Core Steps of a Blown Film Machine
The working process of a blown film machine can be summarized in the following steps:
Melting and Extruding: Plastic granules are heated to a molten state and extruded through a screw extruder to form a tubular melt.
Expansion Molding: Compressed air is injected into the tubular melt, causing it to expand into a thin film bubble.
Cooling and Shaping: The film bubble is rapidly cooled and solidified by a cooling air ring.
Traction and Winding: The formed film is stretched by a traction device and finally wound into a cylinder.
Functions of Key Components
The key components of a blown film machine each have their own function:
Extruder: Heats the plastic raw material. Plasticizing and Extrusion Molding
Die Head: Controls the extruded shape and thickness of the plastic melt.
Air Ring: Provides uniform cooling airflow, ensuring consistent film thickness.
Traction Roller: Adjusts the film stretch ratio and winding speed.
Factors Affecting Film Quality
In actual production, several factors affect the final film quality:
Raw Material Selection: Different plastic granules have significantly different melting characteristics.
Temperature Control: Excessively high or low extrusion temperatures will affect film performance.
Blow-up Ratio: Determines the ratio of longitudinal to transverse strength of the film.
Cooling Efficiency: Affects the film's transparency and surface smoothness.
