EP3232827B1

EP3232827B1 - Tobacco rod maker with tobacco return

Info

Publication number: EP3232827B1
Application number: EP15820492.5A
Authority: EP
Inventors: Mehmet SUCSUZ; Isa DINC; Huseyin AKAKINCI; Murat CAVUSOGLU; Ibrahim SEZEK
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2014-12-19
Filing date: 2015-12-18
Publication date: 2019-05-15
Anticipated expiration: 2035-12-18
Also published as: RU2017125495A3; TR201910594T4; BR112017010477B1; CN106998788A; ES2731245T3; JP2018500029A; KR20170095208A; RU2692847C2; EP3232827A1; JP6924140B2; HUE043726T2; BR112017010477A2; WO2016097296A1; KR102574018B1; PL3232827T3; RU2017125495A; CN106998788B

Description

The present invention relates to apparatus and methods for making a tobacco rod for a cigarette or other smoking article.
In the manufacture of smoking articles such as cigarettes, it is common industrial practice to increase the tobacco density at the extremities of the tobacco rod, to provide so called "dense ends". This helps to prevent tobacco from falling out of the ends of the cigarette tube. In case of filter cigarettes, an increased tobacco density at the filter end of the tobacco rod further helps to ensure good attachment of the tobacco rod to the filter.
In conventional processes, the increased density at the extremities of the tobacco rod is obtained by increasing the amount of cut filler provided at the ends of the tobacco rod.
GB-A-2 072 483 discloses a method for forming tobacco rods with dense ends, in which a continuous stream of cut filler tobacco is provided from a tobacco supply to a perforated endless conveyor belt. The tobacco is held against the conveyor belt by a slightly reduced pressure on the other side of the belt. The tobacco stream is conveyed past a trimming device consisting of two oppositely arranged trimmer disks similar to the trimmer shown in Figure 1. Below the trimmer disks, a rotary brush extracts and removes the excess tobacco. The trimmer disks have so called pockets on their outer periphery. The depth of the pockets corresponds to a different cutting height of the trimmer device, so that the resulting tobacco stream has regions of increased depth at regular intervals along the tobacco stream. When cigarette paper is wrapped around the tobacco stream to form a tobacco rod, the tobacco density is increased in the regions of increased depth. The resulting continuous tobacco rod is cut in the middle of the regions of increased density such that the resulting individual tobacco rods have a region of increased density at each end.
US-A-5 003 996 discloses another method for forming cigarettes with dense ends. A continuous tobacco stream is conveyed on an endless suction band. The tobacco material is conveyed past a trimmer device that cuts the tobacco material at a desired height in order to obtain a tobacco rod having a uniform depth distribution. A rotary cam is provided upstream from the trimming disks for compressing the continuous stream of tobacco at regular intervals. The intervals are such that the compressed portions with increased density are located at the extremities of the eventual tobacco rod. Directly after the cutting device the compressed tobacco will re-expand so that a continuous tobacco stream with increased depth at regular intervals is obtained.
It would be desirable to recover tobacco trimmed from the tobacco stream on the belt, especially, but not only, when a tobacco rod with dense ends is being made. It would also be useful to re-use the recovered tobacco.
GB 880 850 discloses cigarette making apparatus for making tobacco rods with dense ends. Tobacco is deposited from a feeder onto a first belt conveyor on which it is carried to a first wheel. The first wheel has a peripheral duct into which the tobacco is introduced by the first belt conveyor. Tobacco protruding from the duct is trimmed and the trimmings are directed to a peripheral duct on a second wheel, coaxial with the first. The continuous stream of tobacco in the duct of the first wheel is doctored from the duct onto a paper wrapper on a second continuous belt, on which it moves to a wrapping station of the apparatus. The tobacco trimmings are passed from the duct in the second wheel onto a carding belt and from that onto a sieve that allows tobacco strands shorter than a certain length to pass through; this tobacco is returned to the first belt conveyor. The trimmed tobacco that does not pass through the sieve is retained in a hopper from which portions are released at set intervals onto the continuous stream of tobacco from the first wheel before it enters the wrapping station, to provide dense end region in the rod.
According to the invention there is provided apparatus for providing a stream of tobacco to be wrapped to form a tobacco rod, comprising a chamber for cut tobacco filler, a conveyor for receiving cut tobacco filler from the chamber, a trimmer for removing tobacco from the conveyor, a receiver adjacent the trimmer for receiving cut tobacco filler trimmed from the tobacco on the conveyor, a separator connected to the receiver for receiving cut tobacco filler therefrom and separating the received cut tobacco filler into a reusable portion and a discard portion and a return path from the separator for reintroducing the reusable portion to the conveyor, an airstream generator that generates an airstream from the receiver through the separator so that cut tobacco filler that has been removed by the trimmer is transported in the airstream and drawn to the separator, the separator comprising a rotatable foraminous separator drum that allows small particles of tobacco into the interior of the separator drum but not larger pieces of tobacco, the interior of the separator drum being connected to the airstream generator so that the airstream is drawn from the receiver through the separator drum and means for blocking the airstream over a part of the cylindrical surface of the separator drum as it rotates so that the said larger pieces of cut tobacco filler can leave the surface of the separator drum and enter the return path.
The separator drum has a foraminous cylindrical surface, that is, at least a part of the cylindrical surface has holes in it. In some preferred embodiments, this surface is provided by a mesh or sieve. Preferably, the mesh or sieve has holes of diameter 0.3 mm to 0.5 mm, more preferably of diameter 0.315 mm to 0.5 mm.. In some preferred embodiments of the invention, the conveyor is a continuous belt. In some preferred embodiments, the belt is permeable and a partial vacuum can be drawn on one side of the belt to retain cut tobacco filler on the other side. In some preferred embodiments, the reusable portion is returned to the chamber.
In some preferred embodiments, the separator further comprises an upper chamber for receiving the surplus tobacco from the receiver and containing a least an upper part of the separator drum, a lower chamber and an airlock between the upper chamber and the lower chamber that allows re-usable cut tobacco filler to pass from the upper chamber to the lower chamber while substantially preventing the airstream from passing into the lower chamber. In some embodiments, the airlock comprises a rotatable airlock cylinder disposed below the separator drum substantially in the lower chamber parallel to the separator drum and having axially extending resilient vanes that, in use, impinge on the cylindrical surface of the separator drum, the circumferential spacing of the vanes being such that at least one vane is in contact with the separator drum throughout the rotation of the airlock cylinder.
In preferred embodiments, elements of the apparatus of the invention that contact tobacco are made from food grade materials, such as stainless steel.
Also according to the invention, there is provided method of providing a stream of tobacco to be wrapped to form a tobacco rod, comprising providing a stream of cut tobacco filler on a conveyor, trimming tobacco from the said stream, separating the tobacco trimmed from the stream into a reusable portion and a discard portion; and returning the re-usable portion to the said stream, the separating step being achieved using a rotating foraminous separator drum, and accumulated tobacco being periodically removed from a surface of the separator drum with compressed air.
It will be appreciated that any one of the preferred features may be used in conjunction with any one or more of the other preferred features.
The invention will be further described, by way of example, with reference to the drawings, in which:

Figure 1 is a schematic representation of part of a tobacco rod maker incorporating the invention; and
Figure 2 is in more detail part of part of the apparatus shown in Figure 1.

The apparatus shown in Figure 1 provides a stream of tobacco that is used to make a wrapped tobacco rod. The apparatus comprises a tobacco chamber 100 below a continuous belt 102 passing over rollers 104, one of which is driven, so that the belt can move in the direction shown by the arrow A. The belt 102 is air permeable. The lower run of the belt 102 closes the bottom of a vacuum chamber 106, so that air can be drawn through the belt. A trimmer knife 108 is provided immediately below the lower run of the belt. The trimmer knife can be a circular blade rotating on a vertical axle. The height of the blade of the trimming knife is adjustable, and the cutting height can varied if tobacco rods having 'dense ends', as described above, are to be made. A second continuous belt 110 passing over rollers 112 (only one of which is shown in Figure 1) is provided beneath the downstream end portion of the permeable belt 102. One of the rollers 112 is driven so that the belt can move in the direction shown by arrow B
Beneath the trimmer knife 108 is a receiver 114 for trimmed tobacco. The receiver is connected by a channel 116 to a separator 118. The separator 118 has a discard outlet 120 and a tobacco recirculation outlet 122. The discard outlet 120 is in communication with a fan 124. Below the tobacco recirculation outlet 122 from the separator 118 is a third continuous belt 126 running over rollers 128, one of which is driven, so that the belt can be driven in the direction shown by the arrow C. The end of the third belt 126 distal from the separator 118 is above an inlet 130 to the tobacco chamber 100.
In use of the apparatus of Figure 1, cut tobacco filler 132 is supplied (by means not shown) to the tobacco chamber 100. A stream 134 of tobacco is blown (by means not shown) out of the chamber 100 through a conduit 136 toward the upstream end of the permeable continuous belt 102. A partial vacuum is drawn on the vacuum chamber 106 above the lower run of the permeable belt 102 so that the tobacco stream 134 is drawn onto the lower surface of the lower run of the permeable belt. As the permeable belt carries the tobacco stream 134 downstream, it impinges on the trimming knife 108. This cuts surplus tobacco 138 from the stream 134. The vertical position of the trimming knife 108 is adjustable so that the stream has the correct tobacco density (that is, the correct weight of tobacco/unit length). If the tobacco rod being made is one that has 'dense ends', the height of the knife is adjusted from time to time so that the density of the stream downstream of the trimmer knife varies along its length, to provide the 'dense ends'. As the tobacco stream 134 passes the downstream end of the vacuum chamber 106, it is released from the permeable belt 102 and falls onto the upper run of the second continuous belt 110. This carries the tobacco stream to a garniture downstream of the apparatus shown in Figure 1 to be wrapped in a paper wrapper to form a continuous wrapped tobacco rod that can be cut and further processed into cigarettes or other smoking articles.
The surplus tobacco 138 cut from the tobacco stream 134 by the trimming knife 108 includes pieces of tobacco that are within a size range that allows it to be re-used. The surplus tobacco also includes pieces that are too small to be re-used, usually known as tobacco dust. These small pieces are created by the action of trimming the tobacco stream 134 and by the treatment to which the tobacco has been subject upstream of the trimming knife 108, such as being blown along the conduit 136 from the tobacco chamber toward the permeable belt 102. The surplus tobacco falls from the permeable belt 102 into the receiver 114 where it is entrained in air drawn through the receiver by the fan 124. The surplus tobacco is drawn along the channel 116 to the separator 118. The separator and its operation will be described in detail with reference to Figure 2. The separator 118 separates the surplus tobacco into a first, reusable stream 140 that exits the separator through the tobacco recirculation outlet 122 and a second, discard stream containing the tobacco dust that exits the separator through the discard outlet 120. The re-usable tobacco stream 140 is made up of pieces of cut filler that are sufficiently large to be incorporated in the wrapped tobacco rod made from the tobacco stream, and the discard tobacco is smaller pieces. The re-usable tobacco stream 140 drops from the tobacco recirculation outlet 122 of the separator 118 onto the upper run of the third continuous belt that carries it to the inlet 130 of the tobacco chamber 100, for incorporation once more into the tobacco stream 134. In other embodiments, the re-usable tobacco can be directed from the separator to the conduit 136 between the tobacco chamber 100 and the permeable belt 102, or directly to the tobacco stream on the permeable belt.
Tobacco in the discard stream can be used for other purposes, such as the manufacture of reconstituted tobacco sheet.
The separator 118 is shown in greater detail in Figure 2. It comprises an outer housing 200, shown as transparent in Figure 2 for clarity, and having a front wall 202, a rear wall 204, two side walls 206 and a top wall formed by the upper region of the front wall curving over to meet the top of the rear wall. The bottom of the housing 200 is open to provide the tobacco recirculation outlet 122 (Figure 1). The housing has an inlet pipe 210 in the upper region of its rear wall 204. The inlet pipe 210 is connected to the channel 116 between the receiver 114 and the separator. The housing is divided into upper 212 and lower 214 chambers by a rotatable separator drum 216 extending across the width of the housing with its principal axis horizontal. The ends of the separator drum are rotatably mounted in the side walls 206 of the separator housing 200. Two baffle plates 218 extend across the width of the housing 200 either side of the separator drum. The baffle plates 218 extend from the lower region of the separator drum 216 diagonally upwards to meet the front 202 and rear 204 walls of the housing 200, respectively. The lower edges of the baffle plates 218 are separated from the cylindrical surface of the separator drum 216 by a gap sufficient to allow pieces of cut filler to pass between the surface and the baffle plates. The cylindrical surface of the separator drum 216 is foraminous, being a sieve having holes of from 0.3 mm to 0.5 mm, preferably from 0.315 mm to 0.5 mm. In the lower portion of the interior of the separator drum 216, a stator (not visible in Figure 2) extends along the length of the drum adjacent the cylindrical surface and through an arc of about 45° each side of vertical; the stator is effective to blank the holes in the sieve surface of the drum. The interior of the separator drum 216 communicates through the ends of the drum with a bifurcated outlet channel 220 that extends outside the separator housing 200 from the ends of the separator cylinder 216, across the side walls 208 of the housing and across the rear wall 204 of the housing. From the middle of the portion of the outlet channel running across the rear wall 204 of the housing extends the discard outlet 120 of the separator.
Below the separator drum 216 is an airlock in the form of a horizontal rotatable airlock cylinder 222, the ends of which are rotatably mounted in the side walls 206 of the separator housing 200. The cylindrical surface of the airlock cylinder 222 carries six equally spaced apart axially extending resilient vanes 224 of, for example, polyurethane, along its length. At least the uppermost of these impinges on the lower region of the cylindrical surface of the separator drum 216 so that the upper chamber 212 is substantially separated from the lower chamber 214. As a vane in contact with the separator drum surface moves away from that surface as the airlock cylinder rotates, another vane comes into contact with it, maintaining the separation of the chambers. The vanes 224 are readily removable from the airlock cylinder 222 so that worn vanes can be replaced. Access to the vanes is gained through the open bottom of the separator, so that the separator need not be disassembled to replace the vanes.
In use, surplus tobacco is drawn into upper chamber 212 of the separator 118 through the inlet 210 by the entraining air drawn by the fan 124 (Figure 1) through the receiver 114 and the channel 116 between the receiver and the separator (Figure 1). The entraining air is drawn through the sieve surface of the separator drum 216 into the interior of the separator drum and out through the ends of the separator drum into the outlet channel 220 and into the discard outlet 120 of the separator. Small particles of tobacco, too small to be used to make a tobacco rod, pass through the sieve surface of the separator cylinder, drawn by the entraining air, and so pass along the outlet channel 220 to the separator discard outlet 120. Larger pieces of tobacco cannot pass through the sieve surface and are drawn onto it by the entraining air. As the separator drum rotates so that a piece of tobacco on its surface moves down past the lower edge of one of the baffle plates 218, the stator in the interior of the separator drum blanks the holes in the sieve surface so that the piece of tobacco drops off the separator drum 216, into the lower chamber 214 of the separator housing 200, out of the open bottom of the housing and onto the third endless belt 126 to be conveyed to the tobacco chamber 100. Any pieces of tobacco that drop out of the entraining air in the upper chamber 212 of the separator housing will fall onto the baffle plates 218 and either pass through the gap between the baffle plate and the separator drum and directly into the lower chamber 214 or be picked up on the separator drum surface and carried around past the lower edge of the other baffle plate 218 and released into the lower chamber.
Tobacco can be fed from the separator to be reused at rates of up to 20kg/hour.
Provision may be made for cleaning of the separator drum 216. When the tobacco rod making machine stops, the rotation of the separator drum is slowed and compressed air is blown through the cylindrical wall of the separator drum from the inside to the outside to remove tobacco from the outside surface of the drum. The compressed air can be blown for, for example, four seconds.
The apparatus of the invention allows reusable surplus tobacco cut from a stream of cut tobacco filler to be separated from discard surplus tobacco and reused in the manufacture of tobacco rods. The discard portion of the tobacco can be used for other purposes, such as the manufacture of reconstituted tobacco sheet. The separator can be easily attached to and removed form existing tobacco rod making apparatus. The invention allows a reduction in tobacco usage in the manufacture of cigarettes and other smoking articles to be achieved; a reduction of 0.6% or more can be achieved.

Claims

Apparatus for providing a stream of tobacco to be wrapped to form a tobacco rod, comprising a chamber (100) for cut tobacco filler (132);
a conveyor (102) for receiving cut tobacco filler (132) from the chamber (100);
a trimmer (108) for removing tobacco from the conveyor (102);
a receiver (114) adjacent the trimmer (108) for receiving cut tobacco filler (132) trimmed from the tobacco on the conveyor (102);
a separator (118) connected to the receiver (114) for receiving cut tobacco filler (132) therefrom and separating the received cut tobacco filler (132) into a reusable portion and a discard portion;
a return path (126) from the separator for reintroducing the reusable portion to the conveyor (102), and
an airstream generator that generates an airstream from the receiver (114) through the separator (118) so that cut tobacco filler (132) that has been removed by the trimmer (108) is transported in the airstream and drawn to the separator (118),
in which the separator (118) comprises:
a rotatable foraminous separator drum (216) that allows small particles of tobacco into the interior of the separator drum (216) but not larger pieces of tobacco, the interior of the separator drum (216) being connected to the airstream generator so that the airstream is drawn from the receiver (114) through the separator drum (216); and

means for blocking the airstream over a part of the cylindrical surface of the separator drum (216) as it rotates so that the said larger pieces of cut tobacco filler (132) can leave the surface of the separator drum (216) and enter the return path.
Apparatus according to claim 1 in which the return path from the separator (118) for reintroducing the reusable portion to the conveyor (102) includes the chamber (100) for cut tobacco filler (132).
Apparatus according to claim 1 or 2 in which the conveyor (102) is a continuous belt.
Apparatus according to claim 3 in which the belt is permeable and which a vacuum can be drawn on one side of the belt to retain cut tobacco filler (132) on the other side.
Apparatus according to any preceding claim in which the separator (118) further comprises:
an upper chamber (212) for receiving the surplus tobacco from the receiver (114) and containing a least an upper part of the rotating separator drum (216);

a lower chamber (214); an

an airlock between the upper chamber (212) and the lower chamber (214) that allows reusable cut tobacco filler (132) to pass from the upper chamber (212) to the lower chamber (214) while substantially preventing the airstream from passing into the lower chamber (214).
Apparatus according to claim 5 in which the airlock comprises a rotatable airlock cylinder (222) disposed below the separator drum (216) substantially in the lower chamber parallel to the separator drum (216) and having axially extending resilient vanes (224) that, in use, impinge on the cylindrical surface of the rotating separator drum (216), the circumferential spacing of the vanes (224) being such that at least one vane is in contact with the separator drum (216) throughout the rotation of the airlock cylinder (222).
Apparatus according to any preceding claim further comprising a supply of compressed air to the interior of the rotating separator drum (216) actuatable to remove tobacco from the external cylindrical surface of the rotating foraminous cylinder.
Apparatus according to any preceding claim in which the return path (126) from the separator (216) for reintroducing the reusable portion of the cut tobacco filler (132) to the conveyor (102) is from the separator to the chamber (100) for cut tobacco filler (132).
A method of providing a stream of tobacco to be wrapped to form a tobacco rod, comprising:
providing a stream of cut tobacco filler (132) on a conveyor (102);

trimming tobacco from the tobacco on the conveyor (102);

separating the tobacco trimmed from the stream into a reusable portion and a discard portion; and

returning the re-usable portion to the conveyor (102),

in which the separating step is achieved using a rotating foraminous separator drum (216),

further comprising periodically removing accumulated tobacco from a surface of the separator drum (216) with compressed air.
A method according to claim 9 in which the reusable portion of cut tobacco filler (132)is returned to the conveyor (102).
A method according to claim 10 in which the reusable portion of cut tobacco filler (132) is returned to the chamber (100) for cut tobacco filler (132) before it is returned to the conveyor (102).