What are the core components of Dalian blown film unit?

The Dalian blown film unit is a key equipment for plastic film production, widely used in packaging, agriculture, construction and other fields. Its working principle is to heat and melt plastic particles, and then produce a thin film by blowing and molding. The core components of the blown film unit include extruder, die head, air ring, cooling device, traction device, winding device, and control system.

1. Extruder

The extruder is the heart of the blown film unit, responsible for heating and melting plastic particles and extruding them into tubular films. The extruder is mainly composed of the following parts:

Hopper: Used for storing plastic pellets, usually equipped with an automatic feeding system to ensure continuous feeding.

Screw: The screw is the core component of the extruder, which pushes plastic particles forward through rotation and melts them through heating and shear forces during the pushing process. The design and material of the screw have a significant impact on extrusion efficiency and product quality.

Heater: The heater is installed outside the barrel of the extruder and heats the plastic particles to the melting temperature through electric heating or oil heating. Heaters are usually divided into multiple heating zones, and the temperature of each heating zone can be independently controlled to ensure the uniformity of the plastic melt.

Cooling system: The screw and cylinder of the extruder generate a large amount of heat during operation. The cooling system removes excess heat through water or air cooling to prevent equipment overheating.

2. Mold head

The die head is the connecting component between the extruder and blown film forming, responsible for extruding molten plastic into a tubular film. The design and manufacturing accuracy of the mold head have a significant impact on the thickness uniformity and surface quality of the film. The mold head usually consists of the following parts:

Diverter: The splitter is located at the entrance of the mold head and is responsible for evenly distributing the molten plastic to various parts of the mold head, ensuring the uniformity of the film thickness.

Flow channel: The flow channel is the flow channel for molten plastic inside the mold head. The design of the flow channel should minimize flow resistance and ensure the fluidity of the plastic melt.

Mouth mold: The mouth mold is the outlet part of the mold head, responsible for extruding molten plastic into a tubular film. The diameter and gap of the mouth mold determine the thickness and width of the film.

3. Wind ring

The wind ring is a key component used for cooling and shaping thin films in the blown film unit. The wind ring is usually installed below the mold head, which rapidly cools the melted plastic film by blowing cold air to shape it. The main functions of the wind ring include:

Cooling: The melted plastic film is rapidly cooled by blowing cold air to prevent deformation and adhesion of the film.

Forming: By adjusting the air volume and speed of the air ring, the thickness and width of the film are controlled to ensure the dimensional stability of the film.

Uniformity: The design of the wind ring should ensure that the cold air is evenly distributed around the film to prevent uneven film thickness.

4. Cooling device

The cooling device is a component used in the blown film unit to further cool and solidify the film. The cooling device usually includes the following parts:

Cooling roller: A cooling roller is a component used to further cool and solidify thin films, usually made of metal and filled with cooling water inside. The surface of the cooling roller should be smooth to ensure the surface quality of the film.

Cooling bellows: The cooling bellows is a component used to further cool the film, usually installed below the cooling roller, and further cools the film by blowing cold air.

5. Traction device

The traction device is a component used in the blown film unit to pull and stretch thin films. The main functions of the traction device include:

Traction: Pull the film out of the mold head through the traction roller to ensure continuous production of the film.

Stretching: By adjusting the speed of the traction roller, the stretching degree of the film is controlled to ensure that the thickness and width of the film meet the requirements.

Tension control: The traction device should be equipped with a tension control system to ensure that the film maintains appropriate tension during the traction process, preventing deformation and breakage of the film.

6. Roll up device

The coiling device is a component used in the blown film unit to coil thin films into rolls. The main functions of the coiling device include:

Roll up: The film is rolled up into a roll using a roll up roller for easy storage and transportation.

Tension control: The coiling device should be equipped with a tension control system to ensure that the film maintains appropriate tension during the coiling process, preventing deformation and breakage of the film.

Automatic roll change: Modern blown film units are usually equipped with an automatic roll change system to ensure continuous production and reduce downtime.

7. Control system

The control system is the core part used to control the operation of various components in the blown film unit. The main functions of the control system include:

Temperature control: By using temperature sensors and controllers, the temperature of components such as extruders, die heads, and air rings is controlled to ensure the uniformity of the plastic melt and the quality of the film.

Speed control: By using speed sensors and controllers, the speed of components such as extruders, traction devices, and winding devices is controlled to ensure that the thickness and width of the film meet the requirements.

Tension control: By using tension sensors and controllers, the tension of the traction device and winding device is controlled to prevent deformation and breakage of the film.

Automation control: Modern blown film units are usually equipped with automation control systems to achieve automation and intelligence in the production process, improve production efficiency and product quality.

The core components of the blown film unit include extruder, die head, air ring, cooling device, traction device, winding device, and control system. These components work together to ensure efficient production and high-quality output of plastic film. The design and manufacturing accuracy of each component have a significant impact on the quality and performance of the film, so special attention should be paid to the performance and quality of these core components when selecting and using a blown film unit.