Basic Features
This set is suitable for blowing low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE) for inner and outer packaging of textiles, microbial culture, daily necessities, and other civilian and industrial products.
Design Features
The blown film machine mainly consists of an extruder, die head, mold head, cooling device, bubble stabilizer, herringbone plate, traction roller, and winding device.
Extruder
The extruder mainly consists of a screw, barrel, feed hopper, reducer, and drive motor. The reducer drives the screw to rotate within the barrel via a belt drive. The screw employs a special structure, with a special mixing device at a certain section. During operation, it relies on the surrounding plastic for support and centering. The axial force on the screw shaft is borne by a 7310 or 7614 bearing installed between the reducer and the screw. The feed port of the barrel is designed according to the characteristics of the raw material to facilitate smooth entry into the screw grooves and ensure conveying capacity and stable extrusion quality.
Die Head
The die head consists of a filter screen, a filter... The machine consists of three parts: the filter plate, the die head, and the pressure cap. To accommodate the production of plastic raw materials containing numerous impurities, this unit adopts a right-angle die head structure with a large filtration area. Considering the high viscosity of high-pressure, low-pressure, mixed, and recycled materials, the material flow channel design has been rationally selected. The extruder's drive motor extrudes the filter plate, thus allowing for a separate screen changing operation.
The die head utilizes an advanced spiral die structure. Based on the special characteristics of high-pressure, low-pressure, mixed, and recycled polyethylene materials, the design parameters, including the spiral angle, slope angle, shaping angle length, and die opening, have been optimized through multiple comparative tests. This design features high internal pressure, stable and uniform extrusion, good film strength performance, no seam lines, and good compatibility with the extruder. Furthermore, when changing the proportions of high-pressure and low-pressure polyethylene, mixed materials, and recycled materials for blown film production, the die head does not need to be changed. Various die heads can be configured according to user needs. The entire operation can be completed by one person; it is simple, safe, convenient, and quick.
Cooling Device: Composed of a cooling air ring and blower, the cooling air ring is an externally cooled, adjustable type, allowing for adjustment of the inlet air opening. This facilitates operation and is beneficial for controlling film thickness and uniformity.
Bubble Stabilizer: This unit uses an adjustable bubble stabilizer with a shaping ring and shaping rod. It has a wide adjustment range, is easy to operate, and ensures stable bubble tubes, creating conditions for flattening the winding tube.
Traction Auxiliary Machine: The traction auxiliary machine consists of a traction frame, herringbone plate, traction rollers, winding mechanism, and traction motor. The traction motor is an electromagnetic slip differential motor, which drives two pairs of traction rollers and simultaneously the winding machine through a reduction gear. The herringbone plate is fixed to a fixed frame below the traction rollers; the included angle can be freely adjusted according to the thickness of the blown film. The two pairs of traction rollers are composed of rubber and steel rollers, effectively preventing gas escape and ensuring smooth winding. The traction frame adopts a modular structure, making assembly and disassembly convenient. Facilitates transportation and loading/unloading. The winding device employs an efficient central winding mechanism with constant tension. The device consists of a sprocket driving a friction plate, which in turn drives a large gear, which in turn drives the winding shaft, thus ensuring the winding diameter can be increased from small to large. The magnitude of the friction force can be controlled by adjusting the spring force.
Air Compression: Compressed air from the air compressor is sent to the storage tank and enters the central hole of the die head's spiral mandrel through the storage tank's outlet valve. A pressure regulating valve is installed in front of the die head to adjust the air volume and pressure according to the product size requirements. The gas enters the bubble-shaped center through the mandrel's central hole, inflating and extruding plastic into a bubble-shaped film.
Electrical Control: The electrical control system is equipped with a unit control cabinet. The main power button is used to connect the main power supply and turn on the motor switch. The heating elements of the machine body, tee, and die can be controlled separately via push-button switches. Key components utilize thermocouples for automatic temperature measurement and automatic temperature controllers. During normal production, the temperature is automatically controlled to ensure stable and reliable production.
