Applications of Blown Film Extruders
Blown film extruders are key equipment in the plastics processing industry. Their core function is to convert plastic raw materials into thin films through processes such as extrusion, blowing, and cooling. They are widely used across various industries, including:
Packaging Industry
Food packaging: Production of plastic wrap, food bags (e.g., supermarket shopping bags, snack packaging bags), and composite packaging films (for vacuum packaging meat, prepared foods, etc.). These films typically require excellent sealing properties, oil resistance, and transparency.
Daily goods packaging: Manufacturing of garbage bags, express bags, and clothing packaging bags, often using polyethylene (PE). Emphasis is placed on the film's toughness and tear resistance.
Industrial packaging: Production of stretch film (for securing palletized goods) and moisture-proof film (for protecting mechanical parts, building materials, etc.), which demands high strength and tensile performance.
Agriculture
Agricultural films, such as greenhouse films (for heat preservation, light transmission, and promoting crop growth) and ground films (for moisture retention, weed control, and increasing soil temperature), require weather resistance (UV resistance, tolerance to high and low temperatures) and a certain level of light transmittance.
Medical and Healthcare
The production of disposable gloves, protective clothing liners, and infusion bag films requires non-toxic, sterile, and chemically resistant films, typically made from medical-grade polyethylene or polypropylene (PP).
Other Specialty Fields
Geomembranes: Anti-seepage membranes used in water conservancy projects and landfills, which need strong aging resistance and puncture resistance.
Air cushion film (bubble film): Produced using special molds, it is used for cushioning fragile items. The film's sealing properties trap air to form protective bubbles.
What is a Blown Film Extruder?
A blown film extruder is a machine that processes thermoplastic raw materials (e.g., polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC)) into thin films. Its operating principle and core components are as follows:
Operating Principle
Raw material melting: Plastic granules enter the extruder barrel through a hopper. The rotating screw inside the barrel propels the raw material forward, while heat from external heating and the screw's shearing action melts the raw material into a molten state.
Tube extrusion: The molten plastic is pushed by the screw into the die head, where it is extruded through an annular die to form a tubular film (referred to as a "bubble tube").
Blowing and solidification: Compressed air is injected from the center of the die to inflate the bubble tube to the desired width (the film's transverse dimension). Simultaneously, an external cooling air ring cools the bubble tube, solidifying it into a rigid film.
Drawing and winding: The cooled film is stretched and flattened by take-up rollers, then wound into a roll by a winder to complete the production process.
Core Components
Extrusion system: Includes the barrel, screw, and heater, responsible for conveying, melting, and pressurizing the raw material.
Die head: An annular structure that determines the film's thickness and initial shape.
Blowing and cooling system: Comprises an air compressor (to provide blowing air) and an air ring (to cool the bubble tube).
Drawing and winding system: Take-up rollers control the film's longitudinal stretch and speed, while the winder winds the film into neat rolls.
Film Blowing machine Working video
Contact Us
Zhejiang Youjia Machinery Co.,Ltd
Phone (Wechat & Whatsapp)
+8618958800156
Address
No.557, East Three Road, Gexiang New Area, Nanbin Street, Rui'an, Wenzhou, Zhejiang, China
