Patent Publication Number: US-2010108082-A1

Title: Process and device

Description:
FIELD OF INVENTION 
     The invention pertains to the field of processes and devices for production for portion tobacco. 
     BACKGROUND 
     Portion tobacco has received additional attention in recent years, partly due to the restrictions imposed on tobacco smokers. This new demand has led to increased focus on providing means for efficiently producing portion tobacco on an industrial scale, as an alternative to the traditional approach involving for example compression of the tobacco strand during long periods of time. The humidity of the raw product has made the production cumbersome, due to stickiness. This problem has previously been solved by providing the tobacco with a pouch, or through a supplement of additives. 
     GENERAL DISCUSSION 
     The current invention provides a process and a device for the production of portion tobacco without a pouch on an industrial scale, whereby the difficulty of feeding the tobacco strand through the device is solved. 
     As starting material for the process according to the current invention, a strand of tobacco is used. In one embodiment of the invention, the strand is made up of the halves of tobacco leaves that remain after the centrally located stem has been removed. In another embodiment, shredded tobacco leaves are used for manufacturing the strand of tobacco. In yet another embodiment, the strand according to any of the preceding embodiments is further supplied with a tobacco filler comprised of smaller pieces of tobacco. The strand of tobacco may be produced at the site of production, or be pre-ordered and delivered in advance of production. 
     The device comprises a roll, on which a strand of tobacco is wound. This strand is in one embodiment compacted and shaped by being fed through two continuous belts, for example cog belts or V-belts, or other conventional belts, located opposite to each other, which may be manufactured from metal or a polymeric material, preferably from a material that is easily cleaned. The bands may or may not run on tooth wheels. The residence time between the belts, which translates to the length of the feed, is adjusted to get sufficient compaction. The compaction results in a loss of fluid, and thus in a decrease of stickiness of the strand of tobacco. The upper belt, with its curved or grooved upper surface, gives the portions of tobacco a curved upper surface. The lower belt on the other hand has a flat, smooth surface against the strand of tobacco. The lower belt is important for feeding the sticky strand of tobacco, which otherwise tends to get stuck. An alternative for compaction and forming of the strand of tobacco is the use of at least one roll. This roll would be provided with a central groove. For increased feeding speed without detriment to the compaction the device may be fitted with several rolls after one another. The device may be composed of opposite rolls, for the sake of feeding. As an alternative, the upper roll may be accompanied by for example a lower belt, such as a cog belt or a V-belt. To ensure smooth feeding without undue adherence to the rolls, the device may be fitted with doctor blade(s) after the roll(s), i.e. strippers that are in close contact with the rolls. These doctor blades may be spring-mounted and simultaneously keep the strand of tobacco from following the roll or any of the rolls, and guide the strand of tobacco in a straight line between the one or more rolls. 
     The strand of tobacco has considerable resiliency, wherefore compression must be effected with a certain force. This force may be exerted by choosing an appropriate residence time during compression. This chosen time may correspond to a certain length of the belt, or a certain number of rolls. The force may also be controlled by adjustable retaining devices that may be located directly underneath the belts. These retaining devices are preferably located at the side of the belt that points away from the strand of tobacco, and ensure that the belt is in a stretched position. 
     After the strand of tobacco has received the desired shape, individual pieces of portion tobacco are formed by a cutting process. This process comprises a cutting tool, the end of which may have a blunt, V-shaped edge. Thereby, the newly cut portions of tobacco are pushed away from the strand of tobacco, which may constitute an advantage in respect of packaging (cf. below). The cutting tool preferably has low friction, and may be covered by for example Teflon or Impreglon, to reduce adherence to the tobacco. The shape of the cutting tool may moreover assist in forming the cut pieces of tobacco, such as in the form of a pillow. The ground layer beneath the cutting tool is preferably made out of a replaceable polymeric material. On one or both sides of the cutting tool, an optional stripper may be fitted to make the sticky strand of tobacco easier come loose from the cutting tool. The stripper may also ensure that the strand of tobacco remains in close contact with the lower belt or the lower roll, as the case may be. The stripper is lowered concomitantly with the cutting tool, and retains its lower position during a limited period of time, whereby the cutting tool is allowed to be transported to and assume its upper position, ready for cutting of the next portion of tobacco, after the strand has been fed forward to the subsequent cutting position. The positioning in height of the stripper may be accomplished by resilient means, such as a simple spring, still forcing the stripper downwards, when the cutting tool is raised. Also the stripper may assist in forming the portions of tobacco in the desired shape by compacting of the edges of the portion, resulting in the abovementioned appearance of a pillow. The stripper(s) may be covered by for example teflon or Impreglon. Cut portions of tobacco may be separated from each other by a blowing device, for example using compressed air, prior to packaging. The portions of tobacco may then leave the device via a ramp. Alternatively, cutting may be executed directly above the location of packing, making the ramp superfluous. A packaging line may be directly connected to the device described herein. 
     Due to the size of the toothed wheels in closest proximity to the cutting tool, the cutting tool may need to be located at a certain distance from said toothed wheel. In order to ensure safe feeding of the strand of tobacco until cutting, additional, continuous, opposite feeder bands may be used. These bands are preferably made out of a polymeric material, and enclose the strand of tobacco in close proximity. In one embodiment, the feeder bands run on the outside of the toothed wheels that engage the upper belt and lower belt, respectively. In yet another embodiment, the strand of tobacco is throughout the device fed between the feeder bands, whereby the strand of tobacco is never in direct contact with the belts. This may be advantageous for efficient feeding of the strand of tobacco as well as for hygienic reasons. The feeder bands preferably hang on forward tensioning wheels as close to the cutting tool as possible. These forward tensioning wheels are small enough, with a sharp radius, to make the sticky strand of tobacco easier leave the feeder bands before cutting. This sharp radius may make additional strippers superfluous. The feeder bands may also hang on additional tensioning wheels. 
     The method described above comprises one production line. However, the method preferentially comprises more than one production line, for efficiency purposes. The production lines are preferably parallel production lines. 
     The device according to the present invention is preferably controlled by a computerized state of the art control system. 
     The present invention will now be described with reference to the accompanying drawings. The embodiments shall merely be seen as an illustration of the spirit and scope of the current invention, and in no way whatsoever as a limitation. 
    
    
     
       SHORT DESCRIPTION OF THE FIGURES 
         FIG. 1  is a side view of an embodiment of the device for production of portion tobacco, detailing cog belts and feeder bands, and the means to advance these belts, as well a cutting tool. 
         FIG. 2  is a rear view, partly in section of an embodiment of the device for production of portion tobacco along the short side, in detail showing the toothed wheels. 
         FIG. 3  is a side view of the device comprising rolls for compacting, wherein the preferred position of doctor blades appears. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows an inlet  1  into the device  10  for a strand of tobacco, which is wound on a roll (not shown). 
     Following the inlet  1 , the strand of tobacco is engaged by two opposite continuous cog belts  60  and  70 , which are each looped on two toothed wheels  40 ,  41  and  50 ,  51 , respectively. Adjacent parts of the cog belts  60 ,  70  are forced into engagement with the strand by retaining devices  65 ,  66  whereby good compacting of the strand of tobacco is ensured. The length of the two compacting cog belts  60 ,  70  is approximately 30 cm, for sufficient compacting. 
     Opposite continuous feeder bands  20 ,  21  extend from a downstream end of the cog belt to a position in close proximity to the cutting tool  80 . The feeder bands  20 ,  21  run on the outside of the tooth wheels  40 ,  41 ,  50 ,  51  and forward tensioning wheels  71 ,  72  nearby the cutting tool  80  as well as on the additional tensioning wheels  30 ,  31  below and above the cog belts, respectively. The cutting tool  80  is actuated by a pneumatic cylinder  100 . On both sides of the cutting tool  80 , there is mounted two resilient stripper devices  92 ,  94 , which are lowered at the same time as the cutting tool  80 , and by means of in each case a spring (not shown) retain their position for a certain period of time when the cutting tool is returning to its original position, thus holding the strand of tobacco. Immediately downstream of the stripper devices  92 ,  94 , there is a ramp  96 , for transport of the portions of tobacco downwards, in anticipation of packaging. 
     In a magnification of the cutting zone in  FIG. 1 , the cutting zone with the cutting tool  80  and its ground layer  98  is detailed. In the figure, it is clearly seen how the edges of the portions of tobacco  14  are formed from the strand of tobacco  12 , by way of compacting during cutting by the blunt-ended cutting tool  80 . 
     In  FIG. 2 , a rear view of the cog belts  60 ,  60 ,  70  can be seen. The upper cog belts  60 ,  60  are designed with a groove  61 , wherein the strand of tobacco runs. The upstream tooth wheels  40 ,  50  are via respective shafts  45 ,  55  connected to an electrical motor (not shown). A transmission between the two shafts  45 ,  55  makes one motor sufficient for advancing all belts. As is readily seen in  FIG. 2 , two upper cog belts  60 ,  60  in parallel are located opposite one, broader lower belt  70  for efficiency purposes. Moreover, the pneumatic cylinder  100  is shown. 
       FIG. 3  clearly shows two opposite rolls ( 110 ,  111 ) surrounding a strand of tobacco ( 12 ). The doctor blades ( 113 ,  114 ) ensure that the strand of tobacco retains its correct path through the device.