EP1460908A1

EP1460908A1 - Improvements relating to smokable filler materials

Info

Publication number: EP1460908A1
Application number: EP02791917A
Authority: EP
Inventors: Kevin Gerard Mcadam; Gordon R. British American Tobacco GRIERSON; Debra Demeter Woods
Original assignee: British American Tobacco Investments Ltd; British American Tobacco Co Ltd
Current assignee: British American Tobacco Investments Ltd
Priority date: 2001-12-21
Filing date: 2002-12-23
Publication date: 2004-09-29
Anticipated expiration: 2022-12-23
Also published as: RU2293502C2; GB0130627D0; ZA200405835B; MXPA04006160A; BR0215208A; RU2004122619A; CN1617680A; AU2002358221A1; CA2469917A1; WO2003055337A1; JP2005512585A; DE60219956D1; KR20040068292A; AU2002358221B2; US20050098187A1; EP1460908B1; ATE361002T1

Abstract

The present invention provides an agglomerated tobacco filler material comprising dust and binder, the tobacco dust and binder being present at greater than 650 by weight of the agglomerated tobacco filler material, the material having a fill value substantially similar to the fill value of cut tobacco. The present invention further provides a method of making the agglomerated tobacco filler material of the present invention, and a smoking article incorporating said material.

Description

Improvements relating to Smokable Filler Materials

The subject invention relates to smokable filler materials and more particularly to agglomerated tobacco filler material, and smoking articles incorporating such material .

As a result of primary and secondary processing, dust and fines of no further commercial use are produced. The fine tobacco may have a high silica content, which because of its abrasive nature renders the fine tobacco less than desirable for use in a further process which utilises cutting or grinding apparatus. The fine tobacco waste that cannot currently be processed further is taken for landfill. In the current economic climate reduction of landfill is desirable for financial and environmental reasons. Any process which maximises tobacco waste usage has great benefit .

Paper-making processes currently used for making reconstituted tobacco products need a high throughput to make them efficient and cost effective. Paper-making processes may not be suitable for certain factories due to lack of expensive apparatus or low volume of materials. Any process utilising waste without the need for high cost apparatus would be of significant benefit. The utilisation of some tobacco dust in reconstituted products is long since known, for example in products such as reconstituted sheet material, bandcast sheet and extrusion products as previously described in our patents GB 2201081 and GB 2201080. Such products utilise processed tobacco dust and can be incorporated into smoking articles at inclusion levels of up to 30% by weight of material in the tobacco rod. Some of these products, in particular bandcast sheet and products of extrusion, have poor handling properties and are susceptible to degradation during further processing. Such reconstituted products have fill values in the range of 2.5cm³/g to 3.5cm³/g, these fill values being substantially lower than those of cut tobacco (5cm³/g to 6cm³/g) and reconstituted tobacco sheet (8.0cm³/g to 8.5cm³/g) .

The agglomeration of tobacco dust and fines has been previously proposed as a means of generating reconstituted tobacco products.

In US 3,894,544 a process for the production of reconstituted tobacco material is described in which ribs ^• and wastes are moistened with a liquid, kneaded together to form a dough-like mass which is then shaped to form leaf-like structures. The leaf-like structures are spread under pressure to form individual flakes . DE 3 312 159 describes a method of manufacture for tobacco leaf-like material by pelletising a mixture of fine tobacco particles, fibres, water and binder and rolling out the pellets to a desired thickness to give a material that may be added directly to cut tobacco.

US 4,341,228 describes a process in which tobacco dust is mixed with a bonding material, the mixture is then treated so as to form agglomerated fibres . These agglomerated fibres are mixed with tobacco-parts in a slurry and formed into a sheet by means of a paper-making process. That sheet is then dried and shredded. The agglomerated tobacco dust particles are of a size such that they do not pass through a 56 mesh screen, and preferably do not pass through a 20 mesh (0.84mm) screen.

Each of these methods results in a product through compaction with added binders thereby resulting in a dense reconstituted tobacco product.

It is an object of the present invention to provide an agglomerated tobacco product in which tobacco waste, and in particular tobacco dust currently of no commercial value may be utilised to give a product having a fill value substantially similar to that of cut tobacco.

It is a further object of the present invention to provide an agglomerated tobacco product which can use waste of high silica content, such waste usually being of no commercial value in conventional reconstituted tobacco products and processes due to silica being highly abrasive to grinders and cutters used in further processing.

It is an even further object of the present invention to provide an agglomerated tobacco product capable of being used instead of, or in combination with, other reconstituted tobacco material in smoking articles, wherein the fill value of the agglomerated tobacco filler material is substantially similar to that of cut tobacco.

It is a yet further object of the present invention to provide an agglomerated tobacco filler material having acceptable handling properties and reduced frangibility such that the product may be directly incorporated into smoking articles without the need for further processing.

The present invention also has as an object an agglomerated tobacco filler material that is produced using fluidised bed technology and low process temperatures in a one-step procedure.

As referred to herein, ^x fill value' shall be taken as meaning the volume measured in cubic centimetres taken up by 1 gram of product. Fill value is measured using a Borgwaldt Densimeter (DD 60A) by taking a known weight of sample contained in a stainless steel cylinder of known dimensions, for example a cylinder of 3cm radius, and subjecting the sample to pressure from a weighted piston (for example 1kg extra weight) for 30 seconds. The residual height of the compressed sample is measured and converted to volume. Results are recorded in cm³/g. Measurements of fill value were done with the equipment described.

Bulk density shall be taken as meaning the weight of product (grams) per unit volume (cm³) . Results are recorded in g/cm³.

The present invention provides an agglomerated tobacco filler material comprising tobacco dust and binder, the amount of tobacco dust and ' binder being greater than 65% by weight of the agglomerated tobacco filler material, said agglomerated tobacco filler material having a fill value substantially similar to the fill value of cut tobacco.

Preferably the tobacco dust and binder are present at more than about 70% by weight of the agglomerated tobacco filler material, more preferably the tobacco dust and binder are present at more than about 75% by weight, and even more preferably at more than about 80% by weight . Even more preferably the tobacco dust and binder are present at more than about 85% by weight and most preferably are present at more than about 90% by weight of the agglomerated tobacco filler material .

Preferably the agglomerated tobacco filler material has a fill value in the range of about 4.40cm³/g to about 5.50cm³/g, and more preferably is in the range of about 4.90cm³/g to about 5.30cm³/g.

Preferably the agglomerated tobacco filler material has a granule size up to about 3.5mm. More preferably the granule size is at least 0.7mm and not more than about 2.0mm. Most preferably the granule size is in the range of about 0.8mm to about 2.0mm.

Preferably the agglomerated tobacco filler material has a moisture content in the range of about 8% to about 18%. More preferably the agglomerated tobacco filler material has a moisture content in the range of about 10% to about 15.5%.

The agglomerated tobacco filler material of the present invention advantageously has a bulk density substantially similar to that of cut tobacco.

The bulk density value of a product is essentially equal to the reciprocal of the fill value for that product. For the agglomerated- tobacco filler material the bulk density should advantageously be matched to that of cut tobacco, such that the agglomerated tobacco filler material will have a reduced tendency to de-blend when compared with products, such as the products described in GB 2201081, having a bulk density substantially dissimilar to that of cut tobacco.

Preferably the bulk density of the agglomerated tobacco filler material is in the range O.lOg/cm³ to 0.33g/cm³, and more preferably is in the range 0.12g/cm³ to 0.25g/cm³, and even more preferably is in the range 0.12g/cm³ to 0.14g/cm³. Most preferably the bulk density of the agglomerated tobacco filler material is about 0.14g/cm³. Advantageously, the agglomerated tobacco filler material comprises tobacco dust at more than about 70% by weight, preferably more than about 75% by weight. Even more preferably tobacco dust is present in the range of about 75% to about 95% by weight of the agglomerated material. The agglomerated tobacco filler material suitably comprises tobacco dust in the range of about 80% to about 90% by weight of the agglomerated material.

The agglomerated tobacco filler material further comprises a binder, wherein the binder is preferably present in the range of about 1% to about 15% by weight of the agglomerated material . More preferably the binder is present in the range of about 1.5% to about 8% by weight, and is more preferably in the range of about 3.0% to about 6% by weight, and even more preferably is about 5% by weight of the agglomerated material .

When the binder is maltodextrin, the binder is advantageously present in the range of about 1% to about 30% by weight of the agglomerated material. More preferably when the binder is maltodextrin the binder is present at about 27% by weight of the agglomerated material . Suitably the binder is selected from the group consisting of organic binders, such as an alginate, a gum, a cellulose (modified or natural) , a pectin or pectinaceous binder, or the Group I or II metal salts of these binders, such as sodium carboxymethylcellulose (NaCMC) , or sodium alginate; maltodextrin or polyvinylpyrrolidine (PVP) .

Much preferred binders are pectinaceous binders, and most preferably the binder is a pectin.

Other organic binders include soluble alginates, such as ammonium alginate, sodium alginate, sodium calcium alginate, calcium ammonium alginate, potassium alginate, triethanolamine alginate and propylene glycol alginate .

Cellulosic binders include, for example, cellulose derivatives, such as sodium carboxymethylcellulose, methylcellulose, hydroxylpropylcellulose (HPC) , hydroxylethylcellulose or cellulose ethers.

Other binders include gums such as gum arabic, gum ghatti, gum tragacanth, Karaya, locust bean, acacia, guar, quince seed or xanthan gum, or gels such as agar, agarose, carrageenans, fucoidan and furcelleran.

Starches can also be used as organic binders. Other suitable gums can be selected by reference to handbooks, such as 'Industrial Gums', Ed. Whistler (Academic Press). Other suitable binders will be known to a person skilled in the art.

The agglomerated tobacco filler material may additionally comprise a humectant . The humectant may suitably be one or- more of glycerol, sorbitol, diethylene glycol and propylene glycol . Other suitable humectants will be known to a person skilled in the art.

Preferably the humectant is present in the range of 1% to about 5% by weight of the agglomerated material. The humectant improves the flexibility and the moisture content of the agglomerated tobacco filler material such that the filler material is more robust during handling and storage .

The agglomerated tobacco filler material may additionally comprise inert fillers and/or flavourant material .

Suitably the inert filler may be one or more of the group consisting of silicates or alumino-silicates, such as perlite, vermiculite, diatomaceous earth, talc or colloidal silica; chalk, or metal oxides, metal salts or hydroxides such as magnesium oxide, magnesium sulphate, calcium or magnesium carbonate or alumina, or other inert fillers known to those skilled in the art.

The present invention also provides a smoking article comprising a rod of smokable material wrapped in a wrapper, wherein agglomerated tobacco filler material of the present invention is blended with cut tobacco and/or reconstituted tobacco.

Preferably the agglomerated tobacco filler material is present at up to about 25% by weight of the smokable material of the smoking article and more preferably is present at up to about 20% by weight of the smokable material . More preferably the agglomerated tobacco filler material is present in the range of about 2% to aboutl0% by weight of the smokable material, and is even more preferably present in the range of about 5% to about 6% by weight of the smokable material .

The agglomerated tobacco filler material used in a smoking article of the present invention advantageously has a granule size in the range of about 0.7mm to about 3.5mm, preferably in the range of about 0.8mm to about 1.4mm and/or a granule size in the range of about 1.4mm to about 2.0mm.

Agglomerated tobacco filler material having a granule size of less than 0.5mm may suitably be used in subsequent agglomeration steps.

Agglomerated tobacco filler material having a granule size greater than 3.5mm may be ground to a suitable particle size and reused in . subsequent agglomeration steps.

Preferably a smoking article incorporating the agglomerated tobacco filler material of the present invention has a static burn rate substantially similar to a smoking article incorporating blended Virginia tobacco having 10% reconstituted tobacco sheet.

Advantageously a smoking article incorporating the agglomerated tobacco filler material of the present invention has a firmness value substantially similar to that of a smoking article incorporating a standard Virginia blend having 10% reconstituted tobacco sheet. The present invention further provides a robust agglomerated tobacco filler material having improved handling properties. This is particularly advantageous in view of degradation suffered in tobacco primary and secondary processing stages . The agglomerated tobacco filler material has a robustness measured in accordance with the method described in Example 3 below. Robustness may be expressed as the loss of agglomerated tobacco filler material during the milling process, i.e. it is a measure of the size reduction of granules as a result of degradation. Loss of agglomerated product is the difference between the percentage of agglomerated tobacco

filler material retained on sieves of greater then 710μm before milling and the percentage of agglomerated tobacco

filler material retained on sieves of greater then 710μm after milling. Preferably the loss after milling is less than about 45% by weight of agglomerated tobacco filler material, more preferably the loss after milling is less than about 40% by weight of agglomerated material. The loss after milling is even more preferably less than about 32% by weight and is most preferably less than about 20% by weight of agglomerated tobacco filler material. The robustness of the agglomerated product may depend upon the binder used in the agglomeration process. The effectiveness of the binders in making a robust product may be listed from most effective to least effective as

Apple Pectin > PVP > HPC > Alginate > Maltodextrin > CMC.

Preferably the binder providing the most robust agglomerated tobacco filler material is Apple pectin. The present invention further provides a method of producing the agglomerated tobacco filler material of the present invention, wherein tobacco dust of particle size not more than 500μm is fluidised in a stream of warm air and binder is applied to said fluidised tobacco dust, such that an agglomerated tobacco filler material is produced having a fill value substantially similar to that of cut tobacco.

Preferably the inlet temperature of the air is not more than 80°C.

Suitably the binder is sprayed onto the fluidised tobacco dust at a spray rate in the range of about 0.01431/min/kg tobacco dust to about 0.0571/min/kg tobacco dust. Preferably the spray rate is about 0.02861/min/kg tobacco dust.

Suitably the tobacco dust and binder are mixed using the method of the present invention for between 20 and 60 minutes .

Preferably the agglomerated tobacco filler material produced by the method of the present invention has a fill value substantially similar to that of cut tobacco.

In order that the invention may be easily understood and readily carried into effect, reference will now be made to the following examples.

Example 1

Tobacco dust is ground to give a particle size of less than 500μm diameter and a bulk density of between 0.3g/cm³ and 0.38g/cm³. 300-350g of tobacco dust is loaded into the product container of an Aeromatic-Fielder STREA-1. The instrument is operated using the top spray nozzle and an inlet air temperature of 60°C. The outlet air temperature is in the range of 27 to 39°C. The dust is then fluidised in a stream of warm air. The agglomeration fluid, containing the binder, is sprayed onto the fluidised tobacco dust at a spray rate of approximately lOml/min. for between 20 and 60 minutes. The resulting agglomerated tobacco product is thus agglomerated and dried in a single operation. The moisture content of the agglomerated tobacco filler material at the end of the agglomeration process is between 12 and 16%, and is ideally about 14%. Before incorporation into a smoking article, the agglomerated tobacco filler material is conditioned to a moisture content of between 11%. and 16%.

Table 1 shows the fill values for three different tobacco blends and respective agglomerated tobacco filler materials made according to the general method described in Example 1 using Apple pectin as a binder (5% by weight of the agglomerated product) .

Table 1: Fill Values for Tobacco and Agglomerated Tobacco

Example 2

Agglomerated tobacco filler material made according to the general process described in Example 1 comprising tobacco dust at 92% by weight, 3% by weight humectant and 5% by weight binder. Example 3

The robustness of the agglomerated tobacco product was determined for agglomerates formed using a number of different binders.

A Pascall Ball-Mill, having six balls each weighing 22.5g, was used at Speed 9 for a 30 second duration with 10 grams of agglomerated tobacco product. The percentage weight of agglomerated tobacco filler material retained on a sieve of particular screen size before and after milling was recorded, and the frangibility calculated for the different samples.

Frangibility was calculated for each sieve of given screen size as:

Frang (%) = Agglomerate after milling (%) - Agglomerate before milling (%)

The results of the frangibility tests are shown in Table 2.

Table 2: Results of Ball-Milling Tests and Frangibility of Agglomerates

Example 4

Using a STREA-1 fluidised bed and 350g of tobacco dust and a final binder concentration on the agglomerates of 5% weight/weight, a particle size distribution curve was produced for 6 agglomeration runs. The agglomerated particle size distribution is shown in Table 3. Table 3: Sieve Analysis of Tobacco Dust and Tobacco Agglomerates

Example 5

A tobacco blend comprising 6.3kg of blended tobacco minus the standard '10% Reconstituted Tobacco Sheet (RTS) component and 0.7kg (10% by weight) of agglomerated tobacco filler material of 800μm to 1400μm was produced thus using the agglomerated tobacco filler material as an alternative to reconstituted tobacco.

Example 6

A tobacco blend comprising 6.3kg of blended tobacco minus the standard 10% RTS component and 0.7kg (10% by weight) of agglomerated tobacco filler material of 1400μm to 2000μm was produced thus using the agglomerated tobacco filler material as an alternative to reconstituted tobacco. Example 7

A tobacco blend comprising 6.65kg of blended tobacco inclusive of the standard 10% RTS component and 0.35kg (5% by weight) of agglomerated tobacco filler material of 800μm to 1400μm was produced thus using the agglomerated tobacco filler material in combination with reconstituted tobacco.

Example 8

Agglomerated tobacco filler material was made according to the general process described in Example 1 further comprising inert filler material. The agglomerated tobacco filler material comprised 76% by weight tobacco dust, 19% by weight inert filler material and 5% by weight binder.

Example 9

The static burn rates, firmness and ends stability results for smoking articles incorporating the agglomerated tobacco filler material of the present invention are listed in Table 4. Table 4: Static Burn Rate of Smoking Articles

RTS = reconstituted tobacco sheet

Example 10

Physical measurements for smoking articles incorporating the agglomerated tobacco filler material of the present invention are listed in Table 5.

It is interesting to note that as the fill value of the agglomerate is less than that of the tobacco blend, the density of a smoking article incorporating the agglomerated tobacco filler material would be expected to be higher than that of a smoking article not containing the agglomerated material . Instead the physical measurements show that the density of smoking articles incorporating the agglomerated product are lower than smoking articles not containing the agglomerated material .

Table 5 Physical Measurements for Smoking Articles Incorporating Agglomerated Filler

Material

Claims

1. An agglomerated tobacco filler material comprising tobacco dust and binder, the amount of- tobacco dust and binder being greater than 65% by weight of the agglomerated tobacco filler material, said agglomerated tobacco filler material having a fill value substantially similar to the fill value of cut tobacco.

2. An agglomerated tobacco filler material according to Claim 1, wherein the tobacco . dust and binder are present at more than about 70% by weight of the agglomerated tobacco filler material.

3. An agglomerated tobacco filler material according to Claim 2, wherein the tobacco dust and binder are present at more than about 75% by weight .

4. An agglomerated tobacco filler material according to Claim 3 , wherein the tobacco dust and binder are present at more than about 80% by weight.

5. An agglomerated tobacco filler material according to Claim 4, wherein the tobacco dust and binder are present at more than about 85% by weight.

6. An agglomerated tobacco filler material according to Claim 5, wherein the tobacco dust and binder are present at more than about 90% by weight.

7. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said agglomerated tobacco filler material has a fill value in the range of about 4.40cm³/g to about 5.50cm³/g.

8. An agglomerated tobacco filler material according to Claim 7, wherein said fill value is in the range of about 4.90cm³/g to about 5.30cm³/g.

9. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said agglomerated tobacco filler material has a granule size up to about 3.5mm.

10. An agglomerated tobacco filler material according to Claim 9, wherein said granule size is at least 0.7mm and not more than about 2.0mm.

11. An agglomerated tobacco filler material according to Claim 10, wherein said granule size is in the range of about 0.8mm to about 2.0mm.

12. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said agglomerated tobacco filler material has a moisture content in the range of about 8% to about 18%.

13. An agglomerated tobacco filler material according to Claim 12, wherein said moisture content is in the range of about 10% to about 15.5%.

14. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said agglomerated tobacco filler material has a bulk density substantially similar to that of cut tobacco.

15. An agglomerated tobacco filler material according to Claim 14, wherein said bulk density is in the range O.lOg/cm³ to 0.33g/cm³.

16. An agglomerated tobacco filler material according to Claim 15, wherein said bulk density is in the range 0.12g/cm³ to 0.25g/cm³.

17. An agglomerated tobacco filler material according to Claim 16, wherein said bulk density is in the range 0.12g/cm³ to 0.14g/cm³.

18. An agglomerated tobacco filler material according to Claim 17, wherein said bulk density is about 0.14g/cm³.

19. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said agglomerated tobacco filler material comprises tobacco dust at more than about 70% by weight.

20. An agglomerated tobacco filler material according to Claim 19, wherein said agglomerated tobacco filler material comprises tobacco dust at more than about 75% by weight.

21. An agglomerated tobacco • filler material according to Claim 20, wherein said tobacco dust is present in the range of about 75% to about 95% by weight of the agglomerated material .

22. An agglomerated tobacco filler material according to Claim 21, wherein said tobacco dust is present in the range of about 80% to about 90% by weight of the agglomerated material .

23. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said binder is preferably present in the range of about 1% to about 15% by weight of the agglomerated material.

24. An agglomerated tobacco filler material according to Claim 23, wherein said binder is present in the range of about 1.5% to about 8% by weight.

25. An agglomerated tobacco filler material according to Claim 24, wherein said binder is present in the range of about 3.0% to about 6% by weight.

26. An agglomerated tobacco filler material according to Claim 25, wherein said binder is about 5% by weight of the agglomerated material .

27. An agglomerated tobacco filler material according to any one of the Claims 1-22, wherein when the binder is maltodextrin, said binder is present in the range of about 1% to about 30% by weight of the agglomerated material .

28. An agglomerated tobacco filler material according to Claim 27, wherein ^■ when the binder is maltodextrin said binder is present at about 27% by weight of the agglomerated material .

29. An agglomerated tobacco filler material according to any one of claims 1-26, wherein the binder is selected from the group consisting of organic binders, such as an alginate, a gum, a cellulose

(modified or natural) , a pectin or pectinaceous binder, or the Group I or II metal salts of these binders, such as sodium carboxymethylcellulose

(MaCMC) , or sodium alginate; or polyvinylpyrrolidine

(PVP) .

30. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said agglomerated tobacco filler material comprises a humectant .

31. An agglomerated tobacco filler material according to Claim 30, wherein said humectant is one or more of glycerol, sorbitol, diethylene glycol and propylene glycol .

32. An agglomerated tobacco filler material according to Claim 30 or 31, wherein said humectant is present in the range of 1% to about 5% by weight of the agglomerated material .

33. An agglomerated tobacco filler material according to any one of the preceding claims, wherein said agglomerated tobacco filler material comprises inert fillers and/or flavourant material.

34. An agglomerated tobacco filler material according to Claim 33, wherein said inert filler material is one or more of the group consisting of silicates or alumino-silicates, such as perlite, vermiculite, diatomaceous earth, talc or colloidal silica; chalk, or metal oxides, metal salts or hydroxides such as magnesium oxide, magnesium sulphate, calcium or magnesium carbonate or alumina.

35. An agglomerated tobacco filler material according to any one of Claims 1-34, wherein the loss after milling is less than about 45% by weight of the agglomerated tobacco filler material .

36. A smoking article comprising a rod of smokable material wrapped in a wrapper, wherein said smokable material comprises agglomerated tobacco filler material according to any one of Claims 1-35 blended with cut tobacco and/or reconstituted tobacco.

37. A smoking article according to Claim 36, wherein said agglomerated tobacco filler material is present at up to about 25% by weight of the smokable material.

38. A smoking article according to Claim 37, wherein said agglomerated tobacco filler material is present at up to about 20% by weight of smokable material.

39. A smoking article according to Claim 38, wherein said agglomerated tobacco filler material is present in the range of about 2% to about 10% by weight of the smokable material .

40. A smoking article according to Claim 39, wherein said agglomerated tobacco filler material is present in the range, of about 5% to about 6% by weight of the smokable material .

41. A method of producing the agglomerated tobacco filler material of any one of Claims 1-35, wherein tobacco dust of particle size not more than 500μm is fluidised in a stream of warm air and binder is applied to said fluidised tobacco dust, such that an agglomerated tobacco filler material is produced having a fill value substantially similar to that of cut tobacco.

42. An agglomerated tobacco filler material substantially as hereinabove described with reference to the Examples hereof.

43. A smoking article substantially as hereinabove described with reference to the Examples hereof.