Paper converting plant including a rewinder adapted to produce paper logs and having an inlet for feeding a paper web, a winding station where the logs are formed and an exit station for unloading the finished logs. The rewinder has walls delimiting a chamber inside which the logs are formed, and an air suction channel at a lower part of chamber. The suction channel exerts a suction causing the formation of an air flow directed from the top to the bottom inside the chamber. The chamber includes two semi-chambers communicating with the air suction channel such that a vertical air flow directed downwards is generated in each of them, the chamber being provided with a manner for regulating the vertical air flows providing vertically oriented identical air flow rates in the semi-chambers.

A method of winding a pre-impregnated fabric strip onto a sloping surface includes a step of deforming the pre-impregnated fabric strip by applying differing traction forces to the pre-impregnated fabric strip, the traction forces being directed in a longitudinal direction of the strip, the values of the applied traction forces differing across the transverse direction of the strip. The differing traction forces are applied by tensioning the pre-impregnated fabric strip between firstly a pair of brake rollers and secondly a traction device present downstream from the pair of brake rollers, the traction device driving the pre-impregnated fabric strip at speeds that differ across the transverse direction of the strip. The method further includes winding the deformed strip onto a surface of revolution of winding tooling including at least one portion that forms a nonzero angle with the axis of revolution of the surface of revolution.

A method of winding a pre-impregnated fabric strip onto a sloping surface includes a step of deforming the pre-impregnated fabric strip by applying differing traction forces to the pre-impregnated fabric strip, the traction forces being directed in a longitudinal direction of the strip, the values of the applied traction forces differing across the transverse direction of the strip. The differing traction forces are applied by tensioning the pre-impregnated fabric strip between firstly a pair of brake rollers and secondly a traction device present downstream from the pair of brake rollers, the traction device driving the pre-impregnated fabric strip at speeds that differ across the transverse direction of the strip. The method further includes winding the deformed strip onto a surface of revolution of winding tooling including at least one portion that forms a nonzero angle with the axis of revolution of the surface of revolution.

Winding apparatuses for winding sheet material and related methods are disclosed herein. The winding apparatuses can include a set of winding drive rollers. Each drive roller of the winding drive rollers can have drive wheels spaced apart along the respective drive roller with a winding zone between the winding drive rollers. The winding apparatus can also include a feed system positioned before the set of the winding drive rollers for moving sheet material along a travel path in a machine direction into the winding zone.

A variable roll cage machine and process to roll up material, like high expansion force material. The machine includes a roll chamber to receive the material. The roll chamber has a longitudinal central axis and a plurality of rollers located around a circumference of the roll chamber. The plurality of rollers include two roll groups of at least two rollers in each roll group. At least one of the rollers in each roll group is movable toward the longitudinal central axis independent of at least one other roller in the roll group. A material infeed gap is in the circumference of the roll chamber located between the two roll groups and spaced from the at least one of the rollers in each roll group that is movable.

A variable roll cage machine and process to roll up material, like high expansion force material. The machine includes a roll chamber to receive the material. The roll chamber has a longitudinal central axis and a plurality of rollers located around a circumference of the roll chamber. The plurality of rollers include two roll groups of at least two rollers in each roll group. At least one of the rollers in each roll group is movable toward the longitudinal central axis independent of at least one other roller in the roll group. A material infeed gap is in the circumference of the roll chamber located between the two roll groups and spaced from the at least one of the rollers in each roll group that is movable.

Rewinder for making paper logs of paper material including a detection system with optical means adapted to detect, in a succession of predetermined detection times, a succession of diameters assumed in such times by a log being formed in a winding station and a programmable electronic unit which compares the diameters measured by the optical means with a succession of corresponding preset diameters and to calculate a sequence of differences. The processing unit receives a signal relating to the value of the actual diameter of the completed log and determines a parameter related to the trend over time of the differences. Elements for adjusting the thickness of the paper web automatically adjust said thickness if the parameter is between predetermined values and.

Rewinder for making paper logs of paper material including a detection system with optical means adapted to detect, in a succession of predetermined detection times, a succession of diameters assumed in such times by a log being formed in a winding station and a programmable electronic unit which compares the diameters measured by the optical means with a succession of corresponding preset diameters and to calculate a sequence of differences. The processing unit receives a signal relating to the value of the actual diameter of the completed log and determines a parameter related to the trend over time of the differences. Elements for adjusting the thickness of the paper web automatically adjust said thickness if the parameter is between predetermined values and.

The measured winding diameter values Ds1(d) corresponding to the conveying distance d are measured by measuring the diameter of the printing medium M wound on the unwinding roll 71 by the diameter sensor 77. The measured winding diameter values Ds1(d) are smoothed by the low-pass filter to extract the smoothed winding diameter values Ds_avg1(d). By calculating the value of the diameter based on the initial diameter value Do1, the thickness value Tm and the conveying distance of the printing medium M, the calculated winding diameter values Dc1(d) are calculated. An operation of calculating the difference Ddiff1(d) between the calculated winding diameter value Dc1(d) and the smoothed winding diameter value Ds_avg1(d) while compensating for the delay by the low-pass filter is performed whereby the differences Ddiff1(d) are calculated. The calculated winding diameter value Dc1(d) are corrected by the differences Ddiff1(d).

The measured winding diameter values Ds1(d) corresponding to the conveying distance d are measured by measuring the diameter of the printing medium M wound on the unwinding roll 71 by the diameter sensor 77. The measured winding diameter values Ds1(d) are smoothed by the low-pass filter to extract the smoothed winding diameter values Ds_avg1(d). By calculating the value of the diameter based on the initial diameter value Do1, the thickness value Tm and the conveying distance of the printing medium M, the calculated winding diameter values Dc1(d) are calculated. An operation of calculating the difference Ddiff1(d) between the calculated winding diameter value Dc1(d) and the smoothed winding diameter value Ds_avg1(d) while compensating for the delay by the low-pass filter is performed whereby the differences Ddiff1(d) are calculated. The calculated winding diameter value Dc1(d) are corrected by the differences Ddiff1(d).