Method and Apparatus for Forming Tobacco Rods

Abstract

A method of forming tobacco rods comprises providing an endless bead of tobacco, creating regularly spaced apart gaps (14) with no tobacco along the length of the bead, wrapping the bead in an endless length of paper wrapper (16), and cutting through the paper wrapper where it overlays the gaps in order to divide the wrapped bead into individual tobacco rods. The gaps may be created using an ecreteur with trimmer discs configured to trim away the full width of the tobacco rod (10), or by using a rotating screw thread extending into the tobacco.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to a method and apparatus for forming tobacco rods, where the tobacco rods are suitable for the manufacture of smoking articles with closed ends.[0002]Manufactured smoking articles such as cigarettes conventionally comprise a tobacco rod having a wrapping of cigarette paper, and a filter attached to the tobacco rod by a tipping paper, although plain cigarettes, lacking a filter, are also available. In either case, the end of the cigarette which is intended to be lit is often open, so that the tobacco inside the cigarette paper is exposed. This allows leakage or spillage of tobacco from the cigarette, and also allows contaminants and foreign bodies to enter the tobacco.[0003]To address this, it has been previously proposed to close one or both ends of a cigarette by folding or otherwise manipulating a portion of the cigarette paper that extends beyond the tobacco rod. For this, it is necessary to arrange for a tobacco rod...

AI Technical Summary

Benefits of technology

[0007]This results in tobacco rods that have an overhanging portion of paper at one or both ends (depending on the position of the cuts) that can be folded inwards over the tobacco to close the end(s) of the completed smoking article. The method includes the conventional steps for making tobacco rods, plus an extra stage of creating the gaps in the tobacco bead. The extra stage can be readily incorporated into standard production, so existing production lines and methods can be easily adapted to implement the present invention. Moreover, creation of the gaps can be performed rapidly and simply with non-complex equipment and without interruption of the travel of the tobacco through the production process, so production times can be as fast, or nearly as fast, as the production of conventional tobacco rods.

[0013]In a further example, dividing the bead and moving the portions of tobacco apart may comprise moving at least one rotating disc into and out of the bead, the disc rotating about an axis parallel to the bead and having a thickness that increases from the edge to the centre of the disc. This technique may be found more complex to implement than a screw thread as regards processing of a moving tobacco bead. However, rotating discs configured in this way are advantageous in that a single disc or assembly of discs can be used to create gaps of different length.

Problems solved by technology

These older approaches are not well-suited to modem cigarette manufacturing techniques, however.

This is potentially disadvantageous, however.

Tobacco typically comprises a mixture of various smokable materials, and these tend to settle at different depths after vibration or tapping, giving a non-uniform composition to the tobacco rod.

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