The tension adjustment technology of the small precision film longitudinal stretching machine is directly related to the molding quality and production stability during the film stretching process. It is necessary to finely control the tension perception, control logic, equipment coordination and other aspects to ensure that the film will not wrinkle due to insufficient tension or be damaged due to excessive tension during the stretching process.
The basis of tension adjustment lies in accurate tension perception. The small precision film longitudinal stretching machine captures the tension changes of the film in real time during operation by installing high-precision tension sensors at key positions. These sensors can keenly sense the tiny force fluctuations of the film and convert them into electrical signals to transmit to the control system. The installation position and method of the sensor are very sophisticated, and it is necessary to ensure that it can truly reflect the actual force state of the film to avoid distortion of the detection data due to installation deviation. In addition, the selection of the sensor is also very important. According to the material, thickness and stretching process requirements of the film, select products with suitable sensitivity and range to ensure that the tension information can be accurately obtained under different working conditions, providing a reliable basis for subsequent adjustments.
The control system is the core hub of tension adjustment. The advanced control system uses complex algorithms to analyze and judge the tension in real time based on the tension data fed back by the sensor and the preset process parameters. When the tension is detected to deviate from the set value, the control system quickly calculates the required adjustment amount and issues instructions to the actuator. In the design of control logic, it is necessary to ensure the timeliness of adjustment and respond quickly to tension changes, while avoiding over-adjustment that causes system instability. To achieve this goal, PID control algorithms or more advanced intelligent control algorithms are often used to automatically adjust control parameters according to different working conditions, so that the tension adjustment process is smoother and more stable, ensuring that the film is always in a suitable stress state.
The performance of the actuator determines whether the tension adjustment instruction can be effectively implemented. The tension adjustment of small precision film longitudinal stretching machine is usually achieved by actuators such as motors and brakes. The motor controls the traction speed of the film by adjusting the speed, thereby affecting the tension; the brake fine-tunes the tension of the film by applying braking torque. The response speed and control accuracy of these actuators are crucial, and they must have the ability to start and stop quickly and accurately adjust the speed to quickly execute the instructions of the control system. At the same time, the actuators must cooperate and work together. For example, during the acceleration or deceleration of the film, the motor and the brake need to be adjusted synchronously to ensure a smooth transition of tension and avoid sudden changes in the film force due to asynchronous adjustment, which affects product quality.
The roller system is closely related to tension adjustment. The rollers of the small precision film longitudinal stretching machine play a supporting and pulling role in the film transmission process. Their surface characteristics, rotation accuracy and spacing between each other will affect the film tension distribution. Rollers with smooth surfaces and high processing accuracy can reduce the friction resistance between the film and avoid tension fluctuations caused by uneven friction; reasonable roller spacing design helps to keep the film stretched during the stretching process and prevent local tension concentration. In addition, the roller transmission system must have good stability and synchronization to ensure that the speed of each roller is consistent to avoid uneven film stretching due to speed differences, thereby affecting the tension adjustment effect.
In actual production, different film materials and process requirements require differentiated tension adjustment strategies. For film materials with soft texture and easy deformation, a smaller tension should be used for stretching to avoid film damage due to excessive tension; for films with higher strength, the tension can be appropriately increased to achieve the ideal stretching effect. At the same time, different stages of the stretching process, such as preheating, stretching, and shaping, also have different requirements for tension. In the preheating stage, it is necessary to maintain a low and stable tension so that the film is heated evenly; after entering the stretching stage, the tension is gradually adjusted according to the stretching multiple and speed; in the finalization stage, the tension must be controlled within an appropriate range to ensure the stability of the film size. Therefore, operators need to flexibly adjust the tension adjustment parameters according to the specific production situation to meet different process requirements.
Tension adjustment technology also needs to consider dynamic changes in the operation of the equipment. With the increase of production time, equipment parts may wear out, resulting in changes in the performance of the tension control system; fluctuations in external conditions such as ambient temperature and humidity will also affect the physical properties of the film, thereby interfering with tension stability. To cope with these situations, the small precision film longitudinal stretching machine needs to have adaptive adjustment capabilities and be able to automatically correct the tension adjustment parameters according to the equipment status and environmental changes. At the same time, the equipment should be regularly maintained, the performance of key components such as tension sensors and actuators should be checked, and worn parts should be replaced in a timely manner to ensure that the tension adjustment system is always in good working condition and to ensure the quality and efficiency of film production.
