The profile extrusion line can be divided into two types: pre-coextrusion and post-coextrusion according to the forming conditions and forming state of the coextruded material. The former coextrusion means that the two materials are composited in the process of not completing the extrusion and the product has not been formed; the post coextrusion means that one material has been completely formed and then composited with another material. The advantage of post-coextrusion is that it can be used well for waste materials and has good economics.
The profile extrusion line can be divided into organic coextrusion and inorganic coextrusion according to the material of the production and extrusion products. Organic coextrusion consists of the same pre-coextrusion (such as high quality raw materials and added resuscitation materials, eventually co-extruded) and co-extrusion of different materials (such as polymethyl methacrylate and PVC before coextrusion) and soft and hard Post-coextrusion of polyvinyl chloride, inorganic coextrusion can be divided into aluminum-plastic composite co-extruded steel-plastic composite co-extrusion.
The co-extruded plastic profile extrusion line is simpler in process, flexible in application, low in scrap rate, easy to recycle, bond strength control, and other notable features compared to conventional pre-coextrusion. Such technology is now widely used in the manufacture of profiles for doors and windows with sealing strips.
Our company's door and window profile production line uses PVC powder to manufacture various plastic door and window profiles and decorative profiles. With reference to the latest foreign technology, the unit is optimized for design, with the advantages of uniform plasticization, high output and long service life. The unit consists of a cone-type twin-screw extruder, a vacuum setting table, a tractor, a cutting machine and a laminating machine. The composition of the turning frame, the main machine adopts imported DC/AC variable frequency drag, the cutting machine adopts imported PLC control, the temperature control instrument adopts the Japanese RKC company product, the auxiliary machine vacuum pump and the traction motor adopt high quality products, and the maintenance is simple.
The conventional pre-coextrusion profile extrusion line is a process in which more than two extruders extrude molten materials having different rheological behaviors or different colors to the same molding die, and these melts have different respective flow paths in the molding die. Flow in the middle, then merge and extrude at the die, and vacuum in the shaping sleeve to cool the shape.