Paper Rewinder

Paper rewinder is the rewinding machine that is the fastest running mechanical equipment in paper making machinery. Its working speed can reach 1500-1800m/min, even 3000m/min. It plays an important role in the industry. The paper from the paper processing machine must be rewound by the rewinder in order to get the finished paper, and the quality of the finished paper roll is not only determined by the paper making machine, but also the function of the rewinder.

Working principle

The large-web paper roll produced from the paper processing machine is mounted on the unwinding stand of the rewinder. In order to maintain a certain tension of the web, the brake device must be installed on the stand. And the brake motor is installed on the stand. If the paper breaks during the rewinding process, it can also brake quickly and reduce the loss. The web is cut to the desired width by paper carrying roll, paper guide roll and slitter. Then, the paper roll is rewinded according to the required tightness and the diameter of the finished paper roll.

There are many types of rewinders, and other devices can be equipped with the rewinder as needed to become a joint machine. The rewinder can basically be divided into the following five types: overfeed rewinder, underfeed rewinder, single roll rewinder, special rewinder and thin paper rewinder.

Main structure

The paper unwinding section

In the rewinding system, the paper roll is mounted on the paper unwinding stand.  In order to ensure that the width of the sides of the web is uniform, it is necessary to move when the paper roll is unwinding. However, the paper roll can be moved together with the stand in new structure, which ensures greater rigidity of the stand. In addition to manually moving the paper roll, pneumatic, electronic devices and electric methods can be used to adjust the axial movement of the stand, so that the cutting edge of the rewinder can get narrowed, and manual adjustment cannot meet such requirements.

At the starting time of the high-speed rewinding machine, the required acceleration time from zero to 2000m/min is completed in 50-60s, and the deceleration time required for braking is 40s or even shorter, therefore, The paper unwinding brake takes into account the maximum diameter and the braking requirement at the highest speed to reduce the loss of paper that is broken, or it will cause a large amount of waste.

Slitting section

In the rewinder system, the slitting mechanism is a very important part of the rewinder. In order to ensure straight and smooth trimming, the quality control of the finished paper roll is very important, which ensures that the winding is easy and can reduce the fluffing during printing. The slitter should be installed as close as possible to the roll so that it can produce lateral movement during the process.

Winding section

1. Stretching device

The stretching device is set to keep the paper web slit after slitting in order to maintain good slitting operation.

       2. Support roll

Support roll is mainly used to support the paper roll, and it consists of a control cast iron roll or a pipe roll.

       3. Unloader

With the speed is improving, most of the rewinders are equipped with unloaders. Their function is to push the finished paper roll from support roll and discharge it to the ground.

       4. Transmission device

The paper feeding speed of the rewinder is generally about 15-40m/min. In the process, the speed is required to be accelerated, so that the paper roll can be avoided of inconsistent tightness due to tension fluctuation.

Pressure section

      1. Press roll

Press roll has major influence on the tightness control of paper roll.

       2. Hydraulic suspension scale mechanism

In general, the actuators that can be adjusted in pressure use a hydraulic suspension mechanism. A potentiometer attached to the press roll is installed in the system to display the diameter of the finished paper roll, and the signal sent from the potentiometer is transmitted to the pressure program control unit to calculate the pressure, so that the weight can be changed, reaching the oil pressure control.