US3396734A - Machine for producing tobacco product from a fluid tobacco pulp - Google Patents

Description

1968 c. R. JANSSON ,396, 34

MACHINE FOR PRODUCING TQBACCO PRODUCT FROM A FLUID TOBACCO PULP Filed March 12, 1965 INVENT OR CARL RAGNAR JANSSON BY a ATTORNEYS FIGZ' United States Patent 3,396,734 MACHINE FOR PRODUCING TOBACCO PRODUCT FROM A FLUID TOBACCO PULP Carl Ragnar Jansson, Solna, Sweden, assignor to Arenco Aktiebolag, Vallingby, Sweden Filed Mar. 12, 1965, Ser. No. 439,244 Claims priority, application Sweden, Mar. 31, 1964, 3,957/ 64 3 Claims. (Cl. 131-133) ABSTRACT OF THE DISCLOSURE A machine for producing a Web shaped tobacco product, comprising a moving endless belt. A container having a closed top and a small bottom discharge gap formed by a rotating casting roll and a wiper device above said belt. Means for supplying tobacco pulp to said container and means for maintatining the tobacco pulp at a constant level in said container. A pressure source for gas, a gas supply tube opening out above the tobacco pulp level, and a pressure regulator, for maintaining a constant gas pressure above said tobacco pulp level.

The invention relates to a machine for producing a web shaped tobacco product which consists essentially of tobacco powder and a small quantity of a binding agent.

The tobacco product produced by the said machine is primarily intended to be used as filler tobacco for cigars, cigarettes and for similar purposes and also for cigar binders and pipe tobacco, i.e. the tobacco must have good burning qualities. Furthermore, it is desired that the content of binding agent be kept as low as possible, preferably lower than percent by weight, and also that the colour and appearance should substantially agree with that of natural tobacco.

The reconstituted web tobacco which has been most used consists of a film comprising a homogenous mixture of tobacco powder, a binding agent and certain small additives. From the point of view of mechanical strength the content of the binding agent should not be lower than approximately 15 percent by weight, causing it to be less suitable for use as especially filler tobacco or pipe tobacco. A further disadvantage is that this type of reconstituted web tobacco, which has a completely even surface, has a tendency to become so tightly packed, especially in said range of use where the tobacco used is in the form of small strands, that the burning qualities of the tobacco are impaired. Moreover a type of reconstituted Web tobacco consisting of a film of only a binding agent and possibly a small addition of some film strengthening material, and which has an outer coating of tobacco powder adhering to one or both sides, has been known for a long time. The intention here should be to produce a reconstituted web tobacco with high tobacco content and a surface having a wide total area. It is difiicult to achieve a tobacco content, exceeding 85 percent by weight of the prepared web tobacco in such an outer coating and such a tobacco product has been proved to carry certain disadvantages in the form of poor burning properties, since the tobacco becomes all too concentrated in the outer layer.

Using the machine of the invention, a reconstituted web tobacco product having a wide area surface has been achieved, in which a binding agent content can be obtained, which is less than approximately 15 percent by weight of the prepared product, without the occurence of those disadvantages which arise in known products. The desired product is characterized substantially by the combination of a film consisting of a mixture of fine tobacco particles and a binding agent and also an outer "Ice coating consisting preferably of somewhat larger tobacco particles of essentially the same percentage by weight as the tobacco mixed in the binding agent, said coating adhering to at least one side of the film.

The film consisting of the binding agent and the tobacco powder mixed in the same suitably contains approximately 15 percent by weight of the binding agent, which, as was earlier maintained, gives a comparatively strong film. An outer coating which consists of the same weight of tobacco powder per surface unit as in the film and which adheres to one surface of the film gives together with the film a product containing only approximately 8 percent by weight of the binding agent. Despite this low content of binding agent the product has almost the same mechanical strength as the known film of tobacco containing 15 percent by weight of a binding agent.

An essential advantage is that a reconstituted web tobacco product of this nature has good burning qualities due to the tobacco being evenly distributed over the whole cross-section of the web and simultaneously has a porous outer coating where air is free to enter to the relatively sparsely distributed tobacco particles. A tobacco powder produced by dry grinding and which is coarser than that used in the film is suitable for use in the outer coating, whereby the tobacco web obtaines a surface which closely resembles the colour of natural tobacco.

The quality of the web shaped tobacco product according to the invention is, at least concerning cigar binders, to a large extent dependent on the evenness of the film consisting of tobacco powder and a binding agent, and the invention is directed to a machine for producing such a tobacco product, which machine, in a manner known per se, is provided with a movable endless belt, an arrangement for applying a fluid tobacco pulp or paste in the form of a thin film on the belt through a small gap between a casting roll mounted above the belt and a wiper device e.g. a doctor roll rotating in the same direction as the casting roll, from a container tightly abutting said members and situated above the same. A disadvantage with this machine has been that unevenness and grooves often occurred in the produced film and attempts to positively feed the tobacco pulp to the casting roll by means of a pump has not achieved the required result. An essential improvement has, however, been effected by means of the machine according to the present invention, which is characterized in that the container for the tobacco pulp is closed at the top and is provided with a pipe for the supply of tobacco pulp and an arrangement in order to maintain a constant level of the tobacco pulp in the container, in addition to which a further pipe, opening above the level of the tobacco pulp, is connected to a pressure source for gas and a pressure regulator. Consequently the gap between the casting roll and the wiper device can be reducedin comparison with that which is the case when the atmospheric pressure or the pressure from a directly connected pump prevails over the tobacco pulp in the container on producing a film in both cases having a predetermined thickness, and this, in conjunction with the constant pressure reduction of the tobacco pulp in passage through the gap has resulted in a remarkably even film of constant thickness. Since tobacco pump as a rule has thixotropic properties, the container may conveniently be provided with means for agitating the tobacco pulp.

The necessity for the machine to produce a tobacco product with an even surface and a constant thickness in order to enable production of cigar binders is impossible to ignore but above all, because the complete machine constitutes a very large and expensive aggregate, the use of which, from an economic point of view and because of the space it occupies, should not be limited to solely one part of the production of reconstituted web tobacco,

but it must also be usable alternatively for production of reconstituted web tobacco for wrappers where demands for a very even surface and constant thickness are very high.

The invention is further explained in the following with reference to the attached drawing, where FIG. 1 shows an enlarged cross section through a portion of a tobacco product according to the invention taken as an example, and FIG. 2 partly in section diagrammatically shows a vertical projection of an embodiment of a machine according to the invention.

The tobacco product shown in FIG. 1 consists of a 0.2 mm. thick, film produced from a tobacco pulp which is constituted of a mixture of a binding agent 1 and a tobacco powder 2 having a particle size of 0.1 mm. and less. The amount of binding agent constitutes approximately 15 percent by weight of the film. On one side of the film is an outer layer comprised of dry ground tobacco powder 3 having a particle size of 0.2 mm. and larger particles. This tobacco powder 3 has been applied to the film by spraying said powder under high pressure against the nondry film through nozzles, so that the tobacco particles adhere to the binding agent 1 on the surface of the film and partly penetrate the binding material. The amount of said tobacco powder 3 per surface unit of the tobacco product is the same as the amount of tobacco powder 2 mixed in the binding agent. The total amount of binding agent in the finished tobacco product is thus approximately 8 percent by weight.

The machine shown in FIG. 2 has an endless stainless steel belt 4 passing over two rotating wheels 5 and 6 mounted in a frame, of which the wheel 5 is driven by a motor, not shown. Above the belt 4 is arranged a closed container 7 in the bottom of which two rolls, a large casting roll 8 and a small doctor roll 9, rotating in the same direction are driven by the wheel 5 by means of a transmission, not shown, said rolls having a small gap between them. The rolls lie tightly against the container 7 which is filled with tobacco pulp 10 up to a level which in a usual manner is held constant by means of a level control device 26. The container is fed with tobacco pulp through a tube 11 in the upper section of the container 7, which tube is provided with a valve 27 controlled by the level control device 26. Compressed air or some other suitable gas is supplied from a pump 29 driven by a motor 28 through a second tube 12 which opens above the level of the tobacco pulp. The tube 12 is connected with a pressure regulator through a tube 13 which is arranged with its open end in a container 14 containing a fluid 15. The pressure source continuously supplies compressed air or gas, which passes through the tube 13 and flows out through the container 14 the top of which is open whereby a constant pressure corresponding to the column of fluid in the container 14 is maintained in the container 7 independent of variations in the supply of tobacco pulp to the same. Alternatively the pressure regulator can obviously be of a conventional type, such as a spring loaded or weight loaded valve.

In the upper section of the container, four wheels 16 are rotatably mounted, over which an endless belt 17 with bars 18 for agitating the tobacco pulp runs in a closed path above the rolls 8, 9. The agitating arrangement is driven by a motor 19 connected with one of the wheels 16.

A doctor plate 20 is situated under the roll 8- and is pressed against the same, by means of which on rotation of the rolls 8 and 9, the tobacco pulp in the form of a thin film 25 is transferred to the belt 4. Upon movement of the belt 4 in the direction indicated by an arrow, the moist film passes under a number of nozzles 21 connected through a pipe 22 with a pressure source, not shown, and a container for tobacco powder, not shown and through which nozzles the tobacco powder is sprayed at high speed and evenly distributed against the surface of the film 25 on which the tobacco particles adhere to the non-dry binding agent. The web is then dried in a furnace 23 whereafter loosely adhering particles are removed from the web by blasts of air or suction and the web is removed from the belt 4 by means of a doctor blade 24 abutting against the same.

What is claimed is:

1. A machine for producing a tobacco product comprising a movable endless belt, a discharge container closed at the top and situated above said endless belt, a discharge gap in the bottom of said discharge container, means for applying a fluid tobacco pulp comprising a mixture of predominantly tobacco particles and a small amount of a binding agent in the form of a thin film of said mixture on said belt from said discharge gap, means for spraying tobacco particles onto said moist film of tobacco pulp, a first tube supplying tobacco pulp to said discharge container, a second tube opening above the level of said tobacco pulp in said discharge container, a fluid pressure source connected to said second tube and a pressure regulator for said fluid to maintain the pressure constant in said discharge container.

2. A machine for producing a tobacco product as set forth in claim 1 wherein said means for applying a fluid tobacco pulp in the form of a thin film comprises a rotating casting roll and a doctor roll cooperating with said casting roll.

3. A machine as set forth in claim 1 wherein agitating means for said tobacco pulp is provided in said discharge container.

References Cited UNITED STATES PATENTS 1,583,484 5/1926 Morrison et a1.

2,707,472 5/1955 Jurgensen et a1. 131-140 X 2,965,927 12/1960 Crosby et a]. 18-15 3,147,173 9/1964 Eolkin et al 18-9 X FOREIGN PATENTS 1,309,735 10/ 1962 France.

MELVIN D. REIN, Primary Examiner.

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