Method and apparatus in unwinding

Abstract

In the method in splicing in a continuous unwind, the surface speed of a new machine reel (R 2 ) which is brought to the unwind and closed with a leading splice is accelerated in the initial acceleration to make the speed correspond to the speed of the old machine reel (R 1 ) that is becoming empty, so that the fastening splice of the new machine reel can be joined to the web of the old machine reel. The loading affecting the leading splice and/or fastening splice of the new machine reel (R 2 ) during the initial acceleration is reduced. The present invention also relates to an apparatus for implementing the method.

1 . A method in splicing in a continuous unwind, in which method the surface speed of a new machine reel (R 2 ) which is brought to the unwind and closed with a leading splice is accelerated in the initial acceleration to make its speed correspond to the speed of an old machine reel (R 1 ) that is becoming empty, so that the fastening splice of the new machine reel can be joined to the web of the old machine reel, characterized in that the loading affecting a leading splice and/or fastening splice of the new machine reel (R 2 ) during the initial acceleration is reduced by using active and/or passive actuators.  
     
     
         2 . The method according to  claim 1 , characterized in that the loading is reduced by directing air blows and/or suction to suitable locations.  
     
     
         3 . The method according to  claim 2 , characterized in that air is blown towards a splicing gap (N).  
     
     
         4 . The method according to  claim 3 , characterized in that air is blown between contact points (N 1 , N 2 ) restricting the splicing gap in such a manner that the air blow is substantially parallel to a tangent travelling via a contact point (N 1 ) on the periphery of the splicing roll ( 3 ) and a tangent travelling via a contact point (N 2 ) on the periphery of the new machine reel (R 2 ).  
     
     
         5 . The method according to  claim 2 , characterized in that air is sucked from the splicing gap (N).  
     
     
         6 . The method according to  claim 5 , characterized in that air is sucked between contact points (N 1 , N 2 ) restricting the splicing gap in such a manner that the suction of air is substantially parallel to a tangent travelling via a point (N 1 ) on the periphery of the splicing roll ( 3 ) and a tangent travelling via a point (N 2 ) on the periphery of the new machine reel (R 2 ).  
     
     
         7 . The method according to  claim 2 , characterized in that the blow of air is directed in parallel to the surface of the new machine reel (R 2 ) against the direction of rotation of the machine reel.  
     
     
         8 . The method according to  claim 2  or  7 , characterized in that the blow of air is directed in parallel to the web (W) coming from the old machine reel (R 1 ) against the direction of rotation of the web.  
     
     
         9 . The method according to  claim 2 , characterized in that the blow of air is directed in parallel to the outer periphery of the new machine reel (R 2 ) close to the surface of the machine reel in the direction of rotation of the machine reel.  
     
     
         10 . The method according to  claim 2 , characterized in that the flow of air is affected before the splicing gap (N) and/or after the splicing gap (N) by means of mechanical obstacles.  
     
     
         11 . The method according to  claim 10 , characterized in that the obstacle is an article ( 7 ) shaped into a given form from a sheet-like material.  
     
     
         12 . The method according to  claim 10 , characterized. in that the obstacle is a roll ( 8 ) arranged before the splicing gap, which roll touches the web (W) when the web passes by the roll.  
     
     
         13 . The method according to  claim 1 , characterized in that the temperature of the fastening splice and/or leading splice is adjusted to increase the adhesion of the splices.  
     
     
         14 . An apparatus in connection with splicing of a web (W) coming from an old machine reel (R 1 ) and a web of a new machine reel (R 2 ), in which splicing said webs are arranged to be connected to each other by means of a fastening splice, characterized in that the apparatus comprises means for reducing the loading applied to the leading splice and/or fastening splice of the new machine reel (R 2 ).  
     
     
         15 . The apparatus according to  claim 14 , characterized in that the means for reducing the loading applied to the leading splice and/or fastening splice of the new machine reel (R 2 ) comprise one or more active or passive actuators.  
     
     
         16 . The apparatus according to  claim 14  or  15 , characterized in that the device/devices is/are one or more devices that blow or suck air.  
     
     
         17 . The apparatus according to  claim 16 , characterized in that the device is a blow device ( 6 ) which is positioned after the splicing gap and directed towards the splicing gap against the travel direction of the surface of the new machine reel (R 1 ) and the web (W).  
     
     
         18 . The apparatus according to  claim 17 , characterized in that the blow device ( 6 ) is arranged to blow air towards the splicing gap (N) between the contact points (N 1 , N 2 ) in such a manner that the blow of air is substantially parallel to a tangent travelling via a contact point (N 1 ) on the periphery of the splicing roll ( 3 ) and a tangent travelling via a contact point (N 2 ) on the periphery of the new machine reel (R 2 ).  
     
     
         19 . The apparatus according to  claim 16 , characterized in that the device is a suction device ( 9 ) which is located after the splicing gap and directed towards the splicing gap against the travel direction of the surface of the new machine reel (R 2 ) and the web (W).  
     
     
         20 . The apparatus according to  claim 19 , characterized in that the blow device ( 9 ) is arranged to suck air from the splicing gap between the contact points (N 1 , N 2 ) in such a manner that the suction of air is substantially parallel to a tangent travelling via a contact point (N 1 ) on the periphery of the splicing roll ( 3 ) and a tangent travelling via a contact point (N 2 ) on the periphery of the new machine reel (R 2 ).  
     
     
         21 . The apparatus according to  claim 16 , characterized in that one or more devices are arranged to blow air before the splicing gap in parallel to the surface of the new machine reel (R 2 ) against the direction of rotation of the machine reel.  
     
     
         22 . The apparatus according to  claim 16  or  21 , characterized in that the blow of air is directed in parallel to the web (W) coming from the old machine reel (R 1 ) against the travel direction of the web.  
     
     
         23 . The apparatus according to  claim 16 , characterized in that one or more devices are arranged to blow air in parallel to the outer periphery of the new machine reel (R 2 ) close to the surface of the machine reel in the direction of rotation of the machine reel.  
     
     
         24 . The apparatus according to  claim 14  or  15 , characterized in that one or more device/devices is/are one or more mechanical obstacles placed between the splicing gap and/or after the splicing gap.  
     
     
         25 . The apparatus according to  claim 24 , characterized in that the obstacle is an article ( 7 ) shaped into a given form from a sheet-like material.  
     
     
         26 . The apparatus according to  claim 24 , characterized in that the obstacle is a roll ( 8 ) arranged before the splicing gap, which roll touches the web (W) when the web passes by the roll.  
     
     
         27 . The apparatus according to  claim 14 , characterized in that it comprises means for adjusting the temperature of the fastening splice and/or leading splice.