Common faults and solutions of three-layer co extrusion blown film machine

The three-layer co extrusion blown film machine, as an efficient and multifunctional plastic film production equipment, has a wide range of application prospects in modern industry. By reasonably designing the ratio of each layer of materials and optimizing the production process, multi-layer composite films with excellent performance can be produced to meet the needs of different fields. With the continuous advancement of technology, three-layer co extrusion blown film machines will develop towards intelligence, environmental protection, energy saving, high performance, and multifunctionality, bringing more innovation and breakthroughs to the plastic film industry.

Extruders are usually equipped with three independent extruders, each used to extrude different types of plastic raw materials. Each extruder consists of a screw, a barrel, a heating device, a drive motor, etc., responsible for heating, plasticizing, and transporting plastic raw materials to the co extrusion die. The co extrusion die is the core component of a three-layer co extrusion blown film machine, which is designed with multiple flow channels inside to transport different types of molten plastics to different layers of the die. The structure of the mold head and the design of the flow channel directly affect the composite quality and performance of the film.

Common faults and solutions of three-layer co extrusion blown film machine

Uneven film thickness

Uneven discharge of mold head

Reason: There are impurities blocking the internal flow channel of the mold head, or uneven heating of the mold head, resulting in poor flow of plastic melt inside the mold head.

Solution: Clean the flow channel of the mold head, check the heating element of the mold head to ensure uniform heating, and adjust or replace the heating element if necessary.

Uneven cooling of the wind ring

Reason: The air outlet of the air ring is blocked or damaged, resulting in uneven distribution of cooling air.

Solution: Clean the air outlet of the air ring, repair or replace damaged air ring components, adjust the air volume and speed of the air ring to make it uniform and stable.

Unstable traction speed

Reason: Traction motor malfunction, worn transmission components, or uneven traction roller pressure.

Solution: Check the traction motor and control system, repair or replace faulty components; Check transmission components such as belts, chains, gears, etc., and replace worn parts in a timely manner; Adjust the pressure of the traction roller to make it uniform and consistent.

Bubbles appear on the film

Raw materials are damp

Reason: Plastic raw materials become damp during storage, and the moisture turns into steam during heating and plasticization, forming bubbles.

Solution: Dry the damp raw materials and select the appropriate drying temperature and time based on their characteristics.

Extrusion temperature too high

Reason: The heating temperature of the extruder is set too high, causing the plastic raw material to overheat and decompose, producing gas and forming bubbles.

Solution: Reduce the heating temperature of each section of the extruder, and adjust the temperature parameters reasonably according to the melting point and processing characteristics of the raw materials.

There is gas residue inside the mold head

Reason: The air inside the mold head was not completely discharged before starting up, or during the production process, air mixed into the plastic melt.

Solution: Before starting up, fully exhaust the air inside the mold head, check the raw material conveying system and feeding port to prevent air from mixing in.

Poor transparency of thin film

Raw material quality issues

Reason: The plastic raw materials used have poor transparency or contain impurities.

Solution: Replace the raw materials with better quality and higher transparency, filter the raw materials to remove impurities.

Poor cooling effect

Reason: The cooling air temperature is too high, the air volume is insufficient, or the cooling is uneven, resulting in uneven crystallinity of the film and affecting transparency.

Solution: Reduce the cooling air temperature, increase the cooling air volume, and adjust the air ring to ensure even cooling; Check the cooling system inside the membrane bubble to ensure its normal operation.

Wear of mold head and screw

Reason: The mold head and screw wear out after long-term use, resulting in uneven plasticization of the plastic melt and affecting the transparency of the film.

Solution: Repair or replace worn mold heads and screws, regularly maintain equipment, and inspect the wear of mold heads and screws.

The three-layer co extrusion blown film machine can simultaneously extrude three layers of plastic films of different materials, achieving multi-layer composite and meeting the needs of different application scenarios. By designing the proportion of materials in each layer reasonably, films with excellent mechanical properties, barrier properties, heat sealing properties, etc. can be produced. Adopting advanced extrusion technology and control systems can effectively reduce energy consumption and improve production efficiency.

Each extruder heats its own plastic raw material to a molten state and pushes the molten plastic into the co extrusion die through the rotation of the screw. The co extrusion die is the core component of a three-layer co extrusion blown film machine, which is designed with multiple flow channels inside to transport different types of molten plastics to different layers of the die.