Shafts for differential winding are mainly used on paper and plastic film cutters. The shafts consist of a very precise body with felt clamping bands, on which the friction rings slide, thereby equalizing the tension in the individual cut strips. By regulating the air pressure in the shaft, we can control the amount of slippage. At a pressure of 6 bar, the shaft and rings are firmly connected, at a pressure of 0 bar, the rings slide freely on the shaft without any resistance.
The shafts are mainly used on duplex paper and plastic film rewinders. When cutting, the outer rolls grow in diameter faster than the middle rolls. When using classic shafts, the winding on the edge collapses and the winding is loose in the middle of the shaft. Differential shafts equalize the tension in the individual rolls and guarantee that all windings are tightened with the same tension. These are duplex winders from the companies SOMA, Kampf, Varga Flexo, Euromac, Titan and others.
We supply friction rings for bushings with a diameter of 25 mm and a width of 10 mm. It is also possible to combine one support shaft and different sets of friction rings for different socket diameters. Friction rings work in both directions and there are spring loaded models that are used for winding on plastic sleeves.
Special shafts for differential winding are the ideal solution for multiple and independent winding of cylinders on the same shaft, as each of them needs the correct tension of the belt.
During the rewinding process, multiple rolls obtained after the process of cutting plastic film, paper or any other material, it is common for them to have important differences in thickness and, as a result, also differences in belt tension. To solve this problem, these special shafts provide a different control of the rollers blocking the core of each roller on one or more friction rings to obtain a precise rewind and even tension of the belt of each roller.
These special shafts are equipped with nickel-plated steel friction rings with a wide bearing surface and expansion rollers, which guarantee a wider gripping surface compared to rings. This new technology ensures:
- wider bearing area
- no damage to the core of the sleeve/coil
- use with both cardboard and plastic cores
- the smallest dimension
