Extruders: The machine typically incorporates three extruders, one for each layer. Each extruder is responsible for melting and extruding a specific plastic material. These materials can be chosen based on the desired properties of each layer, such as strength, flexibility, or barrier performance.
Die Head: The die head is a crucial component that shapes the molten plastic materials into a tubular structure. It has separate channels for each layer, allowing for the simultaneous extrusion of three different materials. The design of the die head determines the film's thickness profile and width.
Co-extrusion: The molten plastic materials from the three extruders are fed into the die head, where they merge together to form a three-layered structure. The materials flow through their respective channels and combine to create a seamless tubular film.