To meet the needs for certain special functions of plastic film packaging materials in the production process, various characteristic materials (such as breathable, waterproof, heat-insulating, and tough) are blown and co-extruded together to form a multifunctional plastic film, leading to the development of multi-layer co-extrusion blow molding machines. The purpose of multi-layer co-extrusion blow molding machines is to leverage the advantages of multiple materials and circumvent some of the disadvantages of single materials or single-layer blow molding machines. For example, co-extrusion blow molding machines for PP and PE combine the high hardness of PP material and the high brightness of PE material to produce a film that combines both properties.
 Multi-layer co-extrusion blown film machines are further categorized into several types, such as two-layer co-extrusion blown film machines, three-layer co-extrusion blown film machines, five-layer co-extrusion blown film machines, and seven-layer co-extrusion blown film machines, which are all examples of this type of product
 Three-layer co-extrusion blown film machine
The three-layer co-extrusion blown film production line adopts advanced technologies such as a new type of high-efficiency low-energy consumption extrusion unit, IBC film bubble internal cooling system, ±360° horizontal upper traction rotation system, photoelectric automatic correction device, fully automatic rewinding and film tension control, and computer screen automatic control system. Compared with similar equipment, it has the advantages of higher production capacity, good product plasticization, low energy consumption, and easy operation. It completely solves problems such as film curling and uneven rewinding, elevating product quality to a new level. The produced film features high transparency, puncture resistance, high toughness, excellent low-temperature heat sealing performance, good composite fastness, and anti-curling property. Due to its good barrier properties, preservation, moisture resistance, frost resistance, oxygen barrier, and oil resistance, this film can be widely used in light and heavy packaging. It is suitable for various fresh fruits, meat products, pickled vegetables, fresh milk, liquid beverages, medical supplies, and more.  
Five-layer co-extrusion blown film machine
The five-layer co-extrusion blown film unit is primarily suitable for resins with gas barrier properties such as HDPE, MHDPE, LDPE, LLDPE, MLLDPE, PA, and EVOH. The produced films are mainly used as packaging materials for heavy-duty packaging, high-end food bags, vacuum packaging bags, liquid packaging bags, etc., achieving the packaging purposes of preserving aroma, freshness, preventing corrosion, ensuring airtightness, and extending shelf life.