The multi-layer co-extrusion system is the core of a 5-layer stretch film making machine. It is designed to deliver precise material control, stable output, and consistent film structure.
The system uses five independent extruders, each processing a specific polymer material. Temperature, pressure, and output are controlled separately to ensure uniform melting and stable flow. This allows different materials, such as LLDPE, LDPE, or additives, to be processed simultaneously without interference.
All melt streams are combined through a multi-manifold co-extrusion die. Each layer flows in a dedicated channel and merges at the die lip. This design maintains clear layer boundaries and prevents mixing, ensuring a precise multi-layer structure.
The film typically adopts an A-B-C-B-A configuration. Each layer performs a defined function:
- Outer layers provide controlled cling and surface properties
- Intermediate layers improve flexibility and stress distribution
- The core layer delivers strength and puncture resistance
This layered structure allows accurate adjustment of film properties by controlling material allocation and layer thickness.
The co-extrusion system also ensures stable thickness control. Uniform gauge distribution reduces weak points and improves film consistency during stretching and wrapping.
By combining independent extrusion control with a multi-channel die design, the system enables efficient material use and stable production of high-performance stretch film.
