Abstract:This text describes about the advantages and the disadvantages of tension control systems of ring opening and closed-loop in solvent-free laminated machinery.In a conclusion, closed-loop tension control system performs better than ring opening tension control system.As the processed products of flexible packing manufactories are diversified,the packing manufactories are always in requirement of products with thin PE materials or in high stability in sizes,at that occasion,the closed-loop tension control system is a better choice.While the packing manufactories have no such high requirements in products,it is also available to choose the simple one, the ring opening control system.
1.The importance of tension control in solvent-free composites
Due to the small molecular weight of solvent-free adhesives, they have almost no initial adhesion, so tension matching is important in solvent-free composites. Poor tension ratio can cause the following problems:
(1) After winding, the roll skin wrinkles and there is an increase in waste.
(2) The severe curling of the composite film after curing causes manufacturing defects.
(3) When making bags, the heat sealing edge wrinkles
2.Two tension control systems currently used in solvent-free laminating machines
Open loop tension control system: The input terminal inputs the tension value we set, and the equipment controls the torque according to the theoretical value set by the manufacturer to complete the tension output.
Closed loop tension control system: Similarly, the tension value we set is input from the input end, and the floating roller cylinder is filled with compressed air. The tension acting on the film is the sum of the vertical force of the roller gravity and the vertical force of the cylinder. When the tension changes, the floating roller swings, and the position indicator detects the tension change, feedback it back to the input end, and then adjust the tension.
3.Advantages and disadvantages of two tension control systems
(1).Open loop tension control system
Advantage:
The overall design of the equipment will be much simpler, and the volume of the equipment can also be further compressed.
Because the open-loop tension system is relatively simple, the probability of failure during long-term operation of the equipment is low and it is easier to troubleshoot.
Disadvantage:
The accuracy is not high. Due to the direct control of torque, stability and accuracy are not very good during dynamic and static conversion, acceleration and deceleration, and changes in coil diameter, especially when the tension value is set to be small, the tension control is not ideal.
Lack of automatic correction. When external conditions such as substrate film rolls are abnormal, the impact on tension control is relatively significant.
(2) Closed loop tension control system
Advantage:
The accuracy is usually high. The influence of dynamic and static conversion, acceleration and deceleration, and changes in coil diameter on tension control is relatively small, and even smaller tensions can be well controlled.
Post time: Jan-17-2024