Patent Publication Number: US-2019191758-A1

Title: A cleaning unit, a tobacco industry machine for producing multi-segment filter rods and a method for cleaning a train of rod-like elements

Description:
TECHNICAL FIELD 
     The present disclosure relates to a cleaning unit used in tobacco industry machines, for removing contaminations from a train of rod-like elements, a tobacco industry machine for producing multi-segment filter rods and a method for cleaning a train of rod-like elements. 
     BACKGROUND 
     Tobacco industry products, such as cigarettes, may comprise segment filters with various filtering materials such as activated charcoal in a form of a loose granulate located between neighboring segments of a solid form. A segment with activated charcoal can be formed by placing the charcoal between the neighboring solid segments, which typically have a form of rod-like elements having filtering properties or rod-like elements having non-filtering properties, for example comprising aromatic capsules. Manufacturers of filters comprising charcoal or other granulate material aim for placement of portions of the loose material such that the segments neighboring a compartment for granulate materials and other segments in the train of segments are not contaminated with this material. Moreover, manufacturers expect that the granulate material does not get in between side edges of a wrapper which are joined with glue. In case of activated charcoal, charcoal particles which got in between the wrapper and the segments, or between surfaces of the wrapper, are easily visible in a final product. Therefore, there is a need to remove particles of material which are on the segments, before wrapping the train of segments with the wrapper. 
     There are known various methods for removing contaminations. 
     A U.S. patent U.S. Pat. No. 3,482,488 discloses a device for removing contaminations from rod-like elements by means of a rotating brush. A drawback of this solution is a low cleaning efficiency. 
     Removing contaminations by means of suction nozzles is known i.a. from a European patent EP2286681B1. However the solution presented therein removes only a portion of contaminations and does not prevent an uncontrolled dislocation of the contaminations. 
     A PCT application WO2016139198, in the name of the present applicant, discloses suction nozzles arranged on both sides of a moving train of segments. 
     In case of high production speeds, particles of a granulate material (and more generally: loose material), which were not placed in a compartment between the segments, may rebound from the segments and constructional elements of a machine and move above the moving train of segments in a completely uncontrollable manner. None of the abovementioned documents discloses a solution, which would eliminate or limit this phenomenon. 
     The aim of the present invention is to provide a device for producing multi-segment filter rods comprising loose material, wherein particles of the material, which are not placed in compartments between solid segments or are lifted from the surface of the segments, are prevented from displacing in the direction of movement of the train of segments, i.e. that they are prevented from displacing between the consecutive assemblies of the device or zones in which consecutive operations of a filter rods production process take place. 
     SUMMARY 
     There is disclosed a cleaning unit for tobacco industry machines. The tobacco industry machine is configured to process a moving train of rod-like elements separated by compartments and partially wrapped with a wrapper, wherein the compartments are filled with a loose material forming segments of the loose material. The cleaning unit is positioned in the tobacco industry machine in a cleaning zone that is located between: a filling zone for filling the loose material into the compartments between the rod-like elements and a garniture zone for forming the train of the rod-like elements to a continuous filter rod. The cleaning unit is configured to remove contaminations of the loose material from the rod-like elements, the segments of the loose material and the wrapper; The cleaning unit comprises: at least one cleaning element, located in the cleaning zone, for removing the contaminations of the loose material from the rod-like elements; at least one suction element for removing the contaminations of the loose material from the rod-like elements; a shifting mechanism configured to move covering elements to positions in which the covering elements at least partially cover the compartments filled with the loose material between the rod-like elements during the movement of the train in a vicinity of the suction nozzle. The covering elements, at a portion of their track of movement, are configured to move in parallel to the direction of movement of the rod-like elements. The cleaning unit further comprises an outlet partition at an outlet from the cleaning zone for limiting an uncontrolled displacement of contaminations from the cleaning zone to the garniture zone, located above the train of the rod-like elements and having a passage through which the covering elements pass. 
     The cleaning unit may comprise the inlet partition located at the inlet to the cleaning zone for limiting the uncontrolled displacement of contaminations from the filling zone to the cleaning zone. 
     The cleaning unit may comprise an end partition located at the inlet of the garniture zone, for limiting the uncontrolled dislocation of the contaminations from the cleaning zone to the garniture zone located above the train of the rod-like elements and having a notch, through which the edge of the wrapper passes. 
     The cleaning unit may comprise a shield partition having a surface which is in parallel to the direction of movement, located in front of the end partition with respect to the direction of movement, for limiting the uncontrolled dislocation of the contaminations from the cleaning zone on to the rod-like elements of the train. 
     The cleaning unit may further comprise an initial partition located at the outlet of the filling zone, for limiting the uncontrolled dislocation of the contaminations from the filling zone to the cleaning zone. 
     At least one partition may be positioned transversally to the direction of movement. 
     At least one partition may have a form of a flat plate. 
     At least one partition may have a form or arched shaped plate. 
     At least one partition may have the main surface directed at an acute angle with respect to the direction of movement. 
     The covering element may have a thin-walled covering element. 
     The suction element may have a form of a suction nozzle having longitudinal suction opening. 
     The cleaning element may be a scraping element in a form of a brush. 
     The cleaning element may be a scraping element in a form of a compressed air nozzle. 
     There is also disclosed a machine for tobacco industry for producing multi-segment filter rods comprising: a feeding unit for arranging, in a spaced relationship, rod-like elements in a train on a wrapper placed on a garniture belt; a supplying unit for supplying a loose material into compartments between the rod-like elements; a cleaning unit for removing contaminations of the loose material from the rod-like elements; a garniture unit for wrapping the wrapper around the rod-like elements and the loose material to form a continuous filter rod; a cutting head for cutting the continuous rod into multi-segment filter rods. The cleaning unit may be the unit as described above. 
     There is also disclosed a method for cleaning a train of rod-like elements during production of filter rods in a tobacco industry machine, wherein the tobacco industry machine is configured to process a moving train of rod-like elements separated by compartments and partially wrapped with a wrapper, wherein the compartments are filled with a loose material forming segments of the loose material. The method comprises removing contaminations of the loose material in a cleaning zone by moving covering elements to positions in which the covering elements at least partially cover the compartments filled with the loose material between the rod-like elements during the movement of the train in a vicinity of a cleaning element, wherein the covering elements in part of their track of movement are moved in parallel to the direction of movement of the rod-like elements. The method comprises limiting uncontrolled displacement of the contaminations from the cleaning zone by providing an outlet partition at an outlet of the cleaning zone, above the train of rod-like elements, the outlet partition comprising a passage, through which the covering elements pass. 
     By use of the method according to the invention, an uncontrolled displacement of the contaminations from the cleaning zone is limited by application of an outlet partition at an outlet of the cleaning zone, above the train of rod-like elements, comprising a passage, through which the covering elements pass. 
     The solution according to the invention provides very efficient cleaning of the rod-like elements while maintaining a high degree of filling of the compartments with the loose material. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       The present invention is shown by means of example embodiments in a drawing, in which: 
         FIGS. 1 and 2  show fragments of examples of continuous multi-segment rods; 
         FIG. 3  shows an example of a multi-segment rod; 
         FIG. 4  shows schematically a fragment of a machine for producing multi-segment filter rods; 
         FIG. 5  shows a fragment of a machine for producing multi-segment filter rods in a front view; 
         FIG. 6  shows a fragment of a machine for producing multi-segment filter rods in a top view; 
         FIG. 7  shows a cross-section A-A from  FIG. 5  through a compartment with loose material in a train of rod-like elements; 
         FIG. 8  shows a cross-section C-C from  FIG. 5  through the rod-like element and a suction nozzle; 
         FIG. 9  shows a cross-section B-B from  FIG. 5  through the rod-like element in the train of rod-like elements; 
         FIG. 10  shows an embodiment of a cleaning element in a form of two compressed air nozzles; 
         FIG. 11  shows an embodiment in which the compressed air nozzle passes through the suction nozzle; 
         FIG. 12  shows a cross-section D-D from  FIG. 5  through the rod-like element in the train of rod-like elements. 
         FIG. 13  shows a fragment of a machine for producing multi-segment filter rods in a top view. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  show fragments of examples of continuous multi-segment rods CR 1  and CR 2  formed from trains of rod-like elements (segments) S 1 , S 2  and SC respectively, prepared during production, formed by the unit according to the invention, wherein the segments are wrapped in a wrapper  101 . The segments S 1  and S 2  have a solid shape, typically cylindrical, whereas the segment SC is formed from a loose material  102  which is located between the segments S 1  and S 1  or between the segments S 1  and S 2 . The presented continuous rods are cut into multi-segment rods.  FIG. 3  shows an example of a multi-segment rod R 2  produced from the continuous multi-segment rod CR 2 . 
       FIG. 4  shows schematically a fragment of a machine for producing multi-segment filter rods. The machine comprises a feeding unit  1 , which is configured to arrange the rod-like elements S 1  and S 2  as a train ST 1 , wherein the rod-like elements S 1  and S 2  are transported in a substantially preset spaced relationship. The rod-like elements S 1  and S 2  are fed onto a garniture belt  5 . A wrapper, such as a wrapping paper, is fed on a transporter of the garniture belt  5  and the elements S 1  and S 2  are placed on the wrapper  101 . Above the moving train ST 1  there is located a filling unit  103  for supplying the loose material  102 , for example activated charcoal, in order to form the segment SC. Lifted edges of the wrapper  101  and front surfaces of the elements S 1  and S 2  form compartments  105 , into which the loose material  102  is fed from the filling unit  103 . The train ST 2  of the rod-like elements S 1 , S 2  and SC that moves on the garniture belt  5  belt is wrapped in the wrapper  101  by a garniture unit  6 , wherein the edges of the wrapper  101  are lifted on a distance where loose material is filled and cleaned. The garniture belt  5  typically forms a part of the garniture unit  6 . Next to the filling unit  103  there is located a cleaning unit  104  for removing contamination of loose material from the rod-like elements i.e. particles of the loose material which fall onto the surface of the rod-like elements S 1  and S 2  in the preceding step, i.e. when the loose material is supplied from the filling unit  103 . The produced continuous rod CR is transported further and, after the wrapper  101  is glued in the garniture unit  6 , it is cut by a cutting head  8  into individual multi-segment rods R. 
       FIG. 5  shows an enlarged view of a fragment of a machine for producing filter rods. The train ST 1  of rod-like elements S 1 , S 2  passes through a filing zone Z 1  for feeding the loose material, and next as a train ST 2  of the rod-like elements comprising also the loose material, passes through a cleaning zone Z 2  and through a garniture zone Z 3  for forming a continuous filter rod. 
       FIG. 5  presents consecutive steps of a process of feeding the loose material  102  to the compartments  105  in the filling zone Z 1 , wherein the filling unit  103  for supplying the loose material may be constructed in a way as disclosed in the PCT application WO2016139198 (in the name of the present applicant) or according to other prior art embodiments, such as disclosed in U.S. Pat. Nos. 3,545,345, 3,623,404, DE1432720B2, EP0568278B1.  FIG. 5  shows only examples of pockets  103 A of the filling unit  103 . 
     The cleaning unit  104 , located next to the filling unit  103 , is equipped with covering elements  10  mounted on a chain transporter  15 , shown in  FIG. 6 , which is equipped with two chain wheels  16 . The covering elements  10  may have a form of elements as disclosed in PCT application WO2016139198 (in the name of the present applicant). The covering elements  10  on a fragment of their moving trajectory move linearly in parallel to the displacement direction T, which is the direction of movement of the train ST 1 , ST 2  of the rod-like elements, wherein additionally on a certain distance, they move vertically, transversally to the direction of displacement T in order to approach the compartment  105  filled with the loose material  102 , which can be realized by means of a plain linear bearing, while the figure does not show a mechanism for realization of this movement. A downwards movement is indicated by an arrow F, an upwards movement is indicated by an arrow G, and a movement along the train ST 2  is indicated by an arrow H.  FIG. 7  shows the covering element  10  having a thin-walled covering part  10 A, which covers the compartment  105 . 
     In the presented solution, above the track of movement of the train ST 2 , there is located a cleaning element in the presented embodiment having a form of at least one brush  11 ,  11 ′, for sweeping the contaminations, in a form of the loose material  102 , away from the surface of segments S 1 , S 2 . Therefore, the brush  11 ,  11 ′ is a contaminations sweeping element. As shown in  FIG. 8  a cleaning part  11 A (bristles) of the brush  11 ,  11 ′ touches the side surface of the element S 2  (in the presented step of movement of the covering element  10 ). The number of brushes  11 ,  11 ′ in the cleaning zone Z 2  may be provided according to the needs. Above the train ST 1  of the segments, there is located a suction nozzle  12  which may have a plurality of openings or one longitudinal opening located in parallel to the train ST 1  just above elements S 1 , S 2  such that the covering parts  10 A of the covering elements  10  can move below the nozzle  12 , as shown in  FIG. 9 . 
     The cleaning element may also have a form of a compressed air nozzle, which removes contaminations of the side surface of the elements S 1 , S 2 , by blowing them out.  FIG. 10  shows two compressed air nozzles  17  and  18 , which are directed towards recesses formed by the side surfaces of the rod-like elements S 1  and S 2  and the wrapper  101 . The compressed air nozzles  17  and  18  may be directed perpendicularly to the direction of movement of the rod-like elements, or at an angle a with respect to this direction as shown in  FIG. 5 , wherein preferably the angle a is in the range from 30° to 60°, and for example is equal to 45°.  FIG. 11  shows another embodiment, wherein the compressed air nozzle  19  passes through the suction nozzle  12 . Similarly the compressed air nozzle  19  is directed towards the recess between the element S 1 , S 2  and the wrapper  101 . Locating the outlet of the compressed air nozzle  19  within the inlet of the suction nozzle  12  (in principle within the inlet of the suction element) causes additional air turbulences, which enhance lifting of the contaminations from the surface of the rod-like elements S 1 , S 2 . 
     The cleaning element may have a form of an element made of soft plastic covering an edge for removing the contaminations. The plastic cleaning element may be fixed or may be rotatable. 
     The train ST 2  leaving the cleaning zone Z 2  is prepared for forming the continuous filter rod CR from the train, which is realized in the garniture zone Z 3 . In the garniture zone Z 3  there is a glue nozzle  13  and guiding elements (not shown in the drawing for clarity, but known from the prior art) for bending the edges of the wrapper in order to join these edges and glue them in order to form a continuous filter rod. 
     Filling the chamber  105  with the loose material  102  from the pocket  103 A may result in that not the whole amount of loose material is transferred to the chamber  105 . A portion of particles, which have certain velocity, may rebound from the rod-like elements S 1 , S 2  or from the wrapper  101 , and subsequently fall onto the surface of the elements S 1 , S 2 , wherein the falling of the particles of the loose material  102  may occur in any location, for example just before gluing of the edges of the wrapper. 
     Cleaning the contaminations of the loose material in the cleaning unit  104  by means of the cleaning element  11 ,  11 ′ and the suction nozzle  12  may result in removal of most of the contaminations. However, there is a risk that some contaminations are lifted above the elements S 1 , S 2  but not received by the suction nozzle  12 . Therefore, there is a risk that these contaminations will fall further away on the elements S 1 , S 2  or will get in between the edges of the wrapper which will be glued together with the contamination between these surfaces. In order to eliminate the risk of uncontrollable displacement of the contaminations between the filling unit  103 , the cleaning unit  104  and the garniture unit  6 , partitions  14 ,  124 ,  34 ,  44 ,  54  are provided and arranged above the moving train of segments. Due to the fact that the zones of operation of the units may differ from the area occupied by the units themselves, the problem of contaminations displacement may be defined as uncontrollable displacement of the contaminations between the filling zone Z 1 , the cleaning zone Z 2  and the garniture zone Z 3  for forming the rod. 
     In the presented solution there is a significantly high risk of contaminations displacement between the cleaning zone Z 2  and the garniture zone Z 3 , because not all particles of the loose material which are lifted by the cleaning element can be received by the suction nozzle  12 . These particles may fall again on the rod-like elements S 1 , S 2 . The outlet partition  34 , located on the side of the garniture zone Z 3  (at the outlet from the cleaning zone Z 2 ), is intended to limit the uncontrolled displacement of the particles of the loose material from the cleaning zone Z 2  to the garniture zone Z 3 . The inlet partition  24  is located on the side of the filling zone Z 1  (at the inlet to the cleaning zone Z 2 ) and is intended to limit the uncontrolled displacement of the particles of the material from the filling zone Z 1  to the cleaning zone Z 2 . The outlet partition  34  and the inlet partition  24  may be similar to each other. The outlet partition  34  and the inlet partition  24  may be formed as a single part or as multipart partitions.  FIG. 7  shows an exemplary embodiment in which the inlet partition  24  is a two-part partition consisting of parts  24 A and  24 B. Between the parts  24 A and  24 B there is a passage  25 , through which the covering elements  10  may pass. Similarly,  FIG. 8  shows an embodiment in which the outlet partition  34  is also a two-part partition and consists of parts  34 A and  34 B. Between the parts  34 A and  34 B there is located a passage  35 , through which the covering elements  10  may pass. In the embodiment shown in  FIG. 5 , the inlet partition  24  is located in front of the brush  11  and the outlet partition  34  is located behind the brush  11 ′. In another embodiment, the brushes  11 ,  11 ′ can be located in the passages  25 ,  35 . As a result, the passage  25 ,  35  is effectively narrowed in such a way that there is only space for the passage of the covering element  10 . The partitions  24 ,  34  may have surfaces arranged obliquely (at an acute angle) with respect to the direction of the movement T of the train ST 2 , owing to which particles of the contaminations may be rejected aside, outside the track of movement of the train of the rod-like elements. The partitions  24 ,  34  may be flat or arched shaped. In  FIG. 13  the inlet partition  24 ′ is flat and arranged askew while the outlet partition  34 ′ is arched and arranged askew. The end partition  44  is located at the inlet to the garniture zone, just in front of the glue nozzle  13  in the region where the edges of the wrapper  101  are bent towards each other before gluing them. In the lower edge of the end partition  44  there is a notch  20  for receiving the edge of the wrapper  101 , as shown in  FIG. 12 . In order to prevent the displacement of the contaminations to the garniture zone Z 3  for forming the continuous filter rod CR there is provided a shield partition  54  (indicated by dashed line in  FIG. 6 ), the main surface of which is located in parallel to the direction of the movement of the train ST 2 , i.e. horizontal. The shield layer  54  prevents the contaminations displacement to the segments S 1 , S 2  just before the initialization of the process of wrapping the wrapper  101 . The presented embodiment utilizes an initial partition  14  at the outlet of the filling zone Z 1 , between the filling zone Z 2  and the cleaning zone Z 2 , which is intended to protect from the displacement of the contaminations outside the filling unit  103  in the direction of the cleaning unit  104 .