Method and apparatus for applying a material to a wide high-speed web

Abstract

A high-speed apparatus for applying material to cigarette paper during manufacture uses at least two independently operable, moving orifice devices, each positioned to deposit horizontal bands of material on a paper web at the dry end of a Fourdrinier wire. The resulting web may be cut into multiple webs, each web having a width corresponding to the effective width of a moving orifice device. Dynamic optical inspection apparatus evaluates add-on band uniformity, thickness, and/or spacing and adjusts operation of the apparatus accordingly. The apparatus can simultaneously produce both banded and unbanded paper for wrapping tobacco during cigarette manufacturing.

1 . A method of manufacturing a web having an applied pattern of add-on material, the method comprising the steps of: 
 preparing a first slurry of fibrous material and liquid;    delivering the first slurry to a moving wire having a longitudinal direction, a wire width transverse to that longitudinal direction, and a nominal linear speed;    draining the liquid from the first slurry through the moving wire to form a fibrous web;    preparing a second slurry of add-on material;    operating at least one of a plurality of distribution devices, each device having a continuous belt with a plurality of spaced-apart orifices therethrough, a reservoir, a principal length, and angled with respect to the longitudinal direction such that each distribution device covers a corresponding portion of the wire width;    delivering the add-on slurry to the reservoir of at least one distribution device;    moving the continuous belt with a nominal band speed having a velocity component in the longitudinal direction substantially the same as the nominal linear speed; and    depositing transverse bands of the add-on slurry onto the fibrous web through the orifices, where the length of each transverse band is no greater than the portion of the wire width corresponding to the distribution device.    
   
   
       2 . The method of manufacturing of  claim 1  including: 
 delivering the add-on slurry to the reservoir of each distribution device; and depositing transverse bands of add-on slurry in a plurality of longitudinally extending zones which are parallel to each other and together extend substantially across the wire width.    
   
   
       3 . The method of manufacturing of  claim 1  further including the step of: 
 slitting the web into at least two narrower webs, each narrower web having a width corresponding to the distribution device which deposited transverse stripes thereon.    
   
   
       4 . The method of manufacturing of  claim 3 , including the further step of: 
 independently reeling each of the narrower webs for subsequent use.    
   
   
       5 . The method of manufacturing of  claim 1  further including the steps of: 
 optically inspecting the transverse stripes on the web to determine width, and spacing characteristics; and    dynamically adjusting operation of at least one of the distribution devices in response to the optical inspection step to provide uniform width and uniform spacing of the transverse stripes on the web.    
   
   
       6 . The method of manufacturing of  claim 1 , further including the steps of: 
 Supplying the add-on slurry to a plurality of linearly arranged compartments in the reservoir; and    advancing the at least one orifice sequentially through the plurality of linearly arranged compartments.    
   
   
       7 . The method of manufacturing of  claim 6 , further including the steps of: 
 optically inspecting the transverse stripes on the web to determine width and spacing characteristics as a function of lateral location on the web;    dynamically adjusting the pressure in each compartment of the distribution devices in response to the optical inspection step to provide uniform width and uniform spacing of the transverse stripes on the web.    
   
   
       8 . The method of manufacturing of  claim 1 , wherein the first slurry and the add-on material are ingredients of cigarette paper.  
   
   
       9 . The method of manufacturing of  claim 1 , wherein the wire has a width greater than three meters and the linear speed is more than 500 ft./min.  
   
   
       10 . Apparatus for manufacturing a web having an applied pattern of add-on material comprising: 
 a Fourdrinier wire operable to prepare a continuous web of fibrous material which moves in a longitudinal direction at a nominal linear speed, has a width transverse to that longitudinal direction, and a generally planar surface;    at least two distribution devices, each operable to deposit a stream of add-on material on the generally planar surface of the web, each having a reservoir for add-on material, a principal length, and a continuous belt operable to move between the reservoir and the planar surface at a belt speed, including at least one orifice, such that when the orifice aligns with the reservoir a stream of add-on material is deposited on the generally planar surface;    each distribution device being angled with respect to the longitudinal direction such that each distribution device covers a corresponding portion of the web width;    the belt speed having a longitudinal component generally parallel to the longitudinal direction and a transverse component generally perpendicular to the longitudinal direction, the longitudinal component being substantially equal to the nominal linear speed; and    a control system selectively operating each of the distribution devices.    
   
   
       11 . The apparatus of  claim 10 , wherein: 
 each distribution device covers a portion of the width of the web; and    each distribution device deposits a plurality of generally horizontal bands of add-on material on the surface of the web.    
   
   
       12 . The apparatus of  claim 10  further including a cutting device to longitudinally slit the web into parallel narrower webs, each narrower web having a width corresponding to a banded region formed by the respective distribution device.  
   
   
       13 . The apparatus of  claim 10  further including: 
 a drying system operable to dry the web, positioned downstream of the distribution devices;    an optical inspection system operable to determine the width of the bands of add-on material, positioned downstream of the drying system, operably connected with the distribution devices; and    a control system responsive to the optical inspection system to adjust add-on material supply to the distribution devices to provide bands with uniform width and/or thickness.    
   
   
       14 . The apparatus of  claim 10  further including: 
 a drying system operable to dry the web, positioned downstream of the distribution devices;    an optical inspection system operable to determine the spacing between the bands of add-on material, positioned downstream of the drying system, operably connected with the distribution devices; and    a control system responsive to the optical inspection system to adjust operation of distribution device belt speed to provide bands of uniform spacing.    
   
   
       15 . The apparatus of  claim 10  further including: 
 a drying system operable to dry the web, positioned downstream of the distribution devices;    an optical inspection system operable to determine the uniformity and spacing of the bands of add-on material, positioned downstream of the drying system and operably connected with the distribution devices; and    a control system responsive to the optical inspection system to adjust operation of the distribution devices to provide bands with uniform width and spacing.    
   
   
       16 . The apparatus of  claim 10  wherein the distribution devices are parallel to one another and laterally offset.  
   
   
       17 . The apparatus is a cigarette paper making machine.