Winder and a method for winding a roll from a fibrous web

1. A winder ( 1 ) for winding a web roll ( 2 ) from a fibrous web such as a paper web or a web of non-woven material, the winder ( 1 ) comprising:

two support rolls ( 3 , 4 ) for supporting the web roll ( 2 ) during reeling;

a core shaft ( 5 ) for winding the paper roll ( 2 );

at each longitudinal end of the core shaft ( 5 ), a carrier chuck ( 6 ) in which the core shaft ( 5 ) is rotatably journalled;

a frame ( 7 ) in which the carrier chucks ( 6 ) are arranged to be movable towards or away from the support rolls ( 3 , 4 );

a rider roll ( 8 ) arranged to be capable of acting against the web roll ( 2 ) being wound;

a rider roll beam ( 9 ) carrying the rider roll ( 8 ), the rider roll beam ( 9 ) being arranged to be movable in the frame ( 7 ) such that the rider roll ( 8 ) can be moved towards or away from the support rolls ( 3 , 4 );

at least one actuator ( 10 ) for moving the rider roll beam ( 9 ) towards or away from the support rolls ( 3 , 4 );

at least one load cell ( 12 ) arranged to detect the force between the rider roll ( 8 ) and the web roll ( 2 );

at least one actuator ( 11 ) for moving the carrier chucks ( 6 ) of the core shaft ( 5 ) independently of the rider roll beam ( 9 );

at least one load cell ( 13 ) arranged to detect the force with which the carrier chucks ( 6 ) act on the core shaft ( 5 ); and

a logic control system ( 14 ) connected to the load cells ( 12 , 13 ) such that the logic control system ( 14 ) receives measured values for the force between the web roll ( 2 ) and the rider roll ( 8 ) and the force with which the carrier chucks ( 6 ) act on the core shaft ( 5 ),

wherein:

the logic control system ( 14 ) is programmed to calculate the diameter and weight of the web roll ( 2 ) based on machine speed and an assumed thickness and basis weight of the fibrous web being wound,

the logic control system ( 14 ) is arranged to control the actuators ( 10 , 11 ) for the rider roll beam ( 9 ) and the carrier chucks ( 6 ), and

the logic control system ( 14 ) is programmed to control movement of the carrier chucks ( 6 ) and the rider roll beam ( 9 ) such that the sum of the forces detected from the load cells ( 12 , 13 ) and the force resulting from the calculated weight of the web roll ( 2 ) corresponds to a set value for the force between the web roll ( 2 ) and the support rolls ( 3 , 4 ).

2. The winder according to claim 1 , wherein at least two load cells ( 13 ) are arranged to measure the force with which the carrier chucks act on the core shaft, including at least one load cell ( 11 ) on each carrier chuck.

3. The winder according to claim 1 , wherein at least two load cells ( 12 ) are arranged to measure the force between the rider roll ( 8 ) and the web roll ( 2 ), including at least one load cell ( 12 ) placed at each axial end of the rider roll beam ( 9 ).

4. The winder according to claim 1 , wherein the carrier chucks ( 6 ) and the rider roll beam are moved in relation to the support rolls ( 3 , 4 ) based on the calculated value of the web roll diameter.

5. The winder according to claim 1 , wherein the logic control unit ( 14 ) is programmed to calculate an expected value for the force between the rider roll ( 8 ) and the web roll ( 2 ) and an expected value for the force with which the carrier chucks act on the core shaft ( 5 ) which expected force values are based on the calculated diameter of the web roll ( 2 ) and recalculate the value of the web thickness if the measured force values deviate from the expected values.

6. The winder according to claim 1 , wherein the winder further comprises, at each axial end of the rider roll beam ( 9 ) and the core shaft, at least one threaded bar ( 15 ) which extends in the direction of movement of the carrier chucks ( 6 ) and the rider roll beam ( 9 ) and in which the actuators ( 10 , 11 ) for the carrier chucks ( 6 ) and the rider roll beam are arranged on the threaded bar ( 15 ) and comprise threaded pieces arranged to interact with the threaded bar ( 15 ) to move the carrier chucks ( 6 ) and the rider roll beam ( 9 ) towards or away from the support rolls ( 3 , 4 ).

7. A method of winding a fibrous web into a roll ( 2 ) in a winder ( 1 ), the method comprising the steps of:

providing a winder ( 1 ) that comprises: two support rolls ( 3 , 4 ) for supporting the roll ( 2 ) during reeling; a core shaft ( 5 ) for winding the web into a web roll ( 2 ); at each longitudinal end of the core shaft ( 5 ), a carrier chuck ( 6 ) in which the core shaft ( 5 ) is rotatably journalled; a frame ( 7 ) in which the carrier chucks ( 6 ) are arranged to be movable towards or away from the support rolls ( 3 , 4 ); a rider roll ( 8 ) arranged to be capable of acting against the web roll ( 2 ) being wound; a rider roll beam ( 9 ) carrying the rider roll ( 8 ), the rider roll beam ( 9 ) being arranged to be movable in the frame ( 7 ) such that the rider roll ( 8 ) can be moved towards or away from the support rolls ( 3 , 4 );

detecting the force with which the rider roll ( 8 ) acts on the web roll ( 2 );

detecting the force with which the core shaft ( 5 ) acts on the web roll ( 2 );

continuously calculating the weight of the web roll ( 2 ) based on the machine speed, given values for web thickness and basis weight;

continuously calculating the resulting force from the rider roll ( 8 ), the core shaft ( 5 ) and the weight of the web roll ( 2 );

comparing the resulting force to a set desired value for nip force between the web roll ( 2 ) and the support rolls ( 3 , 4 ) to see if the calculated resulting force matches the set desired value for nip force between the web roll ( 2 ) and the support rolls ( 3 , 4 );

when there is a deviation between the calculated resulting force and the set desired value, moving at least one of the carrier chucks ( 6 ) or the rider roll beam ( 9 ) until the deviation is eliminated.