US3081779A - Reconstituting tobacco - Google Patents

Description

March 19, 1963 B. PERRIN 3,081,779

RECONSTITUTING TOBACCO Filed April 25, 1960 illi] m/m me finite rates This invention relates to the manufacture of reconstituted tobacco.

In the manufacture of tobacco articles, such as cigarettes, cigars, smoking tobacco, snuff and other vendible articles, the final form of each article comprises tobacco products such as shredded lamina from the leaf, shredded stem, stem slivers, small particles of leaf and dust, each of which will hereinafter be referred to as a tobacco product.

Proposals have been made to reconstitute tobacco products so that they may be processed and incorporated into tobacco articles. The general idea underlying some of these proposals is to utilize methods similar to those employed in papermaking. Thus a tobacco product is used to form a pulp, the pulp being then beaten or refined, made into a continuous pulpy layer, dried into a continuous paperlike sheet and reeled, all in known fashion. Finally the sheets can be fed into tobacco-cutting machinery.

A disadvantage of the papermaking method lies in the necessity to produce a continuous sheet of great enough strength, without the use of binding agents, to enable such a sheet to be run through the dry-end of a papermaking machine. In some countries the use of such binding agents is prohibited by law and in such a case this requirement of sufficient strength leads to difficulties in preparing the pulp since the fibres from that part of the tobacco plant used in the manufacture of tobacco articles, are not sufficiently strong or sufiiciently numerous, to be generally suitable for the manufacture of paper.

According to the invention there is provided a method of producing reconstituted tobacco from a tobacco product, wherein the said product is mixed with liquid and formed into a pulp, the said pulp is treated and formed into a pulpy layer, the said pulpy layer is transferred onto a conveying surface from which it is stripped and caused to break into pieces, and the said pieces are then dried.

There may be added a further tobacco product at a stage prior to that of drying the said pieces and the said liquor may be water or any other suitable substance.

Further according to the invention there is provided apparatus for producing reconstituted tobacco from a tobacco product, comprising means (e.g. a beater) for mixing the said product and liquid, forming a pulp and treating the said pulp by means (e.-g. a concentrator) for forming the said pulp into a pulpy layer, means (e.g. a couch roll and felt), for transferring the said pulpy layer onto a conveying surface, means (eg a cylinder and a doctor blade) for stripping the said pulpy layer from the conveying surface and causing it to break into pieces, and means (e.g. a tea dryer) for drying the said pieces.

The apparatus may include means for adding further tobacco product at a stage prior to the pulpy layer being broken into pieces, the said means comprising an air-operated spraying unit and a conveying surface, the said further tobacco product being sprayed from the said air-operated spraying unit onto the said pulpy layer as it passes over the said conveying surface.

Apparatus in accordance with the present invention will 3,681,779 Patented Mar. 19, 1963 now be described by way of example, with reference to the accompanying diagrammatic drawing. A beater 1, furnished with a mixture of one or more tobacco products and water, is arranged so that its contents, after having been beaten for a suitable period of time, can be emptied through a pipe 2 into either of tanks 5 and 6. The choice of tank is determined by the condition of valves 3 and 4. The contents of the tanks 5 and 6 can be emptied by means of suitable adjustment of valves 7 and 8, through a refiner 9 and into either of tanks 12 and 13 by means of suitable adjustment of valves 10 and 11.

The pulpy mixture, now in a condition ready for use in a vat machine or concentrator 16, can be fed from either of the tanks 12 and 13 by means of the adjustment of valves 14 and 15 into the vat machine 16. The vat machine is shown diagrammatically to comprise a rotatable mesh cylinder 17, trunnions 1-8, a continuous felt band 19, a couch roll 20 and a final cylinder 21. The pulpy mixture is diluted with water in the vat machine and is formed on the cylinder 17, which is rotated in the direction shown by the arrow, into a continuous layer 22 which is transferred from the cylinder 17 by the couch roll 20 and is carried by the felt band 19 to the final cylinder 21 from which it is removed is discontinuous sheets 24 by a doctor-blade 23.

Over the top of the felt band 19 a tobacco product (e.g. dust or finely ground tobacco particles) is sprayed from a jet 25, which is connected to a source of compressed air as well as to supply of the tobacco product, in known manner, so that the tobacco product is applied evenly and continuously across the width of the continuous sheet 22.

The discontinuous sheets 24 are carried by a conveyor 26 into a dryer 27 of the type known as a tea dryer. This dryer 27 comprises a series of endless bands 28 arrranged one above the other and rotating in the directions as shown by the arrows. The sheets 24 will thus be carried along the full length of each conveyor, being cascaded from the end of one conveyor onto the beginning of the next one. The conveyors 28 are housed in a chamber 29 within which heating means (not shown) such as infra-red heaters or steam coils are provided, and are driven by a variable-speed motor so that the moisture-content of the dried sheets may be controlled within reasonable limits.

The operation of the apparatus of the attached diagrammatic drawing is as follows:

A measured quantity of water and of waste tobacco products, usually in the ratio of 10 parts by weight of water to one part of tobacco, is placed in the beater where a roll in conjunction with bedplates acts on the tobacco products so as to separate the fibres contained therein one from the other and also so as to produce fibrillations at the end of each fibre. When the contents of the beater have been sufficiently worked on so as to be ready for the next stage of the process, an emptying valve is opened and the contents, dropping under the action of gravity, pass into whichever is desired of tanks 5 and 6. While one of tanks 5 and 6 is being filled, the other is supplying the refiner 9, through which the fibres pass on their way to either of tanks 12 and 13. The action of the refiner is similar to that of the beater; its function, however, is to produce fibres in a condition in which they can finally be formed into a sheet in the vat machine 16. The tanks 12 and 13 again form a pair, it being necessary that, while one of the pair is being filled from the previous stages of the manufacturing process, the other is supplying subsequent stages of the process.

The vat machine 16 operates to form a continuous layer on the outside of the wire mesh cylinder 17 in known manner. The sheet is transferred from the cylinder to the couch roll 20 and passes by means of the felt conveyor band 19 under the air-operated dust spray 25. Tobacco dust or particles of small size are sprayed onto the sheet where they fill in the interstices between the fibres. From the felt band 19 the. sheet is transferred to the cylinder 21.

The doctor blade 23 strips the sheet from the surface of the cylinder 21 and, thus, as the cylinder rotates, the sheet builds up against the blade 23 in concertina fashion until, due to its own weight, the sheet breaks into pieces 24 which fall onto the conveyor 26.

The discontinuous sheets 24, are fed into the tea dryer 29 where the drying must be such as to enable the sheets to leave the dryer containing a required amount of moisture. The sheets are then in a state suitable for incorporation in the cutting stage of the tobacco manufacture.

I claim:

A method of producing discontinuous sheets of reconstituted tobacco from a mixture of tobacco product with water only, comprising the steps of adding water to the tobacco product to form a pulp, applying said pulp as a layer to a conveyor surface, stripping the layer from the surface, allowing the stripped layer to remain unsupported so that it breaks into discontinuous sheets due to its own weight and drying the discontinuous sheets to produce reconstituted tobacco of a size and strength suitable for cutting into shreds to be incorporated into cigarettes and containing only the constituents of said tobacco product from which it is made.

References Cited in the file of this patent UNITED STATES PATENTS 61,275 Stayman Jan. 15, 1867 267,764 Wood Nov. 21, 1882 385,038 Brooks June 26, 1888 1,153,892 Carpenter Sept. 21, 1915 1,501,513 Boberg July 15, 1924 1,585,476 Febles May 18, 1926 1,907,046 Darrah May 2, 1933 2,433,877 Wells et a1. Jan. 6, 1948 2,734,510 Hungerford et a1 Feb. 14, 1956 2,812,591 Kling Nov. 12, 1957 2,830,596 Frankenburg et al. Apr. 15, 1958 2,933,090 Hamilton Apr. 19, 1960 FOREIGN PATENTS 658,632 Germany Ian. 14, 1936

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