What is the Manufacturing Process of Blown Film Extrusion?
Blown film extrusion is a versatile and widely-used manufacturing process in the plastics industry. This process is used to create thin plastic films that can be used in a wide range of applications, including food packaging, construction, agriculture, and medical products.
In this article, we will explain the process of blown film extrusion, including the materials used, the equipment required, and the benefits of this manufacturing process.
The Basics of Blown Film Extrusion
Blown film extrusion is a process that involves melting plastic pellets and extruding them through a circular die. As the plastic is extruded, the air is blown into the center of the die, causing the molten plastic to expand into a bubble or tube.
The tube is then cooled and collapsed, creating a thin film that can be wound onto rolls for further processing or use. The thickness of the film can be controlled by adjusting the speed of the extruder, the airflow, and the size of the die.
The blown film machines are a machine that melts plastic particles through a screw and then blows the melted flowing plastic into a film through a specific mold.
Materials Used in Blown Film Extrusion
Blown film extrusion can be used with a wide range of plastic materials, including low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). The choice of material depends on the application and the desired properties of the film.
For example, LDPE is commonly used for food packaging and agricultural films, while HDPE is used for heavier-duty applications such as trash bags and construction films.
The Equipment Required for Blown Film Extrusion
Blown film extrusion requires several pieces of equipment, including an extruder, a circular die, an air ring, and a collapsing frame. The extruder is used to melt and pump the plastic material to the die, while the air ring supplies the air to inflate the bubble.
The collapsing frame is used to cool and collapse the tube into a flat film, which is then wound onto rolls for further processing or use.
The Process of Blown Film Extrusion
The process of blown film extrusion can be broken down into several stages, including:
- Preparing the Material: The plastic pellets are fed into the extruder and melted, creating a homogeneous mass of molten plastic.
- Extrusion: The molten plastic is pumped through the circular die, and the air is blown into the center of the die to create a bubble or tube.
- Cooling: The tube is cooled by passing it through a series of cooling rollers or by blowing air onto it.
- Collapsing: The tube is collapsed by passing it through a pair of collapsing rollers, which flatten it into a thin film.
- Winding: The film is wound onto rolls for further processing or use.
Video of Blown Film Extrusion Process
The Benefits of Blown Film Extrusion
Blown film extrusion offers several benefits over other manufacturing processes, including:
- Cost-effectiveness: Blown film extrusion is a highly efficient and cost-effective process, producing large quantities of film at a low cost.
- Versatility: Blown film extrusion can be used with a wide range of plastic materials, allowing for the creation of films with different properties and applications.
- Consistency: Blown film extrusion produces consistent, uniform films with a high level of clarity and strength.
- Customizability: Blown film extrusion can be customized to produce films with specific properties, such as thickness, width, and color.
- Environmentally-friendly: Blown film extrusion is a low-waste process that produces minimal scrap, making it a more environmentally-friendly option compared to other manufacturing processes.
What are the most common applications for blown film extrusion?
Blown film extrusion is commonly used in the food packaging, construction, agriculture, and medical industries. It is used to produce a wide range of products, including bags, liners, wraps, and tubing.
- Food packaging industry: The blown film extrusion line produced by PLASTER is suitable for the automation production of fruit bags and milk bags because the cone mold of extruders ensures that each runner can clean itself under the PLASTAR's high-speed screws' intense pressure and high-speed scouring after the intense, degree of polishing and coating. It can be equipped with advanced automation features such as centralized feeding, weight control, and batching to enhance productivity and ease during the production of food packaging bags, which helps save energy consumption and cost, and makes producing food packaging bags cheaper.
- Agriculture industry: ABA or ABC three-layer blown film extrusion lines are recommended for the production of agricultural seed packaging films. It is effective for flexible production applications such as agricultural seed packaging films as they boost production and lower the cost of production and have a high degree of hardness and resistance to wear, which makes them suitable for the production of agricultural seed packaging films, liquid packaging film, electrostatic protection film, and many others.
- Medical industry: The recommended blown film extrusion line for medical packaging film is the five-layer co-extrusion blown film line. It can be used to produce symmetric barrier film and asymmetric barrier film. You can make different packaging firms like medical mask packaging bags, outer packaging injection bags, medical mask packaging bags, disposable PE examination gloves, medical packaging bags, drip bags, and other packaging bags.
What materials can be used in blown film extrusion?
Polyethylenes, which include LDPE, LLDPE, and HDPE polymers, are the most common materials used in blown film extrusion lines.
You need to understand the material properties of the resin you want to use for your blown film extrusion line. As much as you would want to use as many materials as you want so as the maximize your blown film extrusion line utilization, it is also important to note that blown film extrusion lines are different and are not designed the same. Therefore, blown film extrusion lines will not be able to accommodate all the types of materials available, which is why polypropylene and polyethylene (LDPE, HDPE, and LLDPE) are mostly used because they work effectively and with minimum complications with a majority of blown film extrusion lines.
What are the benefits of using blown film extrusion for packaging?
Blown film extrusion offers several benefits for packaging applications, including cost-effectiveness, customizability, and the ability to produce consistent, high-quality films.
As urbanization is accelerated, proper goods packaging is urgently needed during transportation from the place of origin to various cities to avoid unnecessary loss. a great deal of goods packaging applies barrier films to extend the shelf life, which reduces costs and increases sales and storage cycles. Blown extrusion molding is used due to its volume of productivity, speed, low cost, flexibility, and post-extrusion altercation option.
Blown film extrusion is a versatile and cost-effective manufacturing process that is widely used in the plastics industry. This process allows for the production of thin plastic films that can be used in a variety of applications, including food packaging, construction, agriculture, and medical products.
By understanding the materials used, the equipment required, and the process itself, it becomes clear why blown film extrusion is a popular choice for manufacturers. Its benefits, such as versatility, consistency, and cost-effectiveness, make it a reliable choice for producing high-quality plastic films.
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