PE Blown Film Extruder Selection by Film Specifications

PE blown film extruder selection matches machine models based on film width, thickness, raw material type and capacity requirements. Die specification, screw diameter, haul-off system and air ring structure directly determine film forming quality. Proper selection avoids uneven thickness, wrinkles and insufficient output. Before purchase, confirm film lay-flat width, thickness, resin grade and daily production schedule as the foundation for model selection. Dalian workshops feature high humidity and partial salt spray. Motors, electrical controls and fasteners shall be protected against corrosion, an important environmental factor for machine selection.

Narrow thin films are mainly for small packaging bags, food inner bags and liners, with lay-flat width 100–400 mm and thickness 0.008–0.03 mm. LDPE or LLDPE are commonly used for lightweight products with low roll output and intermittent production. Small-screw PE blown film extruders (screw diameter 30/35/40 mm) with matching small dies are preferred. These machines occupy little floor space, are easy to commission and switch product specifications, suitable for multi-variety small-batch production. For ultra-thin PE film, high-precision air rings are equipped to stabilize cooling airflow and reduce thickness deviation. Electric control cabinets shall be sealed for dust and moisture protection to safeguard electrical components. Small orders often require frequent width changes; small extruders allow convenient barrel cleaning for frequent product switching.

Medium-width general films include courier bags, industrial packaging films and ordinary plastic bags, with lay-flat width 400–1200 mm and thickness 0.02–0.1 mm. LDPE/LLDPE blends are widely adopted in packaging industry. Medium-size screws (45/50/55/60 mm) with matching dies are selected. Stable extrusion and sufficient air ring cooling support long continuous production. For printable or laminatable films such as courier bags, haul-off systems with stable tension control ensure flat winding and minimize tensile deformation. When adding color masterbatch or defoaming masterbatch, screw L/D ratio shall guarantee full plasticization. Reserve extrusion margin according to film thickness; for thick films, sufficient screw output prevents crystal points caused by inadequate plasticization.

Wide heavy films are greenhouse films, heavy-duty packaging films and PE geomembranes, with lay-flat width over 1200 mm and thickness above 0.1 mm. LDPE, HDPE or modified blends are used for high tensile strength. Large-screw machines (70/80/90 mm and above) with large-bore dies and dual-airflow air rings are adopted. High extrusion volume and large bubble size require reinforced haul-off and bubble stabilizer frames to maintain bubble stability and reduce thickness fluctuation. Thick films need longer cooling time with adjustable air ring airflow. Workshop height must accommodate bubble stretching space. For HDPE heavy packaging films, screw structure shall suit HDPE to improve plasticization and reduce surface crystal points.

Ultra-thin high-clarity films and multi-layer co-extrusion films for premium food packaging and laminating substrates require high transparency and uniform thickness. ABA three-layer co-extrusion PE blown film extruders are applicable. ABA machines extrude different resins in layers: high-clarity skin layers and low-cost core layers to balance performance and cost. They demand higher precision in temperature control, air ring and haul-off, with higher investment than monolayer machines for high-value film production.

Raw material type affects extrusion capacity. HDPE has poor melt flow and lower output with the same screw size; LDPE flows smoothly for stable discharge. Thinner films impose stricter requirements on air ring and bubble control with reliable cooling systems. Thick film production focuses on screw plasticization for uniform melt.

Auxiliary equipment shall also be considered. Monolayer extruders feature simple structure and low maintenance; co-extrusion units have more components and higher maintenance workload. Reserve space for installation, winding, roll change and hoisting access. Power supply capacity shall match total heating and motor power to avoid power shortage.

Submit resin samples to manufacturers for trial runs to verify forming quality, tensile strength and thickness tolerance under target dimensions. After machine arrival, conduct no-load commissioning then gradual material trial production, adjusting air ring, haul-off speed and extrusion temperature for stable bubble. Clean screws and dies regularly. Coastal workshops shall apply external anti-rust treatment to mitigate salt spray corrosion on motors and transmission parts.

Select suitable PE blown film extruders by comprehensively evaluating lay-flat width, thickness, resin type, monolayer/co-extrusion requirement, hourly capacity, workshop conditions and local humid climate. Ensure stable bubble, reduce uneven thickness, crystal points and wrinkles, and continuously produce qualified PE films.