Views: 27 Author: Easttai Publish Time: 2020-11-11 Origin: Site
After the aluminum foil is printed and coated, it needs to be post-printed and slit on the slitting machine to cut the large semi-finished product into the required specifications and dimensions. The semi-finished product cut by running on the slitting machine is a process of unwinding and winding. This process includes two parts: machine speed control and tension control. The so-called tension is to pull the aluminum foil and roll it to the core according to the standard. A certain stretch and tension traction must be applied to the aluminum foil. The tension control force is the tension.
Tension control refers to the ability to permanently control the tension of the aluminum foil when it is conveyed on the equipment. This control must be effective for any operating speed of the machine, including machine acceleration, deceleration and uniform speed. Even in the event of an emergency stop, it has the ability to ensure that the aluminum foil is not damaged at all.
The tension control of the slitting machine is basically manual tension control and automatic tension control. Manual tension control means that when the roll diameter changes to a certain stage during the winding or unwinding process, the operator adjusts the manual power supply device to achieve the purpose of tension control.
Full-automatic tension control is to directly measure the actual tension value of the tape by the tension sensor, then convert the tension data into a tension signal and feed it back to the tension controller. This signal is compared with the tension value preset by the controller to calculate the control signal. The automatic control execution unit makes the actual tension value equal to the preset tension value to achieve the purpose of stabilizing the tension.
The winding and unwinding tension setting of the equipment directly affects the yield of the product. If the tension is too large, the winding is too tight, the aluminum foil is prone to wrinkles, and the tension is insufficient. The aluminum foil is likely to slip on the roll and cause serious misalignment. Unloading, and causing the unwinding shaft to swing greatly during slitting, which affects the cutting quality, so the slitting machine must have a good tension detection system.
1. Slitting machine unwinding tension detection system:
Tension sensor detection It is a direct detection of tension, which is closely combined with machinery and is equipped with a detection method for moving parts. Usually two sensors are used in pairs, and they are installed on the end shafts on both sides of the detection guide roller.
The material belt detects the displacement or deformation of the sensitive element of the tension sensor by detecting the applied load on both sides of the guide roller, thereby detecting the actual tension value, and converting this tension data into a tension signal to feed back to the tension controller.
2. Attenuation and tension compensation of the winding and unwinding tension of the slitting machine: It is generally believed that maintaining the aluminum foil tension constant during the winding and unwinding of the aluminum foil is conducive to the quality of the finished aluminum foil, but it is not the case. The best way is to increase the tension of the aluminum foil according to a certain rule as the diameter or weight of the roll increases, and the smaller the diameter and weight, the tension value will also decrease. Because there are automatic tension control and manual tension control in the slitting operation. Manual tension control requires the operator to continuously adjust the diameter and weight of the master roll.
The automatic tension control system is a pre-set tension attenuation value, which is attenuated according to the change of the material during the operation of the equipment. When setting the automatic tension operation, the initial tension should be set first, and then the tension attenuation value should be set.
Take the attenuation value of the slitting aluminum foil unwinding as an example, the setting principle is: the aluminum foil tension attenuation value (%) is equal to the tension at the end of each roll of aluminum foil minus the initial tension and then divided by the initial tension to obtain the quotient and then multiply by it 100%.
When setting the automatic tension value, it should not be too large, otherwise the surface hardness of the aluminum foil rewinding is high, and the edge warping phenomenon is easy to occur, but the tension should not be too small. Therefore, the quality of rewinding and unwinding during the aluminum foil slitting operation is mainly affected by the change in the tension of the aluminum foil. It can be seen that the control of the rewinding and unwinding control system is the key to the quality.
In summary, when slitting medicinal aluminum foil, you must first choose advanced models, and pay attention to understanding the characteristics of the tension detection and control system used in the equipment during operation, and make reasonable formulations for the aluminum foil materials used. The tension and the tension attenuation and compensation of the winding and unwinding process can realize the soft start and soft stop of the equipment tension to prevent quality problems.
During the slitting operation, you should always pay attention to the change of aluminum foil winding tension, because it is affected by the material quality, weight, thickness uniformity, and cutting speed. When setting the winding tension, it must be consistent with these characteristics of the aluminum foil. adapt.
In order to ensure the accuracy of the tension of the rewinding and unwinding, the tension detection roller of the rewinding and unwinding mechanism should be higher than the maximum speed, and the dynamic balance treatment should be carried out, and the surface should have enough wrap angle during use to provide accurate running tension. Ensure the stability of product quality.