How does the express bag film blowing machine improve the uniformity of film production?
Publish Time: 2025-06-11
With the continuous improvement of the packaging industry's requirements for material quality and production efficiency, the express bag film blowing machine, as a key equipment for manufacturing various plastic films, plays a vital role in ensuring the uniformity of film thickness. Whether it is a special-purpose film such as shed film, composite film, heat shrink film or liquid packaging film, the uniformity of the film directly affects the performance and application effect of the final product.1. Advanced control systemModern express bag film blowing machines are equipped with advanced automatic control systems, which is the basis for achieving uniform film thickness. These systems can monitor and adjust multiple parameters such as extrusion speed, cooling rate and pulling speed in real time to ensure that the film maintains consistent physical properties at all stages. For example, by combining PLC (programmable logic controller) with a touch screen interface, operators can easily set various process parameters and automatically adjust them through a feedback mechanism to cope with possible changes in the production process, thereby achieving the best film thickness control effect.2. Accurate temperature managementTemperature is one of the important factors affecting the quality of film molding. The express bag film blowing machine is usually equipped with a precise temperature control system, including components such as heating coils and cooling fans, which are used to accurately control the melt temperature and cooling rate. Proper temperature setting can not only prevent quality problems caused by overheating or overcooling of materials, but also effectively reduce the uneven film thickness caused by temperature difference. Especially when dealing with multi-layer co-extrusion processes, the temperature difference between the layers must be strictly controlled to ensure the consistency of each layer of film.3. Automatic thickness adjustment deviceIn order to further improve the uniformity of film thickness, many high-end express bag film blowing machines are also equipped with automatic thickness adjustment devices. This device is based on ultrasonic measurement or other non-contact sensor technology, which can monitor the film thickness in real time and automatically adjust the die gap or pulling speed according to the actual measurement results. In this way, even in long-term continuous operation, a stable film thickness distribution can be maintained, which greatly improves the stability of product quality.4. Optimized mold designThe design of the mold is crucial for film forming. A good mold should have a good flow channel design and a smooth surface finish to ensure smooth material flow without stagnation points. In addition, for different types of film requirements, molds with special structures can also be selected, such as spiral mandrel molds, fishtail molds, etc., each of which is suitable for specific application scenarios. By optimizing the mold design, the transverse and longitudinal tensile strength of the film can be effectively improved, thereby enhancing its overall uniformity.5. Efficient cooling systemThe cooling process should not be ignored either. Express bag film blowing machine often uses air ring or water bath to quickly cool and shape to fix the film size. Reasonable cooling layout not only helps to shorten the curing time, but also avoids film deformation or thickness deviation caused by inconsistent local cooling rate. Some new equipment even introduces segmented cooling technology, which can flexibly adjust the cooling intensity of each area as needed, so that the cooling conditions of the film at different positions are more balanced.6. Material selection and pretreatmentIn addition to the above hardware improvements, the selection of raw materials and their pretreatment also have an important impact on the uniformity of the film. High-quality resin raw materials themselves have good processing properties, and proper pretreatment steps such as drying and mixing can remove impurities and balance the moisture content, laying a good foundation for subsequent stable production. Especially for functional films containing additives, ensuring the uniform dispersion of additives in the substrate is of paramount importance.In summary, express bag film blowing machine significantly improves the uniformity of film production by integrating advanced control technology, precise temperature management and automated thickness adjustment devices. At the same time, reasonable design of mold structure, optimization of cooling process, and careful selection and processing of raw materials are also indispensable factors.
