Web splicing method and web splicing apparatus

Abstract

The present invention provides a web splicing method and a web splicing apparatus with which a line velocity on an output side of the splicing apparatus does not fluctuate through a web splicing operation. The method and apparatus are further operable to maintain a line velocity at a predetermined velocity after the web splicing operation. The method of the present invention includes the steps of: connecting a second web Wb fed out from a second roll B to a first web Wa; cutting off the first web Wa at a position between a point at which the second web Wb is connected to the first web Wa and a first roll A; spinning the second roll B to feed out the second web Wb; obtaining a value of a diameter of the second roll B based on a state of an accumulator 4 ; and controlling a circumferential velocity of the second roll B based on the obtained diameter.

1 . A web splicing method, including the steps of: 
 spinning a first roll of web to feed out a first web so as to store a predetermined length of the first web in an accumulator;    stopping the spinning of the first roll;    connecting a second web fed out from a second roll of web to the first web;    cutting off the first web at a position between a point at which the second web is connected to the first web and the first roll;    spinning the second roll to feed out the second web after the first web is cut off;    obtaining information related to a diameter or a radius of the second roll based on a state of the accumulator; and    controlling a circumferential velocity of the second roll based on the information.    
   
   
       2 . The web splicing method according to  claim 1 , wherein the information is obtained based on a change in an amount of web stored in the accumulator.  
   
   
       3 . The web splicing method according to  claim 2 , wherein after the information is obtained, renewed information related to a diameter or a radius of the second roll is obtained based on the information, a rotation of the second roll per a predetermined amount of time, and an amount of time that has passed from when the information is obtained.  
   
   
       4 - 19 . (canceled)  
   
   
       20 . A method for splicing a web, comprising: 
 rotating a first roll of web to feed out a first web;    storing a predetermined length of the first web between a fixed roller and a movable roller in an accumulator, wherein the predetermined length of the first web is associated with a position of the movable roller with respect to the fixed roller;    stopping the spinning of the first roll;    feeding a second web out of a second roll of web;    connecting the second web to the first web;    cutting off the first web at a position between a point at which the second web is connected to the first web and the first roll;    rotating the second roll to feed out the second web after the first web is cut off;    sensing a rotational velocity of the second roll;    sensing a state of the accumulator; and    controlling the rotational velocity of the second roll based on the sensed rotational velocity and the state of the accumulator.    
   
   
       21 . The method of  claim 20 , further comprising obtaining a diameter or radius of the second roll, wherein controlling the rotational velocity of the second roll is further based on the obtained diameter or radius of the second roll.  
   
   
       22 . The method of  claim 21 , wherein obtaining the diameter or radius of the second roll is obtained by sensing the diameter or radius via a sensor.  
   
   
       23 . The method of  claim 21 , wherein obtaining the diameter or radius of the second roll is obtained by calculating the diameter or radius based on the sensed rotational velocity of the second roll and the sensed state of the accumulator.  
   
   
       24 . The method of  claim 20 , wherein sensing the state of the accumulator comprises sensing an amount of web stored in the accumulator.  
   
   
       25 . The method of  claim 24 , wherein sensing the state of the accumulator comprises sensing an actual position of the movable roller with respect to the fixed roller.  
   
   
       26 . The method of  claim 25 , wherein controlling the rotational velocity of the second roll is further based on a comparison of the actual position of the movable roller and a target position of the movable roller.  
   
   
       27 . The method of  claim 20 , further comprising sensing a renewed rotational velocity of the second roll after the rotational velocity is sensed, wherein controlling the rotational velocity of the second roll is further based on the renewed rotational velocity.  
   
   
       28 . The method of  claim 27 , wherein controlling the rotational velocity of the second roll is based on a comparison of the rotational velocity and the renewed rotational velocity.  
   
   
       29 . The method of  claim 1 , wherein the state of the accumulator is determined by sensing an amount of web stored in the accumulator.  
   
   
       30 . The method of  claim 29 , wherein sensing the amount of web stored in the accumulator comprises sensing an actual position of a movable roller of the accumulator with respect to the fixed roller of the accumulator.  
   
   
       31 . The method of  claim 30 , wherein controlling the circumferential velocity of the second roll is further based on a comparison of the actual position of the movable roller and a target position of the movable roller.