Machine for the production of rolls of paper material and relative winding procedure

Abstract

A machine for producing paper rolls includes a first and a second winding rollers rotatably mounted, respectively, about first and second axes; first and second pressure rollers rotate, respectively, about a third axis on a first movable arm, and about a fourth axis on a second movable arm. The rollers define a winding channel for a web of paper around a core, for forming a roll. The core moves by one or more of the rollers, between a position for winding and position for expelling the wound roll. The winding rollers are positioned, relative to the pressure rollers on opposite sides of the channel, relative to movement of the core The movable arms pivot, respectively, on first and second secondary axes such that the rotation of the first and/or the second movable arm moves the first and/or the second pressure roller from or towards the first and/or second winding roller.

1 . A machine for the production of rolls of paper material comprising:
 at least a first and a second winding roller rotatably mounted, respectively, about a first and a second axis of rotation;   at least a first and a second pressure roller designed to rotate, respectively, about a third axis of rotation positioned on a first movable arm, and a fourth axis of rotation positioned on a second movable arm and defining, together with said first and second winding roller, a winding channel for a web of paper around a core rotating about its own axis of rotation, for forming a roll;   said core being designed to be moved by the action of one or more of said first winding roller, second winding roller, first pressure roller and second pressure roller, between an initial winding position of said web of paper and a final position;   the first winding roller and the second winding roller being positioned, relative to said first pressure roller and second pressure roller, on opposite sides of said winding channel, respectively upstream and downstream of said winding channel, relative to the movement of said core during its winding process;   said first and second movable arms pivoting, respectively, on a first and a second secondary axis of rotation, in such a way that the rotation of said first and/or second movable arms moves said first and/or said second pressure roller from or towards said first and/or second winding rollers;   in said initial position, at least three between said first winding roller, second winding roller, first pressure roller and second pressure roller are designed to exercise a simultaneous control of the roll of paper wound around said core; said simultaneous contact lasting until said web of paper wound around said core is designed to be cut.   
     
     
         2 . The machine according to  claim 1 , wherein said initial position corresponds to the zone of said winding channel wherein at least the centre line of said core passes beyond the axis joining the centres of rotation relative to said first and second winding rollers, even more preferably when the profile of the outermost perimeter of said core is tangent to said axis and
 said final position corresponds to the zone of the winding channel wherein said web of paper is designed to be cut.   
     
     
         3 . The machine according to  claim 1 , wherein, in said initial position, said first winding roller second winding roller and first pressure roller are designed to exercise a simultaneous control of the roll of paper being wound around said core 
     
     
         4 . The machine according to  claim 1 , wherein, in said initial position, said second winding roller, first pressure roller and second pressure roller are designed to exercise a simultaneous control of the roll of paper being wound around said core 
     
     
         5 . The machine according to  claim 1 , wherein, in said final position, at least said second winding roller and second pressure roller are designed to exercise a simultaneous control of the roll of paper being wound around said core. 
     
     
         6 . The machine according to  claim 5 , wherein said second winding roller and the second pressure roller are designed to exercise a simultaneous control of the roll of paper wound around a first core which is in said final position and, at the same time, said first winding roller, second winding roller and first pressure roller are in simultaneous control of the roll of paper wound around a second core which is in said initial position. 
     
     
         7 . The machine according to  claim 1 , wherein said first secondary axis of rotation lies in the half-plane determined by said axis and opposite with respect to said winding channel. 
     
     
         8 . The machine according to  claim 7 , wherein said first movable arm is substantially shaped like the letter “V”, in such a way that said “V” has a vertex angle Z defined by the contact of the axes of symmetry respectively referred to the end portions of said arm, at said pressure roller and said axis of rotation, of between 40° and 80°, inclusive, preferably between 45° and 70°, inclusive, more preferably between 50° and 65°, inclusive, even more preferably between 53° and 60°. 
     
     
         9 . A winding process for the production of rolls of paper material, in a rewinding machine according to  claim 1 , comprising the steps consisting of:
 introducing a first core inside a winding channel defined by at least a first and a second winding roller, rotatably mounted respectively about a first and a second axis of rotation of said machine and by at least a first and a second pressure roller, designed to rotate respectively about a third axis of rotation, positioned on a first movable arm, and a fourth axis of rotation, positioned on a second movable arm, in such a way that said first core is in an initial position controlled simultaneously by said first winding roller, second winding roller and first pressure roller,   winding a web of paper, coming from upstream of said winding channel, around said first core rotatable about its own axis of rotation to form a first roll and, simultaneously, moving said first core, by means of said second winding roller, first pressure roller and second pressure roller, until said first partially wound core reaches a positioning downstream of said winding channel, so as to allow said first movable arm to enter in said winding channel cutting said web of paper being wound around said first core,   introducing a second core inside said winding channel, so that said cut web of paper is wound around its own axis of rotation to form a second roll and, simultaneously, moving said second core by means of said first winding roller, second winding roller and first pressure roller, until said second partially wound core reaches a positioning downstream of said winding channel, allowing said first movable arm to enter said winding channel cutting said web of paper being wound around said second core and, simultaneously, expelling said first formed roll by the action of said second winding roller and second pressure roller,   continuing cyclically with the steps just described for forming a third roll, fourth roll, fifth roll, etc.   
     
     
         10 . The process according to  claim 9 , wherein the roll of paper being wound around each of said first and second cores is controlled by the action of at least three of said first winding roller, second winding roller, first pressure roller and second pressure roller, between an initial winding position of said web of paper, wherein it does not have layers of paper wound around said relative axis of rotation and a final position when the winding of the respective roll has been completed. 
     
     
         11 . The process according to  claim 10 , wherein, in said initial position, said first winding roller, second winding roller and first pressure roller exercise a simultaneous control of the roll of paper being wound around said first core or said second core 
     
     
         12 . The process according to  claim 9 , wherein, in said initial position, said second winding roller, first pressure roller and second pressure roller exercise a simultaneous control of the roll of paper being wound around said first core.