I. Core Basic Process
1. Raw Material Preparation: Select appropriate raw materials (such as granular/powdered resins like PVC, PE, and PP) according to product performance requirements. Complete purity and moisture content testing. Some composite profiles require pre-mixing of different components.
2. Plasticizing and Melting Stage: The raw material is fed into the extruder barrel. Heat is generated through external heaters and screw rotation friction, raising the solid material to a completely molten state. Strict temperature control prevents material degradation and ensures melt flowability.
3. Extrusion Molding Stage: The molten material enters the die head under the thrust of the screw. The precise cavity of the die directly determines the final cross-sectional shape of the profile. The melt fills the entire cavity under pressure and shear force within the die.
4. Shaping and Cooling/Curing: The freshly extruded high-temperature profile immediately enters the vacuum shaping system, where it is rapidly cooled using a water tank/air cooling device. Curing is completed while maintaining the preset shape, preventing subsequent deformation.
5. Traction and Fixed-Length Cutting: The traction device pulls out the profile at a uniform speed matched to the extrusion speed, ensuring continuous production. Subsequent fixed-length cutting is completed according to preset dimensions using sawing or other methods.
6. Quality Inspection and Packaging: The cut profiles undergo dimensional accuracy, appearance, and mechanical property testing. Qualified products are packaged and ready for shipment.
II. Special Process Adaptation Instructions
1. Composite Co-extruded Profiles: Requires additional pretreatment of multi-component raw materials and simultaneous feeding across multiple machines. In-mold co-extrusion achieves interlayer bonding of different materials, ensuring adequate interlayer peel strength.
2. Special Engineering Plastic Profiles: Requires improved temperature control accuracy in the plasticizing section. For some types, an aging treatment process is added after extrusion to eliminate internal stress and improve product dimensional stability.
