Method and apparatus for forming a paper or tissue web

Abstract

A method and apparatus for transferring a vibrational force to the wire of a papermaking machine in order to re-align the fibers of the web forming on the wire or to clean press section felts. In some embodiments, the apparatus is a vibrational device including at least one vibration-inducing mechanism, a vibrational head coupled to the vibration-inducing mechanism for vibrating the wire, and a dampening mechanism coupled between the vibrational head and the vibration-inducing mechanism.

1 . A method of forming a web, comprising: 
 discharging stock flow from a headbox onto a wire, the stock flow including water and fibers;    transferring a vibrational force produced by at least one vibration-inducing mechanism to the wire via a vibrational head;    dampening the vibrational force with at least one dampener coupled between the at least one vibration-inducing mechanism and the vibrational head; and    draining at least some of the water from the stock flow to cause the fibers to form a web.    
   
   
       2 . The method of  claim 1 , further comprising adjusting a pressure in the at least one dampener.  
   
   
       3 . The method of  claim 1 , further comprising adjusting the at least one dampener until a phase of vibrational force generated by the at least one vibration-inducing mechanism is substantially constant in a cross machine direction of the wire.  
   
   
       4 . The method of  claim 1 , further comprising adjusting the at least one dampener until a frequency of the vibrational force generated by the at least one vibration-inducing mechanism is substantially constant in a cross machine direction of the wire.  
   
   
       5 . The method of  claim 1 , further comprising controlling a frequency of vibrational force generated by the at least one vibration-inducing mechanism with a feedback control system, the feedback control system receiving signals from the vibrational head representative of at least one of frequency and amplitude of vibrational head movement.  
   
   
       6 . The method of  claim 1 , wherein the at least one vibration-inducing mechanism comprises first and second vibration-inducing mechanisms generating respective vibrational forces.  
   
   
       7 . The method of  claim 6 , further comprising transferring the respective vibrational forces to the wire at different cross-machine directions along the wire.  
   
   
       8 . The method of  claim 7 , further comprising dampening the respective vibrational forces with first and second dampeners, respectively.  
   
   
       9 . A method of producing vibration for processing a layer of material, the method comprising: 
 generating a vibrational force;    transferring the vibrational force to a support;    dampening vibration of the support generated by the vibrational force to generate a dampened vibration;    transferring the dampened vibration of the support to a head coupled to the support; and    dampening vibration of the head independently of dampening vibration of the support.    
   
   
       10 . The method of  claim 9 , wherein generating a vibrational force comprises generating multiple discrete vibrational forces collectively defining the vibrational force.  
   
   
       11 . The method of  claim 9 , further comprising transferring another vibration from a second support to the head.  
   
   
       12 . The method of  claim 9 , further comprising controlling a degree by which the vibration of the head is dampened.  
   
   
       13 . The method of  claim 12 , wherein the degree by which vibration of the head is dampened is at least partially controlled by detection of the dampened vibration.  
   
   
       14 . The method of  claim 12 , wherein the degree by which vibration of the head is dampened is controlled by changing a pressure within a dampener.  
   
   
       15 . A method of producing vibration for processing a layer of material, the method comprising: 
 generating a first vibration;    transferring the first vibration to a first support at a first location;    generating a second vibration;    transferring the second vibration to a second support substantially simultaneous with the first vibration and at a second location disposed from the first vibration;    transferring a third vibration at least partially defined by the first and second vibrations toward a vibrational head;    dampening the third vibration to generate a fourth vibration; and    vibrating a vibrational head with the fourth vibration.    
   
   
       16 . The method of  claim 15 , further comprising controlling at least one of the first and second vibrations based at least in part upon detection of the third vibration.  
   
   
       17 . The method of  claim 15 , wherein the head spans across the first and second supports.  
   
   
       18 . The method of  claim 15 , further comprising adjusting an amount of dampening of the third vibration.  
   
   
       19 . The method of  claim 15 , wherein the first and second locations are spaced along a length of the vibrational head.  
   
   
       20 . The method of  claim 15 , wherein the first vibration has at least one of a frequency and an amplitude different from that of the second vibration.