As a key equipment in the manufacturing process of plastic films, the performance stability and operating accuracy of film blowing machines have a direct impact on the quality and production efficiency of film products. At present, domestic film manufacturers generally adopt manual or semi-automatic control methods, which have the disadvantages of low automation and high labor intensity. However, in the actual production process, film wrinkles and winding have become two major challenges faced by many manufacturers. These two problems not only damage the appearance and application value of the film, but also increase the cost and difficulty of manufacturing. At the same time, since it is difficult to eliminate the wrinkles of the film in time after they are generated, the final film product yield is not high, which seriously restricts the healthy development of my country's plastics industry. Therefore, it is crucial to conduct an in-depth analysis of the root causes of these two problems and find effective prevention and solution strategies to improve the production efficiency and product quality of film blowing machines.
What are the main causes of film wrinkles in film blowing machines?
Improper temperature control
In the film blowing process, temperature is considered to be one of the core factors affecting the quality of the film. As the temperature rises, the gas pressure and shear force increase, causing greater damage to the film, which in turn causes the film to wrinkle to varying degrees. Too high a temperature may over-plasticize the film and increase its fluidity, which may easily cause wrinkles during the blowing process; too high a temperature will cause uneven shrinkage of the film, resulting in local stress concentration, which will reduce the strength of the material and accelerate the aging of the product. Too low a temperature may cause the film to be insufficiently plastic, resulting in an increase in its hardness and easy formation of wrinkles. In addition, due to different blow molding process conditions, the surface state of the film is also very different, which has an important impact on the formation of wrinkles. Therefore, in the process of blowing the film, reasonable temperature control and ensuring that it maintains appropriate plasticity and fluidity are the core measures to prevent wrinkles.
Raw material formula problem
The performance of the film is directly affected by the composition and proportion of the raw materials. During the preparation process, due to temperature changes and changes in various process conditions, the film may shrink, deform or even rupture. If excessive plasticizers or other types of additives are mixed into the raw material formula, this may reduce the softness and toughness of the film, thereby increasing the possibility of wrinkles. In addition, when some non-ionic surfactants are added to the raw materials, the solubility of the material in water will also decrease. In addition, factors such as the moisture content and melt index in the raw materials will also affect the plasticization and blowing effect of the film. In addition, if the stretching speed is too high or the cooling time is too long during the processing, the film layer may break, resulting in wrinkles. Therefore, the selection of high-quality raw materials and the reasonable management of the formula ratio have become the key means to prevent the formation of wrinkles.
Die design defects
In the film blowing machine, the die plays a key role, which determines the shape and size of the film. With the increasing application of film products, higher requirements are put forward for film blowing machines, and the die is one of the most critical components affecting product quality. If there are defects in the design of the die, such as uneven gaps in the die orifice or the inner wall of the die is not smooth enough, then during the blowing process, the film may suffer from uneven stretching and extrusion, resulting in wrinkles. In addition, due to different film blank thicknesses, large temperature differences, and large pressure fluctuations, the film shrinks locally and forms "wrinkles", which will directly affect the appearance quality and service life of the product in severe cases. Therefore, optimizing the design of the die head to ensure that the gap between the die openings is balanced and the internal wall is smooth is a key means to avoid wrinkles.
Improper operation
During the operation of the film blowing machine, various parameters such as temperature, pressure and speed must be carefully controlled. In the actual production process, the film layer undergoes different degrees of deformation due to various reasons, causing wrinkles in the product, and even affecting product quality and output in severe cases. If the operator lacks sufficient experience or skills, he may make operating errors, such as inaccurate temperature adjustment, unstable pressure control, etc., which may cause wrinkles in the film. In production, wrinkles are also prone to occur when the film thickness changes greatly due to equipment failure or human factors. Therefore, increasing the training of operators' skills and improving their operating capabilities have become key measures to prevent wrinkles from forming.
How does the winding run-off phenomenon occur?
Uneven traction tension
During the film winding process, the pulling force is called traction tension. When there are more fibers on the reel, the uneven tension can easily cause yarn breakage and run-off. When the tension of the traction is unevenly distributed, the film may suffer from uneven stretching and squeezing during winding, which may cause the film to run away. Therefore, accurately controlling the tension of the traction and ensuring its stability and uniformity during winding is the core strategy to avoid the film from running away.
Improper adjustment of the winding device
Inside the film blowing machine, the winding device plays a vital role and is responsible for successfully winding the film into a roll. The size of the winding force directly affects the quality of the film and production efficiency. If the winding equipment is not properly adjusted, such as insufficient pressure on the pressure roller and unstable fixation of the core, the film may slip or become loose during winding, which may cause the film to run away during the winding process. In addition, once the winding device fails, it will also affect the normal operation of the entire production process. Therefore, reasonable adjustment of the winding device to ensure its stable and reliable working performance has become a key means to prevent the occurrence of roll running
Difference in film surface tension
The surface tension of the film describes the degree of interaction between molecules on the surface of the film. Due to different film layer structures, the surface tension of the film also varies greatly. When the surface tension of the film is inconsistent, this may cause the film to be unevenly stretched and squeezed during winding, which may lead to the film running away. In actual application, the film will run away to varying degrees due to various reasons. Therefore, optimizing the surface tension of the film to ensure its consistency and uniformity has become an efficient means to prevent it from running away.
Unstable core fixation
In the film blowing machine, the core is a key component used to fix the center position of the film winding. When the film is rolled, the film is wound on the core and stretched and shaped to form a film layer of a certain thickness on the surface of the film. If the stability of the core is not good, the film may shake or deviate during winding, which may cause the core to run away. Due to the large film thickness at the core, it is easy to cause large tension fluctuations and broken wires during winding. Therefore, ensuring the stability and reliability of the core is a key measure to prevent the core from running away.
How to effectively prevent film wrinkles in the film blowing machine?
Optimize the film blowing process parameters
By properly adjusting the process parameters such as temperature, pressure and speed, we can better optimize the film blowing process and thus improve the overall quality of the film. This paper theoretically analyzes the main factors affecting film performance and compares and discusses the films prepared under different conditions. For example, moderately lowering the temperature can help avoid excessive plasticization of the film, thereby improving its hardness and toughness; increasing the blowing volume can make the product have a better surface finish and improve product performance. By reasonably controlling the pressure, it can be ensured that the film is evenly stretched and extruded during the blowing process; the appropriate selection of gas flow can ensure that the film obtains a good surface morphology and maintains good mechanical properties. Moderately speeding up the production speed helps to improve the efficiency of film manufacturing. In addition, this paper also studies the influence of film thickness, initial tension and cooling rate on film performance. By optimizing and adjusting these parameters, we can effectively avoid wrinkles in the film.
Improve die design
Optimizing the die design is one of the effective ways to prevent wrinkles in the film. In order to prevent the wrinkling of the film, the die must be reasonably designed. By optimizing the shape, size and material of the die, we can ensure that the film is evenly stretched and extruded during the blowing process, thereby reducing the formation of wrinkles. At present, there have been some studies on the structure and parameters of film die heads, which are of great significance for reducing the problem of film wrinkles. For example, in order to reduce the resistance of the film during the blowing process, a streamlined die head can be considered; in order to extend the service life of the die head and enhance its stability, we chose materials that can withstand high temperatures and corrosion.
Strengthen raw material quality control
The performance of the film is directly affected by the quality of the raw materials. This article introduces the raw material testing methods and their importance. Therefore, strict quality management of raw materials is one of the key means to prevent film wrinkles. In the process of purchasing raw materials, priority should be given to choosing high-quality and stable suppliers; in the process of using raw materials, core parameters such as moisture content and melting degree must be strictly monitored; in addition, advanced equipment and technology should be used to ensure the production of qualified film products. When formulating raw material formulas, we should carefully control the use of plasticizers, stabilizers and other additives. By adopting these methods, we can ensure the continuous stability of the quality of raw materials, thereby reducing the possibility of film wrinkles.
Regular maintenance of equipment
Regular maintenance of equipment is one of the key measures to prevent film wrinkles. This article introduces a regular maintenance method often used in actual production - the purge method. Regular cleaning, lubrication and inspection of the film blowing machine can timely discover and solve problems and hidden dangers of the equipment; by replacing severely worn components and updating old equipment, the stability and reliability of the equipment can be ensured. In the film production process, it is necessary to regularly detect the change in film thickness and adjust the process parameters to ensure the consistency and qualified rate of the product. Adopting these recommended measures can effectively extend the service life of the equipment and enhance the manufacturing efficiency and quality of the film.
What are the practical tips for solving the problem of winding and running?
Adjust the pulling speed and tension
We can control the tensile and extrusion strength of the film during winding by adjusting the pulling speed and tension, thereby effectively solving the problem of running. Using appropriate pulling speed and tension is one of the keys to improve the quality of winding and reduce running. In the specific operation process, the amplitude and proportion of the pulling speed and tension can be reasonably adjusted according to multiple factors such as the material properties, thickness and width of the film. When a larger pulling force is used, the tension value needs to be increased to prevent the film from running. For example, when dealing with thinner and wider films, we can consider reducing the pulling speed and increasing its tension; for those thicker and narrower films, we can appropriately increase the pulling speed and reduce its tension.
Improve the design of the winding device
In order to solve the problem of roll running, optimizing the design of the winding equipment is considered to be one of the effective methods. The winding device is mainly composed of three parts: the frame, the tension frame and the reel. There is a nonlinear friction phenomenon between the tension frame and the reel, so it is necessary to conduct a mechanical analysis on it. By optimizing the design of the winding device in terms of structure, materials used, and working mechanism, the stability and reliability of the device can be significantly improved. This article analyzes and compares several commonly used winding devices. As an example, we can use an automatic pressure roller system to ensure that the pressure on the film is uniform when winding; in order to adapt to various film specifications and thicknesses, we use an adjustable core fixing device. In addition, the film tension needs to be controlled and adjusted to ensure that the film has sufficient strength after winding and meets the use requirements. Adopting these recommended means will help ensure that the film can maintain a stable and reliable state when winding.
Ensure uniform film surface tension
Increasing the surface tension of the film is considered to be one of the core methods to solve the problem of film running. There are many factors that affect the surface tension of the film, such as material properties, process conditions, and equipment status. By properly adjusting the film production process and formulation, we can ensure that the surface tension of the film remains consistent and uniform. At present, a series of technologies and methods for improving the surface tension of the film have been developed at home and abroad. For example, we can better optimize the plasticization and blowing process of the film by adjusting various parameters of the film blowing machine, such as temperature, pressure, and speed; in order to optimize the surface properties of the film, we add appropriate auxiliary ingredients such as surfactants or dispersants to the formula. In addition, in order to ensure that the film can obtain good tensile strain, it is also necessary to perform a certain degree of annealing treatment to reduce the stress inside the material. Adopting these methods can ensure that the film is evenly stretched and squeezed during the film winding process, thereby effectively solving the problem of running rolls.
Stable core fixation
In order to solve the problem of running rolls, ensuring the stable and reliable fixation of the core is one of the key strategies. The fixing device set on the roll has a good effect on preventing the core from deviating and improving product quality. In the specific operation process, we can use specially designed core fixing tools to ensure the stability and reliability of the core during winding; during the winding process, it is necessary to regularly check and replace the severely worn core and fixing equipment; when it is necessary to replace films of different sizes and thicknesses, the fixing method and placement of the core should be changed in time. In addition, it is necessary to control the winding speed, tension, etc. to ensure that the film can remain flat and uniform after winding. By implementing these strategies, we can ensure that the film maintains a stable state during winding, thereby avoiding the problem of winding.
Film blowing machines often encounter two main problems during operation: film wrinkles and winding winding. This article conducts a comprehensive and in-depth analysis of these two common problems, and points out their causes and degree of harm. After an in-depth discussion of the causes and influencing factors of these two problems, we have given targeted preventive measures and solutions. In practical applications, we have developed a series of practical preventive measures based on specific cases. These suggestions cover many practical skills, including optimizing film blowing technical parameters, optimizing mold design, enhancing quality management of raw materials, regularly maintaining equipment, adjusting traction speed and tension, improving the design of winding devices, and ensuring uniformity of film surface tension and stable fixation of the core. In addition, we have also summarized a complete set of processes and methods for dealing with film wrinkles and winding runaway. By implementing these suggestions, we are able to effectively avoid and deal with film wrinkles and winding problems, thereby improving the manufacturing efficiency of film blowing machines and the quality of products. In addition, by formulating reasonable winding temperature curves and reel speed control procedures, energy consumption can be reduced while ensuring good film quality, thereby reducing production costs. At the same time, we also emphasize the key role of daily maintenance and care of film blowing machines in reducing these problems, and call on film blowing machine operators to strengthen skills training and equipment maintenance awareness, and jointly promote the continuous development and progress of film blowing technology.
