Blown film extrusion lines are commonly used to extrude plastic films for flexible packaging industry.
In a blown film extruder PE granulates (or other polymer) are melted in an extruder and pushed through a circular die extruding a tube of molten polymer. Tube is then inflated to multiples of its initial diameter and cooled to form a thin film. Bobble is later collapsed and re-winded.
Raw material most commonly used are low density polyethylene (LDPE) and High density polyethylene (HDPE). These are often used in blends with other polymers and additives.
Film produced with blown film lines have various applications from film for bags, to shrink film, lamination film, stretch hoods, film for FFS industrial bags, PE film for packaging, barrier and high barrier films and many others. What material each line is capable to produce and with what performances depends highly on its sizes and specifications.