Filter tow strip, filter rod machine, method for producing filter tow strips and method for producing filter rods

Abstract

The invention relates to a filter tow strip, especially twin tow from cross-linked and crimped filaments which form at least two partial strips ( 12 a, 12 b ) that are interlinked by a section of reduced cross-linking density ( 11 ), the linking filaments ( 13 ) being interlooped and/or interlocked in such a manner that the linking filaments form intersections ( 14 ). The filter two strip is characterized in that the maximum cross-cutting force of the partial strips ( 12 a, 12 b ) does not exceed 20 cN on a length of approximately 20 cm of the filter tow strip ( 10 ) and/or the number of the Baking filaments ( 13 ) does not exceed 200 cross-locking and/or cross-looping filaments on a length of approximately 20 cm of the filter tow strip ( 10 ) when impinged with the maximum cross-cutting force.

1 . A filter tow strip, comprising:
 a twin tow made of cross-linked and crimped filaments which form at least two partial strips, and which are connected by a region of reduced cross-linking density,   wherein the connecting filaments are interlooped and/or interlocked in such a way that they form respective intersections,   wherein the maximum cross-separating force of the partial strips does not exceed 20 cN on a length of about 20 cm of the filter tow strip and/or the number of connecting filaments does not exceed 200 cross-locking and/or cross-looping filaments on a length of about 20 cm of the filter tow strip when the filter tow strip is loaded with the maximum cross-separating force.   
     
     
         2 . A filter tow strip according to  claim 1 , wherein the maximum cross-separating force is ≦15 cN. 
     
     
         3 . A filter tow strip according to  claim 1 , wherein the number of cross-locking and/or cross-looping filaments in the region of the reduced cross-linking density is ≦150. 
     
     
         4 . A filter tow strip according to  claim 1 , wherein the partial strips are arranged side by side. 
     
     
         5 . A filter tow strip according to  claim 1 , wherein the partial strips are arranged overlapping one another in the edge region. 
     
     
         6 . A filter tow strip according to  claim 1 , wherein the partial strips are arranged one above the other and the connecting filaments are located in the region of the overlap of the partial strips. 
     
     
         7 . A filter rod machine, comprising at least one spreader nozzle, a drafting mechanism, a spray mechanism, a formatting part, and at least one separating mechanism for separating partial strips of the filter tow strip before the spreader nozzle. 
     
     
         8 . A machine according to  claim 7 , wherein separating mechanism comprises at least two guide rings attached so as to exert a normal force component on the partial strips. 
     
     
         9 . A machine according to  claim 7 , wherein the separating mechanism comprises at least one separating wedge arranged in the conveying direction of the filter tow strip. 
     
     
         10 . A machine according to  claim 7 , wherein the separating mechanism comprises two spreader nozzles having entry openings out of line with one another and arranged so as to exert a normal force component on the partial strips. 
     
     
         11 . A machine according to  claim 7 , further comprising a force measuring apparatus for measuring the tension of the separated partial strips, the force measuring apparatus being directly arranged downstream in situ of the separating mechanism. 
     
     
         12 . A machine according to  claim 7 , further comprising a control mechanism operative to control a conveying speed of individual partial strips with the aid of a tension in the partial strips. 
     
     
         13 . A method for producing filter tow strips, comprising the steps of:
 providing at least two partial strips made of cross-linked and crimped filaments;   connecting the at least two partial strips by a region of reduced cross-linking density,   wherein the filaments in the region of reduced cross-linking density are interlooped and/or interlocked and form intersections such that a maximum cross-separating force of the partial strips does not exceed 20 cN on a length of about 20 cm of the filter tow strip and/or the number of connecting filaments does not exceed 200 cross-locking and/or cross-looping filaments on a length of about 20 cm of the filter tow strip when the filter tow strip is loaded with the maximum cross-separating force.   
     
     
         14 . A method according to  claim 13 , comprising the additional steps of arranging the partial strips side by side and crimping them together. 
     
     
         15 . A method according to  claim 13 , comprising the steps of:
 guiding the partial strips over one another in a partially overlapping manner, and   treating the partial strips so as to produce binding filaments,   wherein the treating step is performed mechanically, by needling, with an air jet or with a water jet.   
     
     
         16 . A method according to  claim 13 , comprising the steps of:
 guiding the partial strips over one another in a completely overlapping manner, and   treating the partial strips so as to produce binding filaments,   wherein the treating step is performed mechanically, by needling, with an air jet, or with a water jet.   
     
     
         17 . A method according to  claim 13 , comprising the additional steps of separating the filter tow strip into the partial strips and placing the separated partial strips in at least one can. 
     
     
         18 . A method according to  claim 13  comprising placing the undivided filter tow strip in a can. 
     
     
         19 . A method for producing filter rods from filter tow strips made of cross-linked and crimped filaments, comprising the steps of:
 conveying a filter tow strip through a preparation part and a formatting part, and   connecting at least two partial strips of the filter tow strip connected to one another by a region of reduced cross-linking density,   wherein the filaments in the region of the reduced cross-linking density are interlooped and/or interlocked in such a way that the filaments form intersections, the partial strips being separated before the formatting part with a maximum cross-separating force, which does not exceed 20 cN on a length of the filter tow strip of about 20 cm.   
     
     
         20 . A machine according to  claim 7 , wherein the filter rod machine is configured as a double filter rod machine. 
     
     
         21 . A method according to  claim 17 , wherein the placing step places the separated partial strips into a divided can having a plurality of depositing regions therein.