. The filler may be of various inorganic compounds, such as calcium carbonate.

The paper wrapping papers made in accordance with the present invention can have a basis weight from about 18 gms to about 40 gs, and particularly from about 22 gms to about 30 gms. A burn control additive may be added if desired. The burn control additive may be an alkali metal salt, such as sodium or potassium citrate, or an acid salt, such as sodium or potassium phosphate. The burn control additive can be added in an amount from about 0.3% to about 16% by weight.

These and other objects of the present invention are also achieved by providing a naturally highly permeable wrapping paper for a smoking article. The wrapping paper includes a wet base of pulp fibers. In accordance with the present invention, a filler is incorporated into the wet base having an average particle size of at least about 2.3 microns. The filler is present in the wet base in an amount up to 45% by weight, which produces a wrapping paper having a permeability of at least 80 CORESTA units.

Other features, objectives and aspects of the present invention are discussed in greater detail below.

Brief Description of the Drawings A complete and capable disclosure of the present invention, including the best form thereof, to one of ordinary skill in the art, is set forth more particularly in the specification reminder, including reference to the accompanying figure, in which : The figure is a graphic illustration of the results obtained in Example 1.

Detailed Description of the Preferred Modalities It is to be understood by one of ordinary skill in the art that the present discussion is a description of only the exemplary embodiments, and are not intended as limiting the broader aspects of the present invention, which are modalized in the exemplary construction.

The present invention relates generally to a method for controlling the permeability of a paper wrapper for a cigar. The permeability of the wrapper is controlled by incorporating into the wrapper a filler having a particular average particle size. More particularly, according to the present invention, the permeability can be controlled exclusively as a function of the particle size of the filler with respect to the total amount of the filler contained in the paper. In other words, the permeability of the paper can be controlled and adjusted without significantly increasing or decreasing the total content of filler beyond conventional levels.

For example, in a preferred embodiment of the present invention, highly permeable natural wrapping papers are produced by incorporating into the paper a filler having a relatively large particle size. Wrapping papers that have high permeability and are used and desired when making smoking articles, such as cigars, that have a rapid burn rate and / or a low tar release. In the past, highly permeable wrapping papers have typically been produced by perforating the paper. Unfortunately, the perforation of the wrapping paper adds to the cost of paper production.The process of the present invention, however, can naturally produce highly permeable cigarette wrapping papers which reduces the need to perforate the paper. In addition, the process of the present invention can be used to increase the permeability of the paper wrap without significantly altering any of the other properties and characteristics of the paper. Actually, wrapping papers having a high permeability can be produced without having to significantly increase or decrease the conventional levels of filler in the paper.

According to the present invention, the highly permeable natural wrapping papers are produced by incorporating into the papers a filler having an average particle size which is larger than the fillers that have been conventionally used in the cigarette paper. For example, the filler may have an average particle size of at least 2.3 microns, and more particularly from approximately 2.3 microns to approximately 12 microns. In most applications, the filler may have an average particle size from about 2.3 microns to about 9 microns and, in a preferred embodiment, it has an average particle size from about 2.3 microns to about 4.0 microns. As used herein, the average particle size refers to the size of a filler as measured and determined by a sedimentation method using, for example, a sedigraph.

By incorporating a filler having a particle size within the range described above, a high permeability paper can be produced. For example, paper may have a permeability greater than 60 units CORESTA, and more particularly greater than 80 CORESTA units.

For example, a wrapping paper can be produced according to the present invention having a permeability from about 100 CORESTA units to about 200 CORESTA units. Of particular advantage, such high permeability levels can be obtained without having to perforate the paper.

The amount of filler added to the paper in general depends on the desired permeability and particle size of the filler used. Of particular advantage, however, the levels of permeability described above can be obtained without substantially increasing the level of filler in the paper of conventional levels. Thus, for most applications, the total filler level in the paper can be from about 20% by weight to about 45% by weight, and particularly from about 30% by weight to about 40% by weight.

In the manufacture of paper wrappers according to the present invention, a single larger size filler may be added to the paper. Alternatively, however, mixtures of fillers of different sizes could be used. For example, mixtures of different fillers of larger size could be added to the paper or a larger size filler could be mixed with a filler having a smaller conventional size. In one embodiment of the present invention, a filler having a particle size from about 2.5 microns to about 4 microns is added to the paper in an amount of about 35% by weight to produce a paper having a permeability greater than 80 units CORESTA .

It is believed that any filler material could be used in the process of the present invention. Such fillers could include, for example, calcium carbonate, titanium dioxide, magnesium carbonate, magnesium oxides and the like. It is also within the scope of the present invention to mix different types of filler materials to obtain a wider range of particle sizes and morphologies. For example, a calcium carbonate filler could be mixed with a magnesium oxide filler. In a preferred embodiment of the present invention, a precipitated calcium carbonate filler having a larger average particle size of 2. 3 micrometers When the fillers are added to the paper, the filler particles interfere with the fiber to fiber bond that occurs between the cellulosic fibers during paper formation. It is believed that the filler particles maintain themselves between adjacent fibers creating an empty space and thereby an increase in the porosity of the paper. It has been discovered by means of the present invention that the degree to which the fiber to fiber link is interrupted by the filler depends not only on the number of particles, but also on the morphology of the particles. In particular, it is believed that as the size of the filler particles increases, the fibers separate further away creating larger pores in the paper. It has also been unexpectedly discovered that as filler particles of larger size are used, the increase in permeability is more linear.

In the incorporation of a larger size filler into a wrapping paper according to the present invention, in one embodiment, the filler can be combined with water to form a filler suspension. The suspension can then be added to a suspension of cellulosic fibers when the paper is formed. For example, fiber in suspension can be formed from a supply of fiber that has been cooked in a digester, washed, bleached and refined. To form the wrapping pallet, the resulting suspension and the suspension fiber mixture can be spread on a screen or a group of screens and dried.

The basis weight of the wrapping paper made according to the present invention is generally not critical. In most applications, however, the paper should have a basis weight from about 18 gms to about 40 gms, and more particularly from about 22 gms to about 30 gms. In a preferred embodiment, a wrapping paper is produced having a basis weight of 28 gms.

The wrapping paper of the present invention could also be treated with a burn control additive. Such burn control additives may include, for example, alkali metal salts, such as potassium or sodium citrate, acid salts, such as sodium or potassium phosphates. The different types of burn control additives can also be mixed and applied to the paper. The burn control additive can be added to the paper in an amount from about 0.3% to about 16% by weight, and in an application from about 0.3% to about 3% by weight.

The present invention could be better understood with reference to the following examples.

EXAMPLE NO. 1 To demonstrate the present invention, several hand sheets were made. One group of sheets contained ALBACAR 5970 calcium carbonate filler having an average particle size of 1.9 microns. ALBACAR 5970, which is sold by Specialty Minerals, Inc. of Adams, Massachusetts, has traditionally been used in the past as a filler in wrapping papers for smoking articles.

In the second group of samples, the sheets contained calcium carbonate filler RX3899 also obtained from Specialty Minerals, Inc. The RX3899 filler has an average particle size of 2.7 microns.

All the manual sheets that were made had a base weight of 28 gms and a filler load of 30% by weight.

The amount of refining supply fiber, however, was varied in each group of samples. Specifically, the hand sheets of both groups of samples were made with linen fiber supplies that recorded 10,000, 14,000, and 18,000 revolutions in a PFI mill. The results are illustrated in the figure.

As is generally known in the art, as the refinement of the supply increases, the permeability decreases as shown in the accompanying figure. The figure, however, also shows that the permeability of the manual sheets of filler axles of larger size was greater than the manual sheets of the filler of smaller size. In addition, the permeability increased more rapidly with respect to the manual sheets made of larger size filler as the amount of refinement of the fiber supply was decreased. Specifically, the permeability of the manual sheets using the larger size filler increased more than 25%.

EXAMPLE NO. 2 In this example, a wrapping paper made using the ALBACAR 5970 filler having an average particle size of 1.9 microns was compared to the wrapping papers made using the ADX 7014 filler having an average particle size of 3.5 microns. Both fillers were obtained from Specialty Minerals, Inc. In this example, the wrapping papers were made using a paper machine. The fillers were made of precipitated calcium carbonate.

Three (3) different wrapping papers were made. The three papers had a base weight of 28 gms. The first processed paper contained ALBACAR 5970 in an amount of 26% by weight. The remaining two papers contained ADX 7014 filler in an amount of 25% by weight and 33% by weight respectively. Once the wrapping papers were made, they were tested for permeability. The following results were obtained: As shown in the table, wrapping papers made using ADX 7014 filler had a higher permeability than wrapping paper made from the conventional ALBACAR 5970 filler. Of particular importance, in Example No. 3, the level of filler in the paper only 7% was increased but paper permeability more than doubled. Because the filler level was increased, the paper strength decreased slightly.

In addition to using larger size fillers to increase the permeability of the wrapping papers, the present invention also relates to using smaller size fillers to make papers under permeable. Such low permeable papers could be used in reducing the smoke stream emanating from the end of the cigar made with paper. For example, it is believed that wrapping papers having a permeability of less than 7 CORESTA units can be made by incorporating in the wrapper a filler having an average particle size of less than about 0.1 microns, such as from about 0.1 microns to about 0.01 micrometers For example, in one embodiment, a calcium carbonate filler having an average particle size of about 0.07 microns can be used to construct a wrapping paper having a permeability of less than 5 CORESTA units, and particularly from about 3 to 4 CORESTA units. Such wraps could be constructed having the same filler levels and other characteristics and properties as mentioned above. The papers could have a higher basis weight, however, such as up to about 60 gms.

These and other modifications and variations to the present invention could be practiced for those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. Furthermore, it should be understood that aspects of the various modalities could be exchanged in whole or in part. Those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention to that described in such appended claims.

It is noted that in relation to this date, the best method known to the applicant parcL carrying out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (24)

1. A process for increasing the permeability of a wrapping paper for a smoking article, characterized in that it comprises the step of: adding a filler to the wrapping paper, the filler has an average particle size of at least 2.3 microns, the filler is added to the wrapping paper in a sufficient amount such that the wrapping paper has a permeability of at least 80 CORESTA units.

2. A process as defined in claim 1, characterized in that the filler has an average particle size from about 2.3 microns to about 9 microns.

3. A process as defined in claim 1, characterized in that the filler has an average particle size from about 3 microns to about 4 microns.

4. A process as defined in claim 1, characterized in that the filler is added to the wrapping paper in an amount of up to about 45% by weight.

5. A process as defined in claim 4, characterized in that the wrapping paper has a basis weight from about 18 gms to about 40 gms.

6. A process as defined in claim 4, characterized in that the filler contains calcium carbonate.

7. A process as defined in claim 5, characterized in that it further comprises the step of adding a burn control additive to the wrapping paper.

8. A process as defined in claim 1, characterized in that the filler is added in combination with a second filler to the wrapping paper, the filler has a larger average particle size than the second filler.

9. A process for producing a wrapping paper highly permeable naturally for a smoking article, characterized in that it comprises the step of: incorporating in a wrapping paper a filler, the filler has an average particle size from about 2.3 microns to about 12 microns, the filler is incorporated in the wrapping paper in a sufficient amount such that the wrapping paper has a permeability of minus 80 CORESTA units, the wrapping paper contains a total level of filler from about 20% to about 45% by weight.

10. A process as defined in claim 9, characterized in that the filler has an average particle size from about 3 microns to about 4 microns.

11. A process as defined in claim 9, characterized in that the wrapping paper has a total level of filler from about 30% to about 40% by weight.

12. A process as defined in claim 11, characterized in that the wrapping paper wrapping paper has a basis weight from about 22 gms to about 30 gms.

13. A process as defined in claim 9, characterized in that the filler contains calcium carbonate.

14. A process as defined in claim 9, characterized in that it further comprises the step of applying a burn control additive to the wrapping paper, the burn control additive is added to the wrapping paper in an amount from about 0.3% to about 12% by weight.

15. A process as defined in claim 9, characterized in that the wrapping paper has a permeability from about 100 CORESTA units to about 200 CORESTA units.

16. A wrapping paper highly permeable naturally for a smoking article, characterized in that it comprises: a moist base made of pulp fibers; a filler incorporated in the wet base, the filler has an average particle size of at least 2.3 microns, the filler is present in the wet base in an amount of up to about 45% by weight; and wherein the wrapping paper has a natural permeability of at least about 80 CORESTA units.

17. A wrapping paper as defined in claim 16, characterized in that the filler has an average particle size from about 3 microns to about 8 microns.

18. A wrapping paper as defined in claim 16, characterized in that the filler is incorporated in the wet base in an amount from about 20% to about 40% by weight.

19. A wrapping paper as defined in claim 18, characterized in that the wrapping paper has a basis weight from about 22 gms to about 32 gms.

20. A wrapping paper as defined in claim 16, characterized in that the filler contains calcium carbonate.

21. A wrapping paper as defined in claim 16, characterized in that the wrapping paper has a natural permeability from about 100 CORESTA units to about 200 CORESTA units.

22. A highly permeable wrapping paper for a smoking article, characterized in that it comprises: a moist base made of pulp fibers; a filler incorporated in the wet base, the filler has an average particle size of at least 2.3 microns to about 9 microns, the filler is present in the wet base in an amount of up to about 40% in pe¬ a burn control additive applied to the wet base, the burn control additive is added in an amount from about 0.3% to about 16% by weight; Y wherein the wrapping paper has a basis weight from about 22 gms to about 30 gms and has a natural permeability of at least 80 CORESTA units.

23. A wrapping paper as defined in claim 22, characterized in that the filler contains calcium carbonate.

24. A wrapping paper as defined in claim 23, characterized in that the filler is present in the wrapping paper in an amount from about 20% to about 40% by weight and wherein the filler has an average particle size from about 2.3 micrometers to about 4.0 micrometers.