A web tension adjustment device includes a pair of guide rollers and a dancer roller. The two guide rollers are spaced at least in a gravity direction and guide continuous paper in transfer. The dancer roller moves within a moving range along a guide shaft extending in a direction intersecting a rotation axis distance direction of the pair of guide rollers at an acute angle, rolls on the continuous paper transferred between the pair of guide rollers and gives tension to the continuous paper, the tension corresponding to an amount of moving from a position between the pair of guide rollers along the guide shaft.

It is described a winding apparatus for wrapping a material around a core of flat shape that rotates around a rotation axis rotating in its turn with a circular trajectory, controlling the laws of motion both of the core rotation around its axis and of the circular trajectory of its rotation axis, motor driven independently by means of electric cams, such as to cancel the variations of position and speed of the material at the entrance of the core The winding apparatus is used for producing electric energy accumulating devices.

The present invention relates to a device (20) for winding a longitudinally cut material web having multiple longitudinal strips (12) on a plurality of winding tubes (16) to form in each case a wound roll. The device comprises an axle (24) and, mounted on the axle, a plurality of ring-shaped winding drives (22) that are individually controllable in their operating position. Each winding drive (22) forms an external-rotor electric motor and comprises a static interior tube (40) and a rotatable external tube (50). The external tube (50) that is rotatable on the rolling bearings (48) bears, on its interior, a device for providing an excitation magnetic field (52) that forms the external rotor of the electric motor.

A machine for manufacturing pre-stretched extendable film rolls provides for a pre-stretch unit (10) of the film (F) and a wrapping unit (100) of the film in roll provided with a series of rolls around which the advancing film is partially wrapped; the pre-stretch unit (10) provides for, in sequence, at least a first pre-stretching roll (12), a pre-stretching auxiliary roll (13) acting against the first roll (12) with the interposition of the film, and a second pre-stretching roll (14) having a speed greater than the speed of the first roll (12) to carry out the pre-stretching of the film; the wrapping unit provides for a wrapping roll (104) for wrapping the pre-stretched film; the pre-stretch unit (10) further provides for a detensioning roll (17) arranged downstream said second pre-stretching roll (14) and having a speed less than said second pre-stretching roll (14) and greater than said wrapping roll (104), so as to obtain a first detensioning of the film after the pre-stretching operation and a second detensioning of the film before the wrapping operation. A high quality pre-stretched film is obtained by this machine.

A machine for manufacturing pre-stretched extendable film rolls provides for a pre-stretch unit (10) of the film (F) and a wrapping unit (100) of the film in roll provided with a series of rolls around which the advancing film is partially wrapped; the pre-stretch unit (10) provides for, in sequence, at least a first pre-stretching roll (12), a pre-stretching auxiliary roll (13) acting against the first roll (12) with the interposition of the film, and a second pre-stretching roll (14) having a speed greater than the speed of the first roll (12) to carry out the pre-stretching of the film; the wrapping unit provides for a wrapping roll (104) for wrapping the pre-stretched film; the pre-stretch unit (10) further provides for a detensioning roll (17) arranged downstream said second pre-stretching roll (14) and having a speed less than said second pre-stretching roll (14) and greater than said wrapping roll (104), so as to obtain a first detensioning of the film after the pre-stretching operation and a second detensioning of the film before the wrapping operation. A high quality pre-stretched film is obtained by this machine.

A control system for controlling operation of main and secondary drive units in a web winder system to provide tension control of a continuous material web is disclosed. The control system causes the main drive unit to operate in a velocity mode to set a linear velocity of the continuous material web. The control system receives inputs from tension and speed detectors in the web winder system that detect a tension and speed of the continuous material web and causes the secondary drive unit to operate in a modified torque regulated closed-loop tension control mode so as to control a tension in the web material, with the control system causing the secondary drive unit to operate according to a torque regulated closed-loop tension control mode and integrate a speed feedback loop into the torque regulated closed-loop tension control mode so as to introduce active damping into the tension control.

A control system for controlling operation of main and secondary drive units in a web winder system to provide tension control of a continuous material web is disclosed. The control system causes the main drive unit to operate in a velocity mode to set a linear velocity of the continuous material web. The control system receives inputs from tension and speed detectors in the web winder system that detect a tension and speed of the continuous material web and causes the secondary drive unit to operate in a modified torque regulated closed-loop tension control mode so as to control a tension in the web material, with the control system causing the secondary drive unit to operate according to a torque regulated closed-loop tension control mode and integrate a speed feedback loop into the torque regulated closed-loop tension control mode so as to introduce active damping into the tension control.

The machine comprises an unwinding section (3) for unwinding parent reels (Ba, Bb) of web material (Na, Nb), and at least one unwinding station (15). A winding device (41, 53) is arranged in the unwinding station, and a longitudinal strip (S) of web material is fed to it and a respective spool (B) of web material is formed in it. A control unit (70) is also provided, configured to control the winding speed of the longitudinal strip (S) in the winding station (15), so as to perform an acceleration cycle to accelerate the winding of the longitudinal strip (S), comprising at least one step of gradually increasing the feeding speed (Vp) of the longitudinal strip (S), wherein the feeding speed is linked to the diameter of the spool (B).

The machine comprises an unwinding section (3) for unwinding parent reels (Ba, Bb) of web material (Na, Nb), and at least one unwinding station (15). A winding device (41, 53) is arranged in the unwinding station, and a longitudinal strip (S) of web material is fed to it and a respective spool (B) of web material is formed in it. A control unit (70) is also provided, configured to control the winding speed of the longitudinal strip (S) in the winding station (15), so as to perform an acceleration cycle to accelerate the winding of the longitudinal strip (S), comprising at least one step of gradually increasing the feeding speed (Vp) of the longitudinal strip (S), wherein the feeding speed is linked to the diameter of the spool (B).

A dunnage conversion system for making a coil of dunnage from a sheet stock includes a coiler, a movable dancer upstream of the coiler and interposed in a path of the sheet stock, and a controller communicatively coupled to each of the coiler and the movable dancer. The coiler is configured to wind the sheet stock, and the controller is configured to control the speed of the coiler based on the position of the movable dancer to control tension of the sheet stock upstream of the coiler. The sheet stock drawn about the movable dancer may be a slit-sheet stock having a plurality of slits configured to expand under tension applied in a feed direction. The controller may be configured to control expansion of the slit-sheet stock upstream of the coiler allowing conversion of the sheet stock into a coil of relatively less dense dunnage prior to or during winding.