FR2547169A1 - Yarn for stringing tobacco leaves - Google Patents

Abstract

Yarn spun from vegetable fibres such as rayon, with a high tenacity, is used for stringing up tobacco leaves. The spun yarn is wound on a bobbin and then passed through a bath of vegetable adhesive using a mixt. of water and starch, such as from maize, with a max. concn. of 2-4%. The mixt. is held for 20 minutes at 95 deg.C and then passed to a vessel to be held at 75 deg.C. A fermentation inhibitor is added at a rate of 1% of the starch content. The adhesive-coated yarn is cured in a furnace for the required hardening time.

Description

String particularly suitable for stringing or
mechanized threading of tobacco leaves
The present invention relates to a string particularly suitable for stringing or mechanically threading tobacco leaves.

 It is known that the cultivation of tobacco requires a great deal of manpower and energy which in recent years has decreased continuously while the cost of available energy has increased significantly.

 Under these conditions it is therefore absolutely necessary to seek a maximum reduction in production costs, and a contribution to this effect may consist of a judicious choice of production processes and levels of mechanization, particularly for operations in which the incidence of human labor seems the greatest.

 Among the operations that have a lot of labor, note the tying or threading and unthreading of the tobacco leaves, these operations being necessary to allow the picked leaves to be exposed to the sun or to place them in premises or suitable facilities to dry them.

For many years, these operations have been carried out by hand but for some time now, special machines have been introduced on the market allowing automatic threading of tobacco leaves with remarkable savings in time and labor. artwork
However, these machines have a drawback resulting from the obligation to use, for threading, a string which, in order to carry the characteristics necessary for the correct functioning of the machine, that is to say not having on its surface surface of imperfections or small fibers of any type, is characterized by a high presence of plastics or, in any case, of substances yes do not have a vegetable or natural origin.

 This can be explained by the fact that the string, both for mechanized or manual threading, must not present in its sliding through the tobacco leaves, resistance to its advance.

 Consequently, the twine which is made from synthetic fibers has the desired characteristics which are imposed, but also has a negative characteristic which can only be remedied by manual stripping, carried out very carefully and by subsequent sieving of the sheets. disengaged. As already mentioned, the tobacco leaves are threaded and tied together by one of the known methods and then they are dried. When the drying is finished, the leaves must also be extracted from the garland and this must be done very carefully; because it is quite common for certain parts of the string to use for threading the leaves remaining between the leaves. @ If this happens, it is necessary to carefully remove the residual parts of the synthetic twine as these residues are extremely dangerous for the consumer and compromise the quality of tobacco.

 The object of the invention is therefore to propose a method of producing twine. particularly suitable for threading tobacco leaves, process by which it is possible to obtain a string of plant origin which has no negative characteristics such as: surface imperfections, the presence of small fibers, and so on, which could compromise the ease of threading and which, even if they are present in small quantities on the tobacco leaves after removal or de-threading, do not modify their initial characteristics.

 The string according to the invention is produced by a particular process which comprises a spinning phase of a textile fiber made manually having a natural origin and which, after a first winding, is caused to pass through a bath of a binding agent, obtained at starting from vegetable substances and studied especially for this operation. After the bath in the binding agent, the string is left to dry and then it is placed in a suitable oven.

A string will be described below by way of nonlimiting example, this string being made of cellulose and being treated according to the aforementioned process
The cellulose sheets are stabilized by caustic soda solutions and they are then subjected successively to all the phases which characterize the process to obtain rayon yarns having high solidity. The yarn is then twisted until a string of suitable dimensions is obtained and the latter is subjected to washing baths, after which is wound on a first coil. At the end of this first phase, the string already has some of the characteristics which are required for use in threading tobacco leaves, and main
ment, the characteristic of a vegetable origin, but it still has small surface fibers <pi can compromise the threading operation. In order to overcome this other drawback, the extremely solid rayon thread passes through a a binding agent whose origin is also vegetable, and which is obtained by a mixture of water and starch, preferably corn, at a maximum concentration of 2 to 4%; the mixture is maintained for 20 minutes at 95 C and it is then transferred to a container whose temperature is 75 G; then, an anti-fermentation agent is added in a proportion of 1% of the percentage of starch present.

The bath in the binding agent makes it possible to coat the outer surface of the twine with a h @ mogen layer which protects it against surface imperfections, also allowing the elimination of small
aforementioned fibers and the strengthening of acquired characteristics.

In addition, after removing the tobacco leaves from the twine, the presence of parts of thread
that on the leaves themselves does not give rise to: long and costly cleaning operations because, since the twine and the binding agent are of a vegetable nature, their presence is not only harmless for smokers but also does not cause no change in tobacco quality.

It is obvious that the use of this string makes it possible to reduce the duration and the cost of the work, without obliging to necessarily have recourse to a sieving operation of tobacco when it has been unthreaded, an operation which independently of the fact that it is long and expensive, does not allow to have the certainty of a complete absence of parts of synthetic thread which are extremely dangerous for the health of the consumer.
which compromises the quality and the taste of your tank.

 It is also obvious that instead of the constituents which have been described, other materials can also be used having identical or similar characteristics without however departing from the scope or the spirit of the invention.

Claims (4)

 1 - Wire or string particularly suitable for threading tobacco leaves, characterized in this rifle is essentially constituted by a wire obtained by twisting vegetable textile fibers such as, for example, high-strength rayon threads.  2 - Wire or twine according to claim 1, characterized in that it is wound on a first coil, and then caused to pass into a bath of a binder of vegetable origin.  3 - Wire or twine according to claim 2 ç characterized in that the binding agent consists of a mixture of water and starch, preferably corn, in a maximum concentration of 2 to 4%, the mixture being maintained for 20 minutes at a temperature of 950C and then being successively transferred to a container whose temperature is 750C ss an anti-fermentation agent is then added in a proportion of 1% of the percentage of starch present in the mixture.  4 - Wire or string according to one of claims 2 or 3, characterized in that said string 2 preferably made of high strength rayon, is placed, after being coated with the binding agent, in a suitable oven for a appropriate duration.