In the solventless compounding process, the tension control requirement is much higher than that of the ordinary composite method, mainly because the solventless composite initial adhesive force is low, the operation control is difficult, and the quality problem is more likely to occur. In addition, the solvent-free composite process requires that the shrinkage rate of the two-layer substrate after bonding should be as uniform as possible, otherwise a "tunnel" phenomenon will occur, so the accuracy of the tension control is higher in the solventless compounding process, which is the operation. The personnel put forward some requirements, not only to thoroughly understand and master the detection method of solvent-free composite tension, but also to have the ability to stably control the tension.

Application of tension control system and selection of winding tension method

The tension of a single-station solvent-free composite device is generally divided into four segments, namely a first unwinding tension, a second unwinding tension, a channel tension, and a winding tension. In the process of changing the coil diameter and production speed, the solvent-free composite tension has constant tension requirements, and on the basis of ensuring the composite quality, it also plays an extremely important role in improving the winding quality.

Single-station solvent-free composite equipment is essential for ensuring tension stability and winding uniformity due to frequent start-up, shutdown, acceleration, and deceleration operations.

The floating roller has the function of absorbing kinetic energy, and the cylinder (low friction cylinder) is used to control the pendulum roller tension control mode in the first unwinding tension, the second unwinding tension, and the channel tension control with constant tension requirement, and the solventless control form can be well ensured. The tension of the composite equipment during acceleration and deceleration is stabilized, and the stretching and relaxation of the film caused by the tension fluctuation are minimized. If the first unwinding tension, the second unwinding tension, and the channel tension are controlled by the bearing type tension sensor, the rotation speeds of the first unwinding unit motor, the second unwinding unit motor, the coating motor, and the composite motor are completely synchronized. In order to ensure the stability of the tension during acceleration and deceleration.

In addition, the flexibility of the guide roller rotation is an important factor to ensure the stability of the tension during the acceleration and deceleration of the solventless composite equipment. Under normal circumstances, the rotation of the guide roller is only synchronized with the movement of the film, so that the ink on the surface of the film is not scratched. This requires that the static friction of the film and the surface of the guide roller is greater than the resistance of the guide roller, so the guide roller must be flexible, and the guide roller with light weight, low friction bearing and high assembly precision can be selected. The method for judging whether the guide roller is flexible or not is that the guide roller can be gently moved by hand to observe the time required for the rotation to stop, and the general requirement is not less than 15 seconds.

The unwinding tension and channel tension of the solvent-free composite equipment are constant tension requirements, and the winding tension control system mainly includes winding tension, winding method and taper. Among them, the winding method includes three types: straight winding, hyperbolic winding and parabolic winding.