What should be noted when operating a three-layer co extrusion blown film machine?

The three-layer co extrusion blown film machine is an efficient equipment used for producing multi-layer composite films, widely used in packaging, agriculture, construction and other fields. Due to its complex structure and high process requirements, special attention needs to be paid to multiple aspects during operation to ensure the normal operation of the equipment, stable product quality, and the safety of operators. The following are the key points to note when operating a three-layer co extrusion blown film machine:

1. Inspection before device startup

Before starting the three-layer co extrusion blown film machine, a comprehensive inspection must be conducted to ensure that the equipment is in good working condition:

Power and gas source: Check if the power connection is normal and if the voltage is stable; Whether the air source pressure meets the requirements and ensures smooth air flow.

Heating system: Check if the temperature controllers in each heating zone are working properly to ensure that the temperature setting values meet the process requirements.

Extruder: Check if the screw and barrel of the extruder are clean to ensure there are no residual materials; Check if the lubrication system is functioning properly.

Mold: Check if the mold is securely installed, ensuring no looseness or damage; Clean the impurities on the surface of the mold.

Cooling system: Check if the cooling water circulation is normal to ensure good cooling effect.

Traction and winding device: Check whether the traction roller and winding device operate flexibly, ensuring no jamming phenomenon.

2. Temperature control

The temperature control of the three-layer co extrusion blown film machine is a key factor affecting product quality. Attention should be paid during operation:

Preheating: Before starting the extruder, the barrel, mold, and die head must be fully preheated, usually for more than 30 minutes, to ensure uniform melting of the material.

Temperature setting: Reasonably set the temperature of each heating zone according to different raw materials and process requirements. Excessive temperature may lead to material degradation, while insufficient temperature may result in uneven extrusion.

Temperature monitoring: Real time monitoring of temperature changes in each heating zone during operation to ensure that temperature fluctuations are within the allowable range.

3. Raw material selection and proportioning

The three-layer co extrusion blown film machine usually uses multiple raw materials for lamination, and attention should be paid to the following during operation:

Raw material quality: Select high-quality raw materials that meet the process requirements, ensuring no impurities or moisture.

Raw material ratio: Based on product performance requirements, accurately control the ratio of raw materials in each layer to ensure uniform thickness of each layer.

Raw material drying: For materials with strong moisture absorption properties (such as nylon, PET, etc.), sufficient drying treatment should be carried out to avoid bubbles or defects caused by moisture.

4. Extrusion process control

The extrusion process is the core link of the three-layer co extrusion blown film machine, and attention should be paid to the following during operation:

Screw speed: Adjust the screw speed reasonably according to the characteristics of the raw materials and product requirements to ensure stable extrusion volume.

Pressure control: Monitor the pressure at the head of the extruder to ensure that it is within a reasonable range, avoiding equipment damage caused by high pressure or uneven extrusion caused by low pressure.

Melt flow: Observe the flow state of the melt to ensure uniform distribution of each layer and avoid interlayer separation or uneven thickness.

5. Control of blown film forming

Blow molding is an important step in the three-layer co extrusion blown film machine, and attention should be paid to the following during operation:

Inflation ratio: Adjust the inflation ratio reasonably according to product requirements to ensure that the thickness and width of the film meet the standards.

Wind ring cooling: Adjust the air volume and pressure of the wind ring to ensure uniform cooling of the film and avoid wrinkles or deformation.

Traction speed: Adjust the traction speed reasonably according to the extrusion speed and product thickness to ensure uniform stretching of the film.

6. Product quality monitoring

During operation, it is necessary to monitor product quality in real-time and adjust process parameters in a timely manner

Thickness uniformity: Use a thickness gauge to measure the thickness of the film and ensure that the thickness of each layer is uniform.

Surface quality: Observe whether the film surface is smooth, free of bubbles, and impurities.

Interlayer bonding: Check the bonding strength between each layer to ensure no delamination.

7. Equipment maintenance and upkeep

The three-layer co extrusion blown film machine is a high-precision equipment that requires regular maintenance and upkeep

Cleaning: Regularly clean the extruder, mold, and air ring to avoid residual materials affecting product quality.

Lubrication: Regularly lubricate moving parts such as screws and bearings to ensure smooth operation of the equipment.

Inspection: Regularly check heating elements, sensors, air circuits, and other components to ensure their normal operation.

8. Safe operation

When operating a three-layer co extrusion blown film machine, safety regulations must be strictly followed:

Protective devices: Ensure that the protective devices of the equipment are intact and prevent operators from coming into contact with high temperatures or moving parts.

Emergency stop: Familiarize yourself with the location of the emergency stop button on the equipment and stop it promptly in case of abnormal situations.

Personal protection: Operators should wear protective gloves, goggles, etc. to avoid burns or mechanical injuries.

9. Fault handling

During operation, various faults may be encountered, and operators need to have basic fault handling skills:

Abnormal extrusion: If the extrusion is uneven or the pressure is abnormal, it is necessary to check the raw materials, temperature, and screw status.

Film defects: If bubbles, wrinkles, or uneven thickness appear, it is necessary to adjust the blowing ratio, cooling air volume, or traction speed.

Equipment malfunction: If there is a malfunction in the heating system or control system, it is necessary to promptly contact professional maintenance personnel for handling.

10. Record and Summary

During the operation process, detailed records of various process parameters and product quality data are required for subsequent analysis and optimization

Operation record: Record key parameters such as temperature, pressure, speed, traction speed, etc.

Quality record: Record the thickness, width, surface quality and other data of the film.

Summary and improvement: Based on recorded data, analyze problems in the production process and propose improvement measures.

The operation of a three-layer co extrusion blown film machine involves multiple stages, requiring operators to have solid theoretical knowledge and rich practical experience. By strictly following operating procedures, adjusting process parameters reasonably, and regularly maintaining equipment, production efficiency can be effectively improved, product quality can be ensured, and the safety of operators can be guaranteed.